Relaxographic studies of aging normal human lenses

Frederick A. Bettelheim, Martin J. Lizak, J. Samuel Zigler

Research output: Contribution to journalArticle

Abstract

Ten excised normal human lenses of various ages were studied. Seven sections of each lens, from anterior outer cortex to posterior outer cortex were imaged and the T1 (spin-lattice) and T2 (spin-spin) relaxation data on each section were collected. T1 and T2 relaxation were analysed by fitting pixel intensity to one term exponential expressions. Both T1 and T2 relaxation times showed minimal values in the nuclear region and maxima at the two outer cortexes. The pre-exponential terms of the fittings of both T1 and T2 relaxation, M1 and M2, were normalized in order to eliminate instrumental variations over a 2 year period. M2 had a maximum in the nucleus and minima in the two cortexes. M1 exhibited minimal value in the nucleus and maxima at the two cortexes. The positional dependence of T2 relaxation times as well as that of M2 indicated that they represent the behavior of the bound water in the lens. The positional dependence of M1 suggests that this relaxation represents the total water that has a minimal value in the nucleus. The T2 relaxation time decreases with increase in the age of the lens at each location. The slope of the change in T2 relaxation time with age is greatest in the outer cortexes and diminishes as one proceeds to the nucleus. T1 relaxation times and M1 do not show significant change with age. This and the age dependence of the other relaxographic parameters imply that the aging of the lens involves major changes in its hydration properties that are more accentuated in the cortexes. The interpretation of these changes is in agreement with the syneretic theory of lens aging.

Original languageEnglish (US)
Pages (from-to)695-702
Number of pages8
JournalExperimental eye research
Volume75
Issue number6
DOIs
StatePublished - Jan 1 2002

Keywords

  • Human lens
  • Hydration
  • Relaxographic imaging
  • T and T relaxation

ASJC Scopus subject areas

  • Ophthalmology
  • Sensory Systems
  • Cellular and Molecular Neuroscience

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  • Cite this

    Bettelheim, F. A., Lizak, M. J., & Zigler, J. S. (2002). Relaxographic studies of aging normal human lenses. Experimental eye research, 75(6), 695-702. https://doi.org/10.1006/exer.2002.2056