Printed vision chart accurately measures visual acuity at home
A printed vision chart can be used at home to measure visual acuity by ophthalmology outpatients with a number of different conditions, according to a study in JAMA Ophthalmology.
The Home Acuity Test (HAT) has the potential to measure visual acuity who do not have access to digital testing.
The diagnostic study included 50 control participants and 100 adult ophthalmology outpatients who reported subjectively stable vision and were attending routine telemedicine clinics.
The mean (SD) test-retest difference in the HAT line score was −0.012 (0.06) logMAR, with limits of agreement (LOA) between −0.13 and 0.10 logMAR for participants in the control group. In these patients, the mean (SD) difference in visual acuity compared with conventional vision charts was −0.14 (0.14) logMAR (range, −0.4 to 0.18 log MAR) (−7 letters), with LOA of −0.41 to 0.12 logMAR (−20 to 6 letters).
The mean (SD) difference in visual acuity was −0.10 (0.17) logMAR (range, −0.5 to 0.3 logMAR) (1 line on a conventional logMAR sight chart) for participants in the ophthalmology outpatients’ group. Worse visual acuity was found using the HAT than in previous in-person tests. LOA were −0.44 to 0.23 logMAR (−22 to 12 letters).
Agreement was good for ophthalmology outpatients and control participants in the visual impairment category.
Crossland MD, Dekker TM, Hancox J, et al. Evaluation of a home-printable vision screening test for telemedicine. JAMA Ophthalmol. Published online January 07, 2021. doi:10.1001/jamaophthalmol.2020.5972