Accommodation mitigation in reverse Shack-Hartmann refraction measurement
Abstract
Purpose : Accommodation is one of the most prevalent impediments of accurate refraction measurements. As accommodation is part of the eye refraction, measurements are often incapable of discerning between the eye accommodation state and the refraction error of an eye. A method to control accommodation during a refraction measurement is required. The desired method would not require cycloplegia and could be implemented anywhere.
Methods : A low-cost, handheld, self-administered refraction measurement prototype device based on the reverse Shack-Hartman technology with accommodation mitigation was developed. The device has two optical channels per eye that are optically overlaid on the retina. An accommodation mitigation channel with a 30° field of view and large depth of focus presents a 3D stereoscopic visual stimulus during the test. A measurement channel implements the reverse Shack-Hartman technology.
An exploratory, single-center, open-label study in healthy volunteers was conducted to compare this device with an autorefractor. 21 subjects between the ages of 18 and 30 are included in the analysis. Each subject underwent 3 autorefractor measurements and 3 measurements on the device. Average refraction numbers were calculated for each device. Double blind BCVA measurements using trial lenses were conducted by an optometrist using ETDRS charts.
Conclusions : The performance of the new device is substantially equivalent to the autorefractor. The expected cost of the device is to be orders of magnitude less than that of the autorefractor. Furthermore, the device is handheld and simple to use. Therefore, it is an accurate alternative to traditional refraction measurements. It provides users with an ability to perform accurate, self-administered refraction measurements conveniently at home.
This is a 2021 ARVO Annual Meeting abstract.