Purchase this article with an account.
Renu V. Jivrajka, Mohamed A. Genead, J. Jason McAnany, Clement C. Chow, Gerald A. Fishman, William F. Mieler; Early Detection of Functional Changes Using Microperimetry on Patients with Subclinical Hydroxychloroquine Toxicity. Invest. Ophthalmol. Vis. Sci. 2012;53(14):971.
Download citation file:
© ARVO (1962-2015); The Authors (2016-present)
The currently accepted screening standards for hydroxycholoroquine (Plaquenil) toxicity include the 10-2 Humphrey visual field (HVF), spectral-domain optical coherence tomography (SD-OCT), fundus autofluorescence (FAF), and multifocal electroretinogram (mfERG). However, each technique has its own unique advantages and disadvantages and each of these methodologies may fail to identify toxicity in some patients. The purpose of this study was to determine if microperimetry could detect functional loss in patients on Plaquenil who did not have evidence of retinopathy as assessed by recommended screening standards.
Participants included eleven patients being treated with 200 or 400 mg/day of Plaquenil for more than 5 years, without visual complaints (visual acuity 20/25 or better), and without a history of diabetes or macular disease. These patients underwent a complete ophthalmic examination that included medical history, best-corrected visual acuity, slit lamp biomicroscopy, funduscopic exam, color vision, SD-OCT, 10-2 HVF, FAF, mfERG, and microperimetry that cover the central 12o centered on the fovea.
The average age of the study cohort was of 55 years (SD = 11). The average total cumulative Plaquenil dose and average daily dose were 1,377 ± 1200 grams and 4.1 ± 1.67 mg/kg/day, respectively. All patients had normal anterior segment and funduscopic exams, full HVFs, and normal FAF. The median retinal sensitivity, as assessed by microperimetery, was 15.3 dB (OD) and 14.4 dB (OS). Given that median sensitivity of the two eyes did not differ significantly (Mann-Whitney Rank Sum Test, p = 0.22), the sensitivity data from the left and right eyes were averaged and compared to the sensitivity values of 32 visually normal subjects. The median sensitivity of the patients (15.5 dB) was significantly lower (Mann-Whitney Rank Sum Test, p < 0.001) than that of the visually normal subjects (17.0 dB).
Plaquenil patients without clinical evidence of retinal toxicity showed reduced retinal sensitivity within the central 12o of the macula, as assessed by microperimetry, suggestive of early functional loss. The sensitivity differences between the patients and controls, while small, suggest that microperimetry may be an additional useful technique for identifying Plaquenil toxicity.
This PDF is available to Subscribers Only