Effectiveness of transepithelial crosslinking in keratoconus patients

Abstract

Introduction. Keratoconus is a progressive corneal ectatic disease characterized by noninflammatory changes in the stromal collagen. This can lead to protrusion and alteration of the central and paracentral cornea. It typically starts to show in the 2nd or 3rd decade of life as progressive myopia and astigmatism, initially affecting one eye and then progressing to both eyes. In corneal cross-linking, riboflavin is used as a photosensitizing factor. When exposed to UV-A radiation, it induces photochemical cross-linking in the corneal stroma, leading to the formation of covalent bonds between collagen molecules. Aim. The aim is to assess the long-term effects of corneal crosslinking in patients with progressive keratoconus who are older than 18 years. Method. This study was performed in Promed Clinic, Chisinau, on 72 eyes of 36 patients with progressive keratoconus over 4 years from March 2019 to March 2023. The crosslinking procedure included the application of 0.1% riboflavin solution containing 20% dextran for 15 minutes before and before irradiation for 30 minutes with ultraviolet type A (3 mW/cm) rays. Patients were evaluated repeatedly at 6, 12, 24, 36, 48 months after the procedure. Patients were examined for corrected and uncorrected visual acuity, refraction with evaluation of the spherical component, max-K, (mean-K), corneal thickness in the central region. Result. All keratometric measurements improved significantly over the study period. Compared to baseline values, a positive dynamics of Kmax parameters was observed, which became statistically significant over 12 and 24 months after crosslinking. The spherical equivalent decreased during the study period from -7.12 D to -5.82 over 24 months after crosslinking, also the cylindrical equivalent decreased from -5.37 D to -4.1 D. The uncorrected visual acuity increased from 0.51 ± 0.27 preoperatively to 0.66 ± 0.28 over 24 months after crosslinking. Conclusions. According to our four-year study, the corneal cross-linking procedure is effective in patients with progressive keratoconus, does not entail major risks, and may obviate the need for keratoplasty in these patients.