alarm-ringing ambulance angle2 archive arrow-down arrow-left arrow-right arrow-up at-sign baby baby2 bag binoculars book-open book2 bookmark2 bubble calendar-check calendar-empty camera2 cart chart-growth check chevron-down chevron-left chevron-right chevron-up circle-minus circle city clapboard-play clipboard-empty clipboard-text clock clock2 cloud-download cloud-windy cloud clubs cog cross crown cube youtube diamond4 diamonds drop-crossed drop2 earth ellipsis envelope-open envelope exclamation eye-dropper eye facebook file-empty fire flag2 flare foursquare gift glasses google graph hammer-wrench heart-pulse heart home instagram joystick lamp layers lifebuoy link linkedin list lock magic-wand map-marker map medal-empty menu microscope minus moon mustache-glasses paper-plane paperclip papers pen pencil pie-chart pinterest plus-circle plus power printer pushpin question rain reading receipt recycle reminder sad shield-check smartphone smile soccer spades speed-medium spotlights star-empty star-half star store sun-glasses sun tag telephone thumbs-down thumbs-up tree tumblr twitter user users wheelchair write yelp youtube

Corneal Diseases

A quick look at some of the most common corneal eye diseases diagnosed and often treated at The O’Byrne Eye Clinic.

“Eye diseases” is a blanket term that refers to a host of diseases relating to the function of the eye. Below we describe some of the more common types of corneal eye diseases and how they are generally treated. For more in-depth information, please speak with your eye care provider at The O’Byrne Eye Clinic.

Corneal Abrasions & Corneal Erosions

The cornea is the clear part in the front of the eye. It’s located over the iris and the round central pupil. It has 5 different layers, the outmost layer being the epithelium. Injuries to the epithelium, including cuts or scratches, are called abrasions. These injuries are usually accidents caused by fingernail scratches, makeup brushes, paper cuts, or rubbing of the eyes. Conditions, such as dry eyes or blepharitis, can predispose people to abrasions. If you have an abrasion, you will experience pain, redness, tearing, and blurred vision.

Treatment for corneal abrasions includes patching of the eye or wearing a bandage contact lens. Most abrasions normally heal in a day or two, unless they are large in which case it can take several days.

Corneal erosions are caused by having the epithelium loosely attached to the underlying layers of the cornea. This usually happens in an area of the cornea where a significant corneal abrasion has occurred. It may also happen due to a disorder called “Mat-Dot-Finger Print Dystrophy”.

The symptoms and treatments for corneal erosion are the same as those for an abrasion. If erosions occur frequently, other treatments are available.

Corneal Ulcers

Corneal ulcers may develop due to corneal trauma, eyelid disease, severe dry eyes, herpes simplex viral infections, fungal infections, parasitic infections, and most commonly by bacterial infections related to contact lens overwear.

Symptoms include pain, redness, tearing, blurred vision, discharge, and sensitivity to light. The treatment depends on the cause of the corneal ulcer.

Herpetic Keratitis

Herpes Keratitis is a viral infection of the cornea caused by the herpes simplex virus (HSV) and usually only affects one eye. Herpetic Keratitis is usually treated with an antiviral eye drop and systematic antiviral medications taken by mouth. If the infection is severe, deep steroid drops may sometimes be used. If left untreated, it can involve the deeper layers of the cornea and cause significant scarring, which can lead to loss of vision.

Herpes Zoster

Most people who develop Herpes Zoster have been exposed to the chicken pox virus as adults. In adulthood, the virus can become reactivated, causing a rash of small blisters in the affected area. This is commonly known as “shingles”.

Unlike chickenpox, shingles is extremely painful. It usually occurs most frequently in the elderly and in immune-compromised patients. It is important to see your ophthalmologist if the rash involves the area around the eye since the virus can infect the eye itself. Eye involvement can be treated but careful follow up is necessary. New oral antiviral medications are indicated and can shorten the duration and severity of symptoms.

Fuchs’ Epithelial Dystrophy

This is a disorder of the innermost layer of the cornea, the endothelium. It is typically found in people over 50 years old and can lead to significant loss of vision over many years. The endothelium pumps water out of the cornea and keeps it clear. Once it fails to function, the cornea becomes thick and blurry as well as lead to eye discomfort. Typical symptoms of this disease include glare, distorted, blurred vision immediately after waking up in the mornings, and pain or grittiness on the surface of your cornea.

Initially, the treatment involves the use of hypertonic saline eye drops and in advanced stages, can lead to a corneal transplant in order to restore vision.


Keratoconus is a disorder that typically affects both eyes in which the cornea becomes thinner over time; eventually leading to a cone-shaped, protruding structure instead of a normal, spherical one. As this abnormality progresses, one’s vision can become very blurry and can only be treated with hard contact lenses. Glasses and soft contact lenses usually do not provide enough support for one to have useful vision. In advanced cases of Keratoconus, even hard contact lenses are no longer capable of correcting vision, in which case a corneal transplant may be indicated and discussed.


A Pterygium is the exuberant growth of the conjunctivia (the clear covering over the white part of the eye) over the cornea. We believe it develops as a result of long term exposure to the sun, especially UV rays, wind, and chronic eye irritation from dry, dusty environments. Dry eyes are more susceptible to the development of a Pterygium.

Pterygia often cause discomfort and redness and may be treated with eye drops or ointments. If it is very large, surgical removal may be necessary. Avoiding the sun, wind, and dusty environments will be important in preventing reoccurrence of the Pterygium after proper surgical removal.