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

Authors: Andrei-Alexandru Szigiato  , Sandeep Singh, Margaret Mills, Kimberly Baynes, Sumit Sharma, Careen Lowder, Peter Kaiser, Sunil Srivastava.  Cole Eye Institute, Cleveland Clinic.

Author Disclosures: A. Szigiato:   None.  S. Singh:   None.  M. Mills:   None.  K. Baynes:   None.  S. Sharma:    Any direct financial payments including receipt of honoraria; Name of for-profit or not-for-profit organization(s); Genentech/Roche, Abbvie, Clearside, Bausch, Eyepoint, RegenxBio. Funded grants or Clinical Trials; Name of for-profit or not-for-profit organization(s); Allergan, Genentech/Roche, Gilead, IONIS, Santen.  C. Lowder:   None.  P. Kaiser:    Any direct financial payments including receipt of honoraria; Name of for-profit or not-for-profit organization(s); Aerie, Aerpio, Allegro, Allergan, Bayer, Biogen, Boehringer Ingelheim, Clearside, Eyevensys, Formycon, Galecto, Galimedix, Genentech, Glaukos, iRenix, Iveric Bio, jCyte, Kala, Kang-hong, Kodiak, Novartis, Omeros, Oxurion, Regeneron, RegenxBio, Retinal Sciences, Santen, Stealth, Verana.  S. Srivastava:    Any direct financial payments including receipt of honoraria; Name of for-profit or not-for-profit organization(s); Bausch, Allergan, Abbvie, Novartis, Eyepoint, iCyte, Adverum, Zeiss. Funded grants or Clinical Trials; Name of for-profit or not-for-profit organization(s); Allergan, Regeneron, Novartis, Eyepoint.

Abstract Body: 

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 (250mg) sodium fluorescein (10%) was adopted instead of the full dose (500mg) at the Cleveland Clinic. In this paper, we compare the image quality, clinical utility, and the side effect profile of half-dose vs full-dose fluorescein in UWFA for a cohort of stable patients.   

Study Design:   Retrospective chart review. This study followed the principles outlined in the Declaration of Helsinki and was approved by the hospital IRB.   

Methods:   Patients with retinal vascular disease were included in the study if they received a half-dose and full-dose UWFA (Optos, Dunfermline, UK) within 6 months at the Cole Eye Institute. Eyes were excluded if they received intraocular injections, laser procedures, recent immunosuppression, and worsened or improved uveitis based on clinical examination. Healthy fellow eyes were included as controls. Quantitative assessment of image quality was performed by measuring vascular segmentation metrics using a machine-learning enhanced automated segmentation platform. Automated scores were compared from late phase UWFA images 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 and compared between groups.   

Results:   There were 56 eyes of 39 patients included for analysis, 43 (77%) uveitic, 5 (9%) diabetic, 4 (7%) normal controls, 4 (7%) with other diagnoses. Patients had no change to their visual acuity (LogMAR mean 0.31±0.61), anterior chamber cell and vitreous cell between visits. Automated segmentation analysis showed mildly increased vessel intensity in the full dose vs half dose images (8.4±2.3% vs 7.5±1.7%, p=0.02, mean±SD). UWFA images were deemed to be of equal quality and leakage in the macula, mid periphery and periphery by both masked reviewers (p>0.05). Side effects following UWFA were nausea (half (n=3, 8%) vs full (n=2, 6%), p=0.69) and urticaria (n=0, 0% vs n=1, 3%, p=0.99) and were not different between groups.   

Conclusions:   In this cohort of patients, half dose UWFA produced images that were of similar quality, clinical utility and with a similar side effect profile compared to full dose. Half dose UWFA can be used to accurately assess the retinal vasculature and could be used primarily as a method to save cost and prevent waste.