Repeated corneal crosslinking (CXL) shows promise in stabilizing progressive keratoconus when the first procedure has failed, a Turkish study reports.

The investigation, published in Cornea, included 12 eyes of 10 patients who underwent repeat CXL. Researchers noted all cases were treated with a second CXL when the disease progressed after the first procedure. The investigators tested for uncorrected and best-corrected visual acuity and performed corneal tomography before and after the repeat procedure.

The average patient age was 23, and investigators said eye rubbing was detected in six subjects.

Prior to the second treatment, researchers noted 11 eyes had maximum keratometry (Kmax) readings of more than 58D (62.2 ± 4.9D). Approximately 19 months following the first procedure, the investigators performed the second CXL treatment on patients who progressed by about 2.3D in Kmax.

The investigators followed up with the patients at 36 months and found Kmax regressed in eight eyes, remained stable in two eyes and progressed in two other eyes. The study noted uncorrected and corrected visual acuity remained unchanged and no complications were observed.

Although repeat CXL treatments appeared to be effective in stabilizing keratoconus progression after failure of primary CXL, progression could be detected after repeated treatment, researchers said. Risk factors should be assessed, and patients with high risk should be followed closely, they added.

The study also recommended patients be followed for at least two years following primary CXL.

“Many studies have shown a long-term stability of progressive keratoconus after CXL with more than 10 years of follow-up, but these long-term prospective reports showed some failures of CXL. The important question is how to manage these failures,” the researchers wrote in their paper. The answer might be another bout of CXL.

Akkaya Turhan S, Aydin FO, Toker E. Clinical results of repeated corneal collagen cross-linking in progressive keratoconus. Cornea. August 30, 2019. [Epub ahead of print].