Overview
Ocular hypotony refers to intraocular pressure less than or equal to 5mmHg, which may lead to complications that may compromise vision. Low IOP can be caused by ocular trauma or surgery, but can also be caused by ocular pathologies including uveitis, retinal detachment and occlusion of the blood flow to the ciliary body. Some medications can also cause ocular hypotony.
Ocular signs include a shallow or flat anterior chamber and low IOP. Examination of the posterior eye can reveal serous choroidal effusion, optic nerve oedema and vascular tortuosity as well as horizontal choroidal folds and macular striae. Chronic hypotony can cause RPE atrophy, which then leads to atrophy of the retina.
Early treatment of ocular hypotony is important to improve the chances of visual recovery, prior to the onset of atrophic changes.
References
Wang, Q. Thau, A. Levin, AV. Lee, D. (2019) Ocular hypotony: A comprehensive review, Survey of Ophthalmology, Volume 64, Issue 5, pp 619-638.