Visual and Refractive Long-Term Outcomes Following Standard Cross-Linking in Progressive Keratoconus Management

Purpose: To analyze the effectiveness and stability of the refractive, topographic and visual outcomes of the standard cross-linking (SCXL) in keratoconus (KC) management. Patients and methods: This study was designed as a retrospective non-comparative study that included 28 KC patients (n=49 eyes) who performed SCXL as a single procedure to treat KC and completed five-year follow-up period. The topographic, refractive and visual data were recorded preoperatively and at 12, 24, 36 and 60 months postoperatively. Results: Forty eyes (81.6%) showed achieved postoperative spherical equivalent (SE) refraction better than the attempted refraction. Ten eyes (20.4%) improved by <1 D, 23 eyes (46.9%) improved from 1 D to <2 D and 7 eyes (14.3%) improved by >= 2 D. Both uncorrected distant visual acuity (UDVA) and corrected distant visual acuity (CDVA) showed statistically significant improvement from preoperative 1.34 +/- 0.29 (mean +/- SD) and 0.74 +/- 0.23 LogMAR to postoperative 0.99 +/- 0.32 and 0.50 +/- 0.22 LogMAR (P<0.0001) respectively. Both Kmax and SE refraction showed statistically significant and stable improvement from preoperative 51.95 +/- 1.90 and -7.90 +/- 3.14 D to postoperative 50.19 +/- 1.96 and -6.35 +/- 2.49 D (P<0.0001) respectively. Two eyes (4%) showed KC progression at the end of 5th follow-up year. Conclusion: SCXL had good effectiveness and stability that halted KC progression over 5-year follow-up period. It had also unexpected improvement in the KC refractive components mainly the spherical and SE components.