Dynamic stimulation of accommodation

Abstract

We describe the analysis of accommodation using wavefront measurements in phakic and pseudophakic eyes. Accommodation measurements were performed in phakic and pseudophakic eyes using a dynamic stimulation aberrometry (DSA) device (Optana) as an attachment to the WASCA aberrometer (Carl Zeiss Meditec AG). Aberrations were measured for distance fixation (3.0 m) and near fixation (0.3 to 0.11 m) presenting different accommodative stimuli (3.0 to 9.0 diopters). The device was able to detect changes in aberrations using near and distance stimulation. Eyes with phakic iris-fixated intraocular lenses (IOLs) showed normal age-correlated accommodation. In pseudophakic eyes, accommodation varied depending on the IOL. With monofocal IOLs (eg, MA60AC, Alcon), there was no accommodation; with an accommodating IOL (eg, Synchrony, Visiogen), there was a low level of accommodation. The DSA device is capable of measuring accommodation using wavefront data. It will help to further analyze changes in accommodation-related wavefront aberrations.

Does astigmatism alter with cycloplegia?

“… 21 , 22 Such a change may be attributed to the several factors such as sectorial differences in the ciliary body, lens, or zonula, external pressures from the lids or extraocular muscles, and crystalline lens tilt changes. 21 , 23 During the dry autorefraction procedure, the accommodation is active, whereas it is inactive in cycloplegic refraction. As the accommodation can be a source of astigmatism in the eye, the absence of it may affect cylindrical power of the eye proportional to non-cycloplegic status.…”