Inter-eye asymmetry of microvascular density in patients on hydroxychloroquine therapy by optical coherence...

To explore the inter-eye retinal microvascular density asymmetry of patients on hydroxychloroquine (HCQ) therapy through optical coherence tomography angiography (OCTA).

40 subjects were enrolled in this cross-sectional study, including 20 systemic lupus erythematasus patients currently treated with HCQ (40 eyes) and 20 age- and sex-matched normal controls (NCs, 40 eyes). OCTA images were obtained to measure macular and peripapillary mircrovasculatures and microstructures, including vessel density, retinal nerver fiber layer thickness, and peripapillary ganglion cell-inner plexiform layer thickness. The absolute values of the difference between right and left eyes were taken as a measure of inter-eye asymmetry.

Macular whole image vessel density (wiVD-M) and perifoveal vessel density (pfVD) of superficial capillary plexus (SCP) were notably reduced in both the right and left eyes of the HCQ treatment group compared with NCs. Specifically, SLE patients treated with HCQ have higher inter-eye asymmetry of wiVD-M of SCP (2.28 ± 1.03 vs 1.27 ± 0.79, p < 0.01) and pfVD of SCP (2.55 ± 1.26 vs 1.78 ± 1.06, p = 0.04) compared with NCs. There were no significant differences in inter-eye asymmetry of structure parameters. Inter-eye asymmetry of wiVD-M of SCP (AUC = 0.80, p < 0.01) and pfVD of SCP (AUC = 0.71, p = 0.02) exhibited greater discrimination power.

SLE Patients treated with HCQ exhibited a notably higher inter-eye vessel density asymmetry compared to that of NCs. Thus, inter-eye vessel density asymmetry could be used to screen for HCQ retinal toxicity.