Comparison of Corneal Biomechanical Efficacy Between Rose Bengal-Green Light and Riboflavin-UVA Crosslinking.

Purpose: To investigate corneal biomechanical changes after corneal cross-linking (CXL) treatments with rose bengal-green light (RB-CXL) and riboflavin-UVA (RF-CXL).
Methods: A total of 60 freshly enucleated lamb eyes were obtained for this experimental study. Fifteen eyes were treated with RB-CXL using 0.1% RB solution (Group 1), 15 eyes were treated with RB-CXL using 0.2% RB solution (Group 2), 15 eyes were treated with RF-CXL using 0.1% RF solution (Group 3), and 15 eyes were used as controls (Group 4). The same treatment protocol (10-minute irradiation using a total of 5.4 J/cm ² energy) was applied to all treatment groups. To evaluate corneal biomechanical changes, the stress-strain test was used for both the treated and control corneas. The elastic modulus was calculated using the tension strain curves obtained during the test.
Results: The average elastic modulus values were calculated to be 18.9, 23.5, 22.3, and 14.1 MPa in Groups 1, 2, 3, and 4, respectively. Statistically significant differences were found between the groups ( p  < 0.001 for Group 1 vs. 2; p  < 0.001 for Group 1 vs. 3; p  < 0.001 for Group 1 vs. 4; p  = 0.002 for Group 2 vs. 3; p  < 0.001 for Group 2 vs. 4; and p  < 0.001 for Group 3 vs. 4).
Conclusions: In this study, the efficacy of RB-CXL treatment applied using different concentrations of RB solutions at a total energy of 5.4 J/cm ² was investigated, and 0.2% RB solution was found to have at least as much and even more effective than the RF-CXL (0.1% RF) on the corneal elasticity module. These results are encouraging for the treatment of ectatic corneas particularly below 400 μm. It is considered that the findings obtained from this study will guide future experimental and clinical studies.