Abstract
Purpose :
Vision loss is a leading complaint among survivors of Ebola Virus Disease. Vision screening tools are needed that can be implemented in cross-cultural settings by technicians with minimal previous health care training. The PREVAIL III Ebola Survivor Study is a 5-year longitudinal study of the medical effects of Ebola Virus Disease (EVD) on survivors sponsored by the US National Institute for Allergy and Infectious Disease and the Liberian Ministry of Health and Social Welfare. We report the practical application of the smartphone-based Peek visual acuity assessment tool in Monteserrado County, Liberia among Ebola survivors and close contacts participating in the study.
Methods :
Non-ophthalmic health care workers were trained to use the Peek Vision Beta application, which presents the tumbling E in ETDRS character sizes. The Moto G smartphone, which contains a 4.5-inch screen and 1280 x 720 pixel resolution, was calibrated for use at 2.4 meters based on the visual angle of ETDRS character size. Visual acuity of each eye was independently tested using an occluder and results documented. 81.4% of survivors and 84.2% of controls failed visual acuity threshold of 20/25 or reported eye complaints and received a second, uncorrected distance visual acuity testing by an ophthalmic technician in a standardized examination lane using a tumbling E chart. Results were categorized as a binary outcome, either “good”(better than 20/40) or “not good” (20/40 or worse visual acuity).
Results :
Of 1092 total eyes examined by both eye technicians and health care workers, vision in was categorized as “not good” in 154 eyes (14.1%) by health care workers and in 103 eyes (9.4%) by eye technicians. Sensitivity for identification of “not good” vision was 73.7% and specificity for “good” vision was 92.1%.
Conclusions :
Health care workers without ophthalmic experience can perform smartphone visual acuity screening. Additional analyses will explore ideal screening cutoffs. These results are significant for capacity building in regions with limited ophthalmic personnel or facilities for both research and clinical care delivery.
This is an abstract that was submitted for the 2016 ARVO Annual Meeting, held in Seattle, Wash., May 1-5, 2016.