A retrospective study to assess visual field improvement following augmented trabeculectomy

Purpose: To explore the visual field (VF) changes two years following augmented trabeculectomy. Methods: A retrospective study of patients who underwent augmented trabeculectomy surgery with mitomycin C by a single surgeon at East Lancashire Teaching Hospitals NHS Trust over 3 years. Patients with a minimum of two years postoperative follow-up were included. Baseline characteristics, intraocular pressure (IOP), VF, number of glaucoma medications, and complications were recorded. Results: In total, 206 eyes were included, 97 (47%) patients were female, and the mean age was 73.8 +/- 10.3 (range 43 to 93) years. One hundred thirty-one (63.6%) eyes were pseudophakic before trabeculectomy. The patients were divided into three outcome groups according to VF outcome. Seventy-seven (37.4%) patients had stable VF, 35 (17.0%) patients showed VF improvement, and 94 (45.6%) had VF deterioration. The overall mean preoperative IOP was 22.7 +/- 8.0 mmHg and postoperative IOP 10.4 +/- 4.2 mmHg, with a reduction of 50.2% (P < 0.001). In total, 84.5% of postoperative patients did not require glaucoma medications. A higher number of patients with postoperative IOP >= 15 mmHg had deteriorating VF (P < 0.001). Based on preoperative MD distribution, VF improvement or stability was more achievable with patients with a preoperative VF defect up to -12 dB (n = 41, 59.4%) and in those with greater than -24 dB (n = 25, 64.1%). Conclusion: Trabeculectomy continues to be an effective means of lowering IOP in patients with uncontrolled glaucoma and is important in stabilizing or improving visual fields. We recommend early trabeculectomy to prevent further VF deterioration. This may help in maintaining VF for driving status and, thus, quality of life.