Intraoperative acetazolamide in the prevention of intraocular pressure rise after pars plana vitrectomy with fluid-gas exchange

Abstract

Purpose: To assess the effect of intraoperative acetazolamide (Diamox) on postoperative intraocular pressure (IOP) in gas-filled, vitrectomized eyes.

Methods: We conducted a prospective randomized clinical trial of 63 consecutive patients undergoing pars plana vitrectomy with total fluid-gas exchange and long-acting intraocular gas tamponade. Patients were randomized by a blind draw to receive either intravenous 500 mg acetazolamide (Diamox) (Group 1) or no treatment (Group 2) at the conclusion of the operative procedure. Intraocular pressures at the conclusion of surgery (IOP-1), 4-8 hours following surgery (IOP-2), and on the first postoperative day (IOP-3) were measured using an Oculab Tono-Pen.

Results: Patients in Groups 1 and 2 showed similar mean IOP on postoperative day 1 (20.48+/-7.84 mmHg versus 19.89+/-7.89 mmHg). A similar incidence of IOP-2 greater than 30 mmHg (1 versus 3 patients with high IOP) and IOP-3 greater than 30 mmHg (4 versus 3 patients with high IOP) was seen. Patients in Group 1 had a lower mean IOP at 4-8 hours postoperatively (16.25+/-6.47 mmHg) than those in Group 2 (20.13+/-6.33 mmHg). No correlation could be demonstrated between IOP-1 and subsequent IOP. However, IOP on the first postoperative day (IOP-3) was strongly correlated with IOP 4-8 hours after surgery (IOP-2) (P = 0.0001). No protective effect of Diamox could be demonstrated on either IOP-2 or IOP-3.

Conclusions: No protective effect against pressure rise could be demonstrated for intraoperative acetazolamide (Diamox) in the prophylaxis of IOP rise following pars plana vitrectomy and total fluid-gas exchange with long-acting intraocular gas.