Prevalence of Keratoconus and Characteristics of Refractive Errors in First-Degree Relatives of Patients With Keratoconus Among Egyptians

Purpose: This study investigated the occurrence of keratoconus among first-degree relatives of patients with keratoconus and evaluated their refractive characteristics. Method: A cross-sectional observational study was conducted on 248 relatives of 52 patients with keratoconus in whom bilateral eye analysis was conducted. Corneal tomography was performed for all participants with a comprehensive analysis of various parameters, including K1, K2, Kmax, elevation, skewing, and thinnest location. In addition, the following data were also analyzed: uncorrected visual acuity, corrected distance visual acuity, refraction measurements alongside a slit-lamp examination, and fundus examination. Results: Among 248 participants, 19 (7.7%) had keratoconus, 3.2% had forme fruste, and 15.3% had suspected keratoconus. Among all studied cases, 73.8% had normal corneas. Significant differences (P = 0.001) were found in the distribution of keratoconus prevalence among brothers, mothers, sons, and sisters (13.6%, 4.3%, 5.6%, and 12.1%, respectively). The presence of refractive errors also showed significant differences between the relatives (P = 0.03). Conclusions: Increased keratoconus prevalence among relatives of patients with keratoconus indicates the vulnerability of this population to the development of the disease, necessitating early screening of this group for detection of keratoconus as early as possible.