Optical coherence tomographic assessment of disc changes and automated perimetric assessment of visual field changes after glaucoma filtration surgery

Abstract

The study was conducted to find out the topographic changes of disc, macular thickness, visual field, and intra-ocular pressure (IOP) after trabeculectomy in different age and sex using Optical Coherence Tomography (OCT) machine, automated perimeter and Goldman applanation tonometer respectively.It was a prospective, interventional case-series conducted at the glaucoma clinic at Regional Institute of Ophthalmology, Kolkata from March 2010 to August 2011. Patients of primary open angle glaucoma who fulfilled the inclusion criteria. The trabeculectomy surgeries were done by a single surgeon. The disc changes, macular thickness, IOP and visual field changes were measured before and after trabeculectomy. Preoperative OCT images of disc and macula, visual field testing by Humphrey automated perimeter and IOP by Goldman applanation tonometry were done/within 3 months prior to surgery and same investigations had been done postoperatively within 2 to 3 months after surgery. Data was collected in a standard data collection form and analysis was done by paired t-test.Significant visual field (mean deviation-MD & pattern standard deviation-PSD in decibel) changes were seen but the nerve fiber thickness in the disc and macula were not increased. Significant reduction of IOP was found after trabeculectomy. Significant visual field (MD& PSD) changes were found after trabeculectomy in early glaucoma patients but disc and macular changes were found to be insignificant.