Most eyes remained stable up to 10 years after the procedure, though outcomes varied by treatment protocol and a small number of patients required later retreatment or transplantation.

CXL uses riboflavin drops and UV light to strengthen the cornea in keratoconus. Photo: Glaukos. Click image to enlarge.

Long-term failure rates after corneal crosslinking for keratoconus remained low across protocols in a study presented at the ARVO conference in Denver, though different techniques lead to visible differences.

The study evaluated 571 eyes from 415 patients with treatment-naïve keratoconus who underwent collagen crosslinking (CXL) over a 14-year timespan. Patients received one of three protocols: conventional (in 31% of patients), accelerated (46%) or iontophoresis (23%). All of the included eyes had at least 12 months of follow-up, and baseline data was collected within six months after the initial procedure. The authors primarily aimed to identify long-term failure rates and risk factors for CXL failure over periods extending up to 10 years and defined failure as the need for repeat CXL or progression to corneal transplantation, including penetrating keratoplasty or deep anterior lamellar keratoplasty. Over the study period, 21 eyes (3.68%) from 18 patients (4.33%) experienced CXL failure. Among these, 11 eyes required corneal transplantation, while the remaining cases underwent repeat crosslinking. The mean amount of time before repeating CXL ranged from about 21 to 53 months depending on the subgroup.

Analysis of the data showed that failure rates increased gradually over time but remained relatively low overall. The researchers’ estimated failure rates were 0.95% at one year, 3.55% at three years, 4.20% at five years and 5.72% at 10 years, without what the authors described as a “difference between repeat CXL and corneal keratoplasty survival curves,” indicating that the rate of progression remained the same regardless of the type of secondary intervention.

However, the study also identified significant differences in failure rates among the three CXL protocols, indicating that treatment type was able to affect long-term outcomes.

The researchers noted that primary CXL provided strong long-term disease control in most keratoconus patients, with a relatively small proportion requiring additional intervention over a 10-year follow-up period.

Original abstracts ©2026 Association for Research in Vision and Ophthalmology.