June 2020
Volume 61, Issue 7
Open Access
ARVO Annual Meeting Abstract  |   June 2020
Effect of inter-individual variations in ocular parameters on optical and mechanical accommodation efficiency
Author Affiliations & Notes
  • Fabrice Manns
    Ophthalmic Biophysics Center, Bascom Palmer Eye Institute, University of Miami Miller School of Medicine, Miami, Florida, United States
    Department of Biomedical Engineering, University of Miami College of Engineering, Coral Gables, Florida, United States
  • Heather Ann Durkee
    Ophthalmic Biophysics Center, Bascom Palmer Eye Institute, University of Miami Miller School of Medicine, Miami, Florida, United States
    Department of Biomedical Engineering, University of Miami College of Engineering, Coral Gables, Florida, United States
  • Yu-Cherng Chang
    Ophthalmic Biophysics Center, Bascom Palmer Eye Institute, University of Miami Miller School of Medicine, Miami, Florida, United States
    Department of Biomedical Engineering, University of Miami College of Engineering, Coral Gables, Florida, United States
  • Gabrielle Monterano Mesquita
    Ophthalmic Biophysics Center, Bascom Palmer Eye Institute, University of Miami Miller School of Medicine, Miami, Florida, United States
    Department of Biomedical Engineering, University of Miami College of Engineering, Coral Gables, Florida, United States
  • Siobhan Williams
    Ophthalmic Biophysics Center, Bascom Palmer Eye Institute, University of Miami Miller School of Medicine, Miami, Florida, United States
    Department of Biomedical Engineering, University of Miami College of Engineering, Coral Gables, Florida, United States
  • Florence Cabot
    Ophthalmic Biophysics Center, Bascom Palmer Eye Institute, University of Miami Miller School of Medicine, Miami, Florida, United States
    Anne Bates Leach Eye Hospital, Bascom Palmer Eye Institute, University of Miami Miller School of Medicine, Miami, Florida, United States
  • Sonia Yoo
    Ophthalmic Biophysics Center, Bascom Palmer Eye Institute, University of Miami Miller School of Medicine, Miami, Florida, United States
    Anne Bates Leach Eye Hospital, Bascom Palmer Eye Institute, University of Miami Miller School of Medicine, Miami, Florida, United States
  • Marco Ruggeri
    Ophthalmic Biophysics Center, Bascom Palmer Eye Institute, University of Miami Miller School of Medicine, Miami, Florida, United States
    Department of Biomedical Engineering, University of Miami College of Engineering, Coral Gables, Florida, United States
  • Arthur Ho
    Brien Holden Vision Institute Limited, Sydney, New South Wales, Australia
    School of Optometry and Vision Science, University of New South Wales, Sydney, New South Wales, Australia
  • Jean-Marie A Parel
    Ophthalmic Biophysics Center, Bascom Palmer Eye Institute, University of Miami Miller School of Medicine, Miami, Florida, United States
    Brien Holden Vision Institute Limited, Sydney, New South Wales, Australia
  • Footnotes
    Commercial Relationships   Fabrice Manns, US Patent 8,425,037 (P); Heather Durkee, None; Yu-Cherng Chang, None; Gabrielle Monterano Mesquita, None; Siobhan Williams, None; Florence Cabot, None; Sonia Yoo, None; Marco Ruggeri, US Patent 8,425,037 (P); Arthur Ho, US Patent 8,425,037 (P); Jean-Marie Parel, US Patent 8,425,037 (P)
  • Footnotes
    Support  NEI Grants: 1F30EY027162, 2R01EY14225, P30EY14801; the Florida Lions Eye Bank and the Beauty of Sight Foundation; Research to Prevent Blindness; Drs. KR Olsen and ME Hildebrandt, Drs. Raksha Urs and Aaron Furtado, the Henri and Flore Lesieur Foundation (JMP).
Investigative Ophthalmology & Visual Science June 2020, Vol.61, 4637. doi:
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    • Get Citation

      Fabrice Manns, Heather Ann Durkee, Yu-Cherng Chang, Gabrielle Monterano Mesquita, Siobhan Williams, Florence Cabot, Sonia Yoo, Marco Ruggeri, Arthur Ho, Jean-Marie A Parel; Effect of inter-individual variations in ocular parameters on optical and mechanical accommodation efficiency. Invest. Ophthalmol. Vis. Sci. 2020;61(7):4637.

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      © ARVO (1962-2015); The Authors (2016-present)

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Abstract

Purpose : To determine the effect of inter-individual variations in ocular biometry on optical and mechanical accommodative efficiencies.

Methods : Following IRB approval, 29 subjects (21 to 68 years, spherical equivalent: -9.38 to +0.38 D) were imaged while focusing on a distant target using a custom-built extended depth OCT system (Ruggeri et al, Biomed Opt Exp 2012; 1506-1520). Images were segmented and corrected for distortions to obtain corneal thickness, anterior chamber depth (ACD), lens thickness (LT), vitreous depth (VD), anterior and posterior corneal and lens curvatures and lens equivalent refractive index (Chang et al, Biomed Opt Exp, 2019; 411-421). For each subject, an accommodation-dependent eye model was created assuming the following accommodative changes based on literature: LT = 0.05mm/D; ACD = -0.0375mm/D; VD = -0.0125 mm/D; ratio of anterior to posterior lens radius of curvature change = 3.5. The anterior radius was adjusted to simulate accommodation ranging from 0 to 10D in 2 D steps. The relationship between lens curvature, lens power, accommodation amplitude, and ocular biometry was quantified.

Results : Lens curvatures and total lens power increased linearly with accommodation. Optical accommodation efficiency (accommodation per lens power change) was 0.81 ± 0.03 D/D (0.73 to 0.90 D/D). It was dependent on ACD (p=0.02), but not VD (p=0.30), corneal power (p=0.17) nor age (p=0.20). Mechanical accommodation efficiency (accommodation per change in anterior lens curvature) was dependent primarily on the equivalent refractive index (p<0.001). It decreased with age (p<0.001) due to a decrease in equivalent refractive index with age (p<0.01).

Conclusions : The inter-individual variability of optical accommodation efficiency is small and caused primarily by variations in anterior chamber depth. The mechanical accommodation efficiency decreases with age due to a decrease in equivalent index with age. Together, these findings suggest that age-related changes in the optical properties of the lens contribute to presbyopia by increasing the force required to accommodate, independent of changes in lens stiffness.

This is a 2020 ARVO Annual Meeting abstract.

 

Figure 1: Curvature and lens power increase linearly with accommodation (Age = 21 years).

Figure 1: Curvature and lens power increase linearly with accommodation (Age = 21 years).

 

Figure 2: Left: Optical accommodation efficiency. Right: Mechanical accommodation efficiency. Red dots = outliers excluded from regression analysis.

Figure 2: Left: Optical accommodation efficiency. Right: Mechanical accommodation efficiency. Red dots = outliers excluded from regression analysis.

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