The optical coherence tomography angiography findings of rheumatoid arthritis patients taking hydroxychloroquine

Abstract

Purpose: The aim of this study is to measure retinal vessel density and thickness of the macula by optical coherence tomography angiography in patients with rheumatoid arthritis taking hydroxychloroquine. Methods: The study included 40 patients with rheumatoid arthritis taking hydroxychloroquine and 20 age-, gender-, and axial length-matched control subjects. Patients were divided into two groups according to the duration of hydroxychloroquine use. Twenty four of the patients were taking hydroxychloroquine for more than 5 years (Group 1), and the rest of 16 were taking hydroxychloroquine for less than 5 years (Group 2). A total of 20 age- and gender-matched volunteers with similar axial length were selected as Group 3. All of the patients underwent optical coherence tomography angiography, and 3 mm × 3 mm scanning mode was chosen for analyzing vascular density and morphological characteristics on the choriocapillaris layer. In addition, Humphrey visual field 10–2 was evaluated in each subject. Results: The temporal deep vascular density was measured as 48.13% ± 8.5% in Group 1, 54.42% ± 10.3% in Group 2, and 60.35% ± 13.1% in Group 3. Deep temporal and deep hemi-inferior vascular density was significantly lower in Group 1 in comparison with Group 3 (p = 0.041 and p = 0.046, respectively). Visual field testing was normal in all patients. Conclusion: The optical coherence tomography angiography findings showed that the parafoveal deep temporal and deep hemi-inferior vascular plexus density was reduced in patients taking hydroxychloroquine for more than 5 years despite having normal perimetry. This observation, which can be obtained only through optical coherence tomography angiography, may be relevant to the early findings of hydroxychloroquine toxicity.