Abstract:
To evaluate the long–term tonometric outcomes of trabeculectomy with adjunctive MMC and its efficacy for achieving a range of target pressures in patients with open–angle glaucoma.
328 patients (421 eyes) with open–angle glaucoma aged 40 years or older at the time of trabeculectomy were enrolled. Patients with coexisting retinal or neurological disease were excluded. The patients were divided into three groups: phakic, pseudophakic and patients with one prior trabeculectomy. Success criteria were defined as follows: A) IOP ≤ 18 mmHg and an IOP reduction of 20%; B) IOP ≤ 15 mmHg and an IOP reduction of 25%; C) IOP ≤ 12 and an IOP reduction of 30%. Kaplan–Meier survival analyses were applied to assess long–term outcomes according to these criteria and the Cox proportional hazard regression was used to determine predictive factors for failure.
The mean IOP for the entire group decreased from a preoperative value of 18.9 mmHg (±6.4) to 11.1 mmHg (±4.6) at one year and 10.6 mmHg (±4.1) at 3 years (p <0.001 for both). The mean (±SD) number of medications decreased from 2.8 (± 1.0) to 0.61 (±1.0) at 36 months (p <0.001). The success rates were 87%, 85% and 80% at one year for criteria A, B, and C respectively, and 68%, 61% and 51% for the same criteria at three years. The success rates were similar in the phakic, pseudophakic and second trabeculectomy groups regardless of the criteria used to define success (p> 0.05 for all comparisons). Laser suture lysis after trabeculectomy was associated with a higher rate of failure. (p < 0.001, HR=1.87)
Trabeculectomy with MMC effectively reduces IOP in open angle glaucoma, but long–term low target pressures are achieved only in half of the cases.
Keywords: intraocular pressure • clinical (human) or epidemiologic studies: outcomes/complications • clinical (human) or epidemiologic studies: risk factor assessment