At the Eye Clinic, our corneal specialists and state-of-the-art equipment allow us to offer excellent medical and surgical treatment of many routine, complex and high-risk corneal and external diseases, as well as the most current vision correction procedures.
What is the Cornea?
The cornea is the eye’s outermost layer. It is the clear, dome-shaped surface that covers the front of the eye and plays an important part in the eye’s visual acuity. The cornea is the transparent covers the iris and pupil in the front of the eye. Corneal tissue consists of five basic layers: epithelium, Bowman’s layer, stroma, Descemet’s membrane and endothelium. Although the cornea is clear, it contains a highly organized group of cells and proteins. Unlike most tissues in the body, the cornea contains no blood vessels to nourish or protect it against infection. Instead, the cornea receives its nourishment from the tears and aqueous humor that fill the chamber behind it.
The cornea, one of the protective layers of the eye, serves two functions:
First, along with the eyelid, eye socket, and sclera (white part of the eye), and the tear film, the cornea shields the eye from dust, germs, and other harmful matter.
Second, as the eye’s outermost lens, it is the entry point for light into the eye. When light strikes the cornea, it bends, or refracts, the incoming light onto the lens. The lens further refocuses the light onto the retina, a layer of light-sensing cells lining the back of the eye.
To see clearly, the cornea and lens must focus the light rays precisely on the retina. This refractive process is similar to the way a camera takes a picture. The cornea and lens in the eye act as would a camera’s lens. The retina approximates the film. If the cornea is unable to focus the light properly, then the retina receives a blurry image.
Our doctors perform a wide variety of corneal procedures to improve and preserve our patients’ vision. Read on to learn more about the different options available.
Vision Correction Options
For patients who are nearsighted, farsighted or have astigmatism
- LASIK vision correction: a popular procedure that uses laser technology to reshape the cornea so light entering the eyes can land directly on the retina. Most patients achieve 20/20 vision after this procedure. We offer blade-free, custom LASIK technology for all patients.
- PRK/ASA: alternatives to LASIK, these procedures produce similar vision results to LASIK but are safer options for people with thin corneas because no corneal flap is required.
- Implanted Contact Lenses (ICL): the Visian ICL® is a biocompatible Collamer lens that is implanted between your iris and natural lens to allow light entering your eye to focus on your retina for clear vision. This may be recommended for patients who have thin corneas, moderate-to-severe nearsightedness, large pupils or a history of dry eye.
- Clear Lens Exchange: similar to cataract surgery, this procedure involves removing your eye’s natural lens and replacing it with a new intraocular lens (IOL) that will provide clear vision.
Cornea Treatment Options
For patients with damaged corneas
- DSEK & DMEK: Descemet’s Stripping Endothelial Keratoplasty (DSEK) and Descemet’s Membrane Endothelial Keratoplasty (DMEK) are corneal transplant techniques. The diseased cell layer of the cornea is removed and corneal tissue from a donor is implanted onto the eye. These are alternatives to a full corneal transplant. DSEK is a partial-thickness corneal transplant using the corneal stroma, Descemet’s membrane and endothelium from the donor tissue; DMEK involves a much thinner donor tissue without stromal tissue.
- DALK: Deep Anterior Lamellar Keratoplasty is a partial-thickness corneal transplant that only involves implanting the corneal stroma layer of donor tissue, preserving your Descemet membrane and endothelium.
- Corneal Collagen Cross-linking (CXL): this is a treatment for keratoconus patients to improve the strength and stability of weakened, bulging corneas. The process involves the combination of liquid riboflavin (vitamin B2) followed by the application of controlled ultraviolet light on the eyes. CXL may reduce the need for a corneal transplant.
- PKP: Penetrating Keratoplasty is a full-thickness corneal transplant this may be required if your entire cornea is diseased. The entire cornea can be removed and replaced with donor tissue from an eye bank.