Cornea


The cornea is the clear part in the front of the eye. It allows light to pass through to the retina unobstructed. The curvature of the cornea bends the light rays and focuses them on the retina, producing clear images in normal vision. Disease or trauma to the cornea can alter its structure and cause vision loss. Changes in corneal shape, thickness, or clarity cause poor vision that can often be corrected with a corneal transplant. There are many different corneal conditions which may be treated with various types of corneal transplants.

What is Fuchs Dystrophy and Corneal Edema?

Fuchs dystrophy is a disease that affects the endothelium layer of the cornea. The endothelial cells normally pump fluid from the cornea to keep it clear. When they die, they cannot be replaced by your body, and as the disease progresses, fluid builds up in the cornea and it becomes swollen (corneal edema). Symptoms of Fuchs Dystrophy include glare and sensitivity to light, fluctuations in vision, foggy or blurred vision, difficulty seeing at night, and in severe cases, eye pain.

In the early stages of Fuchs dystrophy, patients may notice few, if any, problems. Vision is usually hazy in the morning but gets better throughout the day. This is because your corneas swell more when your eyes are closed during sleep.

In the later stage of the disease, vision remains blurry all day. Too much fluid builds up during sleep and not enough dries up during the day. Also, tiny blisters may form in the cornea. The blisters get bigger and eventually break open, causing severe eye pain.

Fuchs dystrophy is an inherited disease, but not everyone who inherits the condition will develop the disease. Vision problems might not appear until age 50 or later. Women are more likely than men to have Fuchs dystrophy.

Other diseases of the cornea can lead to corneal edema, including infections, injury, and having a history of eye surgery.

DSEK & DMEK

In addition to traditional corneal transplant procedures, Houston Cornea Transplant Specialist Dr. Rahul Pandit performs Descemet Stripping Endothelial Keratoplasty (DSEK) & Descemet Membrane Endothelial Keratoplasty (DMEK). These are some of the latest, highly skilled, and most successful techniques in corneal transplantation. These surgeries are used to treat patients with Fuchs dystrophy and other disorders leading to swelling of the cornea, or corneal edema.

What is DSEK?

A DSEK procedure is a partial-thickness corneal transplant that replaces only the ultrathin innermost portion of the cornea, including the endothelium, rather than the full thickness of the cornea as seen in standard corneal transplants. The patient’s endothelium is removed with its underlying membrane and replaced with the healthy inner layer from a donor cornea. The procedure is designed to improve vision in patient suffering from diseases of the cornea that lead to corneal edema and results in visual improvement on the order of weeks to months.

What is DMEK?

DMEK is also a partial thickness corneal transplant that replaces only the microthin endothelial layer and its supporting membrane rather than the ultrathin innermost portion of the cornea tissue that is replaced in DSEK surgery. DMEK is the latest treatment option for decreased vision due to swollen, cloudy corneas caused by Fuchs Dystrophy and other corneal diseases. DMEK has provided patients with the best chance to have the best possible vision with the lowest risk of rejection. However, due to the delicate microthin grafts, this procedure may not be suitable for all patients, and there may be a higher chance of needing to return to surgery early during the healing process to either re-position or replace the graft.