Corneal cross linking is a minimally invasive procedure which treats conditions that cause a weakened cornea such as progressive keratoconus. It is also occasionally referred to as collagen cross linking, CL, or CXL. The procedure strengthens the cornea by creating connections between collagen fibers found within this area of the eye. There are two basic types of corneal cross linking: epithelium-off, in which the outer layer of the cornea is removed prior to the procedure, and epithelium-on, in which the epithelium is left intact throughout.
The best candidates for corneal cross linking have some damage or degeneration to their corneas, but the cornea is not too irregular or misshapen and significant vision loss has not yet taken place. The procedure is best for those who are in the early stages of a disease or damage to the corneas. In addition, cross linking can be a suitable option for patients who have corneal ulcers that do not respond to antibiotics or other procedures. Finally, some patients should undergo corneal cross linking prior to LASIK to strengthen the corneas before they are reshaped.
Before your corneal cross linking procedure is performed, your ophthalmologist will complete an eye exam and measure the thickness of your cornea. This ensures that you are a good candidate for the procedure. They will also create a detailed map of the shape of your cornea; this is known as corneal topography.
The corneal cross linking procedure can be completed in about an hour. If you are receiving an epithelium-off procedure, your ophthalmologist will first remove a small layer of the cornea. Riboflavin (vitamin B2) drops are applied to the eye and allowed to absorb into the cornea. Next, a UV light is applied for up to half an hour before applying bandage contact lenses to the eyes. The procedure is typically not painful, as numbing drops are applied to the eyes and patients are given mild sedation prior to corneal cross linking.
After corneal cross linking, you may experience some mild discomfort which most patients describe as a dry, burning, or gritty sensation in the eye. Pain should not be severe, and you should contact your ophthalmologist if you do experience severe discomfort. Sensitivity to light is also normal during the healing process after corneal cross linking.