Abstract
Purpose: :
To evaluate the incidence of hypotony and sclerotomy leakage after cannula removal on conclusion of surgery following single step 23-gauge transconjunctival vitrectomy and evaluate potential predisposing risk factors.
Methods: :
Retrospective study of eyes undergoing 23-gauge transconjunctival vitrectomy by 2 vitreoretinal surgeons at a single academic institution between March 29th, 2009 and June 1st, 2009. The primary outcome was the incidence of hypotony immediately following removal of all cannulae using a simple removal method or removing each cannula over a light-pipe.
Results: :
Forty-two eyes of 42 patients were recruited. Hypotony (tactile) at conclusion of surgery was present in 15/42 (36%) eyes with no difference between air/gas-filled eyes (8/21) and fluid-filled eyes (7/21, p=0.99). Ten of 19 eyes that had cannulae removed over a light pipe were hypotonous compared to 5/23 in which the light pipe was not used (p=0.04). Use of plugs prior to removing the cannulae resulted in no difference in rates of hypotony (p=0.99). Eyes with hypotony at the conclusion of surgery were more likely to have had longer surgery (p=0.07). The incidence of sclerotomy leak was highest in the dominant hand sclerotomy (67%) followed by the non-dominant hand (52%) and the infusion site (19%, p=0.009). The incidence of hypotony (intraocular pressure <6mmHg) was 1/42 (2%) on the first post-operative day.
Conclusions: :
Hypotony after removal of 23-gauge transconjunctival vitrectomy cannulae is common, especially if removing the cannulae over a light pipe. Nonetheless, the pressure almost always normalizes by the first post-operative day.
Keywords: vitreoretinal surgery • wound healing • intraocular pressure