Topographic and biomechanical comparison of diluted alcohol and iontophoresis-assisted versus accelerated corneal crosslinking in keratoconus

Purpose To compare the corneal biomechanical characteristics following accelerated cross-linking (A-CXL) and diluted alcohol and iontophoresis-assisted corneal cross-linking (DAI-CXL). Methods Forty-nine eyes from 41 patients who underwent DAI-CXL or A-CXL for progressive keratoconus were included. Visual acuity, topographic, and biomechanical data were analyzed preoperatively and 12 months postoperatively. Results A significant decrease in flat keratometry (K1) and thinnest corneal thickness (TCT) was observed in the A-CXL group between baseline and postoperatively (K1, p = 0.001; TCT: p = 0.007). Both groups showed a significant decrease in steep keratometry (K2) and maximum keratometry (Kmax) compared to baseline (K2: p = 0.03, p < 0.001, respectively; Kmax: p < 0.001 for both groups). Postoperatively, highest concavity time (HCT) was significantly lower (p = 0.007), and highest concavity peak distance (HCPD) was significantly higher (p = 0.034) in the DAI-CXL group compared to the A-CXL group. A significant increase in applanation 1 velocity (A1V), HCPD, and deformation amplitude (DA) (p = 0.03, 0.007, 0.02, respectively) and a decrease in Ambrosio relational thickness to the horizontal profile (ARTh) (p < 0.001) were noted in the A-CXL group at 12 months. The DAI-CXL group showed a significant decrease in HCT, integrated radius (IR), and ARTh (p = 0.006, 0.011, 0.009, respectively) between baseline and postoperative assessments. Corvis Biomechanical Factor (CBiF) and E-stage remained stable in both groups. Conclusion DAI-CXL and A-CXL demonstrate comparable efficacy in achieving visual, topographic, and biomechanical stabilization in progressive keratoconus over a 12-month period.