Advanced imaging for the diagnosis of age-related macular degeneration: a case vignettes study

The aim of this study is to evaluate the diagnosis, staging, imaging and management preferences, and the effect of advanced imaging among practising optometrists in age-related macular degeneration (AMD).

Up to 20 case vignettes (computer-based case simulations) were completed online in a computer laboratory in random order by 81 practising optometrists of Australia. Each case presented findings from a randomly selected patient seen previously at the Centre for Eye Health for a macular assessment in the following order: case history, preliminary tests and colour fundus photography. Participants were prompted to provide their diagnosis, management and imaging preference. One additional imaging result (either modified fundus photographs and infrared images, fundus autofluorescence, or optical coherence tomography [OCT]) was then provided and the questions repeated. Finally, all imaging results were provided and the questions repeated a third time.

A total of 1,436 responses were analysed. The presence of macular pathology in AMD was accurately detected in 94 per cent of instances. The overall diagnostic accuracy of AMD was 61 per cent using colour fundus photography. This improved by one per cent using one additional imaging modality and a further four per cent using all imaging. Across all responses, a greater improvement in the diagnostic accuracy of AMD occurred following the presentation of OCT findings (versus other modalities). OCT was the most preferred imaging modality for AMD, while multimodal imaging was of greatest benefit in cases more often misdiagnosed using colour fundus photography alone. Overall, the cohort also displayed a tendency to underestimate disease severity.

Despite reports that imaging technologies improve the stratification of AMD, our findings suggest that this effect may be small when applied among practising optometrists without additional or specific training.