Genetic contributions to glaucoma: heritability of intraocular pressure, retinal nerve fiber layer thickness, and optic disc morphology.

Purpose: The genetic etiology of primary open-angle glaucoma (POAG) is still largely unknown, because of its complexity and disparities in its classification. This study was undertaken to determine the genetic contribution to various early, continuous markers of POAG by assessing the heritability of intraocular pressure (IOP), retinal nerve fiber layer (RNFL) thickness, and neuroretinal rim and optic disc parameters in a genetically isolated population.

Methods: A total of 2620 subjects (mean age, 48 years; range 18-86) from extended pedigrees living in a small town in The Netherlands underwent an extensive ophthalmic examination.