Preferential hyperacuity perimetry to detect hydroxychloroquine retinal toxicity

Purpose: To determine if Preferential Hyperacuity Perimetry (PHP) testing can detect the presence of retinal toxicity due to hydroxychloroquine (HCQ) or chloroquine administration. Methods: Fifteen patients were divided into three groups. Five patients had confirmed HCQ or chloroquine toxicity, five patients had suspected HCQ toxicity, and five patients had history of long-term use of HCQ or chloroquine but no evidence of toxicity. All patients underwent PHP testing. Results: All patients with either known or suspected toxicity based upon standardized visual field testing and/or fluorescein angiography demonstrated significant hyperacuity defects on PHP testing. None of the patients on long-term HCQ therapy, without clinical suspicion of toxicity, demonstrated a PHP hyperacuity defect. Conclusion: Results of this pilot study with patients with known or suspected HCQ or chloroquine toxicity suggest that PHP may be a useful adjunct for testing of patients suspicious for toxicity due to these medications. Further testing is warranted.