۱-اشك پايه (basal tears): درچشمان پستانداران سالم قرنيه پيوسته (24 ساعته) توسط اشك هاي پايه خيس و تغذيه ميگردد. اين اشك باعث لغزنده شدن چشم ها و شستشوي چشمها از ذرات خارجي ميگردد. مايع اشك حاوي آب+موسين+چربي ها+ليزوزيم+لاكتوفرين+ليپوكالين+ايمنوگلوبولين ها+گلوكز+سديم كلرايد+كلرايد پتاسيم+آنتي اكسيدان ها+برخي ويتامينها ميباشد.

2-اشك رفلكس(reflex tears):هر چزي كه باعث تحريك و يا خشك شدن چشم شود، ميتواند توليد اين نوع اشك را افزايش دهد.اين نوع اشك بطورغيرارادي و در پاسخ به مواد محرك چشم نظير ذرات خارجي،گردوغبار،آلرژن ها،پاتوژن ها و مواد محرك ديگري همچون بخارات پياز،گاز اشك آور و افشانه فلفل ترشح ميگردد.اين اشك ها سعي ميكنند تا مواد محرك و آزاردهنده را از چشم ها پاك كنند.باد شديد و نور شديد خورشيد نيز ميتواند باعث توليد اشك رفلكس گردند.اين اشك بيشتر آبكي بوده و از ليزوزويم و ايمنوگلوبولين بيشتري برخورداراست.

3-اشك احساسي و يا گريه(emotional tears/crying): اين اشك هنگام احساساتي شدن انسان ها (استرس هيجاني ) و يا احساس درد فيزيكي ترشح ميگردد. آغازگرهاي هيجاني اين نوع اشك معمولا خشم، اندوه، شادي، ترس، شوخ طبعي و ناكامي ميباشند. تركيبات شيميايي اين نوع اشك با تركيبات دو اشك قبلي متفاوت است. اشك احساسي حاوي هورمونها و پروتئين هاي بيشتري ميباشد. اين اشك حاوي هورمونهاي پرولاكتين، هورمون رشد، آدرنوكورتيكوتروپين، آندروفين و فلز منگنز ميباشد.

نكات جالب درباره اشك و گريه :

1-به غير از انسانها برخي معتقدند فيل ها و گوريل ها نيز ميتوانند گريه كنند اما نه به پيچيدگي گريه انسانها. حيوانات ديگر اغلب هنگام درد كشيدن، وارد شدن اجسام خارجي در چشمها و يا خشك شدن چشمها دچار اشك ريزش ميشوند. حيوانات (به ويژه نوزادان آنها) بصورت آوايي و مانند نوزادان تازه متولد شده گريه ميكنند بدون توليد اشك.

2-غدد اشكي روزانه در حدود 2 قاشق پر چايخوري اشك توليد ميكنند.

3-هر پلك زدن (باز و بسته كردن چشم) در حدود 100-150 ميلي ثانيه بطول مي انجامد. انسانها بطور متوسط هر 2 تا 10 ثانيه يكبار و 10 بار در دقيقه پلك ميزنند.

4-شور بودن اشك عمدتا به علت وجود كلرايد سديم و پتاسيم در اشك ميباشد. ميزان نمك موجود در اشك با ميزان نمك پلاسماي خون برابراست.

5-از آنجايي كه جنين نيز در درون رحم قادر به گريه كردن است بنابراين گريه كردن نميتواند يك رفتارآموختني باشد. اما فرهنگ، سن، جنسيت، فرآيند اجتماعي شدن، شخصيت، روابط و بافت اجتماعي همگي ميتوانند در شكل بيان گريه تعيين كننده باشند.

6-PH اشك اندكي قليايي و خود اشك ترش و شور مزه ميباشد.

7-سرفه شديد، استفراغ، احتقان بيني، آلرژي بيني، التهاب يا عفونت بيني و يا چشم و اختلالات عصبي نيز ميتواند باعث اشك ريزش گردند.

8-گريه كردن در برخي فرهنگها عملي كودكانه و غير موقر محسوب شده و گريستن در انظارعمومي تقبيح ميگردد.

9-علت اشك ريزش هنگام خميازه كشيدن و يا خنديدن وارد شدن فشار به غدد و كيسه اشكي ميباشد. علت ديگر آن ميتواند اين مسئله باشد كه غدد اشكي تحت كنترل سيستم عصبي خود مختار ميباشند. اين سيستم عصبي تمام كاركردهاي غيرارادي را كنترل مي كند. هنگامي كه اين اعصاب تحريك ميشوند (هنگام خميازه) غدد اشكي نيز اندكي تحريك ميگردند.

10-بسياري از افراد به علت مبتلا بودن به خشكي چشم قادر به گريه كردن نميباشند. اما دراختلال ديگري كه در پي آسيب به مغزايجاد ميگردد فرد مبتلا ممكن است بطور مداوم براي ساعتها بدون علت گريه كند.

11-علت سوزش و اشك ريزش چشمها هنگام خرد كردن پياز به علت وجود آنزيمها و آمينو اسيد سولفوكسايد موجود در سلولهاي پياز ميباشد. آمينو اسيد سولفوكسايد توسط آنزيمهاي پياز به سولفينيك اسيد تبديل ميشود، كه بسيار ناپايدار بوده و فورا به گازي فرار تبديل ميگردد. هنگامي كه اين گاز با آب درون چشم (اشك) تركيب ميگردد توليد اسيد سولفوريك ملايمي را ميكند كه باعث سوزش و اشك ريزش ميشود. با افزايش توليد اشك بدن سعي ميكند تا اسيد سولفوريك را رقيق و از چشمها بشويد. براي جلوگيري از سوزش و اشك ريزش چشمها هنگام خرد كردن پياز به توصيه هاي زير عمل كنيد:

* دستان خود وپياز را قبل از خرد كردن با آب خيس كنيد تا گاز متصاعد شده با، آب روي دستها و پياز واكنش نشان دهد نه با اشك چشمها.

* تنها با دهان خود تنفس كنيد. عمل دم گازها را به درون ريه كشانده و عمل بازدم نيز باعث پراكنده شدن گاز ميشود.

* از چاقوي تيز براي بريدن و خرد كردن پياز استفاده كنيد تا سلولهاي كمتري در پياز دچار پارگي شوند.

* قبل از خرد كردن پياز آن را نيم ساعت درون يخچال قرار دهيد. چراكه كاهش دما فعاليت آنزيمهاي پياز و انتشار گاز را كاهش ميدهد.

Onion Goggles

1-نوزادان از گريه به عنوان ابزار بقا استفاده ميكنند. گريه كودكان يك وسيله ارتباطي با مادر بوده و از طريق آن طلب كمك ميكنند. علل اصلي گريه نوزادان گرسنگي، پوشك خيس، كثيف و يا نامناسب، نياز به تماس بدني و نوازش، درد ناشي از گاز معده و روده، سرما و گرماي شديد، كسالت و بي حوصلگي، استرس، محيط پر ازدحام، درد و جلب توجه ميباشد.

2-علل گريه در افراد بزرگسال عمدتا شامل غم و اندوه(49%)، شادي و خوشي(21%)، خشم(10%)، همدردي(7%)، اضطراب(5%) و ترس(4%) ميباشد.

3-انسان ها براي تحت تاثير قرار دادن و برانگيختن احساسات و ترحم ديگران نيز متوسل به گريه ميشوند.

1-هنگامي كه ما دچار استرس هيجاني مي شويم، مغز وبدن ما شروع به توليد تركيبات شيميايي و هورمونهاي خاصي ميكند. گريه كردن كمك ميكند تا اين تركيبات شيميايي زائد كه نيازي به آنها نيست از بدن حذف گردند.

2-اشكهاي احساسي در واقع مواد سمي اي كه در پي استرس هيجاني در خون تجمع مي يابند را از بدن دفع ميكند.

3-اشكهاي احساسي سطح منگنز بدن را كاهش ميدهند. اين مواد معدني بروي خلق و خو تاثير مستقيم ميگذارد. غلظت منگنز اشك احساسي 30 برابر بيشتر از منگنز موجود در سرم خون است.

4-اشك احساسي نسبت به اشك پايه و رفلكس حاوي 24 درصد پروتئين آلبومين بيشتري ميباشد.

5-گريه مانند ادرار و تعريق باعث حذف مواد سمي و محصولات زائد بدن ميشود.

6-گريه يك مكانيسم رايگان، طبيعي و قدرتمند براي كنار آمدن با درد، استرس و اندوه ميباشد.

7- هورمونهايي كه پس از استرس در بدن انباشته ميشوند به حد سطح سمي رسيده و باعث تضعيف سيستم ايمني بدن و ديگر فرآيندهاي بيولوژيكي ميشوند. اشك هاي احساسي به عنوان دريچه اطمينان براي قلب عمل ميكنند.

8-تركيباتي كه حين استرس در بدن تجمع مي يابد با اشك خارج ميگردند. همين امر باعث كاهش استرس ميگردد. اين مواد شامل آندورفين (lucine-enkephaline)، كه در كنترل درد موثر است، پرولاكتين كه در تنظيم توليد شير نقش دارد، و آدرنوكورتيكوتروپين (ACTH) كه يك نشانگر مهم استرس است، ميباشند. سركوب گريه و اشك باعث افزايش استرس ميگردد.

9-نه تنها گريه باعث ارتقاي سطح سلامتي فرد ميشود بلكه در افزايش حس تعلق در گروه نيز تاثير گذاربوده و موجب افزايش حضور و دخالت ديگران در تامين رفاه فرد ميشود. اشك ها يك روش موثر در ايجاد ارتباط بوده و در برانگيختن حس همدردي و دلسوزي سريعتر ازهر ابزار ديگري عمل ميكنند. گريه بطور موثري بازگو كننده آنست كه شما در مورد يك دلمشغولي خاص صادق و بي ريا بوده و در كنار آمدن با آن مشكل مضطرب ميباشيد.

10-گريه عملي طبيعي، سالم و شفا بخش است.

11-گريه در كاهش و جلوگيري از بيماريهاي مرتبط با استرس موثر ميباشد.

12-خنده و گريه دو ابزار كارآمد دركاهش استرس و رهايي ازاحساسات منفي ميباشند.

13-هنگامي كه گريه سركوب ميشود، هيجانات رها نمي شوند و خصايص شخصيتي مخرب همچون پرخاشگري بروز ميكنند.

14- به باور دانشمندان سركوب و امتناع از گريه كار معقولي نيست. اما برخي افراد كه پس از مورد انتقاد قرار گرفتن، مشاجره با دوستان، مواجهه با ناكاميهاي كوچك فورا شروع به گريستن ميكنند، بايد به روانشناس مراجعه كنند. چراكه معمولا علت اصلي اين نوع گريه ها اعتماد بنفس پايين و يا مشكلات رواني مزمن در فرد بوده و بايستي فرد تحت درمان قرار گيرد.

15-انسان ها پس از گريه كردن از لحاظ جسمي و رواني احساس بهتري ميكنند و در واقع سبك و خالي ميشوند. (به علت دفع مواد انباشته شده كه توضيح داده شد)

16-گريه يك ابزار برقراري ارتباط است يك زبان جهاني براي درخواست كمك و حمايت اجتماعي.

17-گريه كمك ميكند به آزاد سازي آندورفين ها به جريان خون. آندورفين ها تركيبات شيميايي اي هستند كه باعث بهبود خلق و خو و تسكين درد ميشوند.

1-زنان 4 تا 5 برابر بيشتر از مردان گريه ميكنند.5.4 بار در ماه.

2-دختران وپسران تا قبل از بلوغ به يك ميزان گريه ميكنند، چراكه ترشح هورمون پرولاكتين كه باعث تحريك توليد اشك ميشود به يك ميزان در هر دو جنس توليد ميشود.

3-پس از بلوغ ميزان ترشح پرولاكتين كه در توليد و تناوب گريه موثر است در زنان 60 درصد بيشتر از مردان ميشود.

4- غدد اشكي مردان از لحاظ ساختاري متفاوت و كوچكتر از غدد اشكي زنان ميباشد. شايد يكي از دلايل بيشتر گريه كردن زنان نيزهمين مسئله باشد. مردان و زنان نميتوانند يكديگر را بخاطر چگونه گريه كردنشان مورد سرزنش قرار دهند.

5-يكي ديگر از علل بيشتر گريه كردن زنان باورهاي فرهنگي ميباشند، كه اجتماع گريه كردن زنان را بيشتر مورد پذيرش قرار ميدهد.

6-مردان آرام، بدون صدا و با اندكي اشك گريه ميكنند. بطوري كه معمولا كاسه چشمان آنها از اشك پر ميشود، اما بندرت اشك به گونه ها سرازير ميگردد.

7-اما زنان معمولا پر سرو صدا و با اشك هاي فراوان گريه ميكنند.

8-مردان اغلب در نتيجه احساسات مثبت و زنان پس از درگيري و مشاجره با ديگران و يا در نتيجه احساس بي كفايتي گريه ميكنند.

همچنان علت و فرآيند اشك هاي احساسي مبهم و رازآلود باقي مانده است. كماكان پرسشهاي بدون پاسخ مانده ي بسياري وجود دارند نظير: چنانچه گريه كردن به منظور كاهش استرس طراحي گرديده پس فلسفه اشك شوق و شادي چيست؟ و يا اگر گريه يك وسيله ارتباطي با ديگر همنوعان است پس چرا انسانها در خلوت وتنهايي خود نيز گريه ميكنند؟    eResearch by Navid Ajamin -- spring 2012

Reference: www.hasht.com

Related To: Overflow Tearing and Chronic Eye Infections in Infants

اشک سه حرف ندارد؛ کلی حرف دارد

Conjunctivitis is the term used to describe inflammation of the conjunctiva—the thin, filmy membrane that covers the inside of your eyelids and the white part of your eye (sclera).

Conjunctivitis is most commonly referred to as red or “pink” eye.

The conjunctiva, which contains tiny blood vessels, produces mucus to coat and lubricate the surface of your eye.When the conjunctiva becomes irritated or inflamed, the blood vessels become larger and more prominent, making your eye appear red. Conjunctivitis may occur in one or both eyes.

Symptoms of conjunctivitis include:

• inflammation of the eye;
• increased tearing;
• soreness of the eye;
• foreign body sensation;
• itchiness of the eye;
• hazy or blurred vision due to mucous or pus;
• excess mucous (pus);
• crusting of eyelashes in the morning.[1]

What causes conjunctivitis?

- Infection is the most common cause.
- Allergy is another common cause. For example, many people with hay fever (allergic to pollen) have red and inflamed conjunctiva.
- Irritant conjunctivitis sometimes occurs. For example, your conjunctiva may become inflamed after getting some shampoo in your eyes. The chlorine in swimming baths is a common cause of mild irritant conjunctivitis.
The rest of this leaflet is about conjunctivitis caused by infection.[2]

What are the most common causes of conjunctivitis in childhood?

Conjunctivitis is an inflammation of the conjunctiva which is usually caused by infection or allergy. It is frequently referred to as pink eye and is the most common acute eye disorder seen by primary care pediatricians and family physicians.

What are the characteristics of allergic conjunctivitis?

Allergic conjunctivitis is characterized by ocular redness and itching. Tearing (clear tears), crusting of the eye lids and photophobia may also be seen. The condition is often recurrent, and seasonal. Children who have allergic conjunctivitis often have a history of other atopic diseases, particularly allergic rhinitis, eczema or asthma.

What are the characteristics of an infectious conjunctivitis?

Infectious conjunctivitis may be bacterial or viral. Bacterial conjunctivitis is twice as common as viral conjunctivitis. Typically in bacterial conjunctivitis the eye is red, there is a purulent discharge, the affected child is often a pre-schooler and there may be an associated otitis media. In viral conjunctivitis there is redness, clear tearing or crusting, usually occurs in an older school age child, and is often associated with pharyngitis.

What organisms are commonly involved in bacterial conjunctivitis?

The most common bacterial organisms causing conjunctivitis are Haemophilus Influenzae and Streptococcus pneumoniae. H. Influenzae conjunctivitis occurs in 40 to 50% of cases and is more likely to be associated with an accompanying otitis media than other organisms. S. Pneumoniae accounts for about 10% of cases and other organisms (Staphylococcus aureus, Bacteroides and Moraxella catarrhalis) account for the remainder.

What is the most common cause of viral conjunctivitis?

Adenovirus conjunctivitis is the most common cause of viral conjunctivitis and may account for up to 20% of infectious conjunctivitis. Outbreaks of adenoviral conjunctivitis have been linked to contaminated equipment in ophthalmology clinics and to swimming pools.

Why is there a need to distinguish viral from bacterial conjunctivitis?

Viral and other non-purulent types of conjunctivitis do not require antimicrobial treatment. Often these children are treated mistakenly for prolonged periods of time with both topical and systemic antibiotics with persistence of the red eye. In some situations the topical antibiotic itself may cause an allergic reaction resulting in a persistent red eye.

What is the pathogenesis of infectious conjunctivitis?

In children the joint communication of the conjunctival sac with the middle ear and nasopharynx probably accounts for the frequent association of otitis media and pharyngitis with acute conjunctivitis.

What is the differential diagnosis of acute conjunctivitis?

In the child with a non-purulent conjunctivitis, one should think of Kawasaki disease, Lyme disease, juvenile rheumatoid arthritis or Steven's Johnson syndrome. When there is decreased vision and light sensitivity the physician must think of uveitis. Trauma and allergic conjunctivitis account for the remainder of the differential diagnosis.

What is the treatment of choice for acute bacterial conjunctivitis?

Acute bacterial conjunctivitis is a self limited condition. However, the use of antibiotic treatment is recommended because it hastens healing considerably and it eradicates the bacterial pathogen allowing children to return to daycare centers and schools within 24 hours of treatment. Topical treatment with polymyxin-bacitracin, garamycin or other suitable topical antimicrobials should be used. There is usually no need to use topical treatment for more than 2 to 5 days when complete resolution should have occurred. Treatment should be applied to both eyes, even if only one eye appears to be infected. Topical application should be applied four times a day.

What approach should be used if the purulent discharge persists despite topical treatment?

If there is persistent eye discharge after Day 4 or 5 of treatment then one needs to consider an alternative diagnosis. The most common occurrence is that of an associated otitis media which has not been recognized or has subsequently developed and requires the use of an oral systemic antibiotic. This occurs most frequently in H. influenzae conjunctivitis. An oral antibiotic which has activity against beta lactamase producing organisms should be used.

What is the treatment for viral conjunctivitis?

Non-purulent viral conjunctivitis requires no treatment.

What is the treatment for allergic conjunctivitis?

Allergic conjunctivitis can be treated with an ophthalmic preparation containing a topical decongestant with or without antihistamine. Prevention of allergic conjunctivitis in susceptible individuals is best treated with topical sodium chromoglycate.[3]

 eResearch by Navid Ajamin -- spring 2012

Image: beauty-and-the-bath.com mezzmer.com bzhealthtips.com optometrist.com.au

Reference:

1. www.mackeyecenter.com/45-conjunctivitis/
2. www.goodtoknow.co.uk/wellbeing/134933/What-causes-conjunctivitis--1
3. www.utoronto.ca/kids/conjunct.htm

As many as 1 in 20 preschoolers wears glasses. If you've got a little four-eyes, use our guide to finding the best pair for her peepers:

Choose a flattering frame. Pick a squarish one for your round-faced cherub, a round shape for your angular angel. And shoot small: Oversize glasses can make a kid look bug-eyed.

Be flexible. You may think plastic styles are cuter (bright colors, fun shapes), and they're fine. If you can't get a good fit, though, metal's easy to adjust, says Dana Cohen, a pediatric optician in Medford, MA. Look for flexible titanium and spring hinges, which bend without breaking as easily.

Focus on the bridge. A too-tight nose pad will pinch and prevent the glasses from sitting close enough to your child's eyes. When it's too wide, the frames slip and slide. You'll know it's right when there's very little space between your child's cheek and the lower rim of the frames.

Ear this. For a child under 3, go for a silicone-covered, wraparound earpiece. For a baby, consider a soft strap that fits around the back of the head (otherwise, good luck keeping them on!).

Opt for safety. Polycarbonate lenses are the most impact-resistant. An antireflective coating will pad the price tag but usually results in sharper vision by letting more light hit the retina.

 eResearch by Navid Ajamin -- spring 2012

Image: knstrct.com finestglasses.com

Reference: www.parenting.com/article/how-to-choose-glasses-for-kids

Parents and coaches play an important role in making sure young athletes protect their eyes and properly gear up for the game. Protective eyewear should be part of any uniform because it plays such an important role in reducing sports-related eye injury.

Eye injuries are the leading cause of blindness in children in the United States and most injuries occurring in school-aged children are sports-related. These injuries account for an estimated 100,000 physician visits per year at a cost of more than $175 million.

Ninety percent of sports-related eye injuries can be avoided with the use of protective eyewear. Protective eyewear includes safety glasses and goggles, safety shields, and eye guards designed for a particular sport. Ordinary prescription glasses, contact lenses, and sunglasses do not protect against eye injuries. Safety goggles should be worn over them.

Currently, most youth sports leagues do not require the use of eye protection. Parents and coaches must insist that children wear safety glasses or goggles whenever they play.

Protective eyewear, which is made of ultra-strong polycarbonate, is 10 times more impact resistant than other plastics, and does not reduce vision. All children who play sports should use protective eyewear-not just those who wear eyeglasses or contact lenses. For children who do wear glasses or contact lenses, most protective eyewear can be made to match their prescriptions. It is especially important for student athletes who have vision in only one eye or a history of eye injury or eye surgery to use protective eyewear.

Whether you are a parent, teacher, or coach, you can encourage schools to adopt a policy on protective eyewear. Meanwhile, parents and coaches should insist that children wear protective eyewear whenever they play sports and be good role models and wear it themselves.[1]

Types of injury
Three types of eye trauma can result from sports injuries: corneal abrasion, blunt injuries and penetrating injuries.

Corneal abrasion, a scrape of the outer surface of the eye, usually is painful but not severe. The most common cause, in sports and recreation, is a scratch from a fingernail. Many professional basketball players wear goggles when they play to protect themselves from such an injury.

Blunt injuries occur when impact from an object (tennis ball, racquet, fist, elbow, etc.) causes sudden compression of the eye.

Mild blunt injuries sometimes only result in bleeding of the eyelids, or a black eye. Also, a subconjunctival hemorrhage may develop. This involves bleeding from the delicate blood vessels of the conjunctive, which lie on top of the white outer coat of the eye. Neither of these types of bleeding poses a threat to the eye itself. However, these injuries may be seen in more severe cases in which the eye is damaged. As symptoms of severe injury are not always obvious, it is crucial that all cases of eye trauma get a thorough eye examination from an ophthalmologist.

One of the common results of more severe blunt trauma is bleeding in the front of the eye between the clear cornea and colored iris. This condition is known as a hyphema. In addition, blunt injury may cause a cut or tear of the eyelids, which may need special suturing. Also, the bony walls surrounding the eye may be fractured by severe blunt trauma. Severe blunt trauma also may damage important structures inside the eye, such as the retina or optic nerve, resulting in potentially permanent visual loss. Therefore, if you suffer a blunt injury to the eye, see an ophthalmologist as soon as possible.

Penetrating injuries occur when a foreign object pierces the eye. A common cause of these injuries in children is BB pellets. Also, a piece of glass from spectacles shattered during sports play sometimes can penetrate the eye. Penetrating injuries often cause severe, sight-threatening damage; they are true emergencies and must be evaluated promptly by an ophthalmologist.

Symptoms and evaluation
The warning signs of potentially serious eye injury include:

• Visual loss

• Bleeding on the surface or inside the eye

• Tears in the outer ocular walls

• A foreign body inside the eye

The evaluation of sports-related eye injuries is the same as for other types of eye trauma. More emergent injuries, such as head trauma with loss of consciousness, are always treated first.

Treatment
Prompt first aid after eye injury may greatly improve the chance of preserving vision. The recommended first aid involves placing a protective cover over the eye to prevent further damage. (If no shield is available, tape the bottom of a paper cup over the eye.) Seek emergency care as soon as possible.

The type of treatment given depends on the injury. Surgery may be required to repair blunt or penetrating injuries.

Prevention
The best treatment is prevention, as the old adage goes. The best prevention of eye injury while involved in sports and recreation is to wear specially designed protective eyewear. Such eye guards, while they cannot eliminate risk, greatly reduce the chance of ocular injury. Regular eyeglasses and contact lenses do not offer adequate protection from sports injuries. As already mentioned, glass lenses may even shatter and cut the eye.

Racquet sports—Stricter standards for eyewear for racquet sports have helped reduce the number of eye injuries from these activities. Research done at the UIC Eye Center and elsewhere has led to the improvement of these eye protection devices.

Today, the standard eye guard designed for use in sports such as racquetball, baseball and basketball is made of polycarbonate (plastic) and has closed lenses and sports frames. Avoid open lenses, as a small ball traveling at high speed can be compressed through the opening and cause severe eye damage.

Collision sports—Total head and face protection is essential for any collision sport, for example, a helmet in football and a face mask in hockey. In hockey the risk of eye injury is not so much from collision as from a flying puck. The standardization and use of face masks in organized amateur ice hockey in Canada led to a 66 percent reduction in eye injuries.

The identification of patterns in sports eye trauma is important in helping prevent many of these injuries. The National Eye Trauma System (NETS) is collecting data on the frequency and types of eye injuries, including those due to sports. The UIC Eye Center is one of 50 regional eye trauma centers that are sending the data to NETS.[2]

 eResearch by Navid Ajamin -- spring 2012

Image: www.eyedocgreg.com health.howstuffworks.com

Reference:

1. www.nei.nih.gov/sports/
2. www.uic.edu/com/eye/LearningAboutVision/EyeFacts/SportsEyeInjuries.shtml

First aid for eye emergencies:

Chemicals in the eye

• Immediately flush the eye with water for at least 15 minutes. Place the eye under a faucet or shower, use a garden hose, or pour water into the eye from a clean container.
• If you are wearing contact lenses, do not wait to remove the lenses. Begin flushing the eye immediately. This may wash the lens out of the eye.
• Do not try to neutralize the chemical with other substances.
• Do not bandage the eye.
• Seek immediate medical attention after flushing.

Particles in the eye

• Do not rub the eye.
• Try to let your tears wash the speck out or irrigate the eye with an artificial tear solution.
• Try lifting the upper eyelid outward and down over the lower eyelid to remove the particle.
• If the particle does not wash out, keep the eye closed, bandage it lightly and seek medical care.

Blows to the eye

• Gently apply a cold compress without putting pressure on the eye. Crushed ice in a plastic bag can be placed gently on the injured eye to reduce pain and swelling.
• In cases of severe pain or reduced vision, seek immediate medical care.

Cuts and punctures to the eye or eyelid

• Do not wash out the eye.
• Do not attempt to remove an object that is stuck in the eye.
• Cover the eye with a rigid shield, like the bottom half of a paper cup.
• Seek immediate medical care.

 eResearch by Navid Ajamin -- spring 2012

Image: en.wikipedia.org/wiki/Ambulance ; www.hkfsd.gov.hk

Reference: www.aoa.org/x4736.xml Related To:First Aid & Emergencies

Age-related macular degeneration (AMD) is a medical condition which usually affects older adults and results in a loss of vision in the center of the visual field (the macula) because of damage to the retina. It occurs in “dry” and “wet” forms. It is a major cause of blindness and visual impairment in older adults (>50 years). Macular degeneration can make it difficult or impossible to read or recognize faces, although enough peripheral vision remains to allow other activities of daily life.[1]

Macular Degeneration - Symptoms and Detection
Symptoms of Dry AMD include the presence of drusens that begin to enlarge. Another symptom is blurry areas in central vision. A symptom of Wet AMD is seeing straight lines as wavy ones.

A visual acuity test can help an eye care professional determine if any central vision is lost. An Amsler grid may also be used to detect AMD. In this test you cover one eye and stare at a black dot that has patterns of straight lines. If these lines appear wavy or are missing then AMD could be present.[2] 

Prevention

There is growing evidence that by improving your diet, you may also improve the health of your eyes. Research has suggested an association between macular degeneration and a high saturated fat diet.

There is also evidence that eating fresh fruits and dark green, leafy vegetables – foods rich in vitamins C and E, selenium, and carotenoids (including beta-carotene, lutein and zeaxanthin) – may delay or reduce the severity of AMD.

Foods to Enjoy

Eat the freshest and brightest fruits and vegetables. Pick the most colorful vegetables and fruits you can find - red, dark green, orange, or yellow. These foods play a key role in keeping your eyes healthy:

Carrots  Corn  Kiwi  Pumpkin  Yellow squash  Zucchini  squash  Red grapes  Green peas  Cucumber Butternut  squash  Green bell  pepper  Celery  Cantaloupe  Sweet potatoes  Dried apricots  Tomato and tomato products  Dark green leafy vegetables  Spinach  Kale  Turnips Collard greens ...

Fish

Eating fatty fish such as salmon, tuna or mackerel two to three times per week can slow the progression of age-related macular degeneration (AMD) according to a study published in the British Journal of Ophthalmology.

This research further confirms earlier studies that suggested eating fish can help reduce the risk of getting AMD and demonstrates that some of those already affected by the disease can benefit as well.

Nuts

Nuts not only contain Omega-3 fatty acids, but also copper which can play a role in preventing age-related eye diseases. Even just a handful of nuts at two or three times a week can reduce your risk of AMD.

Foods to Avoid

A high-fat, high-cholesterol diet can lead to fatty plaque deposits in the macular vessels, which can hamper blood flow and increase the risk of AMD. A diet low in fat promotes good eye health. Skip foods and processed baked goods with high-fat content. In addition recent research has indicated that those consuming red meat (10 times a week or more) were at 47% higher risk for macular degeneration.

Vitamins and Supplements

The National Eye Institute’s Age-Related Eye Disease Study (AREDS) found that taking a specific high-dose formulation of antioxidants and zinc significantly reduces the risk of advanced AMD and its associated vision loss. Slowing AMD’s progression from the intermediate stage to the advanced stage will save the vision of many people.

People who should consider taking the combination of antioxidants plus zinc include those who are at high risk for developing advanced AMD. These people are defined as having either:

1. Intermediate AMD in one or both eyes. Intermediate AMD is defined as the presence of either many medium-sized drusen or one or more large drusen.
2. Advanced AMD in one eye, but not the other eye. Advanced AMD is defined as either a breakdown of light-sensitive cells and supporting tissue in the central retinal area (advanced dry form), or the development of abnormal and fragile blood vessels under the retina (wet form) that can leak fluid or bleed. Either of these forms of advanced AMD can cause vision loss. Ask you doctor if taking this special formulation is right for you and where you can obtain the specific formula in your country.[3]

Grapes May Help Prevent AMD

Can eating grapes slow or help prevent the onset of age-related macular degeneration (AMD), a debilitating condition affecting millions of elderly people worldwide? Results from a new study published in Free Radical Biology and Medicine suggest this might be the case. The antioxidant actions of grapes are believed to be responsible for these protective effects.[4]

 eResearch by Navid Ajamin -- spring 2012

The Amsler Grid

Video: www.webmd.com/eye-health/video/macular-degeneration-test

Image: www.drchristinachoy.com ; www.feastervillefamilyeyecare.com ; jama.ama-assn.org

Reference:

1. en.wikipedia.org/wiki/Macular_degeneration
2. www.eyehealthweb.com/diseases/macular-degeneration
3. www.amdalliance.org/information_prevention.html
4. careyeasy.com/eye-care-news/grapes-may-help-prevent-amd
   

Related To: Facts About Age-Related Macular Degeneration ; Macular Degeneration and Smoking

Further Information:

• The Normal Macula Compared to Wet and Dry Macular Degeneration 
• Macular Degeneration
• Mechanism Linked to AMD Found
• Major breakthrough in early detection and prevention of AMD

• Age-Related Macular Degeneration Treatment

• New treatments revolutionize care for aging eyes 

Do you have or know someone who has anxiety, panic attacks, and Fear of Eyes? Continue reading to learn more about symptoms, causes, and ways to overcome the Fear of Eyes.[1]

Epiphora is an overflow of tears, usually caused by insufficient drainage of the tear film from the eye. The most common cause is a blockage of the lacrimal (tear) ducts located next to the nose , but the condition may also result from the excessive production of tears. Epiphora is a symptom rather than a disease and may be caused by a variety of conditions.

  The purpose of normal tears is to lubricate, nourish, and protect the eye from dust and other irritants. Spread by blinking (about every six seconds), tears keep the surface of the eye optically clear and smooth, and also protect from infection. Tears flow into the eye through ducts from tiny glands located under the upper eyelids and drain from the eye through the puncta (singular: punctum), which are small openings near the nose.[1]

More sinister causes of watery eyes

 Watery eyes can occur at any time, but babies up to 12 months old and people over 60 seem to be more prone.

Watery eyes, sometimes referred to by the medical name of “epiphora” either from the Latin word meaning repetition, or maybe the Greek word meaning bringing upon, can be caused by a few things that are a bit more sinister:

•    Conjunctivitis, of which there are several types ranging from mild to severe, produce red eyes almost always watery eyes.

•    Blepharitis – this is the medical term used for inflamed eyelids with scaly surfaces, a bit like eczema, with smoke and sunlight especially make the eyes water

•    Eyelashes growing inward, so as to contact the eye – there are two ways this can happen. The term “entropion” is used to describe what happens when the lower lid turns inwards (and the eyelash with it), whilst “trichiasis” causes a similar effect, but happens due to the eyelashes themselves growing inwards (curving the wrong way). Whatever way it happens of course, it will be quite uncomfortable.

•    Lower eyelid turning down –called “ectropion”. In this condition, the eyelid turns down and sags outwards, preventing them from effectively draining the tears away.

•    Blocked tear ducts – tears lead outwards to the nose through what’s appropriately called the nasolacrimal duct.  If this is blocked in any way then watery eyes are a consequence.  This can sometimes be just flushed with a syringe and sterile saline or require reconstructive surgery.

Treating Watery Eyes

Mild cases of watery eyes can often be “cured” by waiting and watching – why introduce treatments when nature can and probably will take its course? The various underlying causes of watery eyes need active management:

•    Dry eyes can be treated by a programme of eye drops developed “under the watchful eye” of an Optometrist, taking care not to use drops more than four times a day unless they are in ampules and non-preserved.

•    Infections such as a mild conjunctivitis can be remedied using antibiotics or anti-inflammatories.

•    Allergies are mostly cleared up by use of an antihistamine / mast cell stabilisers – but the best approach is to try and identify the cause of the allergy and remove it if possible.

•    Blepharitis is not always serious and you may not even know you have it; it will of course be spotted by your optometrist if he or she is on the ball. Preservative-free artificial tears can be used as eye drops for treatment of minor cases, antibiotics in more severe cases and steroid creams only in the worst of cases, but then ideally only in the short term.

•    In the cases of the eyelash entropion and ectropion surgical reconstruction is likely to be the best option.

•    Blocked tear ducts – if the watery eye symptoms occur more than ten times a day then surgery to introduce a channel from the eye to the nose may be needed, usually after first injecting a dye into the tear duct to see if and where it comes out.[2]

eResearch by Navid Ajamin -- spring 2012

Image: www.andorrapediatrics.com www.patient.co.uk

Reference:1.www.visionrx.com/library/enc/enc_epiphora.asp 2.optometrist.com.au

Related To: Dacrocystorhinostomy

در هوای آلوده عینک بزنید

چشم‌ها اعضای حساس و آسیب پذیری هستند. با این‌که آلودگی هوا به‌طور مستقیم به چشم آسیب نمی‌رساند، ولی در هوای آلوده بیماری‌های سطح چشم مانند خشکی چشم، حساسیت و عفونت‌های مختلف که ممکن است در سطح پلک اتفاق بیفتند، تشدید می‌شوند و در این شرایط افراد احساس ناراحتی بیشتری می‌کنند.

علاوه بر این تحریکات سطحی مثل خارش، سوزش، اشک ریزش و قرمزی چشم را نیز به‌دنبال خواهد داشت.

اگر فرد دچار یکی از بیماری‌های چشمی باشد، در این شرایط علائم آن افزایش پیدا می‌کند. بنابراین بهتر است ابتدا بیماری زمینه‌ای خود را درمان کند.

عینک آفتابی در هوای ابری

 خوب است بدانید که در هوای ابری هم مقادیر زیادی از اشعه خورشید از میان ابرها عبور می‌کند و پخش نور در قسمت‌های مختلف جو، UV (اشعه ماورای بنفش) قابل توجهی را در محیط ایجاد می‌کند، ولی مسلما کمتر از زمانی است که آفتاب به‌صورت کامل در آسمان وجود دارد.

اگر هوا ابری ولی روشن است، طوری که نور چشمان‌تان را اذیت می‌کند، برای راحتی بیشتر از عینک آفتابی استفاده کنید. در این موارد، بسته به راحتی افراد میزان فتوکرومیک بودن عینک تنظیم می‌شود، مثلا در حالاتی مانند هوای ابری، عینک‌هایی که فتوکرومیک آنها خیلی بالا نیست، مناسبند، چون شیشه عینک کمتر تیره شده و دید فرد را مختل نمی‌کند. eResearch by Navid Ajamin

تصویر: www.iren.ir/Nsite/FullStory/?Id=6297 

منبع:www.tebyan.net/newindex.aspx?pid=198343

In chemistry, hydrophobicity (from the Attic Greek hydro, meaning water, and phobos, meaning fear) is the physical property of a molecule (known as a hydrophobe) that is repelled from a mass of water.

Hydrophobic molecules tend to be non-polar and, thus, prefer other neutral molecules and non-polar solvents. Hydrophobic molecules in water often cluster together, forming micelles. Water on hydrophobic surfaces will exhibit a high contact angle.

Examples of hydrophobic molecules include the alkanes, oils, fats, and greasy substances in general. Hydrophobic materials are used for oil removal from water, the management of oil spills, and chemical separation processes to remove non-polar from polar compounds.

Hydrophobic is often used interchangeably with lipophilic, "fat-loving." However, the two terms are not synonymous. While hydrophobic substances are usually lipophilic, there are exceptions—such as the silicones and fluorocarbons.[1]

thin layers of a waterproof substance on the surface of hydrophilic materials. Hydrophobic coatings are often called water-repellent, which is incorrect, since the water molecules are attracted to the coatings, although extremely weakly, rather than repelled by them.

Hydrophobic coatings are produced in the form of monomolecular layers (adsorbed orientated layers one molecule thick) or lacquer films by treating a material with solutions, emulsions, or less frequently, vapors of hydrophobic agents, which are substances that interact weakly with water but attach themselves firmly to a surface. Substances used as hydrophobic agents include salts of fatty acids and such metals as copper, aluminum, and zirconium; cation-active surface-active agents; and low-and high-molecular-weight organosilicon and organic fluorine compounds.

Hydrophobic coatings protect various materials (metal, wood, plastics, leather, and fabric and nonfabric fibrous ma-terials) from the destructive action of water or wetting. They are used particularly extensively in machine building,construction, and textile production.[2]

If you live in a cold climate, nothing is more frustrating than having your eyeglasses fog up when you come in from the cold. This also can be a safety issue, since it limits your ability to see until the fog clears. Lens fogging can be especially dangerous for police officers and other first responders to emergency situations.

At least one eyeglass lens coating company (Opticote) has created a permanent coating designed to eliminate this problem. The factory-applied coating — called Fog Free — eliminates the condensation of moisture on lenses that causes fogging.

So your lenses and vision stay clear when you make the transition from a cold environment to a warm one. It may also keep your lenses from fogging up during sports and other times you are hot and perspiring.

Fog Free can be applied to plastic, polycarbonate and other eyeglass lenses, including high-index lenses and Transitions photochromic lenses. The anti-fog coating is applied to the lenses before they are cut to fit into your frame at the optical lab. Ask your optical retailer about pricing and availability.

In October 2011, Essilor introduced a line of eyeglass lenses called Optifog, which the company describes as "a breakthrough lens with an exclusive anti-fog property."

The anti-fogging property of Optifog lenses is activated by applying a drop of Optifog Activator to each side of the lens, then wiping the lens with a microfiber cloth to thoroughly spread the liquid across the entire lens surface. This treatment keeps the lenses fog-free for up to one week, according to Essilor.

Lens fogging is caused by tiny water droplets that form by condensation on the surface of eyeglass lenses when the lenses are significantly cooler than the surrounding air temperature. Optifog works by uniformly spreading these water droplets across the lens surface so they become invisible, Essilor says.

Optifog lenses are available in plastic, polycarbonate and high-index plastic lens materials, with or without Essilor's proprietary Crizal anti-reflective coating.[3]

Image: www.oakley.com www.optifog.com 

Reference: eResearch by Navid Ajamin -- spring 2012

1. en.wikipedia.org/wiki/Hydrophobe
2. encyclopedia2.thefreedictionary.com/Hydrophobic+Coatings
3. www.allaboutvision.com/lenses/coatings.htm

Related To: Hydrophobic and Super Hydrophobic ;Anti-Reflective Coating for Eyeglass Lenses

Puffy eyes are the bane of most women's existence. No one wants puffy eyes! The culprit? Could be anything. Too much salt the day before. Too little sleep. Who knows? For one reason or another, you wake up to find you have puffy eyes... and you want to get rid of them.

Puffy eyelids make you look tired and old. While they are usually temporary, they may last days or even weeks. If you are sick or puffy eyes result from irritation, you may find your eyes persistently take on a marshmallow like appearance. What can you do? First and foremost, don't fret! Let's look at the puffy eyes phenomena more in detail to figure out what we can to do help.

Puffy Eyes Causes
What causes puffy eyes? There are all manner of insidious reasons people develop puffy eye syndrome. Here are some typical causes for puffy eyes:

• Fluctuating hormone levels, increasing the likelihood your body will retain fluid around the thin skin underneath your eyes.

• Edema or fluid retention throughout the body. Some causes for this include illness, inflammation and fatigue. Pregnancy also causes increasing edema in women.

• Dehydration, whether from drinking too little water or from a hangover. Either way, the only cure is more water.

• Puffiness resulting from medication use.

• Heredity (yes, your genes can influence your susceptibility to puffy eyes!).

• Allergies, which may also result in itchiness and redness of the eyes and surrounding tissue.

Because the skin underneath our eyes is so delicate, there are almost too many causes to list. Your best bet in the fight against puff? Treat your eyes like queens. That means getting plenty of rest, and avoiding excessive irritants. Consider the skin around your eyes as you would the skin of a newborn baby, and you'll go a long way toward combating under eye puffiness. Let's learn more about eye puffiness...

Conjunctivitis (inflammation of the eye)

What is conjunctivitis?

Inflammation is seen as reddish change in the periphery of the eye often accompanied by a pus-like discharge.

Conjunctivitis is an inflammation of the conjunctiva, which is the mucous membrane covering the white of the eyes and the inner side of the eyelids.

It usually affects both eyes at the same time – although it may start in one eye and spread to the other after a day or two. It may be asymmetrical, affecting one eye more than the other.

There are many causes and the treatment will depend upon the cause.

Conjunctivitis is a common eye condition. It's not serious, but it can be uncomfortable and irritating.[1]

Classification
Classification can be either by cause or by extent of the inflamed area.

By cause

• Allergic conjunctivitis
• Bacterial conjunctivitis
• Viral conjunctivitis
• Chemical conjunctivitis
• Neonatal conjunctivitis is often defined separately due to different organisms

By extent of involvement
Blepharoconjunctivitis is the dual combination of conjunctivitis with blepharitis (inflammation of the eyelids).

Keratoconjunctivitis is the combination of conjunctivitis and keratitis (corneal inflammation).

Episcleritis is an inflammatory condition that produces a similar appearance to conjunctivitis, but without discharge or tearing.[2]

Treatments for various types of conjunctivitis

Bacterial conjunctivitis can be treated by antibiotics

Bacterial conjunctivitis in adults is always caused by infections such as staphylococcus and streptococcus. In children, a common cause is Haemophilus influenza bacteria. Besides eye cleanser and artificial tears for relieving symptoms, the doctor will also prescribe standard antibiotics to treat bacterial conjunctivitis. In most cases, antibiotics are enough and a sample evaluation is unnecessary.

Hereditary gonococcal conjunctivitis requires injection of antibiotics

Newborn babies are at high risk of gonococcal conjunctivitis, which is caused via the contact with their mothers. This type of conjunctivitis results from sexually transmitted diseases on pregnant women, who should be treated with antibiotics to prevent the infection from being passed to their children. Caused by either birth-related bacteria or pink eye exposure, some cases of gonococcal conjunctivitis even occur after several weeks of birth.

Once a child is diagnosed with gonococcal conjunctivitis, the most common treatment is to take an intravenous injection of antibiotics through either veins or muscles. Another treatment is applying silver nitrate and antibiotic ointments to its eye within an hour after birth.

Viral conjunctivitis can be relieved by antihistamine and steroids

Viral conjunctivitis has symptoms such as watery mucus discharge and eye redness. This type of conjunctivitis usually spreads through respiratory infection, so that children with a cold are more likely to be affected. As a result, pink eye epidemics may be aroused among school children via sneezing and coughing. Other reasons that may cause viral conjunctivitis include virus-based illness such as measles and mumps. Viral conjunctivitis can not be cured, only treatments for symptom relief are available. Antihistamine is used to relieve eye itchiness and irritation, and vasoconstrictors are effective for reducing redness. Steroids are also used to control symptoms and speed up recovery, while they may cause cataracts or glaucoma. Most cases of viral conjunctivitis will go away on its own within several days or weeks.

Allergic conjunctivitis require eye drops and mast-cell stabilizer

Allergic conjunctivitis also has various symptoms, including itchiness, stringy mucous discharge and red eye, stuffy and runny nose. People with allergic conjunctivitis can usually get relief from ordinary eye drops, which are helpless for individuals with severe conditions. Serious conjunctivitis should be treated with steroid eye drop medications at the beginning and mast-cell stabilizer for regular use. Due to potential side effects such as cataracts, the use of steroid must be under careful monitoring.

Giant papillary conjunctivitis calls for the use of GP contact lenses

Giant papillary conjunctivitis (GPC) is always found in people wearing soft contact lenses. Other potential risks of GPC include artificial eye and an exposed suture. People with GPC always tear much, produce significant mucus and get itching eyes or eyelid bump. For symptom relief, saline solution can be used to wash the eye’s surface. There are still some remedies for GPC involving soft contact lenses. The most effective way is to remove contact lenses, along with their abnormal immune response. For those persisting in lenses wearing, mast-cell stabilizers may be used. To avoid the recurrence of GPC, it is encouraged to can wear RGP lenses and use strict lenses hygiene.[3]     eResearch by Navid Ajamin -- spring 2012

Reference: 1.www.netdoctor.co.uk 2.en.wikipedia.org/wiki/Conjunctivitis 3.vision.firmoo.com

Nystagmus /nɪˈstæɡməs/ is a condition of involuntary eye movement, acquired in infancy or later in life, that may result in reduced or limited vision.  

http://dl.stream.utah.edu/eccles/NOVEL/WRAY/936-8_CD_hq.mp4

There are two key forms of Nystagmus: pathological and physiological, with variations within each type. Nystagmus may be caused by congenital disorders, acquired or central nervous system disorders, toxicity, pharmaceutical drugs or alcohol. Previously considered untreatable, in recent years several pharmaceutical drugs have been identified for treatment of Nystagmus.[1]

نيستاگموس حركت ناگهاني غير ارادي چشم ها است. نيستاگموس معمولاً دو چشم را گرفتار مي كند وغالباً با نگاه به سمت ويژه اي تشديد پيدا مي كند.

علل نيستاگموس
وضعيت هاي بسياري با نيستاگموس همراهند. گاهي كنترل مغزي حركت هاي چشم ضعيف است كه به ناتوانايي در نگاه كردن ثابت به شي منجر مي شود. برخي از اشكالات نيستاگموس با كاهش ديد همراهند همچنان كه در افراد مبتلا به آلبينوز, افراد نزديك بين يا دوربين يا افرادي كه داراي اسكارهايي روي شبكيه يا عصب بينايي هستند ديده مي شود. به ندرت نيستاگموس در اثر تومورهاي مغزي يا اختلالات عصبي شديد رخ مي دهد مي توان نيستاگموس را در خانواده ها به عنوان مشكل منحصر به فرد و جداي از وضعيت هاي ديگر مشاهده نمود.

در صورت وجود نيستاگموس چه اقدامي مي توان انجام داد؟
ارزيابي كامل متخصص چشم و احتمالاً پزشكان متخصص ديگر بسيار حائز اهميت است. معمولاً مي توان علت را تشخيص داد. عوامل مهم تشخيص به سن شروع, سابقه خانوادگي,‌سلامتي عمومي بيمار يا استفاده از داروهاي ويژه بستگي دارد. چشم پزشك ممكن است نوع نيستاگموس,‌سرعت و جهت آن را بسنجد و مشكلات چشمي ديگر را همچون افتادگي پلك ها، كاتاراكت (آب مرواريد) يا حالت غير طبيعي در شبكيه يا عصب بينايي جستجو كند. آزمايشات خوني يا گرفتن عكس هاي ويژه مي توانند در تشخيص علت مفيد باشند.

آيا مي توان نيستاگموس را درمان كرد؟
گاهي با برطرف كردن علت مي توان نيستاگموس را درمان نمود. اگر چه نيستاگموس غالباً دائمي است اما مي توان بينايي كاهش يافته را با استفاده از عينك و وسايل كمك كننده كاهش بينايي, بهبود بخشيد. اگر چشم-ها در جهت ويژه اي ثابت ترند, استفاده از عينك هاي منشوري يا جراحي عضلات چشمي ممكن است وضعيت سر را بهبود بخشيده و بينايي بهتري را ارائه دهند به ندرت بازخورد حياتي (Biofeed back) و تمارين چشمي مي توانند در كنترل نيستاگموس كمك كنند.

شايع ترين انواع نيستاگموس كدامند؟
به نظر مي رسد ”نيستاگموس حركتي“ از سنين 6 هفتگي تا سه ماهگي شروع مي شود. اعضاء ديگر خانواده ممكن است دچار حركات چشمي غير طبيعي مشابهي نيز باشند, حركت معمولاً افقي است. غالباً نگاه كردن بسيار نزديك به اشياء‌يا ديدن در جهت هاي غير عادي از شدت نيستاگموس مي كاهد و بينايي را بهبود مي بخشد. خوشبختانه حركت چشم هاي بيماران باعث ديدن متحرك اشيا نمي‌شود. با دور شدن اشياء بينايي ممكن است كاهش يابد اما با نزديكي آنها بينايي تقريباً طبيعي است. معمولاً هيچ گونه محدوديتي در پتانسيل يادگيري افراد مبتلا به نيستاگموس حركتي, وجود ندارد.
”نيستاگموس حسي“ با بينايي كاهش يافته به هر دليلي همراه است. نيستاگموس حسي معمولاً در سن 6 تا 8 هفتگي شروع مي شود. چشم ها متحرك به نظر مي رسند و حركت آنها گاه تند و گاه كند است. در اغلب موارد چشم ها به طرف بالا مي چرخند و پلك ها نيز ممكن است تكان بخورند. با بزرگ شدن كودك,‌وي ممكن است روي چشم هاي خود را بفشارد يا اين كه دست خود را جلوي آنها تكان دهد. گاهي علت بينايي كاهش يافته قابل درمان است. همچنان كه در نوزادان متولد شده با كاتاراكت (آب مرواريد) ديده مي شود. وضعيت هاي ديگري كه به ”نيستاگموس حسي“‌منجر مي شوند ممكن است قابل درمان نباشند. با اين حال شناخت علت زمينه اي براي پيش بيني وضعيت كودك در آينده از اهميت ويژه اي برخوردار است.

علل ديگر نيستاگموس كدامند؟
داروها مي توانند علت نيستاگموس باشند. اين نوع نيستاگموس به ندرت با دوبيني همراه است و غالباً ديدن اطراف را با مشكل مواجه مي سازد. علل ديگر شامل نوشيدن پيش از حد الكل يا استفاده از داروهاي كنترل بيماري است. غالباً اين گونه نيستاگموس با قطع مصرف دارو بهبود مي يابد.
برخي از افراد مي توانند ” نيستاگموس ارادي“‌ايجاد كنند همان طوري كه مي توانند گوش هاي خود را تكان دهند. حركت هاي افقي,‌سريع و خوب را مي توان ايجاد كرد و براي مدت كوتاهي آنها را ادامه داد. غالباً اين گونه نيستاگموس براي جلب توجه به كار گرفته مي شود.
”نيستاگموس ناشي از بيماري كمتر ديده مي¬شود. غالباً با نشانه ها و علائم نورولوژيكي كه شدت بيماري را نشان مي دهند همراه است.

خلاصه:
در صورت وجود نيستاگموس معاينه كامل چشمي توسط چشم پزشك ضروري است. دلايل زمينه اي كه اثر نيستاگموس را روي زندگي و بينايي بيمار تعيين مي كنند تا حدود زيادي متغيرند.(۲)

What it means if your child has it..

Having Nystagmus does not have to mean the end of the world for your child. You are the biggest determining factor in what it will mean.  I’ve included some information from the American Nystagmus Network (ANN) here and encourage you to get involved with them. 

I have been involved with them for a very long time and am partly inspired to write this by the many questions parents ask me about my life.

• Don’t limit your child. Vision typically continues to improve until the age of 10 in children with Nystagmus. Don’t train your child to say they can’t do something due to the eye condition. This will set them up to be in a bad way later in life. This doesn’t mean you should sign them up for football, but did you know there are surgeons with Nystagmus?
• If you notice your child is struggling ask them to talk to you about it so you can find ways to help.
• Prepare the teachers for dealing with Nystagmus. Although it is fairly common compared to other things teachers often don’t know what to do.  Give them the resources to work with your child. For example larger font on blue paper is a great technique in the schools.
• Become involved with ANN so you can get support from other parents and/or adults with Nystagmus…you’d be amazed at the resources available.
• Teach your child to honor his/her limits. If your child genuinely can’t do something well teach them to find things they do well and encourage them.
• Treat your child like a normal child.
• Give your child every opportunity to succeed.
• Don’t let your fear run your life or your child’s life.
• Remember every child deserves an abundant life and yours is no different.
• Teach your child not to let fear run his/her life. There are many of us that are successful, it is not a sentence to failure.
• Help your child connect with role models that have abundance and Nystagmus.[3]

Image: www.skillslab.ugent.be Video: The Neuro-Ophthalmology Virtual Education Library

Reference:  eResearch by Navid Ajamin --spring 2012

1. en.wikipedia.org/wiki/Nystagmus
2. lodportal.org
3. homeremediesmd.com/08/30/2011/child-with-nystagmus/

The iris (plural: irides or irises) is a thin, circular structure in the eye, responsible for controlling the diameter and size of the pupils and thus the amount of light reaching the retina. "Eye color" is the color of the iris, which can be green, blue, or brown. In some cases it can be hazel (a combination of light brown, green and gold), grey, violet, or even pink. In response to the amount of light entering the eye, muscles attached to the iris expand or contract the aperture at the center of the iris, known as the pupil. The larger the pupil, the more light can enter.

Etymology
The word iris is derived from the Greek goddess of the rainbow, due to the many colours of the iris.

Embryology
The iris develops from the anterior two layers of an embryonic neuroectoderm structure called the optic cup. The optic cup also produces the iris sphincter and dilator muscles.

General structure

 The iris consists of two layers: the front pigmented fibrovascular tissue known as a stroma and, beneath the stroma, pigmented epithelial cells.

The stroma connects to a sphincter muscle (sphincter pupillae), which contracts the pupil in a circular motion, and a set of dilator muscles (dilator pupillae) which pull the iris radially to enlarge the pupil, pulling it in folds. The back surface is covered by a heavily pigmented epithelial layer that is two cells thick (the iris pigment epithelium), but the front surface has no epithelium. This anterior surface projects as the dilator muscles. The high pigment content blocks light from passing through the iris to the retina, restricting it to the pupil. The outer edge of the iris, known as the root, is attached to the sclera and the anterior ciliary body. The iris and ciliary body together are known as the anterior uvea. Just in front of the root of the iris is the region referred to as the trabecular meshwork, through which the aqueous humour constantly drains out of the eye, with the result that diseases of the iris often have important effects on intraocular pressure, and body provide a lesser secondary pathway for the aqueous humour to drain from the eye.
The iris is divided into two major regions:
The pupillary zone is the inner region whose edge forms the boundary of the pupil.
The ciliary zone is the rest of the iris that extends to its origin at the ciliary body.[1]

From anterior to posterior the iris is organised in the following layers:
1. Endothelial
2. Anterior marginal layer
3. Vascular layer = Stroma
4. Posterior marginal layer = Dilatator layer
5. Epithelial pigment = Stratum pigmenti iridis
6. Retinal layer = Pars iridica retinae

1. The question of the existence of the Endothelial layer is not completely settled. Many researchers assume an anterior membrane of the human iris, others dispute it.
2. The anterior marginal layer is composed predominantly of cells, between which lie numerous nerve endings but few blood vessels. Cells bearing colour material—Chromatophoren—may be present, which together with the stroma gives rise to certain colour changes in the iris. Where the marginal layer is missing, smaller or larger dark-shining openings—so-called crypts—tissue spaces, allow a view of the interior of the spongy iris—stroma. These crypts will be considered later as lacunae.
3. The Vascular layer, or iris-stroma, constitutes the principal bulk of the iris. It consists mainly of numerous blood vessels which radiate in spokes, and therefore run radially from the outer margin of the iris towards the pupil. The blood vessels are enveloped in a thick adventitia of connective tissue fibre, and are surrounded by a loose ramifying network and pigment cells, which fill out the spaces between the blood vessels.
These blood vessels appear as spiral formations below the anterior marginal layer. In these formations they can adapt to the conditions of expansion and contraction of the iris.
Besides the radiating blood vessels of the iris stroma, there is in the iris an arterial ring arising from the annular anastomosis of the ciliary blood vessels—the Circulus arteriosus iridis minor. It is situate at the border between the pupillary zone and the ciliary zone, and is called in Iridology the Iris-wreath.
In a very light iris one can also see a grey band at the pupillary margin. This is composed of smooth muscle fibres which surround the pupil in a ring-formation. They form the sphincter of the iris—Sphincter pupillae —which lies in the iris-stroma.
4. The posterior marginal layer—Dilatator layer—joins on to the posterior surface of the vascular layer. It consists of a continuous layer of spindle-shaped smooth muscle fibres, extending from the outer margin of the iris to the ciliary border near to the pupillary margin. Here it unites with the connective tissue of the sphincter.
5-6. The epithelial pigment forms the posterior surface of the iris and extends to the pupillary margin, around which it runs to the anterior surface of the iris, thereby giving rise to the frequently visible dark-yellow to black-brown pupillary margin.
This margin, where the fibres reflect back, is the only structure in the human body, which as the embryological representation of the central nervous system, provides a surface accessible to view.
This posterior pigment layer consists of two layers of epithelial cells which pass over into one another to the pupillary margin. (Stratum pigmenti iridis with Pars iridica.) Both together form the continuation of the retina as far as the pupillary margin. Thus, this layer of the iritis denoted Retinal, in contrast to the anterior layer which is called the Uveal. (Pars retinalis iridis, and Pars uvealis iridis.)
Apart from the structure referred to above, examination frequently reveals a number of light or dark concentric arc lines. These are seen particularly frequently in a brown iris where they stand out because of their light colour on a dark background. These are the 'contraction rings' of the iris, which in Iridoscopy have a special meaning.
Quite remarkable are the groups of white flakes seen at the periphery of the ciliary zone, and sometimes scattered regularly around the whole iris like a rosary. These will be discussed later under the heading 'Acute or chronic inflammation of the mucous membranes'.
At the periphery, there appears a partial, or frequently entire, dark almost black circle (Scurf rim). In old age it becomes obscured by a silver-grey rim projectingfromthesclera(Sclerotic rim). The black circle is formed by the crypts of the ciliary margin, and the silver-grey rim results from fatty infiltration—it is a sign of senile change (Arcus senilis).[2]

eResearch by Navid Ajamin -- spring 2012

Image: blog.timesunion.com/kristi/files/2009/11/greeneye.jpg ; www.selectspecs.com/info/structure-of-the-eye/; wikimedia.org

Reference:

1. en.wikipedia.org/wiki/Iris_(anatomy)
2. www.ipeerx.com/articles/category/10/message/204/

First and perhaps most obvious, never use a regular towel, paper towel, or washcloth to clean sunglasses.  The reason is that these materials are relatively coarse and can leave behind microscopic scratches.  The scratches are so small that initially you probably won’t notice, but repeated rubbing with these materials over time can cause an accumulation in the number of these mini-scratches which will ultimately decrease the visual acuity of the lenses.  A much better idea is to clean the lenses with a microfiber or lint-free cloth, which can be purchased at pretty much any optical store.

Additionally, never hold your sunglasses by the lenses when you are trying to clean them because this will create smudges on the lenses and, depending on how tight your grip is, could cause microscopic blemishes as well.  This might seem really obvious, but I’ve seen so many people do this that it is worth mentioning.  Always hold your sunglasses by the frame when cleaning the lenses.

For particularly dirty lenses, a simple dry rub may not be adequate and may even exasperate the blemishes.  In these cases, soapy, warm water can work wonders.  Simply run some warm tap water over the lenses, apply a mild soap, rinse and dry with a microfiber or lint-free cloth.  If soapy water is not enough, the next step is to purchase a commercial cleaner designed for sunglass lenses.  The most important thing here is to follow the instructions on the bottle as closely as possible, and of course follow the other tips mentioned above.

 Related To: How to Clean Plastic Sunglass Lenses

Image: ehow.com ; web.tradekorea.com ; aliimg.com                eResearch by Navid Ajamin -- spring 2012

Reference: www.matrixeyewear.com/blog/how-to-clean-sunglasses-without-scratching-the-lenses

The sclera (from the Greek skleros, meaning hard), also known as the white of the eye, is the opaque, fibrous, protective, outer layer of the eye containing collagen and elastic fiber. In humans the whole sclera is white, contrasting with the coloured iris, but in other mammals the visible part of the sclera matches the colour of the iris, so the white part does not normally show. In the development of the embryo, the sclera is derived from the neural crest. In children, it is thinner and shows some of the underlying pigment, appearing slightly blue. In the elderly, fatty deposits on the sclera can make it appear slightly yellow.

The sclera forms the posterior five-sixths of the connective tissue coat of the globe. It is continuous with the dura mater and the cornea, and maintains the shape of the globe, offering resistance to internal and external forces, and provides an attachment for the extraocular muscle insertions. The sclera is perforated by many nerves and vessels passing through the posterior scleral foramen, the hole that is formed by the optic nerve. At the optic disc the outer two-thirds of the sclera continues with the dura mater (outer coat of the brain) via the dural sheath of the optic nerve. The inner third joins with some choroidal tissue to form a plate (lamina cribrosa) across the optic nerve with perforations through which the optic fibers (fasciculi) pass. The thickness of the sclera varies from 1mm at the posterior pole to 0.3 mm just behind the rectus muscle insertions. The sclera's blood vessels are mainly on the surface. Along with the vessels of the conjunctiva (which is a thin layer covering the sclera), those in the episclera render the inflamed eye bright red.
In many vertebrates, the sclera is reinforced with plates of cartilage or bone, together forming a circular structure called the scleral ring. In primitive fish, this ring consists of four plates, but the number is lower in many living ray-finned fishes, and much higher in lobe-finned fishes, various reptiles, and birds. The ring has disappeared in many groups, including living amphibians, some reptiles and fish, and all mammals.
The eyes of all non-human primates are dark with small, barely visible sclera.

eResearch by Navid Ajamin -- spring 2012

Reference: en.wikipedia.org/wiki/Sclera

Eye pain can be a very uncomfortable feeling and sometimes is referred to as a stabbing, throbbing, burning, gritty, sharp, aching or “something in my eye” feeling. Many people seek medical care when eye pain is present and for very good reasons. The causes of eye pain can be one of two forms; ocular pain or orbital pain. The word pain is generally open for interpretation. Some people describe it as in their eyes, around their eyes, behind their eyes, etc.

Causes of Eye Pain

As mentioned before, eye pain can be placed into two categories, ocular or orbital. There could be many reasons why someone is experiencing eye pain, most causes should be treated with the help of a primary care doctor or eye care specialist.

Ocular pain comes from the outer structure of the eye and can be caused by one of the following conditions:

Conjunctivitis – this is the most common eye problem and can be allergic, bacterial, viral, or chemical. Pain is usually mild.
Stye – also called chalazion, causes eye pain due to the irritation it involves. A lump forms within the eyelid and becomes very painful to the touch.
Blepharitis – plugged oil glands at the edges of the eyelid become inflamed and cause pain around the eyelids.
Corneal Abrasions/Ulcers – these two conditions are very common causes of eye pain. Abrasions occur when the cornea of the eye is scratched, and ulcers occur from infections of those abrasions. Many times this will leave a person with the constant feeling that something is in the eye, which can be as annoying as it is painful.
Chemical Burns – this can be extremely painful and is caused by flash burns or exposure to chemicals such as acid.

Orbital pain is usually caused by a disease of the eye and can be described as a deep, dull ache behind or within the eye itself. Some of the diseases that can cause orbital pain are:

Glaucoma – glaucoma in general in mostly painless, but as the pressure builds up, orbital pain occurs and the condition can become serious.
Migraines – very common form of eye pain that is associated with headaches.
Optic Neuritis – this condition is the inflammation of the optic nerve, which connects to the back of the eye. Viral or bacterial infections can be the cause of this painful condition.
Iritis – the iris is the colored part of the eye, and when this becomes inflamed it can cause a deep pain.
Trauma – this could be a variety of things ranging from a blow to the eye with an object to scratches to car crashes. These events can cause a large amount of eye pain.

Treatment for Eye Pain

If you’re experiencing eye pain, you should consider seeking medical attention. If you think you know what the problem is and do not feel like you’d need a doctor, you can try different things at home such as flushing your eyes with lukewarm water or commercial eye solutions. Also, try to avoid touching or rubbing your eyes as this usually increases irritation. This will only make the situation worse, and could cause further damage. If the pain is mild, you can try taking over the counter pain relievers such as ibuprofen. If you can see the debris in your eye, and flushing your eye out with water hasn’t worked, do not attempt to remove the debris. Instead seek medical attention. In fact, the only thing you should do as a “home remedy” is flush your eyes out with water or solution or take a pain reliever. All other treatments should be done by the doctor who can determine the severity of the pain and if there are other problems like an eye disease or other health problem. Treatments will vary depending on the severity of the eye pain and the uniqueness of your situation.

Tips to Treat and Prevent Eye Pain

Here are some tips that you can consider to adopt for pain-relief.

Put The Pain On Ice - If you get socked in the eye it is recommended immediately applying an ice pack to your eye for 15 minutes. Cold can reduce the pain and swelling.

Make Yourself Cry - To combat dry eye, bathe your eyes with artificial tears. These products mimic real tears. They are available at most drugstores.

Compress It - The first symptoms of a sty are teariness, sensitivity to light, and the feeling that something is in your eye. Then the lid reddens, swells and hurts. A sty is a low-grade infection of the eyelid. For quick relief, place a washcloth soaked in warm water over the sty for 15 minutes every 2 hours. The compress will liquefy the oils and allow them to drain. This treatment will cure most sties. Do not rub your eye and do not wear eye makeup.

Irritate Your Eye - To dislodge any speck of dust or grit, wash out your eye with saline solution, preferably one without preservatives. Do not use tap water, distilled water, or eyedrops unless you have splashed your eye with a caustic chemical and there is nothing else available.

Dab Away The Invader -If the fleck or speck is on the white part of your eye, it is recommended to try to dislodge it gently with a damp cotton swab.

Give Dry Eyes The Cold Treatment -To ease dry eyes, apply a bag of crushed ice or ice cubes to the affected eye for 5 minutes every 2 hours. Or use a cold egg right out of the refrigerator. Just take the whole egg with the shell intact and gently press it against your sore eye.

Flip Your Lid - Another way to dislodge a painful particle is to pull your upper lid down over the lower lid. Pulling down your lid will allow the foreign body to wipe off on the skin of the lower lid so you can dislodge it. eResearch by Navid Ajamin -- spring 2012

Image: www.habermonitor.com ; www.missouripersonalinjurylawyerblog.com ; careyeasy.com

Reference: www.fitnesslines.com/diseases/eye-care/eye-paincauses-and-treatment-of-eye-pain-tips-to-treat-eye-pain/

Toxoplasmosis is a parasitic disease caused by the protozoan Toxoplasma gondii. The parasite infects most genera of warm-blooded animals, including humans, but the primary host is the felid (cat) family. Animals are infected by eating infected meat, by ingestion of feces of acat that has itself recently been infected, or by transmission from mother to fetus. Cats are the primary source of infection to human hosts, although contact with raw meat, especially pork, is a more significant source of human infections in some countries. Fecal contamination of hands is a significant risk factor.[1]

What is Toxoplasmosis of the eye and what causes it?

A germ called toxoplasma can cause infection within the eye. This is known as toxoplasmosis of the eye. The infection causes damage to the eye that can lead to visual impairment.

Many animals are infected with this germ, including cats. The germ is found in the faeces of these infected animals. A person can catch an infection if they eat food dirtied by faeces with the toxoplasma germ. Foods that can lead to an infection include some uncooked meats, unpasteurised milk and raw vegetables. The toxoplasma germ does not survive cooking or boiling.

Most adults do not know they have caught an infection. Most adults do not develop any problems from a toxoplasma infection and do not get toxoplasmosis of the eye. In fact most adults in the UK, if tested, have had a toxoplasma infection at some time in their lives but have normal eyes.

Toxoplasmosis of the Eye is mainly a problem for unborn babies

  If a pregnant mother becomes infected with toxoplasma the germ can also infect the unborn child. A Toxoplasma infection in an unborn child is more serious than in an adult. The infection can cause inflammation and damage to many parts of the body. The eye is often affected (toxoplasmosis of the eye). The most common part of the eye to become affected is the retina and choroid. This is called retinochoroiditis. When the inflammation settles a scar is usually left on the retina.

How does toxoplasmosis of the eye affect the way a child sees?

Most young children will feel their vision to be 'normal' as they have never known anything else but their own visual world. At first they assume that everyone else has vision the same as their own. They do not realise that other people see things differently.

The toxoplasma germ can cause scarring of any part of the retina. But it tends to cause scarring of the central bit. If this happens then the central part of the vision will also be missing. The child will not usually notice if a part of the retina away from the centre is scarred.

Toxoplasma can affect one or both eyes. If the central bit of the retina in both eyes is scarred then the child will have blurred vision with the central part missing. The vision around the sides will still be OK. This vision is useful for getting around and not bumping into things. The child will however have difficulty reading and recognising faces. Sometimes fast to-and-fro movements of the eyes occur. This is called Nystagmus. Squint may also develop.

Sometimes Toxoplasma can cause other eye conditions

Toxoplasma usually causes inflammation and scarring of the retina and choroid. It can however also cause other eye conditions. These include:

1. Clouding of the lens (cataract)
2. The eye can be smaller than usual (microphthalmia)
3. Loss of some of the communication wires from the optic nerve (optic atrophy)
4. Damage to the 'vision' parts of the brain (cerebral visual impairment)

Toxoplasma may cause other conditions to develop

Other conditions can also develop because of a Toxoplasma infection. These include:

1. Epilepsy
2. Difficulty with hearing
3. Learning difficulties
4. Blockage of the flow of fluid in the brain (hydrocephalus)

Fortunately most children do not develop these other problems.[2]

eResearch by Navid Ajamin -- spring 2012

Image: www.aperfectworld.org ; www.rvahouston.com ; en.citizendium.org ; images.birthdayinabox.com

Reference:

1. en.wikipedia.org/wiki/Toxoplasmosis
2. www.ssc.education.ed.ac.uk/resources/vi&multi/eyeconds/Toxop.html

Related To: Toxoplasma and the eye

Diabetes is a disease that occurs when the pancreas does not secrete enough insulin or the body is unable to process it properly. Insulin is the hormone that regulates the level of sugar (glucose) in the blood. Diabetes can affect children and adults.

How does diabetes affect the retina?

پنج دليل عمده سوزش چشم عبارت است از: عوامل محيط زيستي، بيماري، عفونت، عوامل شيميايي و اسيدي سوزش آور و جراحت در چشم. عوامل محيط زيستي همچون آلودگي هوا، دود سيگار يا گرد و غبار است كه موجب سوزش و آلرژي ميشوند. عوامل سوزش آور چشم مواردي از قبيل مصرف مواد شيميايي، صابون، استفاده از لنز آلوده و يا استفاده دائم از لنز را شامل ميشود.

عفونت مانند pinkeye ميتواند ويروس، باكتري و يا از نوع قارچي باشد. شما ممكن است به طور تصادفي چشم خود را بخارانيد و موجب سوزش چشم شويد. چشم شما ميتواند حتي هنگامي كه بيش از حد در معرض نور خورشيد قرار ميگيرد نيز بسوزد، شما ممكن است يك عفونت ويروسي و يا باكتريايي، سرماخوردگي يا آلرژي داشته باشيد كه باعث سوزش چشم شود و خشكي مزمن و ادواري چشم نيز ممكن است منجر به سوزش چشم شود.

هنگامي كه يك سوزش مزمن يا مكرر را تجربه ميكنيد و هيچ چيز به التيام آن كمك نميكند، هنگامي كه دچار يك سوختگي با مواد شيميايي ميشويد و يا چشم شما قرمز ميشود و زماني كه چشم شما ترشحاتي را توليد كرده و يا خوني ميشود، بايد به پزشك مراجعه كنيد.

همچنين اگرمتوجه تغييراتي در بينايي و درد غيرقابل تحمل شديد، هنگامي كه شما يك آلرژي سختي را تجربه ميكنيد، اگر بيماريهايي چشمي همانند آب مرواريد يا آب سياه داريد، اگر سوزش چشم شما همراه با سر درد، تب و يا ميگرن است و يا اگر مبتلا به ديابت هستيد بايد حتما براي معاينه و درمان به چشم پزشك مراجعه كنيد.

تشخيص و درمان:

اگر چشمان شما به طور دورهاي يا دائم خشك ميشود شما ميتوانيد با نظر پزشك از قطره و پماد استفاده كنيد.

يك چشم پزشك ميتواند به طور دقيق آزمايشاتي را انجام دهد كه مشخص ميكند شما در خطر ابتلا به خشكي مزمن چشم هستيد و اين آزمايشات ميتواند نوع درمان مناسب با چشم شما را مشخص كنند.

هنگامي كه در معرض نور خورشيد قرار ميگيرد از عينك آفتابي استفاده كنيد و يا هنگامي كه در آب كلردار مشغول شنا هستيد حتما از عينكهاي مخصوص استفاده كنيد.

در هنگام كار با مواد شيميايي همچون شويندهها و سفيدكنندهها بايد از عينكهاي ايمني آزمايشگاهي استفاده كرد و نيز در هنگام شستشو مراقب باشيد كه صابون به داخل چشم نرود و از دست زدن و يا ماليدن چشم خودداري كنيد.

عمل گذاشتن لنز درچشم بايد رعايت نكات بهداشتي و با توصيه چشم پزشك صورت گيرد، لنزهاي آلوده ميتواند باعث عفونت و سوزش چشم شود.(۱)

آلرژی یعنی این که بدن نسبت به برخی از عوامل خارجی واکنش بیش از حد نشان دهد. در حالت معمولی وقتی بدن در شرایط خاصی قرار می گیرد ممکن است پوست، بافت های مخاطی، بینی و چشم به عوامل محرک آن محیط واکنش نشان دهند که این امری طبیعی است، اما گاهی اوقات این واکنش بدن به آن عوامل خارجی از حد طبیعی بیشتر است که به آن افزایش حساسیت گفته می شود لذا در واقع آلرژی واکنش افزایش حساسیتی نسبت به عوامل محرک خارجی است. آلرژی دارای طیف وسیعی است و از خفیف شروع می شود و تا شکل شدید آن که به شکل آسم است ادامه پیدا می کند. آلرژی می تواند به شکل تحریکات و حساسیت های پوستی مانند قرمزی، خارش، سوزش، تغییر رنگ پوست، حتی کهیر تظاهر کند.

در آلرژی چشمی، چشم دچار قرمزی، خارش، سوزش و ریزش اشک می شود که باید آن ها را جدی گرفت. در چشم ملتحمه چشم در تماس مستقیم با مواد حساسیت زای موجود در هوا قرار می گیرد.

در ملتحمه تعداد زیادی رگ، سلول های ایمنی و مواد دفاعی وجود دارد که باعث حفاظت لایه های داخلی تر کره چشم در برابر عفونت ها و عوامل خارجی می شود. هرگاه کنترل طبیعی این واکنش های دفاعی به هم بخورد واکنش های حساسیتی ایجاد می شود لذا چشم ها به شدت می خارد، پلک ها متورم و سنگین می شوند و ممکن است به نور هم حساسیت ایجاد شود.

 هنگامی که ذرات معلق در هوا پخش می شوند، در حالت معمولی چشم همه افراد قرمز می شود اما اگر چشم قدری بیشتر از حالت طبیعی واکنش نشان دهد این حالت آلرژی چشمی است. حال ممکن است در مرحله ای فرد هیچ گونه واکنش آلرژی نداشته باشد یا ممکن است در ابتدای طیف آلرژی باشد. لذا این افراد علاوه بر خارش و سوزش در بافت های مخاطی آبریزش بینی دارند و به دفعات زیاد عطسه می کنند، حتی ممکن است این افزایش حساسیت، پوست را هم درگیر کند و اختلالات تنفسی مانند آسم را ایجاد کند.

آلرژی چشمی منجر به آسم نمی شود اما ممکن است فردی که در ابتدای طیف واکنش های آلرژی زاست دچار آلرژی چشمی شود اما هیچ وقت آلرژی تنفسی پیدا نکند. به عبارت دیگر اگرچه آلرژی چشمی در ابتدای واکنش آلرژیک است اما ممکن است این عوامل محرک یا همان آلرژن ها برای هر فردی متفاوت باشد و هر فرد نسبت به یک ماده خاص حساسیت داشته باشد و عوامل محرک برای همه افراد یکسان نباشد.

 برای بسیاری از بیماران این سوال پیش می آید آیا می توان عامل حساسیت زا را از بین برد تا بدن نسبت به آن واکنش نشان ندهد، جواب این سوال این است که خیر، تا زمانی که عامل محرک خارجی وجود داشته باشد می تواند روی چشم اثر بگذارد و علائم بالینی در فرد تظاهر کند. از طرفی چون نمی توانیم عامل محرک را در محیط حذف کنیم لذا به طور کامل نمی توانیم از ابتلاء به این بیماری پیش گیری کنیم اما می توانیم تا حدودی با عوامل ایجاد آلرژی چشمی مقابله کنیم.استفاده از عینک آفتابی یکی از مواردی است که به کمک آن می توان تا حدودی از تماس مستقیم عوامل محرک با چشم جلوگیری کرد. سلول هایی در داخل عروق خونی وجود دارند که در شرایط خاص مانند وجود عوامل محرک در محیط تحریک می شوند. این سلول ها پس از تحریک شدن، آزاد و از عروق خونی بدن خارج می شوند. خارج شدن این سلول ها از عروق خونی سبب ایجاد واکنش های آلرژی زا می شود که به صورت خارش، قرمزی و سوزش در بدن تظاهر می کند. هنگامی که این سلول ها در پوست آزاد شوند پوست دچار کهیر و هنگامی که در ناحیه تنفسی آزاد شوند به صورت آسم پدیدار می شود. یکی از علامت های بارز آلرژی، خارش است و وقتی نقطه ای از بدن که احساس خارش در آن جا وجود دارد خارانده می شود موجب می شود که عروق خونی گشادتر و تعداد بیشتری از سلول های عروق خونی که در بالا ذکر شد آزاد می شود وقتی هم که تعداد بیشتری از این سلول ها آزاد شود فرآیند خارش تشدید می شود.

 آماری در زمینه مبتلایان به آلرژی ها وجود ندارد اما تعداد این مبتلایان بسیار زیاد است افرادی هم که زمینه آلرژی دارند بیشتر در معرض خطر هستند و واکنش آلرژی چشمی در این افراد بیشتر است.

 از عوامل شیمیایی می توان به ذرات معلق پراکنده در محیط کارخانه ها و یا ذرات آلوده کننده هوا اشاره کرد که سبب تحریک چشم ها و مخاط می شود. عوامل فیزیکی هم عواملی مانند گرده گل ها و گیاهان، ذرات خاک، مو، کرک و پر حیوانات هستند که ممکن است یک چشم را و یا هر دو چشم را درگیر کنند.

ممکن است آلرژی از دوران کودکی شروع شود اما زمان اوج ابتلا به آلرژی در دوران نوجوانی و جوانی است که بدن بیشترین شدت واکنش آلرژی را دارد و سپس در سن میانسالی خودبه خود کاهش پیدا می کند.

 همیشه پیش گیری آسان تر از درمان است اما چون نمی توانیم عوامل حساسیت زا را از محیط حذف کنیم می توانیم با استفاده از عینک آفتابی تا حدودی از ورود عوامل محرک به چشم جلوگیری کنیم. در صورت شدت بیماری نیز می توان با مراجعه به پزشک متخصص چشم و طبق نظر ایشان داروهایی را استفاده کرد که پاسخ بدن به عوامل محرک را کاهش داد. در صورتی که آلرژی چشمی درمان نشود فرد دچار مشکل و ناراحتی می شود و کیفیت زندگی وی پایین می آید ضمن این که در صورت خاراندن چشم، ممکن است عوامل عفونی و آلودگی نیز وارد چشم شود و مشکلات بیشتری را برای بیمار ایجاد کند. اگرچه آلرژی معمولا روی دید افراد تاثیر ندارد اما در حال حاضر در مقالات جدید عنوان شده است افرادی که در سن اوج ابتلا به آلرژی چشمی هستند ممکن است در اثر خاراندن چشم دچار قوز قرنیه چشم نیز شوند.(۲)                    eResearch by Navid Ajamin -- spring 2012

منبع:

۱.http://www.shahmir.org/news.php?item.616

۲.http://salamatnews.com/viewNews.aspx?ID=31500&cat=11

Dry eye syndrome

Keratitis sicca; Xerophthalmia; Keratoconjunctivitis sicca

Dry eye syndrome is when the eye is unable to maintain a healthy layer of tears to coat it.

Causes, incidence, and risk factors

Dry eye syndrome often occurs in people who are otherwise healthy. It is more common with older age, because you produce fewer tears with age.

In rare cases, it can be associated with rheumatoid arthritis, lupus erythematosus, and other similar diseases. It may also be caused by heat (thermal) or chemical burns.

In areas of the world where malnutrition is common, vitamin A deficiency is a cause. This is rare in the United States.

Signs and tests

Signs include:

Tests may include:

• Slit lamp (biomicroscope) exam of the film of tears (a dye such as fluorescein may be placed in the eye to make the tear film more visible)

• Schirmer's test -- measures the rate of tear production using a calibrated paper wick placed on the edge of the eyelid

Treatment

Treatments may include:

Surgery may be used if the eyelids are in an abnormal position.

Expectations (prognosis)

Most patients with dry eye have only discomfort, and no vision loss. With severe cases, the clear window on the front of the eye (cornea) may become damaged or infected.

Complications

Ulcers or infections of the cornea are serious complications.

Calling your health care provider

See your health care provider immediately if you have dry eyes and have:

Prevention

There is no way to prevent dry eye syndrome. You can prevent complications by using wetting and lubricating drops and ointments. eResearch by Navid Ajamin -- spring 2012

Image: www.coolhealthtips.com www.beltina.org/pics/dry_eye_syndrome.jpg

Reference: www.ncbi.nlm.nih.gov/pubmedhealth/PMH0001462/

افتادگی پلک چیست ؟

این بیماری به افتادگی پلک فوقانی اطلاق شده و می تواند یک یا هر دو پلک را در گیرد . در فرم خفیف بیماری افتادگی پلک در حد بالای مردمک چشم می باشد ولی در موارد شدیدتر افتادگی پلک منجر به پوشاندن قسمتی از مردمک شده به طوری که میدان بینایی فوقانی را کاهش می دهد .

پتوز می تواند: یک یا هر دو چشم را درگیر کند. وراثتی باشد.در بدو تولد بروز کند.در سنین بالاتر اتفاق بیفتد.

پتوز در کودکان
پتوز مادرزادی به معنای وجود پتوز در بدو تولد می باشد. اگر کودکی با پتوز متوسط تا شدید متولد شود، ممکن است برای تکامل بینایی نیازمند درمان فوری باشد.
پتوز مادرزادی اغلب در اثر نقص در تکامل عضله بالابرنده پلک فوقانی که عضله لواتور نام دارد، اتفاق می افتد. اگرچه معمولا یک اختلال مجزا می باشد، ولی در موارد مادرزادی، ممکن است همراه با اختلالات زیر باشد:
اختلال حرکات چشمی
بیماری های عضلانی
تومورهای پلک یا سایر تومورها
اختلالات عصبی
عیوب انکساری
پتوز مادرزادی معمولا با گذشت زمان بهبود نمی یابد.

چرا این بیماری رخ می دهد ؟
این بیماری می تواند در زمان تولد تظاهر کند که افتادگی پلک مادر زادی اطلاق می شود همچنین زمانی که عضلات بالا برنده پلک تشکیل نشده باشد افتادگی پلک مادر زادی است .در نوع ناشی از افزایش سن، تاندون عضلات با لا بر پلک از محل اتصا لشان بر روی پلک جدا شده و در نتیجه افتادگی پلک رخ می دهد که معمولا در سنین بالای ۰ ۵- ۴۵ سال رخ می دهد و در اثر پوست اضافی در پلک می باشد .
علائم و نشانه های پتوز کدامند؟
شایعترین علامت آشکار پتوز در کودکان، افتادگی پلک می باشد. در پتوز مادرزادی، اغلب عدم تقارن چین پلک فوقانی وجود دارد. کودکان مبتلا به پتوز ممکن است برای دیدن مجبور شوند گردن خود را به عقب خم کنند یا ابروها را به سمت بالا بکشند. این مانورهای سر و صورت نشان می دهند که کودک سعی می کند برای دیدن از هر دوچشم استفاده نماید. بعد از گذشت چند سال، این وضعیت های غیر طبیعی سر ممکن است منجر به اختلالات ظاهری سر و گردن شوند.
مشکلات ناشی از پتوز در کودکان کدامند؟
شایع ترین اختلال جدی مرتبط با پتوز دوران کودکی، آمبلیوپی (تنبلی چشم) می باشد. به دو علت پتوز می تواند ایجاد تنبلی چشم کند:
انسداد مسیر بینایی در موارد پتوز شدید
ایجاد آستیگماتیسم و تاری دید ناشی از آن
بعلاوه پتوز ممکن است در صورت وجود انحراف چشم آن را مخفی نماید و این مورد نیز می تواند منجر به تنبلی چشم شود.

پتوز مادرزادی چگونه درمان می شود؟
در اغلب موارد، پتوز کودکان با جراحی درمان می شود. اگر تنبلی چشم هم وجود داشته باشد، ممکن است درمان با قرار دادن پوشش بر روی چشم سالم، استفاده از عینک یا قطره چشمی ضروری باشد. تشخیص لزوم انجام جراحی و انتخاب روش مناسب،

بر اساس عوامل زیر صورت می گیرد:
سن کودک
درگیری یک یا هر دو پلک
شدت پتوز
قدرت عضلات بالا برنده و پایین آورنده  پلک
وضعیت حرکات چشمی
در اوایل دوران زندگی معمولا ضرورتی به انجام جراحی برای موارد خفیف تا متوسط پتوز وجود ندارد. هم در موارد مذکور و هم موارد شدیدی که تحت عمل جراحی قرار گرفته اند، باید به طور منظم  از نظر تنبلی چشم، عیوب انکساری و حالت های وابسته توسط چشم پزشک بررسی و در صورت نیاز تحت درمان قرار گیرند.
علل پتوز بالغین چیست؟
شایعترین علت پتوز در بالغین، کشیدگی یا جداشدگی تاندون عضله لواتور از روی پلک می باشد. وقوع این فرایند ممکن است ناشی ازعلل زیر باشد:
افزایش سن
به دنبال جراحی کاتاراکت (آب مروارید) یا سایر جراحی های چشمی
ضربه به چشم
پتوز بالغین همچنین ممکن است عارضه ای از سایر بیماری ها مانند بیماری های عصبی یا عضلانی و در موارد نادر تومورهای حدقه چشم باشد که عضله بالابرنده پلک یا عصب آن را درگیر می کنند
پتوز چشم راست- بعد از عمل
 
پتوز بالغین چگونه درمان می شود؟
چشم پزشک می تواند بررسی جامعی  از مشکل شما به عمل آورده و راجع به روش های درمانی مختلف و عوارض وخطرات احتمالی آن ها اطلاعات لازم را در اختیار شما قرار دهد.
برای تشخیص علت پتوز و انتخاب بهترین روش درمانی ممکن است نیاز به انجام آزمایش خون، عکسبرداری های مخصوص و یا سایر آزمایشات باشد. در صورت یافتن علت زمینه ای باید ابتدا این مورد اصلاح گردد، اما در اغلب موارد، درمان نهایی جراحی است که نوع جراحی نیز بر اساس شدت پتوز و سایر یافته های بالینی تعیین می گردد.
 درمان
درمان این بیماران با عمل جراحی صورت می گیرد جراحانی که در این عمل مهارت دارند می توانند جراحی را تحت بیحسی موضعی انجام دهند ولی گاهی تحت بیهوشی عمومی هم صورت می گیرد. در طی این عمل اتصال عضله بالا برنده پلک با محل اتصالشان بر روی پلک مجددا برقرار می شود ولی به طور شایعتر در نوع مادر زادی عضله را کوتاه می کنند عمل اصلاح افتادگی پلک عمل بسیار ظریفی است و مدت زمان آن برای هر چشم ۴۵ دفیفه تا یک ساعت می باشد . در افتادگی پلک ناشی از افزایش سن اکثرا نیاز به عمل بلفاروپلاستی ( برداشتن پوست اضافه پلک ) نیز وجود دارد .

خطرات جراحی پتوز کدامند؟
خطرات جراحی پتوز شامل عفونت، خونریزی و کاهش بینایی می باشد، ولی وقوع این عوارض بسیار نادر است. بلافاصله بعد از عمل، ممکن است چشم بطورکامل بسته نشود، ولی این عارضه معمولا مقطعی است. در طی این مدت می توان از قطره و پماد برای محافظت چشم استفاده نمود. اگرچه ظاهر پلک بطور قابل توجهی اصلاح می شود، اما ممکن است پلک ها کاملا قرینه به نظر نرسند. در اغلب موارد بعد از جراحی در نگاه به پایین پلک عمل شده نسبت به طرف مقابل مختصری بالاتر قرار می گیرد و شب ها مختصری باز می ماند که این دو عارضه مشکل آفرین نیستند. در موارد نادر، حرکات کامل پلک قابل برگشت نیست. در برخی موارد، ممکن است بیش از یک بار عمل جراحی لازم باشد.

توصیه ׃
بیمار میبایست دو هفته قبل از عمل جراحی داروهایی که شانس خونریزی حین عمل یا پس از عمل جراحی را افزایش می دهند مثل آسپیرین، دیکلوفناک، بروفن، وارفارین ، …… را قطع نماید .
خلاصه
پتوز در بالغین و کودکان با انجام جراحی قابل درمان است و این درمان علاوه بر اصلاح وضعیت ظاهری می تواند باعث بهبود بینایی نیز شود. در پتوز کودکان، انجام معاینات منظم چشم پزشکی در سال های اول زندگی برای پیشگیری و درمان تنبلی احتمالی چشم از اهمیت ویژه ای برخوردار است.

 eResearch by Navid Ajamin --spring 2012

منبع: www.pezeshkan.org 

 تصویر: www.beltina.org bestpractice.bmj.com www.persianv.com http://www.rch.org.au

کوررنگی یک بیماری اختلال ارثی است که در آن فرد قادر به تشخیص یک یا برخی رنگ‌ها نمی‌باشد. سلول‌های مخروطی چشم افراد کوررنگ فاقد رنگ‌دانه‌هایی هستند که موجب دیدن رنگ‌ها می‌شوند. به همین دلیل این افراد برخی رنگ‌ها را به شکل طیفی از رنگ‌های خاکستری و سیاه می‌بینند.

کوررنگی انواع مختلفی دارد که شایع‌ترین آن‌ها عدم توانایی در تشخیص رنگ سبز و قرمز از یکدیگر است.

داشتن مشکل در تشخیص اینکه جسمی قرمز است یا سبز، و یا آبی است یا زرد اصلی‌ترین علامت کوررنگی است. بر خلاف تصور عامه، دید افراد کور رنگ به ندرت خاکستری است.

کور رنگی یک بیماری ارثی وابسته به کروموزوم X مغلوب است که در مردان بیشتر دیده شده و تقریباً همیشه از مادر به پسر به ارث می‌رسد. (توضیح: زنان دو کروموزوم X و مردان یک کروموزوم X و یک کروموزوم Y دارند. در بیماری‌های وابسته به کروموزوم X مغلوب در زنان باید هر دو کروموزوم X معیوب باشند تا بیماری رخ دهد. اگر یک کروموزوم X معیوب باشد بیماری رخ نمی‌دهد ولی قابل انتقال به فرزندان است. در مردان معیوب بودن تنها کروموزوم X سبب بیماری می‌شود. بنابراین، فردی که مبتلا به کوررنگی است، مادرش یا مبتلا به کور رنگی است و یا ناقل بیماری.) در این اختلال کروموزومی سلول‌های مخروطی در شبکیه که مسئول درک رنگ هستند دچار اختلال هستند و به همین دلیل بیمار رنگ‌ها را درست تشخیص نمی‌دهد.

کور رنگی ممکن است بر اثر بیماری‌های عصب بینایی یا شبکیه نیز رخ دهد. در این موارد، فقط چشمی که مشکل دارد دچار کور رنگی می‌شود و بیماری در طول زمان تشدید می‌گردد بطوریکه ممکن است تبدیل به کوررنگی کامل شود که در آن بیمار دیدی خاکستری دارد. این بیماران معمولاً در تشخیص آبی و زرد مشکل دارند.

 کور رنگی هیچ درمانی ندارد. تشخیص زودرس کوررنگی می‌تواند مانع بروز مشکلات آموزشی در کودکان شود. در این صورت بهتر است والدین کودک با معلم او صحبت کنند.

بعضی از بیماران از لنزهای مخصوصی استفاده می‌کنند که هم بصورت لنز تماسی و هم بصورت لنز عینک وجود دارد.

در بسیاری موارد بیماران به جای تشخیص رنگ ممکن است ترتیب قرار گیری را بخاطر بسپارند. بعنوان مثال بیمار بخاطر می‌سپارد که چراغ قرمز همیشه بالای چراغ راهنمایی و چراغ سبز پایین قرار دارد.

انواع کوررنگی

کوررنگی انواع مختلفی دارد که شایع‌ترین آن‌ها عدم توانایی در تشخیص رنگ سبز و قرمز از یکدیگر است. عدم تشخیص هیچ‌یک از رنگ‌ها یکی از گونه‌های بسیار نادر کوررنگی است، و در آن فرد اشیاء را همچون در فیلم‌ها و یا عکس‌های سیاه و سفید می‌بیند.

رنگ‌های رنگین‌کمان در فرد مبتلا به پروتانوپیا.

رنگ‌های رنگین‌کمان در فرد مبتلا به دوترانوپیا.

مونوکروماسی 

مونوکروماسی و یا کوررنگی کامل نوع نادری از این اختلال است که در آن هیچ‌یک از انواع سلول‌های مخروطی فعال نیستند و فرد قادر به تشخیص هیچ رنگی نیست.

دی‌کروماسی 

دی‌کروماسی در صورتی ایجاد می‌شود که یکی از سه نوع سلول مخروطی فاقد رنگ‌دانه باشد.

1. پروتانوپیا نوعی دی‌کروماسی است که در آن گیرنده‌های رنگ قرمز کاملاً غیرفعال می‌باشند. در این صورت فرد این رنگ را تیره و مایل به سبز می‌بیند.
2. دوترانوپیا شایع‌ترین نوع کوررنگی است که در آن گیرنده‌های رنگ سبز کاملاً غیرفعال می‌باشند. در این حالت فرد قادر به تشخیص دو رنگ سبز و قرمز از یک‌دیگر نیست.
3. تری‌تانوپیا نوع نادری از دی‌کروماسی است که در آن گیرنده‌های آبی کاملاً غیرفعال می‌باشند و فرد قادر به تشخیص این رنگ نیست.

رنگ‌های رنگین‌کمان در فرد مبتلا به تری‌تانوپیا.

سه‌رنگی غیرعادی

سه‌رنگی غیرعادی (Anomalous trichromacy) یکی از انواع شایع کوررنگی است که در آن هر سه نوع سلول مخروطی فعال هستند ولی در اثر جهش، تحریک‌پذیری یکی از آن‌ها نسبت به طیف نور تغییر یافته‌است.

1. پروتانومالی یکی از این حالات است که حساسیت گیرنده‌های رنگ قرمز تغییر می‌یابد و تشخیص دو رنگ قرمز و سبز (زیرا طول موج‌هایشان به هم نزدیک‌تر است) را برای فرد دشوار می‌کند.
2. دوترانومالی نوع بسیار شایعی از کوررنگی است که در آن تشخیص دو رنگ قرمز و سبز به علت کاهش حساسیت گیرنده‌های رنگ سبز دشوار می‌شود.
3. تری‌تانومالی نوع نادری است که در آن حساسیت سلول‌های مخروطی فرد نسبت به رنگ آبی کاهش می‌یابد و فرد در تشخیص رنگ‌های زرد و آبی دچار مشکل می‌شود. برخلاف سایر گونه‌ها، تری‌تانومالی وابسته به جنس نیست و تعداد زنان و مردان مبتلا به آن همسان است.eResearch by Navid Ajamin -- spring 2012   

مرتبط با:Ishihara Test for Color Blindness      منبع: fa.wikipedia.org/wiki

تصویر: healthlob.com www.milenyumtasarim.com i.bnet.com/blogs

LASIK eye surgery is not an option for every person who wishes to correct their vision. Generally, it is highly advised that people under the age of 18 wait until their eyesight stabilizes after their growing period. Pregnant women should not undergo this surgery as well since the eye has a tendency to change shape during pregnancy.

Potential side-effects are possible right after the LASIK procedure. Some patients develop dry eyes and become sensitive to light after the surgery. Some develop temporary visual problems such as glare or halos around objects, particularly at night. This can make night driving difficult and potentially dangerous. Your eye surgeon may prescribe medication in the form of eye drops to help alleviate most of these symptoms.

There are a few extreme but rare cases where negative results are permanent. The changes made to the cornea of the eye using LASIK eye surgery cannot be reversed or altered. Additional surgeries may correct some small errors, but in the event that a rather large mistake was made, the damage will be irreversible. There are also situations where the surgery may not produce desirable results and the outcome prevents the patient from using glasses or contact lenses, thus leaving them without an available form of vision correction.

Supplementary surgeries to correct minor mistakes are common. Each operation, of course, adds medical costs and recovery time. In addition, the initial surgery doesn't always produce the desired result in one try, especially for those with extremely poor vision to begin with. In this case, further treatments may be needed to enhance the patient's vision.

A patient of LASIK eye surgery can expect to pay several thousands of dollars for the procedure. Despite the fact that it is a medical procedure and that it has great benefits, most insurance companies do not cover the costs related to LASIK under their belief that this type of eye surgery is elective and not necessary since there are other forms of vision correction. Most patients have to pay for the surgery out of their own pockets because of this.[2]

Patients will most likely experience burning, itching and discomfort in the eyes immediately following LASIK surgery. The eyes may be bloodshot and watery, and vision may be blurry. Light sensitivity, glare and "halos" around light sources, such as lamps and streetlights, may also occur. Lubricating eye drops and ointments are used to aid in the healing process and prevent excessive discomfort, although sometimes a pain reliever may be necessary. The Food and Drug Administration (FDA) recommends that patients who have LASIK take three days off from work after the procedure.

Additional difficulties with the eyes and vision may occur as a result of LASIK four weeks to six months following the procedure. A patient may continue to experience glare, halos and double-vision, or a noted reduction in night vision. Vision can fluctuate for up to six months. Dry eyes during this period are also common, and a doctor may recommend continued use of lubricating drops or gels. Patients who experience extremely dry eyes may consider a procedure to have plugs placed in the tear ducts to keep tears from draining from the eyes' surface. Sometimes, the corneal flap will become infected or grow back abnormally.

In some cases, a patient may experience loss of vision following LASIK that cannot be corrected with glasses, contact lenses or additional surgery. Glare, halos and reduced night vision may persist, and some patients will develop permanently dry eyes that require therapeutic use of lubricating eye drops or gels. LASIK surgery can result in an overcorrection or undercorrection of the patient's vision, making use of corrective lenses necessary. The FDA warns that patients with serious vision impairments may not experience optimal results with LASIK surgery and recommends discussing potential outcomes with one's physician before making the decision to have the procedure done.[3]

LASIK surgery does not always result in 20/20 vision without the aid of glasses or contact lenses. Occasionally, the surgery can result in an over- or under-correction of vision. When this occurs, a patient may need additional surgery to achieve the desired correction, putting herself at additional risk for other complications. In some cases, the ideal correction may never be attained, even with additional treatment: the patient will always require glasses or contacts to have perfect vision.

There is a tiny risk of developing a corneal infection with LASIK. Though rare, such an infection is a fairly serious complication. If not treated promptly it can result in a scarred cornea or a severe and permanent loss of vision. Doctors regularly prescribe antibiotic eye drops post-procedure to prevent infections, but you should contact your doctor immediately if you suspect that you have developed an infection.

A common complication following LASIK surgery is dry eye syndrome. Patients with this condition cannot produce enough tears to keep their eyes comfortably moist. According to Medicinenet.com, dry eyes syndrome is a temporary condition in most patients and self-resolves shortly after the surgery. However, the condition can remain or become worse in certain patients --particularly those that had dry eyes before the surgery --and they can suffer from burning, redness, a scratchy feeling in the eyes, or even reduced vision. Dry eye syndrome is typically treated by applying artificial tears to the eyes, or with medication that increases tear production.

Sometimes the surgeon can remove too much tissue from the cornea or cut the corneal flap too deeply. If this happens, keratectasia--a bulging of the cornea --can occur, which results in distorted vision. This distortion cannot be repaired through surgery, although certain types of contact lenses may be used to keep the cornea in place. Patients with thin corneas are at the greatest risk for this complication and might be advised against LASIK surgery.

LASIK surgery can also result in problems with seeing bright objects in the dark or at night. Patients see starbursts, halos or glare around bright objects in dark places, making driving at night or in low light difficult or impossible. This condition may eventually improve, but for some people it is a permanent visual defect.

Very rarely, there can be a problem with the creation of the corneal flap, equipment malfunction, scarring, or medical malpractice in the course of a LASIK surgery. As a result of such errors, a patient can have a permanent loss or reduction of vision.[4]

This condition is extreme inflammation of the cornea following the Lasik procedure, and if not treated it will interfere with the corneal tissue healing process and can lead to loss of vision.

If the beam from the laser has not been positioned precisely above the centre of the eye, then the surface of the cornea may be irregular, this can cause double vision or ‘ghost images’. The eye will need re treatment by the enhancement surgery process.

There is a possible new treatment for keratectasia known as ‘Ectasia’, (Corneal Collagen Cross Linking) or CXL. Riboflavin eye drops (vitamin B2) are used and then activated by ultraviolet light. This tends to strengthen the collagen connective tissue within the cornea and correct the bulging on the eye’s surface.[5]

Ectasia Corneal ectasia (also called "kerectasia" or "keratectasia") is an infrequent but serious complication of LASIK surgery.

keratectasia /ker·a·tec·ta·sia/ (ker″ah-tek-ta´zhah) protrusion of a thinned, scarred cornea.[6]

"Ectatic changes can occur as early as 1 week after LASIK, or they can be delayed up to several years after the initial procedure. In many cases, [corneal transplant] is eventually performed to manage this complication... The continuously growing popularity of refractive surgery procedures, namely LASIK, has caused increased concern regarding the serious complication of keratectasia." (Meghpara et al, 2008)

IMPORTANT NOTICE: Due to the failure of LASIK surgeons to report LASIK complications as required by federal law, patients who experience ectasia after LASIK should file a MedWatch report with the FDA.

In an apparent attempt to hide the truth about post-LASIK ectasia, LASIK surgeons may deliberately misdiagnose post-LASIK corneal ectasia as post-LASIK keratoconus. Keratoconus is a naturally occuring disorder of the cornea which usually affects both eyes and typically begins during puberty or late teen years. If a patient did not have keratoconus or early signs of keratoconus before LASIK and experienced steepening of the cornea with vision loss after LASIK, then the correct diagnosis is likely ectasia.[7]

If the laser removes too much tissue during LASIK or the flap made too deep, the structure of the cornea can be weakened. This weakening can cause the cornea to bulge forward in an irregular fashion, causing increasing astigmatism and distorted vision that cannot be corrected with eyeglasses, contact lenses, or a LASIK enhancement procedure. In its most extreme form, treatment of ectasia may require a corneal transplant.

A corneal transplant is performed by replacing damaged central corneal tissue with healthy tissue from a donor. Corneal transplants are performed routinely in the United States, however this surgery still has a certain amount of risk attached to it.

Patients with thin corneas have a higher risk of developing ectasia. Keratectasia after LASIK is similar to a condition that afflicts 1 in 2,000 people, called keratoconus.

Patients with keratectasia should not have additional eye surgery that removes corneal tissue. Rigid gas permeable (RGP) contact lenses are often the treatment of choice for restoring good vision. A new treatment to strengthen the cornea called C3-R (Corneal Collagen Cross-Linking Riboflavin) is showing promise in controlling corneal ectasia. The non-invasive procedure consists of placing riboflavin eye drops on the eye and activating it with UV light. The activated riboflavin penetrates the cornea and strengthens the corneal tissue, stabilizing the corneal shape.[8]

Reference: eResearch by Navid Ajamin -- spring 2012

1. en.wikipedia.org/wiki/LASIK
2. www.ehow.com/about_5372842_disadvantages-lasik-surgery.html
3. www.ehow.com/about_5038447_lasik-postsurgery-problems.html
4. www.ehow.com/about_5372069_disadvantages-laser-eye-surgery.html
5. www.costforlasereyesurgery.com/lasik-eye-surgery-complications.html
6. medical-dictionary.thefreedictionary.com/keratectasia
7. lasikcomplications.com/ectasia.htm
8. www.refractivesource.com/patients/complications/keratectasia.htm