Abdelghany AA, Toraih EA, Abdelaziz EZ, et al. - Researchers, for the first time, examined the correlation of collagen COL4A3 (rs55703767), COL5A1 (rs7044529), and COL4A4 (rs2229813) variants with the response to corneal collagen cross-linking (CXL) with riboflavin and ultraviolet A in patients with keratoconus (KC). In total, 147 eligible patients with KC were genotyped for the specified collagen variants using real-time TaqMan-based polymerase chain reaction. Data reported that 82 patients (55.8%) had post-CXL successful outcomes. The overall analysis showed that minor allele frequencies of COL4A3, COL5A1, and COL4A4 variants were 0.22, 0.22, and 0.38, respectively. Among other study variants, the COL4A3 (rs55703767) variant may be implicated in the treatment response of CXL riboflavin/ultraviolet A in patients with KC in the study population. Large-scale studies of replication and follow-up in various ethnic groups are justified.