Cornea Specialists in Fresno

The cornea is the clear dome at the front of the eye. It does most of the eye's focusing, so when it's misshapen, cloudy or scarred, vision suffers in ways that glasses often can't fully fix.

Our cornea specialists treat keratoconus, Fuchs dystrophy and corneal scarring. Their services include corneal cross-linking, corneal transplants (DSAEK and DMEK), anterior segment reconstruction, keratoprostheses (artificial corneas), pterygium surgery and specialty contact lens fittings.

Keratoconus

In keratoconus, the cornea gradually thins and bulges forward into a cone shape. It usually starts in the teens or twenties and can keep getting worse for years. It generally affects both eyes, often one more than the other. Its cause isn't fully understood: it runs in families, and it's linked to allergies and eye rubbing.

Signs of keratoconus include:

• blurry or distorted vision
• worsening nearsightedness or astigmatism, with frequent prescription changes
• glare, halos and sensitivity to light
• ghost images or double vision in one eye

Early on, glasses or soft contact lenses can often correct it. As it progresses, specialty contact lenses usually give the clearest vision. More about keratoconus.

Corneal cross-linking

Corneal cross-linking is an FDA-approved treatment that can stop keratoconus from getting worse. It strengthens the cornea by creating new bonds between the collagen fibers it's made of. It's also used for corneal ectasia, a similar weakening that can, rarely, follow LASIK or other laser vision correction.

How it's done:

1. Numbing drops are put in your eye.
2. The cornea's thin surface layer, the epithelium, is gently removed.
3. Riboflavin (vitamin B2) drops are applied for about 30 minutes.
4. The cornea is exposed to a controlled ultraviolet light, which, with the riboflavin, forms the new bonds.
5. A bandage contact lens goes on to protect the eye while the surface heals.

The treatment takes about an hour, and you'll need someone to drive you home. Discomfort and light sensitivity for the first few days are normal. Call us right away if you have severe pain, a sudden change in your vision, or the bandage lens comes out.

Cross-linking works best before keratoconus has caused major vision loss, which is why early diagnosis matters, especially for teenagers and young adults whose astigmatism keeps changing. It stops the cone from getting worse but doesn't undo it, so most patients still need glasses or contact lenses afterward. Many insurance plans cover FDA-approved cross-linking for keratoconus that's getting worse, and we'll check your benefits before treatment.

Fuchs dystrophy

Fuchs dystrophy is an inherited condition in which the cells lining the inner surface of the cornea gradually stop working. Those cells pump fluid out of the cornea; as they fail, the cornea swells and clouds. It usually shows up after 50. A typical early sign is vision that's blurry when you wake up and clears as the day goes on. At first, special drops or ointment can draw out the extra fluid. Once your vision is affected, a corneal transplant can restore it.

Corneal transplants

When part of the cornea is too damaged to see through, it can be replaced with healthy donor tissue. Modern transplants often replace only the layer that's diseased:

• DMEK and DSAEK (types of endothelial keratoplasty) replace only the cornea's inner layer, usually for Fuchs dystrophy or for swelling after other eye surgery. They go in through a small incision, and compared with a full-thickness transplant, vision recovers faster and the risk of rejection is lower.
• A full-thickness transplant replaces the whole center of the cornea, for scarring or disease that goes through all its layers.
• A keratoprosthesis, an artificial cornea, is an option for some people whose donor transplants have failed, or are likely to.

Corneal scars and injuries

Scars left by infections, injuries or past surgery can blur vision, depending on how deep they are and where. Specialty contact lenses can often sharpen vision over a scar; when they can't, a transplant can. Pink eye or a scratched cornea?

Pterygium

A pterygium is a fleshy, wedge-shaped growth on the white of the eye that can spread onto the cornea. It's linked to years of sun, wind and dust, so it's common in people who work outdoors. A small one can be managed with lubricating drops and UV-blocking sunglasses. If it grows toward the center of your vision, causes astigmatism or keeps the eye irritated, it can be removed in surgery; covering the area with a small tissue graft lowers the chance that it grows back.

Specialty contact lenses

For a cornea that's irregular, from keratoconus, a transplant or a scar, specialty lenses often give far clearer vision than glasses can. Scleral lenses are large, rigid lenses that vault over the cornea and rest on the white of the eye. The layer of fluid under them smooths out the irregular surface, and keeps the eye moist, which also helps severe dry eye. Rigid gas-permeable lenses are another option. Eyeglasses and contact lenses.

Cornea questions

Can I have LASIK if I have keratoconus?

No. LASIK thins the cornea, which can make keratoconus worse, so we check every LASIK patient for it. Some people with thin or irregular corneas have other options. Eye surgery options for thin corneas.

Does rubbing my eyes make keratoconus worse?

It's thought to. If you have keratoconus, or itchy, allergic eyes, try not to rub them, and ask us about treating the itch.

How long does a corneal transplant take to heal?

After a partial-thickness transplant such as DMEK, vision usually improves over weeks to a few months. A full-thickness transplant can take a year or more to reach its best.