Abstract
Purpose::
Retinal toxicity from hydroxychloroquine, though rare, remains a problem with long-term usage of the medication. Early recognition, prior to permanent visual loss remains difficult. Previous publications have indicated hyperacuity may be altered in patients with hydroxychloroquine toxicity. However, an accurate instrument to measure such alterations has not been available. We attempted to determine if Preferential Hyperacuity Perimeter-Foresee PHP, (Notal Vision, Israel) can identify patients with known hydroxychloroquine macular toxicity.
Methods::
Six patients were evaluated under an IRB approved protocol at Lahey Clinic. Three patients had confirmed hydroxychloroquine toxicity based upon clinical examination, visual field (VF) testing and fluorescein angiography (FA) demonstrating a bull’s eye pattern (Group A). Two patients had possible toxicity based upon depressed central field on VF testing, but no evidence of bull’s eye pattern on exam or FA (Group B). One patient had no evidence of hydroxychloroquine toxicity, but had been on the medication for 12 years (Group C). All patients underwent PHP testing.
Results::
All patients in Group A demonstrated significant hyperacuity defect on PHP visual field testing. One of the patients in Group B demonstrated a similar pattern while the second patient was normal. The patient in Group C did not demonstrate a visual field defect on PHP.
Conclusions::
PHP was successful in identifying all patients with known toxicity. It was also able to detect scotoma in one patient with possible toxicity, but without bull’s eye pattern on flourescein angiography. PHP may be particularly valuable as a screening tool as it is highly resistant to image degradation and suitable for assessing retinal function in patients with increasing opaque media- a common problem with screening of patients on hydroxychloroquine. PHP may be a valuable device in recognizing early toxicity prior to the development of irreversible field loss. Further study is warranted.
Keywords: drug toxicity/drug effects • detection • retina