ESCRS - POCOR174 - Long-Term Outcomes Of Repeated Corneal Collagen Cross-Linking For Progressive Keratoconus After Primary Treatment: A 5-Year Case Series

Long-Term Outcomes Of Repeated Corneal Collagen Cross-Linking For Progressive Keratoconus After Primary Treatment: A 5-Year Case Series

Published 2026 - 44th Congress of the ESCRS

Reference: POCOR174 | Type: Free paper | DOI: 10.82333/6tew-k173

Authors: Dr Efe Koser* 1 , Dr Nilay Kandemir Besek 1 , Dr Seda Liman Uzun 1 , Dr Burcu Kemer Atik 1 , Dr Sibel Ahmet 1 , Dr Sevgi Tongal 1 , A/Prof. Ahmet Kirgiz 1

1Ophthalmology,Beyoglu Eye Training and Research Hospital,Istanbul,Türkiye

Purpose

To evaluate long-term clinical and tomographic outcomes of repeated corneal collagen cross-linking (CXL) performed due to progression after primary CXL in patients with keratoconus.

Setting

Single tertiary referral center, Department of Ophthalmology, cornea unit. Medical records of 1801 patients who underwent corneal CXL between January 2016 and 2021 were retrospectively reviewed; 472 had a minimum follow-up of 5 years. Among these, records of patients who underwent repeated CXL for documented progression were analyzed.

Methods

Four eyes of four patients (mean age 22.7 ± 4.57 years; 3 females, 1 male) with progressive keratoconus after primary CXL underwent repeated CXL. Patients were followed preoperatively and at 6 months, 1, 2, 3, 4, and 5 years postoperatively. The mean follow-up duration was 99.5 ± 20.8 months. Best-corrected visual acuity (BCVA, logMAR), endothelial parameters (endothelial cell density [ECD], hexagonality [HEX], coefficient of variation [CV]), and tomographic indices (maximum keratometry [Kmax], flat keratometry [K1], steep keratometry [K2], symmetry index front [SIF], symmetry index back [SIB], keratoconus vertex front [KVF], and keratoconus vertex back [KVB]) were analyzed. Due to the small sample size, nonparametric tests were used.

Results

The mean age at primary CXL was 18.25 ± 3.77 years, and the mean interval between primary and repeated CXL was 51.75 ± 8.05 months. Mean Kmax decreased significantly after repeat CXL, from 67.44 ± 6.29 D preoperatively to 62.75 ± 4.50 D at 5 years (p = 0.013). Significant changes over time were observed in SIF (p = 0.024) and KVF (p = 0.011). BCVA, ECD, HEX, CV, K1, K2, SIB and KVB showed no statistically significant change during follow-up (p > 0,05). Pairwise comparisons between preoperative and postoperative measurements did not reach statistical significance, likely due to limited statistical power. No intra- or postoperative complications were noted.

Conclusions

Repeated CXL may provide long-term stabilization of corneal topography in eyes with progression after primary treatment, without significant endothelial compromise. This procedure may represent a safe therapeutic option for selected patients, although larger studies are needed to confirm these findings.