Short-term changes in the optic nerve head and visual field after trabeculectomy

Aims or Purpose To evaluate short-term changes in optic nerve head topography and visual field induced by surgical reduction of intraocular pressure. Methods A prospective study was performed on 56 eyes of 56 patients with uncontrolled primary open-angle glaucoma despite maximum medical therapy, which underwent trabeculectomy. Optic nerve head evaluations by means of Heidelberg Retina Tomograph, and visual field tests were performed pre-operatively, and at 3 and 6 months after surgery. Differences in intraocular pressure, visual field indices, and Heidelberg Retina Tomograph parameters were evaluated with the t-test for paired data. A linear regression model was calculated to analyze the relationship between intraocular pressure reduction and visual field changes, and optic nerve head changes. Results Mean intraocular pressure decreased from 24.4 +/- 5.0mmHg to 12.1 +/- 3.1mmHg (month 3, P<0.001), and 10.6 +/- 2.8mmHg (month 6, P<0.001) after trabeculectomy. Mean retinal nerve fiber layer thickness (baseline, 0.19 +/- 0.034; month 3, 0.24 +/- 0.039, P=0.05; month 6, 0.21 +/- 0.037, P=0.05) showed a statistical significant change compared with baseline values. Conclusions In this 6-months study, a significant increase in retinal nerve fiber layer thickness was detected after glaucoma filtration surgery. Eye (2011) 25, 1057-1063; doi:10.1038/eye.2011.119; published online 27 May 2011