Application of optical coherence tomography angiography for microvascular changes in patients treated with hydroxychloroquine: a systematic review and meta-analysis

Background Retinal toxicity with long-term hydroxychloroquine (HCQ) treatment is a major concern. This systematic review aims to assess the application of optical coherence tomography angiography (OCTA) to detect microvascular alterations in patients under HCQ. Methods PubMed, Scopus, Web of Science, and Cochrane Library databases were systematically searched until January 14, 2023. Studies using OCTA as a primary diagnostic method to evaluate the macular microvasculature of HCQ users were included. Primary outcomes were macular vessel density (VD) and foveal avascular zone (FAZ) at the superficial (SCP) and deep (DCP) capillary plexus. Meta-analysis was performed using a random-effects model. Results Of 211 screened abstracts, 13 were found eligible, enrolling 989 eyes from 778 patients. High-risk patients due to longer duration of treatment presented lower VD in the retinal microvasculature than those with low-risk in SCP (P = 0.02 in fovea; P = 0.004 in parafovea) and in DCP (P = 0.007 in fovea; P = 0.01 in parafovea). When compared with healthy controls, HCQ users had lower VD in both plexus-no quantitative synthesis was presented. Conclusions Microvascular changes were found in autoimmune patients under HCQ treatment without any documented retinopathy. However, the evidence produced so far does not allow to draw conclusion concerning the effect of drug as studies were not controlled for disease duration.