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Bianca M. Maceo, David Borja, Derek Nankivil, Stephen Uhlhorn, Esdras Arrieta, Fabrice Manns, Arthur Ho, Robert C. Augusteyn, Jean-Marie Parel; Age-Related Changes in the Anterior and Posterior Surface Lens Curvatures during Simulated Accommodation in Hamadryas Baboons. Invest. Ophthalmol. Vis. Sci. 2011;52(14):3403. doi: https://doi.org/.
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© ARVO (1962-2015); The Authors (2016-present)
To compare changes in the anterior and posterior lens surface curvatures with age and accommodation in hamadryas baboon lenses.
Lens shape was measured during ex vivo simulated accommodation on 19 hamadryas (2.3-28 years) baboon lenses from 14 donors (PMT 22.4±13 hours). Tissue samples were mounted in a lens stretching system (Ehrmann et al, Clin Exp Opt, 2008) and stretched in a step-wise fashion (0.25mm/step up to 2.5mm radially). The lens cross-sectional profile was imaged at each step with a custom designed time-domain optical coherence tomography (OCT) system (Uhlhorn et al, Vis Res, 2008). The lens contours were extracted from the images and the central 6mm zone was fit with a conic section to determine the surface curvatures. The ratio of anterior to posterior lens curvature (Ca/Cp) was calculated for all lenses in the unstretched and stretched states and the dependence of the ratios with age and accommodation were quantified.
The average ratio for the young baboon lenses (2.3-8.3 years) was 1.05±0.14 in the unstretched state and 0.59±0.11 in the stretched state. When lenses were stretched (disaccommodated), the anterior surface of the young lenses flattened more than the posterior (p≤0.01). The average ratio for the old baboon lenses (21-28 years) was 0.63±0.15 in the unstretched state and 0.55±0.06 in the stretched state.
Young baboon lenses free of zonular tension are symmetric antero-posteriorly: the lens surface curvatures are roughly equal. With age and with accommodation, the lens becomes asymmetric with an anterior to posterior curvature ratio of approximately 0.6.Support: NIH Grant 2R01EY14225, 5F31EY15395; Australian Government CRC Scheme (Vision CRC); Florida Lions Eye Bank; NIH Center Grant P30EY14801; an unrestricted grant from Research to Prevent Blindness; Henri and Flore Lesieur Foundation (JMP).
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