Corneal Collagen Crosslinking in Progressive Keratoconus

Purpose: To report the clinical efficacy and safety of progressive keratoconic eyes in Korean patients treated with accelerated corneal cross-linking. Methods: This retrospective study focused on progressive keratoconic eyes in Korean patients that underwent accelerated corneal cross-linking from February 2015 to October 2015. Keratoconus was diagnosed in 45 eyes in 30 patients. After accelerated corneal cross-linking with VibeX rapid solution, best corrected visual acuity, maximum keratometry, mean keratometry, corneal thickness, corneal astigmatism, and endothelial cell count were measured at the preoperative visit and post operation 1 week, 1 month, 3 months, and 6 months. Results: Best corrected visual acuity (log MAR) was 0.51 +/- 0.23 at pre operation and 0.51 +/- 0.26 at post operation 6 months, showing no improvement. The maximum keratometry measured with Auto K, Pentacam, and Orbscan II at pre operation was 49.11 +/- 4.5 D, 48.37 +/- 3.31 D, and 48.98 +/- 4.88 D and changed to 49.29 +/- 4.34 D, 46.99 +/- 3.63 D, and 47.01 +/- 3.62 D post-operatively, respectively. Only Pentacam and Orbscan II measurements showed a statistically significant decrease (p < 0.05). Corneal thickness (at the thinnest area) was measured with Pentacam and Orbscan II; pre-operative and post-operative 6 month data showed changes from 485 +/- 26.27 and 479.24 +/- 27.89 to 471.64 +/- 27.12 and 472.52 +/- 25.36, respectively. Only the Pentacam method resulted in a statistically significant decrease. Endothelial cell count was measured with confocal microscopy and showed a statistically significant difference between pre-operative 2,857 +/- 390.49/mm(2) and post-operative 6 month 2,639.21 +/- 249.92/mm(2). Conclusions: This 6-month follow-up study of Korean keratoconus patients who underwent accelerated corneal cross-linking indicates that the method is effective in stabilizing the progression of keratoconus, according to maximum keratometry change. With regard to endothelial cell count change, further long-term evaluation is required. Other than endothelial cell count change, this procedure is expected to show long-term safety comparable to that of conventional corneal cross-linking.