Value of Red Targets and Pattern Deviation Plots in Visual Field Screening for Hydroxychloroquine Retinopathy

Abstract

To compare the value of red vs white 10-2 visual field testing in patients with different levels of hydroxychloroquine exposure and retinopathy in reference to recent American Academy of Ophthalmology recommendations on screening for hydroxychloroquine retinopathy that advised the use of 10-2 visual field testing with a white test object. We studied retrospectively 13 patients using hydroxychloroquine who had undergone both red (FASTPAC) and white (SITA) 10-2 automated visual field testing in the course of their management. On clinical grounds, they were judged to have no retinopathy, early retinopathy, or moderate or severe hydroxychloroquine retinopathy. White visual field diagrams were difficult to interpret, but pattern deviation plots consistently showed parafoveal sensitivity losses in early retinopathy. Red fields often showed more prominent scotomas in early retinopathy but sometimes showed irregular losses that were hard to evaluate. Either modality showed clear losses in moderate retinopathy. On repeated testing, the pattern deviation plots were somewhat more consistent than red fields in showing parafoveal damage. With white 10-2 visual field hydroxychloroquine screening, the use of pattern deviation plots should be standard practice. Red testing appears to be more sensitive for early retinopathy but may be slightly less specific or consistent. We believe the main application for red testing is in screening for the earliest signs of retinopathy. Either red or white fields should be acceptable for hydroxychloroquine screening, as long as the clinician is sensitive to the characteristic patterns of early parafoveal damage and is prepared to retest fields and add objective tests.