title: Early effect of hydroxychloroquine therapy: relationship between cumulative dose and retinal thickness.
abstract: 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.
authors: Department of Ophthalmology, International Medical University , Jalan Rasah, Seremban , Malaysia .
authors: Puneet
authors: P
authors: Agarwal
authors: Yuk Hei
authors: YH
authors: Wong
authors: Esha
authors: E
authors: Dasgupta
authors: Renu
authors: R
authors: Agarwal
authors: Bethel Indira
authors: BI
authors: Livingstone
authors: Srinivasan
authors: S
authors: Ramamurthy
authors: Gun Suk
authors: GS
authors: Chyn
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D018501:Antirheumatic Agents / Q000008:administration & dosage / Q000627:therapeutic use*; D016022:Case-Control Studies; D004305:Dose-Response Relationship, Drug; D005260:Female; D006801:Humans; D006886:Hydroxychloroquine / Q000008:administration & dosage / Q000627:therapeutic use*; D008297:Male; D008875:Middle Aged; D010349:Patient Compliance; D012160:Retina / Q000187:drug effects* / Q000473:pathology; D012216:Rheumatic Diseases / Q000188:drug therapy / Q000503:physiopathology; D041623:Tomography, Optical Coherence; D014792:Visual Acuity; D055815:Young Adult
chemical_list: D018501:Antirheumatic Agents; D006886:Hydroxychloroquine
keywords: Cumulative dose; OCT; hydroxychloroquine; retinal thickness