CHICAGO – Hydroxychloroquine-related ocular toxicity is rare, but does occur and should be considered in any treated patient complaining of blurred vision, Dr. Alvin Wells said at the symposium.
He described a case involving a 21-year-old woman who was referred for rash and color changes of her hands and feet. She had a weakly positive antinuclear antibody (ANA) titer, and there was concern about possible lupus.
The patient's chief complaint was redness of the face in the presence of cold fingers and toes.
On physical examination she was found to have significant mild erythematous rash on the face and chest, and mild Raynaud's changes of the digits without ulceration or loss of digital pulp. Her laboratory study findings were completely normal except for an ANA titer of 1:640.
The patient was started on hydroxychloroquine at a standard dose of 200 mg twice daily along with 10 mg nifedipine every Monday, Wednesday, and Friday nights. A follow-up visit was scheduled for 8 weeks, but within 10 days she called in complaining of headaches and blurred vision.
Although ocular toxicity is more common with chloroquine, it does occur with hydroxychloroquine as well, and the effect is dose dependent, said Dr. Wells, who is director of the rheumatology and immunotherapy center at Duke University Medical Center in Durham, N.C.
Risk increases with doses greater than 6.5 mg/kg. This patient, who weighed only 110 lbs, was receiving a dose of about 8 mg/kg, he said.
The risk is also increased in those with higher body mass index and those with diabetes.
Affected patients may present with corneal deposits, and retinopathy may also occur. Blurred vision is the most common complaint, and examination of the macula will reveal a “bull's eye maculopathy,” Dr. Wells said.
The effects are reversible upon discontinuation of the drug in 95% of cases, he noted.
Affected patients should have a baseline evaluation within 1 year (and preferably within 6 months), and if it is normal, they should be evaluated yearly thereafter, he recommended.
Dr. Wells reported that he has received consulting fees or other remuneration from Abbott, Amgen, Bristol-Myers Squibb, Genentech, Pfizer, and UCB.