Abstract
Purpose: :
Rarebit perimetry (RBP) was developed for the detection of early damage to the afferent visual system. Testing is performed on a standard personal computer with a 15" LCD screen and utilizes suprathreshold stimuli that probe for the completeness of the neuroretinal architecture. Previous studies have shown that RBP is able to detect visual field defects in glaucoma and neuro-ophthalmologic disorders. Rarebit perimetry has also been shown to be more sensitive to early and subtle damage to the afferent system compared to standard automated perimetry (SAP). The purpose of the study was to determine the feasibility of bedside testing with rarebit perimetry and compare results with standard automated perimetry.
Methods: :
29 eyes of 15 patients admitted with neurologic or neurosurgical disease affecting the afferent visual system were tested. Visual fields using RBP were tested on a laptop computer at the bedside, while visual fields tested using SAP (Humphrey field analyzer) were performed in the clinic. Results of the two tests were compared by a neuro-ophthalmologist blinded to the diagnosis.
Results: :
21 of 29 (72%) visual fields corresponded between RBP and SAP. Additionally, RBP detected 5 defects (17%) in patients who had normal results on SAP. Finally, 15 of 15 patients preferred RBP for ease of testing and convenience.
Conclusions: :
Rarebit perimetry is an easy, convenient, and reliable way to test the afferent visual pathways at the bedside.
Keywords: perimetry • visual fields • visual impairment: neuro-ophthalmological disease