Corneal edema is a type of ocular edema. Corneal edema can sometimes develop cataract eye surgery but it can also result from infection, various ocular diseases or complications associated with prolonged use of contact lenses. It is estimated that 0.1% of patients undergoing cataract surgery will develop this problem.
Cornea is situated at the frontal part of the eye. Transparent in color, it covers the colored iris of the eye. Cornea is composed of thin layers of tissue; cornea is responsible for about two-thirds of focusing power of the eye. The cornea allows the rays of light to enter the eye, and it focuses the image. Clarity of the cornea is a prerequisite for clear and sharp vision.
The endothelium of the cornea is responsible for regeneration of cornea cells and constant removal of fluid from cornea. When any kind of damage occurs, these cells fail to regenerate and fluid accumulated in cornea. This results in swelling, or edema, of cornea and progressive clouding of the vision.
Corneal edema symptoms
One of the most prominent symptoms of corneal edema is blurred vision. Blurriness occurs as the cornea becomes overly hydrated by accumulated fluid. The symptom is usually worse in the morning, or in the first waking hours, and it gradually improves throughout the day. Corneal edema causes many unpleasant visual disturbances such as halos or rainbows around streetlights.
In advanced stages of the edema, symptoms may include blisters at the surface of the eye, nerve ruptures and severe pain accompanied with itching, burning, and redness of the eyes.
Corneal edema causes
Corneal edema may develop as a result of congenital hereditary endothelial syndrome, posterior polymorphous dystrophy, Chandler syndrome, Acute narrow-angle glaucoma, herpetic disciform keratitis, corneal transplant rejection, surgical trauma, or older style intraocular lenses. Abnormal swelling of the cornea is more likely to occur in people 50 years of age and older. Older patients who have less endothelial reserve are more prone to develop corneal edema.
Corneal edema treatment
Treatment of corneal edema depends on the severity of the condition. In very mild cases, there will be no treatment at all. However, doctors may sometimes recommend antibiotics and anti-inflammatory eye drops, or use of concentrated saline eye drops to draw fluid from the eye and reduce the swelling.
In severe cases, patients will have serious problems with vision and doctors may recommend surgery. Surgery normally involves transplanting either the entire cornea or just the abnormal endothelial layer of the cornea from an organ donor.