The incidence of irreversible retinal toxicity in patients treated with hydroxychloroquine: a reappraisal.

PURPOSE

To define the risk of hydroxychloroquine (HCQ)-related retinal toxicity in patients with rheumatoid arthritis (RA) and systemic lupus erythematosus (SLE) who are receiving recommended dosages of the drug (< or =6.5 mg/kg/day).

DESIGN

Prospective cohort study, from 1985 to 2000.

PARTICIPANTS

Greek patients with RA (n = 335) and SLE (n = 191) treated with HCQ, 400 of whom had completed at least 6 years of treatment.

METHODS

Ophthalmologic evaluation was performed every 6 months from 1985 to 1995, and yearly thereafter. This consisted of best-corrected visual acuity, color vision testing, static central visual field testing, fundoscopy, electroretinography, and fluorescein angiography, when indicated.

MAIN OUTCOME MEASURES

Fundus lesions attributed to HCQ.

RESULTS

No HCQ retinal toxicity was noted in any of the 526 patients during the first 6 years of treatment. Two (3.4%) of the first 58 long-term (>6 years) treated patients developed HCQ-related maculopathy at 8 and 6.5 years of treatment, despite regular ophthalmologic evaluation. On follow-up 7 and 9 years after cessation of HCQ treatment, both patients had stable eye disease. No HCQ retinal toxicity was observed in the subsequent 342 patients who were treated for >6 years. Overall, the incidence of HCQ-related retinopathy in 400 patients who were treated with recommended dosages of the drug for a mean of 8.7 years was reduced to 0.5%.

CONCLUSIONS

After a baseline ophthalmic examination to confirm the absence of preexisting fundus pathology, patients with normal renal function may receive HCQ at a maximal daily dosage of 6.5 mg/kg and continue safely for 6 years. However, annual screening is recommended in patients who have taken the drug, even in recommended doses, for >6 years.