The effect of ageing on in vivo human ciliary muscle morphology and contractility

Abstract

Purpose. To assess the effect of ageing on in vivo human ciliary muscle morphology and contractility during accommodation. Methods. Seventy-nine subjects, aged 19–70 years were recruited. High-resolution images were acquired of nasal and temporal ciliary muscle in the relaxed state, and at stimulus vergence levels of -4 and -8 D, using anterior segment optical coherence tomography (AS-OCT). Objective refractions and axial lengths were also recorded. Linear regression analysis was performed to determine the effect of age on nasal and temporal ciliary muscle morphologic characteristics. Results. Ciliary muscle anterior length decreased significantly with age both nasally (R = 0.461, P = 0.001) and temporally (R = 0.619, P < 0.001) in emmetropic eyes. In a subset of 37 participants, ciliary muscle maximum width increased significantly with age, by 2.8 µm/year nasally (R = 0.54, P < 0.001) and 3.0 µm/year temporally (R = 0.44, P = 0.007), while the distance from the inner apex of the ciliary muscle to the scleral spur decreased significantly with age on both the nasal and temporal aspects (R = 0.47; P = 0.004 and R = 0.43; P = 0.009, respectively). During accommodation, changes to ciliary muscle thickness and length remained constant throughout life. Conclusions. The human ciliary muscle undergoes age-dependent changes in morphology that suggest an antero-inwards displacement of muscle mass, particularly in emmetropic eyes. However, the morphologic changes observed appear not to affect the ability of the muscle to contract during accommodation, even in established presbyopes, thus supporting a lenticular model of presbyopia development.

Publication DOI: https://doi.org/10.1167/iovs.10-6447
Divisions: Life & Health Sciences > Ophthalmic Research Group
Life & Health Sciences > Vision, Hearing and Language
Life & Health Sciences
Life & Health Sciences > Optometry
Additional Information: Creative Commons Attribution Non-Commercial No Derivatives
Uncontrolled Keywords: ocular accommodation,adult,aged,aging,eye axial length,biometry,ciliary body,emmetropia,female,humans,male,middle aged,muscle contraction,smooth muscle,presbyopia,ocular refraction,optical coherence tomography,young adults,Ophthalmology,Sensory Systems,Cellular and Molecular Neuroscience
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Related URLs: http://www.scop ... tnerID=8YFLogxK (Scopus URL)
PURE Output Type: Article
Published Date: 2011-03-28
Published Online Date: 2010-11-11
Authors: Sheppard, Amy ( 0000-0003-0035-8267)
Davies, Leon N. ( 0000-0002-1554-0566)

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