The use of digital cameras in a mobile retinal screening environment

Aims To assess how successfully digital camera technology might be incorpor ated into a mobile screening environment. Methods One hundred and ninety-seven people had their fundi photographed us ing a Topcon/Imagenet digital system and 534 using a Canon CR5/Ris-Lite sys tem in addition to concurrent 45 degrees CP4NM Polaroid photography. One hu ndred and eighteen randomly selected patients were also sent for 7 field st ereo photography as a gold standard. An acceptability questionnaire was ans wered by a random sample of these photographed Results For the detection of any retinopathy, digital pictures had a sensit ivity of 0.74 (95% confidence interval (CI) 0.68-0.80) whilst Polaroid was 0.72 (95% CI 0.66-0.78) and for referable retinopathy digital pictures had a sensitivity of 0.85 (95% CI 0.80-0.90) and Polaroid was 0.90 (95% CI 0.86 -0.94). A concurrent ophthalmoscopic evaluation improved the sensitivity to 0.92 (95% CI 0.86-0.98) for detection of any retinopathy whilst the sensit ivity at the referral level was improved to 0.95 (95% CI 0.91-0.99). Twenty -nine of 176 respondents experienced flash discomfort with the Polaroid sys tem with only four of 154 describing 'some' discomfort from the digital sys tems which have a lower flash power (10 W vs. 300 W) and a faster recovery time. Conclusions This study indicates that digital systems are a feasible and ac ceptable alternative to Polaroid-based cameras for use in a mobile environm ent.