Correlative Characteristics of Multidimensional Clinical Parameters and Predictive Value of Epithelial Thickness Variation in Chinese Patients with Keratoconus

Background Keratoconus (KC) is a bilateral, progressive, and non-inflammatory corneal ectatic disorder. This study aimed to characterize disease-specific features of KC in a Chinese population and analyze correlations among multidimensional clinical parameters using a large-scale clinical dataset, to support precision clinical screening and personalized treatment strategies. Methods Clinical records of 1,219 patients with KC treated between January 2019 and December 2023 were retrospectively analyzed. Collected variables included demographic characteristics, axial length (AL), intraocular pressure, and corneal parameters, including morphology and epithelial thickness. Statistical analyses were performed using SPSS version 26.0. Pearson’s correlation analysis was used to assess linear relationships between continuous variables, while one-way analysis of variance followed by Tukey’s honest significant difference post-hoc test were used to compare differences among the KC severity groups. Results The mean patient age was 22.32 ± 6.65 years, with adolescents and young adults accounting for more than 80% of the cohort. Unilateral surgery was performed in 90.0% of the cases, with a median interval of 17 days between bilateral procedures. The thinnest corneal point was predominantly located inferotemporally (right eye mean vector: 0.34 ± 0.22; left eye mean vector: 0.73 ± 0.26). The AL was significantly shorter in the maximum keratometry (Kmax) ≥ 58 D group than in the Kmax < 48 D group (P < 0.001). The AL was significantly longer in the thinnest corneal thickness (TCT) > 490 µm group than in the groups with TCT < 490 µm (P < 0.01). Non-contact tonometry exhibited a strong negative correlation with Kmax (r = -0.7) and a strong positive correlation with the TCT (r = 0.61). Among epithelial parameters, the difference between the minimum and maximum corneal epithelial thickness demonstrated the strongest correlation with Kmax (r = -0.83). Conclusions KC in the Chinese population is characterized by a marked clustering in adolescence and a tendency toward initial unilateral presentation. Shorter AL may be associated with an increased risk of severe disease. Corneal epithelial thickness variation, particularly the minimum–maximum difference, serves as a highly sensitive indicator of KC severity, offering valuable insights for the development of precision screening and early intervention strategies.