TNOA Journal of Ophthalmic Science and Research (Jan 2021)
To compare and correlate visual field changes detected by perimetry with retinal nerve fiber layer and ganglion cell layer thickness observed using spectral domain optical coherence tomography in primary open angle glaucoma
Abstract
Aim: To evaluate the damage pattern of retinal ganglion cells at different stages of glaucoma in patients with primary open-angle glaucoma (POAG) by observing peripapillary retinal nerve fiber layer (RNFL) and macular ganglion cell layer-inner plexiform layer (GCL-IPL) thickness measured by spectral domain optical coherence tomography (SD-OCT) and their correlation with visual field (VF) changes. Materials and Methods: Descriptive cross-sectional study done on patients with POAG presenting to a tertiary eye center in Eastern India. Peripapillary RNFL thickness and macular GCL-IPL thickness were measured using SD-OCT. VF assessment was done using the Humphrey Field analyzer. Patients were divided into early, moderate, and advanced (severe) groups following Hodapp, Parrish, and Anderson's criteria. Results: Seventy-seven eyes of 40 patients with POAG were included in the study. The average age of the patients was 59.23 ± 9.56 years. Early, moderate, and advanced glaucoma changes were seen in 34 (44.15%), 23 (29.87%), and 20 (25.98%) eyes, respectively. Superior peripapillary RNFL thinning was noted in early glaucoma. As the disease progressed, inferior peripapillary RNFL showed significant thinning in the advanced glaucoma group as compared to early and moderate groups. Inferior macular GCL-IPL thickness showed more thinning as the severity of the disease progressed. In all stages of glaucoma, peripapillary RNFL and GCL-IPL thickness showed positive correlation with the VF mean deviation. Conclusion: Both peripapillary RNFL and macular GCL-IPL thicknesses should be assessed along with VF defects to monitor the severity of the disease in POAG. Macular GCL-IPL thickness changes are well correlated with changes in visual function and RNFL structure in glaucoma.
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