Differences in the accommodation stimulus response curves of adult myopes and emmetropes: a summary and update

Abstract

This paper has been often cited as evidence that accommodation responses at near may be primarily reduced in adults with progressing myopia and not in stable myopes and/or that challenging accommodation stimuli (negative lenses with monocular viewing) are required to generate larger accommodation errors. As an analogy, animals reared with hyperopic errors develop axial elongation and myopia. Retinal defocus signals are presumably passed to the retinal pigment epithelium and choroid and then ultimately the sclera to modify eye length. A number of lens treatments that act to slow myopia progression may partially work through reducing accommodation errors.

Low-dose (0.01%) atropine eye-drops to reduce progression of myopia in children: a multicentre placebo-controlled randomised trial in the UK (CHAMP-UK)—study protocol

“…[19] However, an accommodative effect cannot be ruled out in humans. [20] We will study the effect of atropine on the lens and ciliary muscle by measuring the anterior chamber depth with laser biometry and assessing changes in ciliary muscle using anteriorsegment optical coherence tomography (OCT).…”

Effect of apparent depth cues on accommodation in a Badal optometer

“…The refractive error (F 1, 28 = 0.86, p = 0.36) and the interaction ‘Configuration*RefractiveError’ were not statistically significant (F 3, 84 = 0.35, p = 0.79). While it has been suggested that accommodative inaccuracies associated with myopia may be better analysed in terms of age of onset (early‐onset or late‐onset) or progression (stable or progressing), these results indicate that under the conditions of the study myopes accommodated similarly to emmetropes …”

Effect of Experimental Conditions in the Accommodation Response in Myopia

“…Our study aimed to determine how the experimental conditions may affect (or interact with) the accommodative response. 18 It is likely that the rate of myopia progression 3,11 (which was unknown in this study) might have biased the differences among refractive error groups. In addition, given that late onset myopes were in our study an average of 3.00 D less myopic than early onset myopes and that subjects with low myopia (less than |1.00| D) often use correction only for certain activities (e.g., driving), we speculate that the relationship between the magnitude of the refractive error and whether subjects wore correction during all day or just during some specific activities might have also been a confounding factor in our results.…”

“…The accommodative response may be affected by all the previously mentioned experimental conditions, but also by the observer's refractive error. A large number of studies have attempted to disentangle the possible effect of refractive status in accommodative response (see Schmid and Strang 18 for a recent review). Some studies concluded that myopes accommodate significantly different than emmetropes [1][2][3][4]7,9,13,15 while others did not find a clear association between accommodation and refractive error.…”