Imaging Characteristics and Clinical Utility of Half-Dose versus Full-Dose Ultrawidefield Fundus Fluorescein Angiography

Abstract

PurposeIn early 2022, a fluorescein shortage occurred in the United States. To meet the standard of care for patients who required ultra-wide fundus fluorescein angiography (UWFFA), a regimen of half-dose (250mg) sodium fluorescein (10%) was adopted instead of the full-dose (500mg) at the Cole Eye Institute (CEI). In this paper, we compare the image quality, clinical utility, and the side effect profile of half-dose vs full-dose fluorescein in UWFFA for a cohort of stable patients. DesignRetrospective chart review. Subjects, Participants, and/or ControlsPatients with retinal vascular disease were included if they received half-dose and full-dose UWFFA (Optos California, Dunfermline, UK) within 6 months at the CEI. Eyes were excluded if they received intraocular injections, laser procedures, new immunosuppression, and worsened or improved inflammation on clinical examination. Methods, Intervention, or TestingQuantitative assessment of vascular leakage was performed using a machine-learning enhanced automated segmentation platform. Leakage from late-phase UWFFA images was compared between half-dose and full-dose images. Qualitative assessment of image quality and relative vascular leakage was performed by 2 masked independent reviewers. Side effects after fluorescein administration were recorded for each patient. Main Outcome MeasuresMasked leakage grading and automated leakage scores. ResultsThere were 52 eyes of 35 patients, 42 (81%) uveitic, 5 (9%) diabetic, and 4 (8%) normal controls. Patients had no change to their visual acuity (LogMAR mean 0.3±0.6), anterior chamber and vitreous cell between UFFWA’s. UWFFA images were deemed of equal quality and leakage by both masked reviewers (78-87% agreement, kappa 0.642). Automated leakage analysis showed mildly increased leakage in half-dose images overall (3.8% vs 2.8%, p=0.01), and in the macula (1.5% vs 0.6%, p=0.01). Side effects included nausea (half (n=3, 9%) vs full (n=2, 6%), p=0.69) and urticaria (n=0, 0% vs n=1, 2%, p=0.99) and were not different between doses. ConclusionsIn this cohort, half dose UWFFA produced images that were of similar quality, clinical utility and with a similar side effect profile compared to full dose. Half dose UWFFA can be used to accurately assess the retinal vasculature and could be used primarily as a method to save cost and prevent waste.