Temperature affects the biomechanical response of in vitro non-human primate lenses during lens stretching

Bianca Maceo Heilman; Heather Durkee; Cornelius J Rowaan; Esdras Arrieta; Shawn P Kelly; Klaus Ehrmann; Fabrice Manns; Jean-Marie Parel

doi:10.1016/j.exer.2022.108951

Temperature affects the biomechanical response of in vitro non-human primate lenses during lens stretching

Exp Eye Res. 2022 Mar:216:108951. doi: 10.1016/j.exer.2022.108951. Epub 2022 Jan 17.

Authors

Bianca Maceo Heilman¹, Heather Durkee¹, Cornelius J Rowaan², Esdras Arrieta², Shawn P Kelly¹, Klaus Ehrmann³, Fabrice Manns¹, Jean-Marie Parel⁴

Affiliations

¹ Ophthalmic Biophysics Center, Bascom Palmer Eye Institute, University of Miami Miller Medical School, Miami, FL, USA; Department of Biomedical Engineering, University of Miami College of Engineering, Coral Gables, FL, USA.
² Ophthalmic Biophysics Center, Bascom Palmer Eye Institute, University of Miami Miller Medical School, Miami, FL, USA.
³ School of Optometry and Vision Science, University of New South Wales, Sydney, NSW, Australia.
⁴ Ophthalmic Biophysics Center, Bascom Palmer Eye Institute, University of Miami Miller Medical School, Miami, FL, USA; Department of Biomedical Engineering, University of Miami College of Engineering, Coral Gables, FL, USA; School of Optometry and Vision Science, University of New South Wales, Sydney, NSW, Australia. Electronic address: jmparel@med.miami.edu.

PMID: 35051430
DOI: 10.1016/j.exer.2022.108951

Abstract

Purpose: To determine the effect of temperature on the accommodative response of non-human primate crystalline lenses during simulated accommodation.

Methods: Eight lenses from 7 cynomolgus monkeys (Macaca fascicularis, ages: 4.5-7.3 years; post-mortem time: 17.0 ± 16.4 h) were mounted in a lens stretcher. Stretching experiments were performed on each lens at 24 °C (room temperature), then the tissue was warmed to 35 °C (intraocular temperature) and the stretching experiments were repeated. The lens diameter, thickness, anterior and posterior surface radii of curvature, optical power, and the stretching force (load) were measured at each stretch position and the linear optomechanical relationships were quantified: load-lens diameter, load-thickness, power-load, load-anterior radius, and load-posterior radius. The rate of change for each parameter was quantified by performing a linear regression. The slopes of the linear regressions were compared at the two temperatures using a paired sample t-test.

Results: The average changes in the lens with stretching at 24 °C and 35 °C were: 3.07 ± 0.17 and 2.58 ± 0.15 for load-lens diameter (g/mm), -2.38 ± 0.20 and -2.00 ± 0.32 for load-thickness (g/mm), -13.35 ± 1.21 and -13.75 ± 1.26 for power-load (D/g), 0.41 ± 0.10 and 0.34 ± 0.05 for load-anterior radius of curvature (g/mm), and 1.35 ± 0.24 and 1.31 ± 0.35 for load-posterior radius of curvature (g/mm), respectively. The changes in load-diameter and load-thickness with lens stretching were significantly different for the two temperatures.

Conclusions: Temperature influences the change in lens shape observed during simulated accommodation in non-human primate lenses. These results suggest that lens stretching experiments and other optomechanical measurement techniques on ex vivo crystalline lenses be conducted at 35 °C and that the temperature of the tissue sample be documented and maintained constant to ensure repeatability.

Keywords: Accommodation; Crystalline lens; Temperature.

Publication types

Research Support, N.I.H., Extramural
Research Support, Non-U.S. Gov't

MeSH terms

Accommodation, Ocular / physiology*
Aging / physiology
Animals
Biomechanical Phenomena / physiology
Body Temperature / physiology*
Lens, Crystalline / diagnostic imaging
Lens, Crystalline / physiology*
Macaca fascicularis
Stress, Mechanical*
Temperature*
Tomography, Optical Coherence

Abstract

Publication types

MeSH terms

Grants and funding