topographic evaluation in relatives of patients with keratoconus

purpose: to evaluate topographic corneal changes in relatives of patients with keratoconus (kcn). methods: this study was performed on 300 eyes of 150 relatives of 45 kcn patients. complete slit lamp examination, refraction, and corneal topography was performed on all eyes. the topographic indices for diagnosis of keratoconus was based on rabinowitz criteria. results: the study included 84 (56%) female and 66 (44%) male subjects. mean age was 32.4 ± 15 years (range, 16-83). kcn was detected in 14% of the subjects and 7.3% were diagnosed as kcn suspect. the overall prevalence of astigmatism was 58% including in 42.1% in the kcn group, 66.7% in the kcn suspect group, and 49.6% in the normal group. thirty one eyes had high regular astigmatism (> 1.5 diopters) including, 17 (54.8%) in the kcn group and 14 (45.2%) in the normal group. oblique astigmatism was seen in 33 eyes (11%) including 34.2% in the kcn group, 47.6% in the kcn suspect group, and 4.6% in the normal group. conclusion: relatives of kcn patients have a high prevalence of undiagnosed kcn. corneal topography is very important for the diagnosis of kcn and kcn suspects in family members of kcn patiens. therefore, keratorefractive surgery should be considered cautiously in these individuals.