Temporal Wedge Defects in Glaucoma: Structure/Function Correlation With Threshold Automated Perimetry of the Full Visual Field.

Abstract

We used the Open Perimetry Interface (OPI) to design a static automated perimetry test of the full visual field. About half of our glaucoma cohort had defects in the far peripheral inferotemporal visual field that correlate well with related damage to the superior nasal optic disc. To test the hypothesis that in glaucoma patients with mild visual loss, perimetric nerve fiber bundle defects present outside 30 degrees will correlate well with areas of Cirrus ocular coherence tomography (OCT) retinal nerve fiber layer thinning. We tested 27 consecutive glaucoma subjects with mild vision loss (mean deviation better than -4 dB) with a SITA standard test, 2 size V custom OPI tests (OPI 30-2 and OPI Peripheral) and Cirrus OCT. Two observers assigned qualitative grades to each type of visual field test based on their level of correlation with OCT retinal nerve fiber layer and ganglion cell thickness. Discrete temporal wedge defects were found on the OPI peripheral V test in 26% of cases whereas more extensive inferior temporal loss (including inferior temporal wedge defect region) was present in 22% of other cases. OCT data correlated best with the OPI peripheral test for 8 glaucoma subjects. The OPI central 30-2 test correlated best for 9 glaucoma subjects; the remainder of subjects had equal central/peripheral correlations. About half of our glaucoma cohort have defects in the far peripheral inferotemporal visual field that correlate well with related damage to the superior nasal optic disc. Adding a threshold automated perimetry test of the far periphery improves structure/function correlations and adds useful clinical information.