Oral fluorescein angiography in the diagnosis of paediatric optic nerve abnormalities

FFA is a well-established investigation for the diagnosis of optic nerve abnormalities, requiring an intravenous cannula and extended imaging acquisition time. Cannulation can present a challenge in paediatric patients and whilst oral FFA has been used for decades, it has been limited by imaging technology and unconfirmed image acquisition timings. For years, we have used a modern ultra-widefield retinal camera, and established imaging time-points to demonstrate dynamic optic nerve head changes upon ingestion of fluorescein and collected a database of oFFA images for various presentations.

Using an established protocol, optic nerve colour images were obtained, followed by oral administration of fluorescein dye. The optic nerves are then imaged at established intervals. An interpretation of oFFA tutorial was delivered to consultant ophthalmologists and trainees. Subsequently, these groups were assessed using a series of fifteen cases with the sensitivity and specificity of the test determined.

Our study presents a series of images and descriptions for common optic nerve abnormalities in paediatric populations. In the interpretation part of the study, overall sensitivity of 76.8% in the consultant group vs 63.3% in the combined consultant + trainees and specificity of 87.5% vs 68.4% in the combined group.

This is the first study that describes characteristic features of several common, and serious, optic nerve abnormalities specifically for oFFA interpretation in a paediatric population. It also highlights the rapid accumulation of oFFA interpretation skills in non-specialist consultant and trainee ophthalmologists such as to obtain a high diagnostic accuracy with high sensitivity and specificity.