Heritability of Anterior Chamber Indices in Rural Population.

OBJECTIVE: To examine the heritability of the anterior chamber depth, angle, and volume as well as the corneal volume and diameter using Pentacam in households living in underserved rural areas of Iran.

MATERIALS AND METHODS: This cross-sectional population-based study was conducted in randomly selected households living in 2 rural districts in the south and north. The data of subjects above 5 years and households in which at least 2 members (father or mother and a child) had Pentacam data were analyzed. Each subject underwent a comprehensive ophthalmic examination, with emphasis on the measurement of visual acuity and refraction, biomicroscopy, and Pentacam imaging. Heritability was estimated to investigate familial aggregation of anterior chamber indices, and the effects of age, sex, and living area were controlled for as confounding factors.

RESULTS: Of the 3851 selected individuals, 3314 participated in the study. After applying the exclusion criteria, the data of 1383 subjects from 382 households were included in the analysis. The mean age of the participants was 37.23±19.35 years (range, 6 to 93 y). The highest and lowest heritability estimates were related to the anterior chamber angle (72%) and corneal diameter (28%), respectively. The heritability percentages of the anterior chamber depth, anterior chamber volume, and corneal volume were 47%, 39%, and 57%, respectively.

CONCLUSIONS: The high heritability of the anterior chamber angle points to a high correlation between this phenotype and genetic factors. Further genetic and molecular investigations are suggested to find the related genes and understand the etiology of glaucoma.