Keratoconus is a disease of the eye in which the front, clear part of the eye, or cornea, begins to lose its shape and part of the cornea actually begins to bulge out in a “cone” sort of shape. Keratoconus is generally diagnosed by optometrists when a patient comes in to the office with complaints of poor vision and other symptoms such as “ghosting” or double vision, light sensitivity, or an increased desire to rub their eyes. These problems are caused by the fact that a smooth and regular corneal surface is necessary to bend light into a focused beam for good vision, and the changes to the cornea in keratoconus disrupt this smooth corneal surface.
Keratoconus is generally managed with contact lenses intended to provide that smooth and regular surface on the front of the eye that the patient’s own cornea is not providing. Unfortunately, the small, rigid contact lenses often used, can become decentered on the irregular corneal surface, and can be quite uncomfortable. Eventually, if the cornea becomes too misshapened, a corneal transplant may become necessary.
The good news is that in recent years two new treatments have been developed or improved for keratoconus. The first is the scleral lens. These lenses rest on the white part of the eye, or sclera, and forms a dome over the clear, central cornea. The scleral lens is more comfortable than a traditional contact lens that rests on the cornea because the sclera is less sensitive than the cornea, and because scleral lenses create a chamber of lubricating fluid in the space between the lens and the front of the eye. Not only are these lenses more comfortable, but by vaulting over the patient’s own cornea and creating a new smooth surface to interact with incoming light rays, they make great visual improvement possible.
The other exciting development is corneal cross linking. This procedure involves saturating the corneal tissue with Riboflavin drops which are then activated by ultraviolet light. This procedure creates links between the collagen fibers that make up the structure of the cornea, causing them to create a more rigid network that will better maintain its shape. While this procedure is not yet FDA approved in the United States it is used with some success in other countries, and is in clinical trials in the United States currently. To find a site in your state, check the list of clinical centers on the National Keratoconus Foundation website.