Dynamic retinoscopy is a good option to measure accommodative amplitude in lieu of the subjective push-up technique, a study in Optometry and Vision Science suggests.

Researchers from Texas compared measurements of open-field autorefraction and modified dynamic retinoscopy for accommodative amplitude and found the agreement between them was less than two diopters with no systematic bias.

The study measured accommodation using two objective techniques on 95 patients. Investigators measured monocular accommodative amplitude with subjects viewing printed letters 0.9mm in height with their dominant eye and distance refraction. For the retinoscopy, subjects held a near rod and viewed the target at the closest point of clear vision. The examiners then performed dynamic retinoscopy along the horizontal meridian and identified the physical location of neutrality of the reflex, which was converted to accommodative amplitude in diopters.

The researchers performed autorefraction and obtained repeated measures beginning from a target demand of 2.5D and increasing in discrete steps until there was no subsequent increase in accommodative response. Investigators also measured distance over-refractions for both techniques to adjust accommodative amplitude for any uncorrected refractive error.

The study reported the overall difference was 0.02 ± 0.97D, with limits of agreement spanning -1.87D to 1.92D. Additionally, the investigators observed no significant linear relationship between the magnitude of the accommodative amplitude and the differences between techniques.