Rarebit Perimetry in the Evaluation of Visual Field Defects in Idiopathic Intracranial Hypertension

Abstract

Rarebit perimetry (RBP) is a new perimetric technique that has been reported as a sensitive test for the evaluation of the neural structure of the visual system. The aim of this study was to compare RBP with standard automated perimetry in detecting the visual field defects of patients with idiopathic intracranial hypertension (IIH). Twenty-five patients with IIH and 16 healthy controls were considered. Visual fields were analyzed with Marco automated static perimeter with threshold and central 30-2 programs (MP 30-2) and rarebit perimetry. A visual field was classified into 3 zones for both tests as central, paracentral, and peripheral zones. Mean sensitivity (MS) recorded by the MP 30-2 was compared with the mean hit rate (MHR) recorded by RBP for each zone. MS recorded by MP 30-2 and MHR recorded by RBP for each zone were significantly lower in the IIH group than in healthy control eyes (p < 0.001). Good correlation was present between the visual fields recorded by both tests. Although the sensitivity and specificity values for each zone were lower in the RBP group than the MP 30-2 group, RBP was found to be efficient to differentiate between the visual fields of normal and IIH-affected eyes. The average RBP test duration was significantly shorter than the MP 30-2 test duration (p < 0.001). CONCLUSIONS. RBP is a rapid, comfortable, and widely accessible perimetric test giving reliable results in detecting visual field defects in IIH.