Complications of accelerated corneal collagen cross-linking: review of 2025 eyes.

Purpose: To evaluate the early- and late-stage complications of accelerated cross-linking (A-CXL) in a large case series and investigate the relationship of A-CXL complications with ocular and systemic conditions accompanying keratoconus.

Methods: Retrospectively, records of 2025 eyes of 1184 patients diagnosed with keratoconus between March 2013 and 2020 who underwent A-CXL (18 mW/cm for 5 min) treatment were reviewed. Comorbid ocular and systemic diseases other than keratoconus were recorded. In the postoperative follow-up, early and late complications and their association with accompanying diseases were examined.

Results: The mean age of patients was 26.16 ± 6.05 (range 18-42), and the mean follow-up time was 3.40 ± 1.63 years (range 1-8 years). Vernal keratoconjunctivitis (3.7%) was the most common disease accompanying keratoconus. Less frequently, systemic allergic diseases (2.9%) and Down syndrome (2.3%) were observed. The most common complication in the early postoperative period was haze formation (9.1%), while failure of the treatment (4.2%) occurred in the late period. Other common complications were loss of two or more Snellen lines (2.4%) and delayed epithelial healing (1.8%). There was a significant relationship between vernal keratoconjunctivitis and delayed epithelial healing (p = 0.011). Statistically significant relationships were found between Down syndrome and haze formation (p < 0.001) and sterile infiltrate formation (p = 0.041).

Conclusion: Although A-CXL complication rates are low, vernal keratoconjunctivitis following A-CXL might increase the risk of delayed epithelial healing, and similarly corneal haze and sterile infiltrates might be observed more frequently in patients with Down syndrome.