Abstract Background/Aims Hydroxychloroquine (HCQ), a frequently-used therapy in rheumatology, can be associated with retinal toxicity. More stringent screening and monitoring guidelines for HCQ-related retinopathy were published by the Royal College of Ophthalmologists (RCOphth) in 2018. Recommendations include: 1) baseline retinal screening within six-twelve months of commencing HCQ; 2) subsequent annual monitoring for at-risk patients, specifically: concurrent tamoxifen-use, estimated glomerular filtration rate (eGFR) <60ml/min/1.73m2, HCQ dose >5mg/kg/day; 3) annual monitoring for all other patients after five years continuous treatment; 4) patient education on HCQ retinopathy. We quantified the rheumatology HCQ exposure and estimated burden on ophthalmology, to inform the development of HCQ retinal screening services. Methods Cross-sectional data were extracted for patients established on HCQ between 1995-2020 including: weight; eGFR; concomitant retino-toxic medication; concomitant retinal pathology; HCQ dose and duration; documentation of patient education on retinal side-effects. Documentation of relevant ophthalmic testing at baseline (i.e. at time of starting HCQ) were recorded, specifically colour fundus photography, spectral domain optical coherence tomography (SD-OCT) and 10-2 Humphrey visual field (HVF) testing as necessary. Subsequent monitoring with 10-2 HVFs, SD-OCT, autofluorescence (AF) and electrodiagnostic tests (EDTs) as appropriate annually from baseline and from 5 years was recorded. Results 150 patients were included, 84% female, with a mean baseline age of 50.7 years (SD 14.8) and mean weight of 76.4kg (SD 17.6). 63% were on HCQ >5 years (mean duration 7.0 years, SD 5.1). At time of auditing, 50% (75/150) patients had permanently ceased HCQ (62% due to treatment >5 years). 60% patients had documented evidence of education regarding HCQ retinopathy. Of the 150 patients, 39% had baseline risks for retinopathy. 6% had a baseline eGFR <60ml/min/1.73m2. 32% were commenced on HCQ dose greater than 5mg/kg/day. No patients were on concomitant tamoxifen; one patient was on a known retino-toxic drug (quinine). 4% of patients had pre-existing retinal pathology. Of the 75 patients still taking HCQ at time of auditing, 27 (36%) had baseline risk factors warranting yearly retinal screening and 44 (58%) had been on treatment >5years. Most ophthalmology reviews were put on hold until a screening service was established. Of the small number (5.3%) that had baseline ophthalmic screening, 12.5% had colour photography and 75% had SD-OCT. No patients required HVF testing or EDTs. Annual screening revealed 50% of patients had 10-2 HVFs; 75% had SD-OCT; 75% had AF. Only one patient developed maculopathy, not attributed to HCQ. Conclusion Our results demonstrate the need for service development to facilitate adherence to RCOphth guidance. Up to 40% of patients started on HCQ have baseline risks for retinopathy, most due to dosing >5mg/kg/day warranting yearly screening. Our findings will inform development of a rheumatology HCQ retinal screening pathway and services, to ensure safe long-term use of HCQ. Disclosure C. Lee*: None. M. Dey*: None. M. Hng: None. S. Peterson: None. I. Rahiman: None. M. Elshafei: None. C. Estrach: None. N.J. Goodson: None.