Why are people over age 40 more likely to develop primary open-angle glaucoma?

While the exact cause of primary open-angle glaucoma (POAG) remains unknown, its increased incidence in individuals over age 40 is associated with degenerative changes in the eye's outflow channels for aqueous humor fluid.1

As the eye ages, these drainage pathways may experience structural or functional decline, which can lead to increased resistance to fluid outflow and a subsequent rise in intraocular pressure. This pressure, if sustained, can cause atrophy of the optic nerve fibers, resulting in the characteristic vision loss associated with the disease. Because glaucoma is a progressive condition that often lacks early symptoms, the increased risk associated with aging makes early diagnosis through regular intraocular pressure screening vital for preserving vision.12