Collagen cross-linking (CXL) is a safe and effective procedure to stop progression of keratoconus. However, corneas with a maxK of more than 55 to 58 diopters (D) have been suggested to have an increased failure rate. We report results of CXL for progressive keratoconus in corneas with a maxK of 55 D or more.
Retrospective follow-up. Twenty-eight eyes of 22 patients from 12 to 38 years were treated with CXL for progressive keratoconus. All patients had a preoperative maxK of at least 55 D. Patients were examined on 2 or more occasions after treatment, with a mean follow-up of 22 months. At all visits, patients received routine clinical examination with slit-lamp biomicroscopy, determination of corrected distance visual acuity (CDVA), and Pentacam tomography.
The average preoperative maxK was 61.2 ± 3.7 D. After CXL, maxK significantly decreased to 59.5 ± 3.7 D at the last recorded visit. In 27 eyes, keratoconic progression seemed to have stopped, and in 14 eyes maxK improved with more than 2.0 D decrease, whereas 1 eye showed an increase in maxK of more than 2.0 D. The average CDVA remained unchanged after CXL treatment, although 11 eyes improved and 2 eyes had an unexplained loss of CDVA.
CXL treatment in eyes with advanced progressive keratoconus prevented further progression in 27 of 28 eyes. Progression in cases with advanced keratoconus should not exclude CXL as a treatment to preserve visual acuity or as a supplement to other treatment modalities to delay or avoid keratoplasty.