Swept source optical coherence tomography angiography in patients treated with hydroxychloroquine: correlation with morphological and functional tests.

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.