Fluorescence Lifetimes in Patients With Hydroxychloroquine Retinopathy

PURPOSE. To investigate fundus autofluorescence lifetime features in patients with hydroxychloroquine (HCQ) retinopathy, and to identify early markers of retinal alterations in patients due to HCQ. METHODS. Patients attending screening for HCQ retinopathy were imaged with a fluorescence lifetime imaging ophthalmoscope. Mean retinal fluorescence lifetimes (Tm) were obtained in a short spectral channel (SSC, 498-560 nm) and a long spectral channel (LSC, 560-720 nm). Screening modalities included fundus images, fundus autofluorescence intensity images (FAF), spectral-domain optical coherence tomography (SD-OCT), visual fields, and multifocal electroretinogram (mfERG). RESULTS. Forty-two eyes of 21 patients on HCQ therapy and 40 eyes of 20 healthy age-matched controls were included. Fourteen eyes of 7 patients with HCQ retinopathy (mean age, 66.1 [SD, 7.7] years) and 28 eyes of 14 patients (mean age, 46.1 [SD, 7.9] years) receiving HCQ without retinopathy were identified. Patients with HCQ retinopathy showed a parafoveal ring-shaped or oval area of prolonged mean fluorescence lifetimes. In these areas, mean (+/- SEM) lifetimes were 374 +/- 7 ps in the SSC, and on average 19.4% longer compared to the control group (P = 0.0001). Patients on HCQ without retinopathy had retinal fluorescence lifetimes that were similar to the control group. CONCLUSIONS. This study shows that HCQ retinopathy displays characteristic mean fluorescence lifetimes.