Abstract
Purpose :
Intravenous fluorescein angiography (IV FA) is considered the gold standard in visualizing retinal vasculature. However, the complications of injection combined with potentially adverse side effects limit more widespread use in general practice. In the past, oral fluorescein angiography (OFA) has been examined as a potential alternative, but poor image quality and late phase only angiography were limiting factors. Recent advancements in modern laser based fundus photography systems have the potential to increase the clinical usefulness of OFA.
Methods :
Retrospective analysis of 25 patients that received OFA was conducted. Age range: 25-91 years. Weight range: 150-330 lbs. Exclusions: pregnant or breast feeding patients and those with phenylketonuria or soy allergy. Patients were dilated with 1% tropicamide. After obtaining informed consent, weight and blood pressure readings, patients were given the option of sugar free liquid versus capsular formulations of sodium fluorescein (NaF), at a dose of 25-30 mg/kg, based on previous literature. After NaF, patients were photographed via ultra-wide field laser scanning ophthalmoscope (UWF-SLO) every 2 min for 30 min.
Results :
Time from ingestion to first observable fluorescein ranged from 2-12 min. Eighty five percent of the patients showed observable fluorescence at 8 min, with a max at 15-22 min. Choroidal flush was not observed in OFA. Early, mid and late phases were observed in 90% of patients. Capsular formulation increased time in all phases. Patients weighing over 250 lbs showed decreased contrast on angiogram. There were no allergic reactions. Most common complaint was temporary dysgeusia.
Conclusions :
OFA is a simple and effective alternative to IV FA. Longer transit times allow for bilateral panning UWF-SLO photos to be obtained by even a novice photographer. Costs are similar but OFA does not require a nurse or physician for administration. Elimination of needles, infectious waste and potential for injury, along with painless administration and low incidence of allergic reaction make OFA appealing. To our knowledge this is the first time a sugar free mix has been used for OFA. While variations in contrast relative to weight need optimization, this preliminary study demonstrates that OFA is a good in office diagnostic tool and has potential to be used as a screening tool.
This is an abstract that was submitted for the 2017 ARVO Annual Meeting, held in Baltimore, MD, May 7-11, 2017.