Detection of Visual Loss in IIH with Static Automated Perimetry: Temporal Wedge Defects

Abstract

Purpose : The peripheral visual field outside of the central 30° is rarely tested with static automated perimetry. We performed a cross-sectional clinical study to characterize visual loss across the full visual field in idiopathic intracranial hypertension (IIH) patients with mild central visual loss.

Methods : We tested the full visual field (64 central and 64 far peripheral test locations: 50° nasal, 80° temporal, 30° superior, 45° inferior) of one eye of 39 IIH patients using threshold static perimetry (stimulus size V) on the Octopus 900 perimeter running the Open Perimetry Interface. The subjects met the Dandy criteria for IIH and had at least Frisén grade 1 papilledema with better than -5 dB mean deviation (MD) centrally. Two observers (MW, AS) evaluated the visual field defects, adjudicated any differences and reviewed OCT data.

Results : We found a greater magnitude of loss with MD peripherally than centrally (central 26°): -3.43 dB vs -1.37 dB, p < 0.001, Wilcoxon). There were about 30% more abnormal test locations identified in the periphery and the mean defect depth increased with eccentricity. The most frequent defect found was a temporal wedge defect in the periphery. While the presence of papilledema limited correlation, 47% of the temporal wedge defects had OCT RNFL deficits of the related superior nasal optic disc. Other common defects were inferonasal loss, superonasal loss, superior and inferior arcuate defects (Figure). Seven patients (18%) had visual field defects in the periphery with normal central visual field testing.

Conclusions : In IIH patients, we found significantly more visual loss outside 26° of the visual field compared to inside 26° with the depth of the defect increasing with eccentricity. Temporal wedge defects were the most common visual field defect, occurring mostly in the far periphery. Static threshold perimetry of the full visual field appears to be clinically useful in IIH patients.

This abstract was presented at the 2019 ARVO Annual Meeting, held in Vancouver, Canada, April 28 - May 2, 2019.

 

Percentage of various visual field defects found in IIH patients with mild visual loss.