Retinal nerve fiber layer and visual field changes in patients undergoing trabeculectomy at Sub-Himalayan Region

Abstract

Introduction: Glaucoma constitutes a group of multifactorial optic neuropathies with changes in intrapapillary and parapapillary regions of optic nerve head and retinal nerve fiber layer (RNFL). Optical coherence tomography (OCT) measurement of peripapillary RNFL thickness may be the best among the currently available digital imaging instruments for detecting and tracking optic nerve damage in glaucoma. Objective: Analyzing changes in RNFL and visual field (VF) before and after trabeculectomy. Materials and Methods: The RNFL measurement using Topcon 3D OCT and VF assessment with Octopus 900 perimeter of 27 patients undergoing trabeculectomy were done at 1 week preoperatively and 1 week, 1 month, and 3 months postoperatively. Results: All the four RNFL quadrants showed improvement in thickness which was either numerically or statistically significant. In the VF analysis, the mean sensitivity (MS) was 8.73 ± 4.5493 at 1 week preoperatively. The mean value for MS at 3rd month was 9.859 ± 5.5606 (P = 0.043). Statistically significant improvement was observed at 3rd month postoperatively. The mean deviation observed within 1 week preoperative period was 19.044 ± 4.6111. The mean value was 18.26 ± 5.164 (P = 0.003) at 1 month. The mean value came equal to 17.926 ± 5.4928 (P = 0.012) at 3rd month. Statistically significant improvement was observed postoperative follow-up period. Conclusion: The vision in patients of primary open angle glaucoma can be restored through early detection of glaucoma by OCT and perimetry. As there is improvement in RNFL thickness and global indices of VF in patients undergoing trabeculectomy, further visual deterioration can be avoided.