May 1999
Volume 40, Issue 6
Free
Articles  |   May 1999
Age-related changes in human ciliary muscle and lens: a magnetic resonance imaging study.
Author Affiliations
  • S A Strenk
    Department of Surgery (Bioengineering), UMDNJ-Robert Wood Johnson Medical School, New Brunswick, New Jersey, USA.
  • J L Semmlow
    Department of Surgery (Bioengineering), UMDNJ-Robert Wood Johnson Medical School, New Brunswick, New Jersey, USA.
  • L M Strenk
    Department of Surgery (Bioengineering), UMDNJ-Robert Wood Johnson Medical School, New Brunswick, New Jersey, USA.
  • P Munoz
    Department of Surgery (Bioengineering), UMDNJ-Robert Wood Johnson Medical School, New Brunswick, New Jersey, USA.
  • J Gronlund-Jacob
    Department of Surgery (Bioengineering), UMDNJ-Robert Wood Johnson Medical School, New Brunswick, New Jersey, USA.
  • J K DeMarco
    Department of Surgery (Bioengineering), UMDNJ-Robert Wood Johnson Medical School, New Brunswick, New Jersey, USA.
Investigative Ophthalmology & Visual Science May 1999, Vol.40, 1162-1169. doi:
  • Views
  • PDF
  • Share
  • Tools
    • Alerts
      ×
      This feature is available to authenticated users only.
      Sign In or Create an Account ×
    • Get Citation

      S A Strenk, J L Semmlow, L M Strenk, P Munoz, J Gronlund-Jacob, J K DeMarco; Age-related changes in human ciliary muscle and lens: a magnetic resonance imaging study.. Invest. Ophthalmol. Vis. Sci. 1999;40(6):1162-1169.

      Download citation file:


      © ARVO (1962-2015); The Authors (2016-present)

      ×
  • Supplements
Abstract

PURPOSE: To use high-resolution magnetic resonance (MR) images of the eye to directly measure the relationship between ciliary muscle contraction and lens response with advancing age. METHODS: A General Electric, 1.5-Tesla MR imager and a custom-designed eye imaging coil were used to collect high-resolution MR images from 25 subjects, 22 through 83 years of age. A nonmagnetic binocular stimulus apparatus was used to induce both relaxed accommodation (0.1 diopter [D]) and strong accommodative effort (8.0 D). Measurements of the ciliary muscle ring diameter (based on the inner apex), lens equatorial diameter, and lens thickness were derived from the MR images. RESULTS: Muscle contraction is present in all subjects and reduces only slightly with advancing age. A decrease in the diameter of the unaccommodated ciliary muscle ring was highly correlated with advancing age. Lens equatorial diameter does not correlate with age for either accommodative state. Although unaccommodated lens thickness (i.e., lens minor axis length) increases with age, the thickness of the lens under accommodative effort is only modestly age-dependent. CONCLUSIONS: Ciliary muscle contractile activity remains active in all subjects. A decrease in the unaccommodated ciliary muscle diameter, along with the previously noted increase in lens thickness (the "lens paradox"), demonstrates the greatest correlation with advancing age. These results support the theory that presbyopia is actually the loss in ability to disaccommodate due to increases in lens thickness, the inward movement of the ciliary ring, or both.

×
×

This PDF is available to Subscribers Only

Sign in or purchase a subscription to access this content. ×

You must be signed into an individual account to use this feature.

×