The cornea makes up the front window of the eye, and helps focus light for good, clear vision. The cornea also has the responsibility of protecting the eye from outside particles. All five layers of the cornea receive nutrients from the tear film that covers the outside of the eye, and from the fluid, aqueous, that fills the front chamber of the eye. Any conditions that damage a layer of the cornea may cause vision changes and, in some cases, pain. Understanding some of the more common corneal eye diseases may help prevent damage to the cornea.
Fuchs' Dystrophy
Fuchs' dystrophy causes endothelial cells in the cornea to deteriorate, and results in swelling of the cornea, according to the National Eye Institute. This occurs when the decrease in the number of endothelial cells result in a decreasing ability to move water out of the corneal layers, which leads to swelling of the cornea. And when the cornea swells, vision blurs. Fuchs' dystrophy may cause small, raised blisters to form on the cornea, and can cause severe pain. Treatment for Fuchs' dystrophy includes using medicated eye drops to reduce corneal swelling. If blisters appear on the surface of the eye, the doctor may recommend using ointment in the eye to provide relief to pain and irritation. Patients may also wear soft contact lenses to help protect the front surface of the eye. Some patients have severe damage to the cornea, resulting in poor, uncorrectable vision. In such cases, the doctor may recommend a corneal transplant.
Shingles
Some people who had chickenpox as children may have the dormant version of the virus flare-up as shingles. A painful, itchy rash appears over an area of the body, and may accompany a fever and lethargy. If the rash involves the face or neck, the eyes may be affected, and this is known as herpes zoster of the eyes. In such cases, the cornea becomes inflamed, and scarring may occur. This causes permanent damage to vision. Shingles may disappear for a time then reappear. Some patients find that flare-ups often occur during times of stress. Eye doctors treat shingles with oral anti-viral medications and medicated eye drops.
Corneal Ulcer
Corneas damaged from injury or disease may develop "a deep infection and inflammation," according to the Kellogg Eye Center. Doctors refer to this corneal damage as a corneal ulcer, or keratitis. The condition causes severe pain, light sensitivity and blurry vision. They whites of the eyes may also appear red and irritated. Doctors treat this condition with medicated eye drops. In cases where the cornea has severe scarring, the doctor may recommend a corneal transplant to improve vision.
