3 Home-based Visual Acuity tests validated for use as supplement to in-office tests

Although Visual Acuity is a key aspect of Ophthalmology, the options for at-home VA assessments were quite limited so far. In a recent study published in JAMA Opthalmology, 3 at-home visual acuity tests were validated by comparing them with in-office visual acuity measurements, the uses of which can be extended to teleophthalmology care.

Between July 2020 and April 2021, The participants who were eligible and who had a Visual Acuity of 20/200 or better were recruited from 4 university-based ophthalmology clinics (comprehensive, cornea, glaucoma, and retina clinics). Participants were prospectively randomized to self-administer 2 of 3 at-home VA tests which comprised of a printed chart, mobile phone app, and website within 3 days before their standard-of-care clinic visit. The participants were made to complete a survey that checked the utility of the at-home tests. At the clinic visit, the best-corrected Snellen distance acuity was measured as the reference standard.

When the Covid-19 pandemic was on the surge, eye care professionals were concerned about their exposure to patients while their concern to provide the best health care remained.

Published data regarding teleophthalmology during the pandemic is limited. However, a study looking at ophthalmology visits insured by Blue Cross Blue Shield of Michigan found a 4-fold increase in virtual visits when compared to baseline data from the first 3 months of the pandemic.

Telehealth technology is on a rise but the need to endure the maintenance of the quality of these virtual checks is crucial. A key factor in evaluating and treating patients during eye care visits is the VA measurement.

Of 218 randomized participants, 51.3% completed 2 of the 3 at-home tests and submitted results. The mean age of those completing the tests was 63.8 (13.0) years (range, 18-78). There was a relatively equal number of participants from the 4 clinics and no difference in rates of participation. There were no obvious differences between the participants who completed the tests vs those who did not, based on age, sex, clinic, zip code, or training time

There were 4 major findings in this study:

1. all 3 at-home self-administered VA tests were valid within 1 line of in-office Snellen acuity. These results were similar to other smartphone-based tests, including Peek Acuity, with a mean difference of −0.07 logMAR between the in-office ETDRS acuity and the Peek Acuity app administered in the clinic with staff guidance. The Home Acuity Test, an open-source VA screening test that was validated under home conditions, also performed similarly with a mean difference of −0.10 logMAR compared with the ETDRS logMAR chart in the clinic.

2. The printed chart had the smallest mean difference and greatest correlation compared with the in-office acuity measurement, although there was no statistically significant difference between the 3 tests. In this study, the mean difference between the University of Arizona printed chart and Snellen acuity was −0.07 logMAR, which was similar to the findings in Chen et al and Siktberg et al. This study is one of the first to test a mobile phone app and web-based test under home conditions.

3. Older participants in the study were more likely to be enrolled in the mail-only cohort compared with the randomized cohort, suggesting older participants may not have had adequate access to internet or iOS devices to qualify for randomization in this study. As many older patients may benefit from at-home acuity testing, access to technology for this group appeared to be a barrier for some patients.

Thus all 3 tests were found easy to use and the participants found future at-home testing quite interesting. However, the participants wanted the at-home tests to be used as a supplement to in-office tests and not as a replacement for them as reflected by their feedback.

Read the full article here: https://jamanetwork.com/journals/jamaophthalmology/fullarticle/2790590?utm_campaign=articlePDF&utm_medium=articlePDFlink&utm_source=articlePDF&utm_content=jamaophthalmol.2022.0396