Tele-Ophthalmology for Retinal Health Surveillance in Denmark.

In this commentary paper, we discuss the potential of population health surveillance of retinal health in Denmark using optometrist-based opportunist retinal examination with tele-ophthalmology pathway. Using 12 months of data from 79 high-street optometrist stores, we imaged 355,818 unique individuals, which corresponds to 5.99% of the entire population of Denmark and equates to an average of 29,652 individuals each month, corresponding to 0.50% of the population. Coverage was highest among those aged 41-80 years, with coverage rates of between 8.17% and 8.68%. We also observed higher participation rates in female individuals (6.77%) than in male individuals (5.19%). Using Wilson score intervals with finite-population correction, we demonstrate that when such a large sample of the entire population is examined, prevalence estimates can be obtained with very narrow 95% confidence intervals. These results suggest that community imaging can provide stable, near real-time indicators of retinal disease at the population level. Selection bias is discussed to understand the limitations of data.