Chances are you went to see your ophthalmologist or optometrist because you were not seeing as well as you used to see out of your glasses or contacts. But instead of simply getting a new prescription, you were diagnosed with a progressive, sight threatening condition. You probably left the office with questions such as- “What is keratoconus and what are my options?”
Keratoconus is a condition that causes the clear, normally sphere-shaped, front part of the eye to bulge forward into a cone-like protrusion. The front part of the eye, the cornea, thins as it protrudes and causes vision to blur.
Fortunately there are several options to help preserve and/or maintain your vision.
Option 1: Contact lenses
Blurred vision due to a bulging cornea is best corrected with a hard contact lens, but wearing a hard contact lens isn’t always easy, especially if you have keratoconus. The more the bulge, the more difficult it is to wear a contact lens; moreover, wearing a hard contact lens does not stop or slow the progression of keratoconus.
Option 2: Corneal cross-linking
Keratoconic corneas appear to be abnormally weak and flexible. A cornea can be made stronger and more rigid with a procedure called corneal cross-linking. Corneal cross-linking is best used when keratoconus is first diagnosed or only moderately advanced since its main effect is to arrest the progression of the corneal bulging.
Corneal cross-linking is an in-office procedure that has been proven to strengthen and stabilize corneas with early or moderate keratoconus. It received FDA approval in April, 2016 and can be used without or after Intacs implantation.
Option 3: Intacs®
Intacs are small, curved, permanent, plastic implants that are placed in the peripheral cornea. Intacs have proven to be an effective way to treat moderate keratoconus when vision can no longer be corrected with glasses or contact lenses.
Intacs have a special FDA approval, and the surgical procedure to implant them takes only a few minutes. The procedure usually improves vision by two or more lines on a standard eye chart. Intacs may not stop the progression of keratoconus and thus their implantation may be followed by corneal cross-linking.
Option 4: Bowman Layer Transplantation
As bulging becomes extreme, the cornea thins and cannot be effectively strengthened by cross-linking. Bowman layer transplantation is a sutureless procedure that can be used to strengthen and stabilize corneas that are too thin to cross-link.
Bowman’s layer is a very thin (10 micron), strong layer of specially organized collagen fibers just beneath the surface (epithelium) of the cornea. Disintegration of Bowman’s layer is the first microscopically observable change of keratoconus.
Transplanting an isolated Bowman layer from a normal cornea can strengthen a keratoconic cornea and reduce its bulging even in eyes with advanced progressing keratoconus. Bowman layer transplantation flattens the keratoconic cornea into a more normal position that makes it easier to wear contact lenses. Bowman layer transplantation is a sutureless procedure that is done in the operating theater.
Option 5: Corneal transplantation
Sutured corneal transplants have better success when used for keratoconus than in any other application. Even old studies demonstrate that about 95% of patients with keratoconus can achieve 20/40 or better vision with a corneal transplant, and new and improved methods of corneal transplantation (e.g., partial transplants) are now available to further improve keratoconus transplant outcomes.
Despite these positives, sutured corneal transplants are generally used only as a last resort in the treatment of keratoconus. A primary goal of modern techniques such as cross-linking, Intacs implantation, and Bowman layer transplantation is to preserve vision while avoiding the need for sutured corneal transplantation.
Parker Cornea offers all of these interventions other than contact lens fitting. Please consider getting help early to arrest the progression of this debilitating condition. Learn more about keratoconus here: http://parkercornea.com/keratoconus/