A Johns Hopkins Study

A paper from Dr. David Friedman’s team at Wilmer Eye Institute at Johns Hopkins that was published examined whether the refractive error measured with the SVOne wavefront aberrometer is repeatable and comparable with the Topcon KR-800S, a standard autorefractor, in a community screening setting in an elderly population. Topcon is a company highly regarded in ophthalmology that makes many ophthalmic equipment, which is trusted to be accurate and reproducible.

Background: The Sample Population

Johns Hopkins Study Sample

Results of the Study

Graph of Results of JHU Study

The investigators found that, when compared to the Topcon autorefractor, the SVOne “has a near perfect agreement for spherical equivalency (M) and a weaker, but still good correlation between astigmatic measurements of both devices (J0 and J45). Similar results were discovered for the repeatability between two SVOne trials.” J0 and J45 measure cylinder power. The cylinder power component of a spectacle prescription is an indication of the amount of astigmatism in an eye. The investigators concluded: “The SVOne may be useful for quickly and easily identifying elderly individuals with refraction errors in resource-poor settings that may benefit from spectacle correction.” William Plum, Varshini Varadaraj, Niccolo Dosto, Sean Thompson, Prateek Gajwani and David Friedman MD, John Hopkins University Medical School, “Evaluation of a handheld, smartphone-based wave front aberrometer for community screening refraction in an elderly”,  Opotm Vis Sci. 2021