If intraocular pressure is low (less than 6.5 mm Hg) it is called statistical hypotony, and if the reduced IOP causes a decrease in vision, it is called clinical.
Hypotony has many causes including post-surgical wound leak from the eye, chronic inflammation within the eye including iridocyclitis, hypoperfusion, tractional ciliary body detachment or retinal detachment.
[5] Eye inflammation, medications including anti glaucoma drugs, or proliferative vitreoretinopathy causes decreased production.
[6] Increased outflow or aqueous loss may occur following a glaucoma surgery, trauma, cyclodialysis cleft or retinal detachment.
[6] Chronic ocular hypotony may be treated with intraocular injection of sodium hyaluronate.