In vivo study of changes in refractive index distribution in the human crystalline lens with age and accommodation
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Description
PURPOSE: Magnetic resonance imaging (MRI) was used to map the refractive index distribution in human eye lenses in vivo and to investigate changes with age and accommodation.---- METHODS: Whole-eye MR images were obtained for sagittal and transverse axial planes in one eye each of 15 young (19–29 years) and 15 older (60–70 years) subjects when viewing a far (6 m) target and at individual near points in the young subjects. Refractive index maps of the crystalline lens were calculated by using a procedure previously validated in vitro.---- RESULTS: A central high refractive index plateau region and sharp decline in refractive index at the periphery were seen in all three groups. The peripheral decline was steepest in the older lenses and least steep in the young accommodated lenses. Average lens thickness increased (+0.27 mm; P < 0.05) and equatorial diameter decreased (–0.35 mm; P < 0.05) with accommodation. Axial thickness (+0.96 mm; P < 0.05) and equatorial diameter (+0.28 mm; P < 0.05) increased with age. The central index (1.409 ± 0.008) did not differ between groups. The axial thickness of the central plateau increased with age (+0.83 mm; P < 0.05) but not significantly with accommodation. The equatorial diameter of the central plateau increased with age (+0.56 mm; P < 0.01) and decreased with accommodation (–0.43 mm; P < 0.05).---- CONCLUSIONS. The refractive index of the central plateau region does not change significantly with accommodation or ageing, but its size increases with age and the peripheral decline in refractive index becomes steeper in older lenses.
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ID Code: | 20183 | ||||
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Item Type: | Contribution to Journal (Journal Article) | ||||
Refereed: | Yes | ||||
ORCID iD: |
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Measurements or Duration: | 10 pages | ||||
Keywords: | Accommodation, Age-related Changes, Crystalline Lens, MRI, Refractive Index | ||||
DOI: | 10.1167/iovs.07-1443 | ||||
ISSN: | 0146-0404 | ||||
Pure ID: | 33628227 | ||||
Divisions: | Past > QUT Faculties & Divisions > Faculty of Health Past > QUT Faculties & Divisions > Faculty of Science and Technology Past > Institutes > Institute of Health and Biomedical Innovation Current > Schools > School of Optometry & Vision Science |
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Copyright Owner: | Consult author(s) regarding copyright matters | ||||
Copyright Statement: | This work is covered by copyright. Unless the document is being made available under a Creative Commons Licence, you must assume that re-use is limited to personal use and that permission from the copyright owner must be obtained for all other uses. If the document is available under a Creative Commons License (or other specified license) then refer to the Licence for details of permitted re-use. It is a condition of access that users recognise and abide by the legal requirements associated with these rights. If you believe that this work infringes copyright please provide details by email to qut.copyright@qut.edu.au | ||||
Deposited On: | 28 Apr 2009 05:21 | ||||
Last Modified: | 03 Jun 2024 11:58 |
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