Evaluation of an indirect ophthalmoscopy digital photographic system as a retinopathy of prematurity screening tool.

PURPOSE: To determine whether digital retinal images obtained from an indirect ophthalmoscopy imaging system (Keeler) can be accurately graded for clinically significant retinopathy of prematurity (ROP) by masked experts.

METHODS

The medical records of infants screened for ROP who had posterior pole images acquired using the Keeler system during routine ROP examinations were retrospectively reviewed. Two reviewers, masked to patient demographics and clinical examination findings, graded the images for: (1) quality (good, fair, poor); (2) number of gradable quadrants, from 0 to 4; and (3) posterior pole disease (none, pre-plus, plus). The accuracy of grading Keeler images for clinically significant ROP (defined as pre-plus or plus disease) was compared to results of clinical examination.

RESULTS

One eye each of 253 infants was included. The mean postmenstrual age at examination was 35 weeks (range, 30-42). Grader 1 found the quality of 94% of images to be fair or good; grader 2, 83% of images. Grader 1 judged 87% of images to have ≥3 gradable quadrants; grader 2, 77% of images. The sensitivity and specificity of grading pre-plus or worse disease on Keeler images were 100% and 86%, respectively, for grader 1, and 94% and 89%, respectively, for grader 2.

CONCLUSIONS

Digital retinal images obtained by the Keeler system can be read with high sensitivity and specificity to screen for clinically important ROP. The Keeler system may be a valuable tool for ROP screening at remote locations (ie, via telemedicine).