Imaging Characteristics and Clinical Utility of Half vs Full Dose Ultra-Widefield Fluorescein Angiography

Abstract

Purpose : In the spring of 2022, a nationwide fluorescein shortage occurred, limiting the supply and requiring a rationing of fluorescein. To meet the standard of care for patients who required ultra-wide fluorescein angiography (UWFA), a regimen of half dose (HD, 250mg) sodium fluorescein (10%) was adopted instead of the full dose (FD, 500mg) at the Cleveland Clinic. In this paper, we compare the image quality, clinical utility, and the side effect profile of HD vs FD fluorescein in UWFA for a cohort of stable patients.

Methods : A retrospective cohort study was conducted. Patients with retinal vascular disease were included in the study if they received a HD and FD UWFA (Optos 200Tx, Dunfermline, UK) within 6 months at the Cleveland Clinic. Eyes were excluded if they received intraocular procedures, recent immunosuppression, and worsened/improved uveitis on clinical exam. Healthy fellow eyes were included as controls. Quantitative assessment of vascular leakage was performed using a machine-learning enhanced automated segmentation platform. Leakage from late-phase UWFA images was compared between HD and FD 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.

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 (LogMAR mean 0.3±0.6), anterior chamber cell and vitreous cell between UFWA’s. Automated leakage analysis showed mildly increased leakage in HD images in the macula (1.5% vs 0.6%, p=0.01) and periphery (3.6% vs 2.4%, p=0.006). UWFA images were deemed of equal quality and leakage by both masked reviewers (p>0.05). Increased background signal was attributed to manual adjustment of exposure during image acquisition, and did not impact clinical interpretation of the images (Figure 1). Side effects included nausea (HD (n=3, 9%) vs FD (n=2, 6%), p=0.69) and urticaria (n=0, 0% vs n=1, 2%, p=0.99) and were not different between doses.

Conclusions : In this cohort, we could not detect a difference in quality, clinical utility and side effect profile between HD and FD UWFA. HD UWFA can be used to accurately assess the retinal vasculature with lower cost and less waste.

This abstract was presented at the 2023 ARVO Annual Meeting, held in New Orleans, LA, April 23-27, 2023.

 

Full (A) and half (B) dose UWFA in a patient with stable retinal vasculitis.