The aetiology of chronic simple glaucoma is obscure. It may result from a senile sclerotic process of the smaller intra-ocular vessels, and secondarily of the ocular tissues. This may lead to a silting up of the aqueous outflow of the anterior chamber and consequent increase in intra-ocular pressure. Posteriorly this may cause ischaemic atrophy of the optic-nerve fibres which causes atrophic cupping of the disc and restriction of the visual fields.
Known risk factors include age greater than 40 years, a positive family history (increases risk of glaucoma by 10-fold, particularly in siblings), Afro-Caribbeans, diabetes, thyroid eye disease and myopia.
Last reviewed 01/2018