Corneal Cross-Linking for Keratoconus
By Dr. Adel Barbara, MD, FRCOphth — Ophthalmologist, Cornea & Refractive Surgery
Last medically reviewed: September 2026
Corneal cross-linking (CXL) is intended to stabilize a cornea affected by progressive keratoconus. Its primary purpose is disease control—not removal of glasses and not a guaranteed improvement in vision.
How does CXL work?
Riboflavin and controlled ultraviolet-A light are used to create additional bonds within corneal collagen and increase biomechanical resistance. Epithelium-off CXL has the largest body of evidence; other protocols may be considered according to corneal thickness and clinical circumstances.
Who may benefit?
In adults, CXL is usually considered when serial examination, topography or tomography supports progression. No single number proves progression; corneal shape, thickness profile, refraction and vision are interpreted together.
Keratoconus can progress more aggressively in younger patients. Dr. Barbara’s clinical approach for patients under 18 is to recommend CXL at diagnosis once the diagnosis and medical suitability have been confirmed, rather than necessarily waiting for repeat scans to demonstrate further change.
What happens during and after treatment?
Treatment is generally performed with topical anaesthesia. With epi-off CXL the epithelium is removed, riboflavin is applied and the cornea receives controlled UVA exposure. A bandage contact lens is normally used while the surface heals.
Pain, light sensitivity, tearing and blurred vision are common during the first days. Vision may fluctuate for weeks. Increasing pain, marked redness, discharge or sudden visual loss requires prompt review.
What CXL cannot do
CXL does not return the cornea to its original shape. Glasses and specialist contact lenses may improve vision but do not stop progression. Visual rehabilitation with lenses, ICRS or CAIRS is a separate decision.
Risks
Possible complications include delayed epithelial healing, infection, haze, scarring and loss of vision. Careful selection, sterile technique and follow-up reduce risk but cannot eliminate it.
Read: monitoring or cross-linking? →
Professional sources
General information only; it does not replace individual examination and advice.
