The Utility of a Smartphone-Based Retinal Imaging Device as a Screening Tool in an Outpatient Clinic Setting
Authors: Ajay Mittal, BS; Victor Sanchez, BA; Keer Zhang; Siva Iyer, MD; Mark Sherwood, MD
University of Florida
Purpose: Smartphone-based retinal screening has the potential to provide low-cost, scaleable ophthalmic care in under-resourced areas. Within primary care clinics, telemedical ophthalmoscopy use could confer benefits in triaging who needs further eye care. This study aims to test its ability to record the optic nerve and assess the potential of utilizing a smartphone ophthalmoscope, D-EYE, as a screening tool for glaucoma.
Methods: Over 150 enrolled participants were surveyed and had a 30-second video recording of their non-dilated eyes captured using D-EYE. A preliminary data set of 20 participants, 15 healthy and 5 glaucomatous, was graded independently by 2 resident ophthalmologists. Another dataset of 114 participants, 105 healthy and 9 glaucomatous, was graded by 4 other residents using the best-captured frames from the 30-second videos to determine whether still-images alone could provide a comparable result as the full video. The grading criteria for both data sets included ability to visualize the optic nerve, subjective clarity measurements, cup-to-disc ratios, and likelihood of reporting patients for additional care.
Results: In the 20 participants video-only dataset, the optic nerve could be visualized in 93% of cases for healthy eyes and 80% of cases for glaucomatous eyes with high inter-rater reliability (IRR: 1.0). Mean reported cup-to-disc ratios was .29 for healthy participants (kappa=0.441) and .58 for those with +dx (kappa=0.167). Likelihood of reporting participants for additional care (graded on a scale of 1-5) was 2.36 in healthy and 4.18 for +dx (kappa= 0.611). Difference was statistically significant (p<.001). In the 114 participants still image-only dataset, the optic nerve was visualized in 76% of samples on average. Mean likelihood of referral by residents was poor at 1.8 for glaucoma and 2.13 for non-glaucoma (combined kappa= 0.15). This larger data set is being reanalyzed using the full video samples for efficiency comparison.
Conclusions: Current analysis indicates that the D-EYE may be useful for glaucoma screening. The data suggests a notable difference in the quality of data captured and referral recommendation between best still-images and the full 30-second video.