Purpose To evaluate swept source optical coherence tomography angiography (SS-OCTA) in patients treated with hydroxychloroquine (HCQ) for more than 5 years and to compare results with the tests currently recommended for screening of HCQ retinopathy.

Methods In this controlled pilot study, consecutive patients treated with HCQ for more than 5 years underwent SS-OCTA, SS-OCT B-scan and en-face C-scan, fundus autofluorescence (FAF), 10–2 automated visual field (AVF) testing and multifocal electroretinography (mfERG). On SS-OCTA, evaluation of the retinal superficial capillary plexus, middle capillary plexus, and deep capillary plexus (DCP) and the choriocapillaris (CC) was obtained.

Results We included 10 patients under HCQ treatment (20 eyes, mean age 38.91±11.73 years) and 18 healthy control patients (36 eyes, mean age 38.87±8.6 years). Mean duration of HCQ treatment was 10.0±3.25 (5–15) years and HCQ cumulative dose/body weight was 15.86±5.56 g/kg. The HCQ group showed a reduction of the vessel density in the 1 mm central, in the nasal and temporal subfields of DCP and in the 1 mm central subfield of CC, an increased foveal avascular zone in the three capillary plexuses, a greater frequency of CC flow voids and a reduced foveal choroidal thickness (p<0.05). Best-corrected visual acuity (BCVA), mfERG, SS-OCT B-scan and C-scan, AVF and FAF were normal in 20/20 eyes (100%).

Conclusions In patients treated with HCQ for more than 5 years, choroidal thinning and flow abnormalities at SS-OCTA in the retinal capillary plexuses and CC may be observed even if BCVA, FAF, mfERG, AVF and SS-OCT are normal.