To investigate the possible association between serum uric acid levels, serum C-Reactive Protein (CRP), and age-related macular degeneration (ARMD). A total 232 patients of the eye department at Hospital Tuanku Ja'afar, Negeri Sembilan, Malaysia were recruited over 9 weeks. Participants were divided into ARMD (Non-Neovascular ARMD, and Neovascular ARMD) and control groups. 107 participants with non-neovascular ARMD, 6 with neovascular ARMD, and 119 controls participated in the study. The control patients had a similar average Serum Uric Acid level to the average of all patients with ARMD (P = 0.617).
BACKGROUND: Hydroxychloroquine (HCQ) is widely used for long-term treatment of autoimmune diseases such as rheumatoid arthritis. However, its long-term use is known to be associated with visual changes due to retinal damage. Retinal damage associated with long-term HCQ therapy is preventable if the drug is discontinued early when the patients are still asymptomatic. In view of contrasting reports from previous studies, we investigated the association of prolonged HCQ therapy with retinal thickness in macular area.
METHODS: This study included 48 patients on long-term HCQ therapy and 38 healthy controls. All subjects underwent examination for corrected visual acuity, fundus photography, visual fields and SD-OCT for retinal thickness.
RESULTS: Visual acuity, visual fields, fundus photography and SD-OCT did not reveal changes consistent with diagnosis of established HCQ retinopathy in any of the subjects from HCQ group. Retinal thickness in central, parafoveal and perifoveal areas did not show significant differences between HCQ and control groups. However, we observed negative correlation between cumulative dose and retinal thickness in the parafoveal (p = 0.003) and perifoveal areas (p = 0.019) but not in the central area.
CONCLUSIONS: Correlation of cumulative dose with retinal thickness in parafoveal and perifoveal areas and not the central area is in accordance with the late appearance of HCQ-induced bull's eye retinopathy. Hence screening of asymptomatic patients using OCT seems to be of great importance for early detection of retinal changes.
KEYWORDS: Cumulative dose; OCT; hydroxychloroquine; retinal thickness