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Age-related changes in human ciliary muscle and lens: a magnetic resonance imaging study.
Invest Ophthalmol Vis Sci. 1999 May; 40(6):1162-9.IO

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.

Authors+Show Affiliations

Department of Surgery (Bioengineering), UMDNJ-Robert Wood Johnson Medical School, New Brunswick, New Jersey, USA.No affiliation info availableNo affiliation info availableNo affiliation info availableNo affiliation info availableNo affiliation info available

Pub Type(s)

Journal Article
Research Support, U.S. Gov't, P.H.S.

Language

eng

PubMed ID

10235549

Citation

Strenk, S A., et al. "Age-related Changes in Human Ciliary Muscle and Lens: a Magnetic Resonance Imaging Study." Investigative Ophthalmology & Visual Science, vol. 40, no. 6, 1999, pp. 1162-9.
Strenk SA, Semmlow JL, Strenk LM, et al. Age-related changes in human ciliary muscle and lens: a magnetic resonance imaging study. Invest Ophthalmol Vis Sci. 1999;40(6):1162-9.
Strenk, S. A., Semmlow, J. L., Strenk, L. M., Munoz, P., Gronlund-Jacob, J., & DeMarco, J. K. (1999). Age-related changes in human ciliary muscle and lens: a magnetic resonance imaging study. Investigative Ophthalmology & Visual Science, 40(6), 1162-9.
Strenk SA, et al. Age-related Changes in Human Ciliary Muscle and Lens: a Magnetic Resonance Imaging Study. Invest Ophthalmol Vis Sci. 1999;40(6):1162-9. PubMed PMID: 10235549.
* Article titles in AMA citation format should be in sentence-case
TY - JOUR T1 - Age-related changes in human ciliary muscle and lens: a magnetic resonance imaging study. AU - Strenk,S A, AU - Semmlow,J L, AU - Strenk,L M, AU - Munoz,P, AU - Gronlund-Jacob,J, AU - DeMarco,J K, PY - 1999/5/11/pubmed PY - 1999/5/11/medline PY - 1999/5/11/entrez SP - 1162 EP - 9 JF - Investigative ophthalmology & visual science JO - Invest. Ophthalmol. Vis. Sci. VL - 40 IS - 6 N2 - 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. SN - 0146-0404 UR - https://www.unboundmedicine.com/medline/citation/10235549/Age_related_changes_in_human_ciliary_muscle_and_lens:_a_magnetic_resonance_imaging_study_ L2 - https://iovs.arvojournals.org/article.aspx?volume=40&issue=6&page=1162 DB - PRIME DP - Unbound Medicine ER -