Trabeculectomy Versus 2-iStent and Prostaglandin Study

Trabeculectomy Versus 2-iStent and Prostaglandin Study

Investigators hypothesize that the synergistic action of iStent in increasing aqueous outflow through the trabecular meshwork and use of prostaglandin analog such as travoprost or latanoprost to increase uveoscleral outflow will achieve good Intra-ocular Pressure (IOP) control with minimal complications in Primary Open Angle Glaucoma (POAG) patients with suboptimal IOP on 2 or more medications compared to mitomycin C (MMC) augmented trabeculectomy.

This will be a prospective randomized controlled study.

20 phakic or pseudophakic open angle glaucoma patients with an IOP in the range of 18-30 mmHg on 2 or more topical glaucoma medications will be randomly selected to undergo either (1) mitomycin-augmented trabeculectomy or (2) placement of 2 iStent devices and initiation of a daily prostaglandin analog. This study is looking at the combined effects of the 2 iStents and a prostaglandin analog as a method to achieve low IOP. At 3 months (+/- 2 weeks) postoperatively, the iStent patients will be left only on the prostaglandin analog with a washout performed for any other hypotensive medication used. Patients who had a trabeculectomy will be have a terminal washout of all IOP-lowering medications at 3 months (+/- 2 weeks) post-surgery. The IOP will then be measured for both groups at 4 months (+/- 3 weeks) postoperatively.

Inclusion Criteria:

• Patients who have mental capacity to give consent
• Age >= 21 years
• Pseudophakic or phakic without visually significant cataract
• Open angle glaucoma
• IOP in the range of 18-30 mmHg with 2 or more topical medications
• Cup-disc ratio =< 0.9
• Best corrected visual acuity of 20/100 or better

Exclusion Criteria:

• Inability to give consent
• Inability to tolerate or presence of allergy to prostaglandin analogs
• Patient preference for non-surgical treatment or preference for either of the recommended surgical modalities in the study
• Age < 21 years
• Visually significant cataract that would benefit from cataract surgery, as determined by the treating surgeon in consultation with the patient
• Secondary glaucoma or angle closure glaucoma
• Aphakia
• Prior glaucoma incisional surgery (trabeculectomy, tube surgery, other Microinvasive Glaucoma Surgery (MIGS) surgeries, deep sclerectomy)
• Prior laser trabeculoplasty < 90 days prior to screening or absolute failure of prior laser trabeculoplasty.