Abstract
Purpose :
Data on heritability of anatomic traits in primary angle closure glaucoma (PACG) is sparse. The purpose of this study was to estimate the heritability of ocular biometric and anterior chamber morphologic parameters and to determine predictors of angle closure concordance in South Indian probands with primary angle closure suspect (PACS) or primary angle closure (PAC)/PACG and their siblings.
Methods :
We prospectively collected data on a cohort of probands with PACS or PAC/PACG and their full siblings aged ≥ 30 years in South India. All subjects received a standardized ophthalmic examination, A-scan ultrasonography, pachymetry, and anterior segment optical coherence tomography imaging (ASOCT). Heritability was calculated using residual correlation coefficients adjusted for age, sex, and home setting. Concordant siblings pairs were defined as both proband and sibling with PACS or PAC/PACG. Predictors of angle closure concordance among sibling pairs were calculated using multivariable logistic regression models, corrected for collinearity.
Results :
345 sibling pairs participated, including 121 sibling pairs concordant for angle closure and 224 discordant sibling pairs. All anterior chamber parameters were highly heritable (p<0.001 for all), Table 1. Similarly, all iris parameters, axial length, lens thickness (LT), central corneal thickness, anterior lens curvature, lens vault (LV), spherical equivalent, and intraocular pressure were moderately to highly heritable (p<0.004 for all). LV and LT were significantly more heritable among concordant sibling pairs (p<0.05 for both). In contrast, ASOCT angle parameters had statistically insignificant heritability estimates. In multivariable analyses, siblings older than their probands were more likely to be concordant for angle closure (OR=1.05 (95% CI 1.01, 1.09)) and siblings with a deeper anterior chamber depth (ACD) compared to their probands were less likely to be concordant for angle closure (OR=0.74 (95% CI 0.64, 0.86)), Table 2.
Conclusions :
Iris, anterior chamber, and lens parameters were significantly heritable while angle parameters were not. LT and LV were significantly more heritable among concordant siblings and may play important roles in the pathogenesis of angle closure disease. Siblings who are older or have a shallower ACD have a greater likelihood of angle closure and may need more careful disease monitoring.
This is a 2021 ARVO Annual Meeting abstract.