Comparing a Home Vision Self-Assessment Test to Office-Based Snellen Visual Acuity

Abstract

Purpose

To evaluate the agreement of a home vision screening test compared to standard in-office technician-measured Snellen visual acuity to allow for remote screening and triaging of patients.

Patients and Methods

In this prospective study, English-speaking patients with in-office ophthalmology appointments from May to August 2020 and visual acuity better than 20/125 were asked to complete a home vision test one week before their scheduled in-office appointment. The home vision test was a modified ETDRS chart displayed in a PDF document that could be printed or viewed on a monitor. The primary outcome was the mean difference between office-based and home visual acuity.

Results

Eighty-two eyes of 45 patients were included in the study with 45 study eyes analyzed. The mean difference between office-based and home visual acuity was −0.02 logMAR (SD 0.15, P=0.28) among study eyes. Of these eyes, 91% demonstrated agreement between the two methods within 0.2 logMAR of the mean difference, and 60% had agreement within 0.1 logMAR of the mean difference. There were no significant demographic or ocular risk factors leading to a greater difference between the tests.

Conclusion

There was good agreement between the home and in-office Snellen tests for patients with vision better than 20/125. The home vision test can be used to remotely determine if there is a significant vision change of >0.2 logMAR or approximately 2 lines of visual acuity.

Keywords:

• telemedicine
• tele-ophthalmology
• home vision test
• vision screening

Acknowledgment

We thank Joseph Miller, MD, MPH and his team at the University of Arizona for developing and providing access to the home vision PDF. We thank Benjamin Arnold, PhD (UCSF) for guidance on statistical analysis.

Disclosure

Dr Julie M Schallhorn reports personal fees from Zeiss, Allergan, Vanda, and Long Bridge Medical, outside the submitted work. The authors report no other conflicts of interest in this work.

Additional information

Funding

This work was supported in part by the following grants: National Institutes of Health [NEI K12EY031372]; Research to Prevent Blindness unrestricted grant and National Institutes of Health [NIH-NEI P30 EY002162 – Core Grant for Vision Research]. The sponsors or funding organizations had no role in the design or conduct of this research.