This procedure (sometimes referred to as corneal collagen cross-linking or CXL) uses riboflavin drops combined with UVA light to strengthen the cornea. The procedure is designed to stop further progression of corneal ectasia (or thinning), which is typically seen in patients with keratoconus and in patients who have had LASIK or RK eye surgery.
There are two forms of CXL: epithelium-off (epi-off) and epithelium-on (epi-on). Epi-off CXL involves removing the corneal epithelium and dropping a formula of riboflavin solution on the cornea for a period of time followed by controlled UVA light exposure. The epi-on procedure uses a different concentration of riboflavin solutions and different exposure time with UVA, and does not involve the removal of the corneal epithelium.
Intacs are prescription corneal implants that were previously used as a form of refractive surgery for treating low level myopia and nearsightedness. Recently, this surgical option has been approved for use in treating keratoconus.
These surgically applied plastic implants are inserted just under the eye’s surface in the periphery of the cornea and help re-shape and reinforce the cornea, thereby eliminating some or all of the irregularities caused by keratoconus in order to provide improved vision. The procedure takes approximately 10 minutes to complete.
Scleral contact lenses are large-diameter lenses that provide clear and comfortable vision for keratoconus patients because the lenses do not actually touch the cornea. Instead, scleral lenses vault over the entire corneal surface, resting on the “white” portion of the eye known as the “sclera.” The space between the back and front portions of the scleral lens is filled with unpreserved sterile saline solution, which means that the eye always remains in a liquid environment. Scleral lenses cover a larger portion of the sclera, whereas semi-scleral lenses cover a smaller area.
These larger lenses also are more stable than conventional gas permeable contact lenses, which move with each blink because they cover only a portion of the cornea. Moreover, scleral lenses do not fall out, bits of grit do not lodge behind them during wear, and they are surprisingly comfortable to wear when fitted properly.
Hybrid contact lenses, which were specifically designed to treat keratoconus, combine a rigid center that is highly oxygen-permeable with a soft “skirt” on the peripheral. These lenses were designed specifically for keratoconus, and the central gas permeable zone of the lens vaults over the cone-shaped cornea for increased comfort. Hybrid contact lenses provide the crisp optics of a gas permeable contact lens and wearing comfort that rivals that of soft lenses.
CXL with Contact Lenses
Depending on the severity of keratoconus damage, some patients who undergo the CXL procedure may need to be fitted for scleral or other contact lense
CXL with Intrastromal Ring Implants
Using a combination of corneal crosslinking and intrastromal ring implants has demonstrated promising results for treating keratoconus.
CXL with Conductive Keratoplasty
Depending on the severity of keratoconus damage, many patients are good candidates for the CXL procedure combined with a procedure called conductive keratoplasty (CK). This combination can eliminate or reduce the need for glasses or contacts.
Intrastromal Ring Implants with Glasses or Contact Lenses
The placement of ring implants remodels and reinforces the cornea, thereby eliminating some or all of the irregularities caused by keratoconus. This can improve uncorrected vision, however, depending on the severity of the keratoconus, glasses or contact lenses may still be needed for functional vision.
Some people with keratoconus cannot tolerate a rigid contact lens or they reach the point where contact lenses or other therapies no longer provide acceptable vision. With new technology, corneal transplants can be avoided most of the time. In very rare cases, some keratoconus patients reach a point where contact lenses and other therapies are not effective.
