A comparison of structural and functional changes in patients screened for hydroxychloroquine retinopathy.

PURPOSE: The aims of this retrospective study were to compare the results of recommended screening tests for hydroxychloroquine-related retinal toxicity and analyze disparities between the structural and functional findings. METHODS: Thirty-four patients (31 women and 3 men) were included in the study. All were evaluated with standard automated perimetry using the 10-2 and/or 24-2 visual field program (Zeiss, Meditec), multifocal electroretinography (mfERG), spectral-domain optical coherence tomography (SD-OCT), and short-wavelength fundus autofluorescent imaging (SW-FAF). The results for the right eye from each patient were analyzed. Visual fields were classified as normal or abnormal based on pattern deviation plots, and mfERGs based on a comparison of R5 ring ratios to values from 20 controls. The SW-FAF images were examined for areas/rings of abnormal hypo- and/or hyperautofluorescence, and the SD-OCT line scans were classified as abnormal based on visual inspection and thickness measurements of the outer segment plus retinal pigment epithelial layer and total receptor layers compared to mean thicknesses from 35 controls. RESULTS: Fifteen patients had abnormal results on at least one test; however, only two patients had abnormal results on all four tests. Excluding SW-FAF, seven of the 15 had abnormal visual fields, mfERG ring ratios, and SD-OCTs. The remaining eight had either abnormal mfERGs and/or visual fields and normal SD-OCTs. We found no evidence of abnormal SD-OCTs in the presence of normal mfERG and visual field results. CONCLUSIONS: The findings suggest that functional deficits precede structural changes seen on SD-OCT in these patients.

Quantitative Fundus Autofluorescence in HCQ Retinopathy.

Purpose: To increase our understanding of the mechanisms underlying hydroxychloroquine (HCQ) retinopathy, analyses by quantitative fundus autofluorescence (qAF) and near-infrared fundus autofluorescence (NIR-AF) were compared to results obtained by recommended screening tests. Methods: Thirty-one patients (28 females, 3 males) were evaluated with standard automated perimetry and spectral domain optical coherence tomography (SD-OCT); 28 also had multifocal electroretinography (mfERG). Measurement of short-wavelength fundus autofluorescence (SW-AF) by qAF involved the use of an internal fluorescent reference and intensity measurements in eight concentric segments at 7° to 9° eccentricity. For semiquantitative analysis of NIR-AF, intensities were acquired along a vertical axis through the fovea. Results: Four of 15 high-dose (total dose >1000 g, daily dose >5.0 mg/kg) patients and one of 16 low-dose (total dose <1000 g, daily dose 4.4 mg/kg) patients were diagnosed with HCQ-associated retinopathy based on abnormal 10-2 visual fields, SD-OCT, and SW-AF imaging. Three of the high-dose patients also had abnormal mfERG results. Of the five patients exhibiting retinopathy, two had qAF color-coded images revealing higher intensities inferior, nasal, and lateral to the fovea. The abnormal visual fields also exhibited superior-inferior differences. Mean NIR-AF gray-level intensities were increased in four high-dose patients with no evidence of retinopathy. In two patients with retinopathy, NIR-AF intensity within the parafovea was below the normal range. One high-dose patient (6.25 mg/kg) had only abnormal mfERG results. Conclusions: These findings indicate that screening for HCQ retinopathy should take into consideration superior-inferior differences in susceptibility to HCQ retinopathy.