Diabetic retinopathy screening: can the viewing monitor influence the reading and grading outcomes.

Purpose: To evaluate the accuracy of different viewing monitors for image reading and grading of diabetic retinopathy (DR).

Design: Single-centre, experimental case series-evaluation of reading devices for DR screening.

Method: A total of 100 sets of three-field (optic disc, macula, and temporal views) colour retinal still images (50 normal and 50 with DR) captured by FF 450 plus (Carl Zeiss) were interpreted on 27-inch iMac, 15-inch MacBook Pro, and 9.7-inch iPad. All images were interpreted by a retinal specialist and a medical officer. We calculated the sensitivity and specificity of 15-inch MacBook Pro and 9.7-inch iPad in detection of DR signs and grades with reference to the reading outcomes obtained using a 27-inch iMac reading monitor.

Results: In detection of any grade of DR, the 15-inch MacBook Pro had sensitivity and specificity of 96% (95% confidence interval (CI): 85.1-99.3) and 96% (95% CI: 85.1-99.3), respectively, for retinal specialist and 91.5% (95% CI: 78.7-97.2) and 94.3% (95% CI: 83.3-98.5), respectively, for medical officer, whereas for 9.7-inch iPad, they were 91.8% (95% CI: 79.5-97.4) and 94.1% (95% CI: 82.8-98.5), respectively, for retinal specialist and 91.3% (95% CI: 78.3-97.1) and 92.6% (95% CI: 81.3-97.6), respectively, for medical officer.

Conclusion: The 15-inch MacBook Pro and 9.7-inch iPad had excellent sensitivity and specificity in detecting DR and hence, both screen sizes can be utilized to effectively interpret colour retinal still images for DR remotely in a routine, mobile or tele-ophthalmology setting. Future studies could explore the use of more economical devices with smaller viewing resolutions to reduce cost implementation of DR screening services.