Is Low Intraocular Pressure Post Trabeculectomy a Risk Factor for Future Outcome?

Abstract

Purpose: : Ocular hypotony is associated with increased inflammation and poor bleb function. This study aims to determine whether day 1 postoperative hypotony is a risk factor for later failure of trabeculectomy surgery in patients with releasable sutures.

Methods: : A consecutive case series of 102 eyes of 89 patients with primary open angle glaucoma who underwent trabeculectomy for uncontrolled intraocular pressure (IOP) despite maximally tolerated medical treatment. Patients with a day 1 post op IOP of less than 6 mm Hg were compared to those with an IOP of greater than or equal to 6 mm Hg. The success rates between the two groups were examined. Failure was defined as an IOP of 18 mm Hg or more or the commencement of ocular hypotensive medication.

Results: : Twelve (12 %) trabeculectomies had a day 1 post op IOP of less than 6 mm Hg and a mean follow up of 21 months. The remaining 90 (88 %) trabeculectomies had a day 1 IOP of greater than or equal to 6 mm Hg and a mean follow up of 18 months. At last follow up 6 (50 %) were successful in the less than 6 mm Hg group compared with 90 (76 %) in the greater than or equal to 6 mm Hg group (P = 0.01 log-rank test).

Keywords: trabecular meshwork • aqueous