Abstract
Purpose :
To quantitatively analyze choriocapillaris alterations using swept-source optical coherence tomography angiography (SS-OCTA) in eyes presenting with severe hydroxychloroquine (HCQ) retinopathy and to compare it with patients taking HCQ without toxic retinopathy and healthy controls.
Methods :
In this cross-sectional study, macular 6x6 mm SS-OCTA scans were analyzed in eyes with either severe HCQ toxic retinopathy, or under HCQ without retinal toxicity, as well as in healthy age and sex-matched controls. The choriocapillaris en face slabs were extracted from the SS-OCTA device. En face choriocapillaris flow images were compensated with en face choriocapillaris structure images, followed by Phansalkar local thresholding using window radius 4 and 8 pixels. Percentage of flow deficits (FD %), as well as FD number, size, and total area, were computed for comparison.
Results :
Seventy-six eyes of 38 patients under HCQ (mean age 49.89±11.68 years) and sixty eyes of 34 age-matched controls (mean age 54.30±14.85 years) were included in this study. Among the patients under HCQ, fourteen eyes (7 patients) presented with severe HCQ toxicity, while sixty-two eyes (31 patients) had no signs of toxicity. FD%, the average size of FDs, and the number of FDs were significantly different between the severe HCQ toxicity, no HCQ toxicity, and controls (p-value < 0.001 for all comparisons, for both radius 8 and 4 pixels). Compared to controls and eyes with no HCQ toxicity, the eyes with severe HCQ toxicity had a significantly higher FD% (p-value 0.009 and <0.001 for radius 8 pixels, p-value <0.001 and <0.001 using radius 4 pixels, respectively), a significantly lower number of FDs (p-value 0.005 and <0.001 using radius 8 pixels, p-value 0.005 and <0.001 using radius 4 pixels).
Conclusions :
Our results suggest an involvement of the choriocapillaris in severe HCQ retinal toxicity, therefore expanding the current knowledge of the (inner) choroidal involvement in the pathogenesis of HCQ retinopathy.
This abstract was presented at the 2022 ARVO Annual Meeting, held in Denver, CO, May 1-4, 2022, and virtually.