Background and purpose: The corneal collagen crosslinking procedure has been clinically performed worldwide for approximately 20 years. The aim of the study was to analyze the long-term outcomes of corneal crosslinking at the University Eye Hospital in Tübingen.
Methods: In this retrospective study 136 consecutive eyes with progressive keratoconus from 107 patients were included. The observational period was from December 2008 to March 2018. The parameters analyzed were best corrected visual acuity (BCVA) and the keratometry values from elevation maps measured using a Scheimpflug camera.
Results: The study population of 107 patients included 96 (90%) male and 11 (10%) female subjects and the mean age was 23 ± 8 years. The mean observation time between corneal collagen crosslinking and the last follow-up examination was 42 ± 29 months. The mean postoperative BCVA showed a significant improvement from baseline at each point of postoperative measurement. The mean astigmatism and the mean Kmax showed a statistically significant reduction in the first 6 postoperative months. The mean thinnest point of the cornea showed a significant reduction in the first 6 months, after which the cornea thickness stabilized. No serious adverse events relating to the treatment were registered.
Conclusion: Long-term outcomes after corneal collagen crosslinking showed a significant reduction of the keratometry values and the BCVA was significantly higher compared to the preoperative value at all times of observation. In conclusion, corneal collagen crosslinking was shown to be an effective and safe treatment for progressive keratoconus.
Keywords: Corneal crosslinking; Keratectasia; Keratoconus; Keratometry; UVA.