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

Purpose: In early 2022, a fluorescein shortage occurred in the United States. To meet the standard of care for patients who required ultrawidefield fundus fluorescein angiography (UWFFA), a regimen of half-dose (250 mg) sodium fluorescein (10%) was adopted instead of the full dose (500 mg) at the Cole Eye Institute (CEI). In this paper, we compare the image quality, clinical utility, and the side-effect profile of half-dose versus full-dose fluorescein in UWFFA for a cohort of stable patients. Participants: Patients with retinal vascular disease were included if they received half-dose and full-dose UWFFA (Optos California) 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: Quantitative 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 Measures: Masked leakage grading and automated leakage scores. Results: There 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 (logarithm of the minimum angle of resolution 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; K, 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 = Conclusions: In this cohort, half-dose UWFFA produced images that were of similar quality, clinical utility and with a similar side effect profile compared with 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. Financial Disclosure(s): Proprietary or commercial disclosure may be found in the Footnotes and Disclosures at the end of this article. Ophthalmology Retina 2024;8:981-986 (c) 2024 Published by Elsevier Inc. on behalf