*Unpaired t test, RNFL: Retinal nerve fibre layer, MD: Mean deviation, PSD: Pattern standard deviation, VFI: Visual field index, RA: Rim area, CDR: Vertical ...
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Original Article
Comparison of relation between visual function index and retinal nerve fiber layer structure by optical coherence tomography among primary open angle glaucoma and primary angle closure glaucoma eyes Aparna Rao Department of Glaucoma Services Head Glaucoma Services, Lakshmi Varaprasada Rao Prasad Eye Institute, Patia, Bhubaneswar, Orissa, India
Purpose: To compare the visual field index (VFI) in primary open angle glaucoma (POAG) and primary angle closure glaucoma (PACG) eyes, and to study the correlation with disc variables on optical coherence tomography (OCT) in all stages of severity. Materials and Methods: Thirty POAG and PACG underwent Humphrey visual field 24‑2 along with detailed examination. They also underwent stratus OCT imaging of the optic nerve and retinal nerve fiber layer (RNFL). The correlation of VFI with RNFL thickness was compared in POAG and PACG. Results: The VFI significantly differed between POAG and PACG, with POAG eyes apparently having a better VFI at all severities of glaucoma. There were statistically significant differences in the superior max (Smax) and inferior max (Imax) in early and moderate POAG and PACG eyes. In early
Introduction Visual Field Index (VFI) is a measure of the patient’s overall visual function as compared to an age‑adjusted normal population.[1] Access this article online Quick Response Code: Website: www.ojoonline.org DOI: 10.4103/0974-620X.127911
and moderate glaucoma, multivariate regression showed that maximum correlation of the VFI was seen with the mean deviation (b = 1.7, P 22 mm Hg on at least three separate occasions and glaucomatous optic neuropathy with visual field loss consistent with optic nerve damage in at least one eye. In primary open angle glaucoma (POAG), there were open angles on gonioscopy, and primary angle closure glaucoma (PACG) was diagnosed if the above criteria were met, in the presence of an occludable angle, having at least 180 degrees of synechial closure on indentation/manipulative gonioscopy, as per International Society of Geographical and Epidemiologic Ophthalmology (ISGEO) guidelines. Patients with a visual acuity of less than 20/60, media opacities, any other ocular pathology, refractive errors > ±6 D, secondary glaucomas, or those unable to review periodically, were excluded from the study. Full threshold achromatic 24‑2 perimetry was performed using Humphrey field analyzer, (Model 750, Zeiss Humphrey systems, San Leandro). Perimetry was repeated at least twice, till a reliable and consistent visual field result was obtained. Reliability criteria for Visual field (VF) results were fixation loss ≤ 33%, false positive response ≤ 20%, and false negative response ≤ 20%. Severity was staged as early if mean deviation (MD)
