Interethnic differences in post-procedural outcomes of corneal crosslinking for progressive keratoconus: A longitudinal cohort study

Abstract

Purpose To assess interethnic differences in the prevalence of keratoconus and identify interethnic differences in safety and efficacy of crosslinking. Methods Participants diagnosed with progressive keratoconus and that received crosslinking treatment between January 1st 2012 and October 31st 2019, were included in this study. Participants received 12 months follow-up at the tertiary ophthalmology treatment centre of the University Medical Centre Utrecht (Utrecht, The Netherlands). A questionnaire addressing ethnicity, consanguinity, and educational level was conducted. Thinnest pachymetry and maximum keratometry values were chosen as indices for disease progression. A mixed effect model was used to examine associations between ethnicity, baseline clinical parameters, and treatment efficacy. Fisher’s exact test was used to identify differences in post-operative complications. Results 467 eyes of 318 patients were identified and considered eligible for analysis. At baseline North African and South American subjects were relatively over-represented (χ2, P < 0.001). Compared to Europeans, no ethnicity showed a significantly different disease progression 12-months post-crosslinking (P > 0.05). The overall post-operative complications rate was 3.2% (n = 15). There was no statistically significant difference in the number of infiltrates, persistent stromal scars, re-crosslinking or corneal transplantation between the ethnic groups and the European reference group (All P > 0.05). Conclusion Despite the relative overrepresentation of non-European patients at our keratoconus treatment centre, this study reports no differences between Middle Eastern, North African, Sub-Saharan African, South American, Caribbean, Asian ethnic groups and a European reference group after crosslinking for progressive keratoconus in terms of complication rates, keratometry progression, or corneal thinning at 12-month follow-up.