No abstract

Purpose To examine the impact of surgical Intraocular pressure (IOP) reduction on visual function using various methods to define visual field (VF) progression. Methods A retrospective chart review was conducted on consecutive glaucoma patients who underwent surgical IOP reduction between January 1, 2002 and December 31, 2007. All subjects had glaucomatous optic neuropathy, a minimum of 5 preoperative and 5 postoperative visual fields, and were followed for a minimum of 2 years both before and after surgery. VF progression was determined using Guided Progression Analysis (GPA), linear regression analysis of the visual-field index (VFI), and individual sensitivity values using Progressor™ software. Results Seventeen eyes of 17 patients (mean age 77.9 ± 9.9 years) were enrolled. Subjects were followed for a mean 5.8 ± 2.4 years prior to surgery and 4.5 ± 1.5 years following surgery. Mean postoperative IOP (11.3 ± 4.2mmHg) and medications (1.3 ± 1.3) were significantly (p<0.001 and p=0.01) reduced compared with prior to surgery (18.0 ± 3.9mmHg, 2.4 ± 0.9 respectively). The number of eyes judged to have VF progression using any method during the postoperative period (3 of 17, 17.6%) was significantly (p=0.03) reduced compared to the preoperative period (9 of 17 eyes, 52.9%). Using VFI criteria, 8 eyes were judged to have preoperative VF progression and 1 eye had persistent VF progression during the postoperative period. None of the eyes judged to have preoperative VF progression using EMGT (n=4) and Progressor criteria (n=1) demonstrated persistent VF progression during the postoperative period. Among eyes with preoperative VF progression, the postoperative slope of mean deviation (−0.21 ± 0.23 db/yr) was significantly (p=0.03) reduced compared with prior to surgery (−1.01 ± 0.23 db/yr). Conclusions Despite differences in the criteria used to define visual field progression, glaucoma surgical IOP reduction significantly reduces the incidence and rate of visual field progression.