Initial results from mechanical compression of the cornea during crosslinking for keratoconus. (15th March 2014) - Beckman Rehnman, Jeannette
Abstract Purpose To compare refractive changes after corneal crosslinking with and without mechanical compression of the cornea. Methods In a prospective, open, randomized case‐control study conducted at the Department of Ophthalmology, Umeå University Hospital, Sweden, sixty eyes of 43 patients with progressive keratoconus aged 18–28 years planned for corneal crosslinking and corresponding age‐ and sex‐matched control subjects were included. The patients were randomized to conventional corneal crosslinking (CXL; n = 30) or corneal crosslinking with mechanical compression using a flat rigid contact lens sutured to the cornea during treatment (CRXL; n = 30). Subjective refraction and ETDRS best spectacle‐corrected visual acuity (BSCVA), axial length measurement, keratometry and pachymetry were performed before and 1 and 6 months after treatment. Results The keratoconus patients had poorer BSCVA, higher refractive astigmatism and higher keratometry readings than the control subjects at baseline (p < 0.01). In the CXL group, BSCVA increased from 0.19 ± 0.26 to 0.14 ± 0.18 logMar (p = 0.03), and the spherical equivalent improved from −1.9 ± 2.8 D to −1.4 ± 2.4 D (p = 0.03). Maximum keratometry readings decreased after CXL from 53.1 ± 4.9 D to 52.6 ± 5.2 D (p = 0.02), and the axial length decreased in the CXL group, likely due to post‐treatment corneal thinning (p = 0.03). In the CRXL group, all the above variables were unaltered (p > 0.05). Conclusion At 6 months, the refractive results from CRXL did not surpass those of conventional CXL treatment. Rather, some variables indicated a slightly inferior effect. Possibly, stronger crosslinking would be necessary to stabilize the cornea in the flattened configuration achieved by the rigid contact lens.