Long-term follow-up of visual field progression after trabeculectomy in progressive normal-tension glaucoma.

Abstract Objective To evaluate the long-term effects of trabeculectomy on the progression of visual field damage in patients with progressive normal-tension glaucoma (NTG). Design Retrospective, noncomparative, interventional case series. Participants Twenty-three patients with NTG who had significant progression of visual field damage preoperatively and underwent trabeculectomy using antimetabolites. Methods Visual field testing using the Humphrey Visual Field Analyzer was periodically performed before and for at least 5 years after surgery (mean, 6 years). The time course of the mean deviation (MD) and mean of total deviations (TD mean ) in four separate subfields, superior and inferior cecocentral and superior and inferior arcuate fields, were analyzed using a linear mixed effects model. Main outcome measures Intraocular pressure (IOP), preoperative and postoperative regression coefficients of the time course of MD or TD mean in the four subfields, corresponding to the rate of progression of visual field damage. Results IOP significantly decreased from 16.2 ± 1.8 mmHg preoperatively to approximately 11 mmHg during the postoperative follow-up period ( P P P P mean change were significantly negative ( P P P = 0.72) and did not change significantly after surgery ( P = 0.15). Conclusions Trabeculectomy was statistically associated with slowing further progression of visual field damage in patients with progressive NTG. The progression, however, did not completely stop over the 6-year postoperative follow-up period.