Postsurgical hypotony: relationship to fistulization, inflammation, chorioretinal lesions, and the vitreous

Multiple retinal haemorrhages (decompression retinopathy) following paracentesis for macular branch artery occlusion

“…The inferior oblique inserts into the submacular area and its action causes horizontal folding of the choroid. 7 Perhaps the mechanical structural stresses associated with sudden IOP lowering in an already ischaemic macular lead to capillary fragility. The finding of a macular haemorrhage immediately following the paracentesis would be consistent with this.…”

A prospective study of combined phacoemulsification‐trabeculectomy versus conventional phacoemulsification in cataract patients with coexisting open angle glaucoma

“…None of the eyes were re-operated in the observation period. In this paper we define ocular hypotony to be ∞10 mm Hg, and hypertension to be ±21 mm Hg (Schubert 1996).…”

The surgical management of chronic hypotony due to uveitis

“…1,2 It is commonly seen in patients with a history of ocular trauma, previous vitreoretinal surgery, particularly if complicated by proliferative vitreoretinopathy, and in cases of long-standing uveitis. While mild hypotony is often transient and is of little consequence, a pressure below 4-6 mmHg can have deleterious effects on ocular function and if sustained can lead to phthisis.…”

“…While mild hypotony is often transient and is of little consequence, a pressure below 4-6 mmHg can have deleterious effects on ocular function and if sustained can lead to phthisis. 1,[3][4][5][6] Anterior vitreous traction on the ciliary processes is considered to be one of the mechanisms by which hypotony is induced in post-traumatic or postvitrectomy cases. [7][8][9][10] In these cases, removing antero-posterior traction, and epiciliary membranes can lead to a moderate increase in intraocular pressure.…”

“…Hyperacute ocular inflammation can induce a significant drop in intraocular pressure, which usually resolves once the inflammatory episode is brought under control. 1,4 This form of hypotony is likely mediated by the secretion of prostaglandins such as PGF 2 -a, which increase uveoscleral outflow. [13][14][15] Chronic uveitis can lead to the development of cyclitic membranes, which both increase outflow by placing traction on the ciliary processes, and decrease secretion by directly damaging the ciliary epithelium.…”