The Cornea

The cornea is a dime-sized clear tissue that is the front of the eyeball. It is the eye’s outermost layer, normally invisible when viewed straight on. It helps direct light rays towards the lens for focusing, and allows light to pass through it to reach the back of the eye.

In order for vision to be clear, the cornea must be clean and clear. Corneal disease can cause the cornea to become opaque or cloudy, preventing light from passing through clearly. Corneal scars, scratches, surface roughness, and irregular curvature will distort vision, and are frequently associated with sensitivity to light.

Fuchs’ Dystrophy

Fuchs’ dystrophy is an inherited eye disease that causes the cells in the endothelium, the last layer of the cornea, to deteriorate. This leads to distorted vision and corneal swelling (corneal edema). This condition affects both eyes and is more common in women than men.

Although this condition is inherited, symptoms do not usually appear until the patient is over the age of 50. Patients with Fuchs’ dystrophy may experience blurred vision as the first sign of this condition. Blurred vision occurs in the morning as a result of fluid accumulating in the cornea while you sleep. As this fluid evaporates throughout the day, vision may improve. Progressive swelling and thickening of the cornea may also lead to painful erosions and difficulty recovering from cataract surgery.

Treatment for Fuchs’ Dystrophy

While there is no cure for Fuchs’ dystrophy, there are several treatment options available to help relieve the symptoms of this condition and to prevent permanent damage. In its early stages, Fuchs’ dystrophy can often be treated with a salt solution to remove fluid from the eye and reduce swelling. In more advanced stages, Fuchs’ dystrophy may begin to interfere with daily activities and prevent patients from functioning normally. In this stage, patients may require a corneal transplant to replace the cornea with full, thick layers that allows them to see clearly. The DSAEK procedure is an innovative partial corneal transplant procedure performed on an out-patient basis.

Keratoconus

Keratoconus is a very rare eye condition in which the normally round, dome-like cornea becomes thin and develops a cone-like bulge. Keratoconus literally means “cone-shaped cornea.” As light enters the cone shaped cornea, it is bent and distorted and unable to come to a point of clear focus on the retina, causing blurred vision. Keratoconus can make some activities difficult, such as driving, typing on a computer, watching television or reading. This condition is typically not associated with redness, inflammation or other “acute” symptoms and therefore may go undetected for a long period of time.

Keratoconus usually begins during teenage years. In most patients, it progresses for several years before stabilizing in the third to fourth decade of life. In severe cases it can continue to worsen. In these cases the cornea continues to thin and bulge outward, further blurring vision. Scarring of the cornea can also develop.

Treatment for Keratoconus

The treatment approach to keratoconus follows an orderly progression from glasses to contact lenses to corneal transplantation. Glasses are an effective means of correcting mild keratoconus. As the cornea steepens and becomes more irregular, glasses are no longer capable of providing adequate visual improvement. Contact lenses are the next approach to treatment.

Many keratoconus patients will never require surgery, but it is an option in severe and advanced cases. If Dr. Fedyk determines significant scarring of the cornea, he may recommend corneal transplant surgery. In this procedure, the scarred tissue is replaced with a section of donated cornea. About 10 to 20% of keratoconus patients will eventually require a corneal transplant. However, a corneal transplant is not a cure. Following a successful corneal transplant, most patients still need glasses, soft contacts, or RGP contact lenses for adequate vision.