Corneal stromal depth of the demarcation line in 'accelerated corneal cross-linking' with different concentrations of riboflavin solutions.

Abstract

The aim of this study is to compare the effect of different riboflavin solutions (hypotonic and isotonic) used during accelerated corneal cross-linking (CXL) on the mean depth of the demarcation line (DDL) formed in corneal stroma. This prospective, cross-sectional study included 38 eyes of 26 patients. All patients underwent accelerated CXL due to progressive keratoconus. When the corneal epithelium was removed, 17 eyes of 12 patients with corneal thickness < 400µm were categorized as Group 1, and 21 eyes of 14 patients with corneal thickness > 400µm as Group 2. Hypotonic riboflavin was applied to Group 1 patients, and isotonic riboflavin to Group 2 patients. Anterior segment optical coherence tomography was performed on all patients by two independent observers at the end of the first and third months. Group 1 included 5 male and 7 female patients with an average age of 25.1 ± 8.0years, whereas Group 2 included 7 male and 7 female patients with an average age of 31.8 ± 10.12years. At the end of the first month, the mean DDL in Group 1 and Group 2 was 180.32 ± 10.26 and 287.21 ± 15.01µm, respectively. This difference was statistically significant (p < 0.05). Application of different riboflavin solutions was observed to have an effect on measured corneal thickness after saturation and the depth of the demarcation line. The use of hypotonic riboflavin results in swelling of the cornea and more superficial localization of the stromal demarcation line after CXL.