This article is more than 5 years old. Information may no longer be current.
Threshold Amsler grid helps identify scotomas in patients taking hydroxychloroquine
Threshold Amsler grid testing may be beneficial for detecting shallow scotomas in patients taking hydroxychloroquine, according to a study. Standard Amsler grid screening was not as effective in detecting shallow scotomas or areas of depressed retinal activity secondary to drug toxicity, the study authors said.
A. Almony and colleagues at the Doheny Eye Institute in Los Angeles studied 56 patients with rheumatologic diseases who were taking hydroxychloroquine and 12 people not taking hydroxychloroquine. All subjects underwent standard Amsler grid, red Amsler grid and threshold Amsler grid screening.
No scotomas were observed in patients who had never been treated with hydroxychloroquine. Of those who had been treated with the drug, standard Amsler grid screening detected scotomas in two of the 56 patients. Six patients were identified by red Amsler grid testing, and 37 scotomas were identified by threshold Amsler grid testing. In addition, the average area of scotomas detected was larger with threshold testing than with the other two methods.
The study is published in the May issue of the British Journal of Ophthalmology.