LAUSR

Hydroxychloroquine (HCQ) has long been associated with a low prevalence (0.5%) of retinal toxicity with possible irreversible sight loss. New retinal imaging techniques have suggested a significantly increased prevalence of HCQ retinopathy (7.5%). In light of this result, the American Academy of Ophthalmology (AAO) in 2016 and subsequently the Royal College of Ophthalmologists (RCO) in 2018 produced new screening guidelines. We report the HCQ retinopathy screening results for all patients referred to our Ophthalmology department from 1/11/2017 to date. We collected prospective data from all patients referred for HCQ screening. Patients were screened according to the new RCO guidelines. We recorded each patient's dose and duration of HCQ treatment, their weight and renal function, and concurrent use of tamoxifen to determine their risk factors. Retinal images: colour fundal photos, ocular coherence tomography (OCT) and auto-fluorescence (AF), were performed on all patients (baseline tests), and visual acuity, automated central visual field testing (Humphrey 10:2) and multi focal electroretinography (mfERG) performed as indicated for those at risk, needing annual testing. We have diagnosed two definite cases of hydroxychloroquine retinopathy, giving us a prevalence of 2/639 (0.31%) of all screened, and 2/308 (0.64%) of those considered to be at risk according to RCO guidelines. 711 patients have been referred to our screening service so far. 639 of these have been screened with 72 failing to attend. 308 of all those screened have been categorised to be at increased risk of retinopathy: duration of treatment >5 years (224), dose > 5mg/kg/day (40), eGFR< 60ml/min/1.73m2 (111) and use of tamoxifen (0). 64 have multiple risk factors. 119 of those screened have completed their second cycle of screening, with 48 patients failing to attend for this repeat screening. Our results for HCQ retinopathy screening suggest a prevalence more in keeping with the originally proposed figure than that in the recent literature; this may be multifactorial. We have a smaller number of patients, with fewer of those patients in the higher risk categories than in the study that prompted the change in screening guidelines. We only have baseline or two years of serial images for each patient at present, the comparison of multiple serial images may highlight more cases of retinopathy. More data is needed before we can suggest our figures are statistically different. A. Gobbett None. J. Smith None. C. Bracewell None.