Prospective analysis of optic nerve head parameters before and after trabeculectomy at a tertiary institute of the Himalayan foothills (optical coherence tomography-based study)

Introduction: Glaucoma is a group of acute and chronic, progressive, multifactorial optic neuropathies in which intraocular pressure (IOP) and other contributing factors are responsible for a characteristic, acquired loss of retinal ganglion cell axons leading to atrophy of the optic nerve. Early detection of glaucoma through the use of optical coherence tomography (OCT) and perimetry and intervention through trabeculectomy in patients showing deterioration can avoid further damage to vision. Objective: The objective of the study was to analyze the optic nerve head (ONH) pParameters before and after trabeculectomy. Materials and Methods: This study was to prospectively study ONH before and after trabeculectomy using OCT in primary open-angle glaucoma in patients attending the Department of Ophthalmology, Indira Gandhi Medical College, Shimla. Results: The IOP decreased from 26.93 ± 2.786 mm to 11.81 ± 3.552mm Hg (P < 0.05) in the 3rd month. The rim area preoperatively was 0.5037 ± 0.27646 and at 3 months postoperatively was 0.6707 ± 0.29319 (P = 0.008), which was statistically significant. The mean value of rim volume preoperatively was 0.0463 ± 0.01904 and at 3 months was 0.0630 ± 0.0336 (P = 0.036), showing statistical significance. The preoperative cup area was 2.064 ± 0.5043, and at the 3rd month, it was 1.9393 ± 0.58619 (P = 0.027), showing statistical significance. The mean value of cup volume preoperatively was 0.6981 ± 0.33874 and at 3-month postoperative was 0.5933 ± 0.31274 (P = 0.000). Cup volume also showed a significant improvement postoperatively. Conclusion: ONH changes, being the physical manifestations of the IOP force distribution in the tissues, are essential to glaucoma pathophysiology. The early detection of glaucoma through the use of OCT and intervention through trabeculectomy in patients showing deterioration (progressive patients) can avoid further damage to the vision.