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Accommodation and presbyopia in the human eye. Changes in the anterior segment and crystalline lens with focus.
Invest Ophthalmol Vis Sci. 1997 Mar; 38(3):569-78.IO

Abstract

PURPOSE

To characterize changes in the sagittal dimensions of the human crystalline lens and anterior segment as a function of accommodation, to determine the potential age dependence of these changes, and to evaluate these changes in relation to the development of presbyopia.

METHODS

Scheimpflug slit-lamp photography, as well as a variety of standard ophthalmologic methods, was used to collect information about lens and anterior segment sagital dimensions in a population of 82 adults with refractive error < or = magnitude of 2.0 diopters and at least 0.25 diopter of accommodation for subjects 18 to 70 years of age. Data were analyzed statistically for dependence on accommodation, age, and age dependence of accommodative rate.

RESULTS

The rate of change per diopter of accommodation for each measured variable within the lens is independent of age for the entire adult age range. With increasing accommodation, the lens becomes thicker and the anterior chamber shallower along the polar axis. This increase in sagittal lens thickness is entirely because of an increase in the thickness of the lens nucleus. Because the anterior and posterior halves of the nucleus increase in thickness at approximately the same rate with accommodation, the increase in lens thickness results from equal changes in the lengths of the anterior and posterior portions.

CONCLUSIONS

Because changes along the sagittal axis of the anterior segment with accommodation are independent of age, any explanation of presbyopia that relies on simple changes in the rates of lens thickening and anterior chamber shallowing with age does not hold. In light of other age-related changes in the anterior segment and lens (e.g., increased sharpness of lens curvature, increased lens sagittal thickness, decreased anterior chamber depth), it appears that compensatory mechanisms to preserve far vision with age also preserve the rate of change per diopter of sagittal spacings.

Authors+Show Affiliations

Center for Biophysics, Rensselaer Polytechnic Institute, Troy, New York 12180-3590, USA.No affiliation info availableNo affiliation info available

Pub Type(s)

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

Language

eng

PubMed ID

9071209

Citation

Koretz, J F., et al. "Accommodation and Presbyopia in the Human Eye. Changes in the Anterior Segment and Crystalline Lens With Focus." Investigative Ophthalmology & Visual Science, vol. 38, no. 3, 1997, pp. 569-78.
Koretz JF, Cook CA, Kaufman PL. Accommodation and presbyopia in the human eye. Changes in the anterior segment and crystalline lens with focus. Invest Ophthalmol Vis Sci. 1997;38(3):569-78.
Koretz, J. F., Cook, C. A., & Kaufman, P. L. (1997). Accommodation and presbyopia in the human eye. Changes in the anterior segment and crystalline lens with focus. Investigative Ophthalmology & Visual Science, 38(3), 569-78.
Koretz JF, Cook CA, Kaufman PL. Accommodation and Presbyopia in the Human Eye. Changes in the Anterior Segment and Crystalline Lens With Focus. Invest Ophthalmol Vis Sci. 1997;38(3):569-78. PubMed PMID: 9071209.
* Article titles in AMA citation format should be in sentence-case
TY - JOUR T1 - Accommodation and presbyopia in the human eye. Changes in the anterior segment and crystalline lens with focus. AU - Koretz,J F, AU - Cook,C A, AU - Kaufman,P L, PY - 1997/3/1/pubmed PY - 1997/3/1/medline PY - 1997/3/1/entrez SP - 569 EP - 78 JF - Investigative ophthalmology & visual science JO - Invest. Ophthalmol. Vis. Sci. VL - 38 IS - 3 N2 - PURPOSE: To characterize changes in the sagittal dimensions of the human crystalline lens and anterior segment as a function of accommodation, to determine the potential age dependence of these changes, and to evaluate these changes in relation to the development of presbyopia. METHODS: Scheimpflug slit-lamp photography, as well as a variety of standard ophthalmologic methods, was used to collect information about lens and anterior segment sagital dimensions in a population of 82 adults with refractive error < or = magnitude of 2.0 diopters and at least 0.25 diopter of accommodation for subjects 18 to 70 years of age. Data were analyzed statistically for dependence on accommodation, age, and age dependence of accommodative rate. RESULTS: The rate of change per diopter of accommodation for each measured variable within the lens is independent of age for the entire adult age range. With increasing accommodation, the lens becomes thicker and the anterior chamber shallower along the polar axis. This increase in sagittal lens thickness is entirely because of an increase in the thickness of the lens nucleus. Because the anterior and posterior halves of the nucleus increase in thickness at approximately the same rate with accommodation, the increase in lens thickness results from equal changes in the lengths of the anterior and posterior portions. CONCLUSIONS: Because changes along the sagittal axis of the anterior segment with accommodation are independent of age, any explanation of presbyopia that relies on simple changes in the rates of lens thickening and anterior chamber shallowing with age does not hold. In light of other age-related changes in the anterior segment and lens (e.g., increased sharpness of lens curvature, increased lens sagittal thickness, decreased anterior chamber depth), it appears that compensatory mechanisms to preserve far vision with age also preserve the rate of change per diopter of sagittal spacings. SN - 0146-0404 UR - https://www.unboundmedicine.com/medline/citation/9071209/Accommodation_and_presbyopia_in_the_human_eye__Changes_in_the_anterior_segment_and_crystalline_lens_with_focus_ L2 - https://iovs.arvojournals.org/article.aspx?volume=38&amp;issue=3&amp;page=569 DB - PRIME DP - Unbound Medicine ER -