Comparison of anterior segment parameters in standard and accelerated cross-linking

Aim: Our aim was to compare the standard and accelerated procedure for corneal collagen cross-linking (CXL) as regards the changes in anterior segment parameters. Material and Method: We included 121 eyes of 92 patients who had undergone CXL with a diagnosis of progressive keratoconus in the study. The patients were classified into 2 groups as Group 1 - accelerated CXL and Group 2 - standard CXL. The distance corrected visual acuity (DCVA), manifest refraction and corneal topography were evaluated before and 6 months after CXL in all patients. Results: The mean decrease in mean keratometry (Km) measurements between the pre-CXL and 6 months after CXL timepoints was 0.181 ± 0.895 D in group 1 and 0.408 ± 0.711 D in group 2 (p<0.001). The mean decrease in steepest keratometry (Kmax) measurements between the pre-CXL and 6 months after CXL timepoints was 0.13 ± 1.46 D in group 1 and (p=0.537) and 0.69 ± 1.44 D in group 2 (p<0.001). The mean increase in anterior chamber depth (ACD) measurements between the pre-CXL and 6 months after CXL timepoints was 0.028 ± 0.088 mm in group 1 (p=0.061) and 0.003 ± 0.084 mm in Group 2 (p=0.420). The mean increase in anterior chamber volume (ACV) measurements between the pre-CXL and 6 months after CXL timepoints was 3.1 ± 11.89 mm3 in group 1 (p=0.148) and 0.19 ± 12.72 mm3 in group 2 (p=0.868). The mean increase in anterior chamber angle (ACA) measurements between the pre-CXL and 6 months after CXL timepoints was 0.25 ± 2.73° in group 1 (p=0.532) and 0.50 ± 4.88° in group 2 (p=0.478). There was no statistically significant difference between the two groups as regards the mean changes in the ACD, ACV and ACA measurements between the pre-CXL and 6 months after CXL timepoints. Conclusion: We found that standard and accelerated CXL both resulted in flattening of keratometric values. However, neither procedure resulted in a significant change in ACD, ACV or ACA values, and we therefore found no significant difference between the anterior segment parameters as measured following standard and accelerated CXL. Key Words: Cross-linking, Accelerated Cross-linking, Keratoconus, Ocular Anterior Chamber, Anterior Chamber Depth.