Changes in monkey crystalline lens spherical aberration during simulated accommodation in a lens stretcher

8 págs.; 7 figs.; 2 apps.© 2015 The Association for Research in Vision and Ophthalmology, Inc. PURPOSE. The purpose of this study was to quantify accommodation-induced changes in the spherical aberration of cynomolgus monkey lenses. METHODS. Twenty-four lenses from 20 cynomolgus monkeys (Macaca fascicularis; 4.4-16.0 years of age; postmortem time 13.5±13.0 hours) were mounted in a lens stretcher. Lens spherical aberration was measured in the unstretched (accommodated) and stretched (relaxed) states with a laser ray tracing system that delivered 51 equally spaced parallel rays along 1 meridian of the lens over the central 6-mm optical zone. A camera mounted below the lens was used to measure the ray height at multiple positions along the optical axis. For each entrance ray, the change in ray height with axial position was fitted with a third-order polynomial. The effective paraxial focal length and Zernike spherical aberration coefficients corresponding to a 6-mm pupil diameter were extracted from the fitted values. RESULTS. The unstretched lens power decreased with age from 59.3±6 4.0 diopters (D) for young lenses to 45.7±6 3.1 D for older lenses. The unstretched lens shifted toward less negative spherical aberration with age, from -6.3±0.7 lm for young lenses to-5.0±0.5 lm for older lenses. The power and spherical aberration of lenses in the stretched state were independent of age, with values of 33.5±6 3.4 D and-2.6±0.5 lm, respectively. CONCLUSIONS. Spherical aberration is negative in cynomolgus monkey lenses and becomes more negative with accommodation. These results are in good agreement with the predicted values using computational ray tracing in a lens model with a reconstructed gradient refractive index. The spherical aberration of the unstretched lens becomes less negative with age.Supported by National Institutes of Health Grants R01EY14225, R01EY021834, and F31EY021444 Ruth L. Kirschstein National Research Service Award individual predoctoral fellowship [BM]), and center Grant P30EY14801; Australian government Cooperative Research Centre Scheme (Vision CRC); Florida Lions Eye Bank; Karl R. Olsen and Martha E. Hildebrandt; an unrestricted grant from Research to Prevent Blindness; Henri and Flore Lesieur Foundation (JMP); Spanish government Grant FIS2011-25637; and European Research Council Grants ERC-2011-AdG-294099 and CSIC i-LINKþ0609Peer Reviewe

The Zonules Selectively Alter the Shape of the Lens During Accommodation Based on the Location of Their Anchorage Points

PURPOSE. To determine the role of anterior and posterior zonular tension on the optomechanical lens response during accommodation simulation. METHODS. Ten eyes from nine hamadryas baboons (4.9 ± 0.7 years) and 20 eyes from 18 cynomolgus monkeys (5.4 ± 0.3 years) were dissected, leaving the lens, zonules, ciliary body, hyaloid membrane, anterior vitreous, and a segmented scleral rim intact. The lens preparation was mounted in a lens stretcher, and the outer scleral shell was displaced radially in a stepwise fashion. The load, lens, and ciliary body diameters, lens power, lens thickness, and the anterior and posterior radius of curvature were measured during stretching. The zonular fibers attached to either the posterior or anterior lens surface were then carefully transected and the experiment was repeated. Zonular transection was confirmed in four eyes via laser scanning confocal microscopy after immunostaining. The effect of zonular transection on the tissue response to stretching was quantified. RESULTS. Without anterior zonules, 48% and 97% of the changes in anterior and posterior radii are retained. Without posterior zonules, 81% and 67% of the changes in anterior and posterior radii are retained. The changes in lens shape were reduced after transecting either the anterior or posterior zonules; however, both surfaces still changed shape. CONCLUSIONS. While either the anterior or posterior zonules alone are capable of changing the shape of both lens surfaces, the anterior zonules have a greater effect on the anterior lens surface, and the posterior zonules have a greater effect on the posterior lens surface

Isolated human crystalline lens three-dimensional shape: A comparison between Indian and European populations

6 pags., 2 figs., 2 tabs.There have been many studies on lens properties in specific populations (e.g. in China, Europe, Singapore, etc.) some of which suggest there may be differences between populations. Differences could be caused by ethnic or environmental influences or experimental procedures. The purpose of this study is to evaluate if any differences exist between Indian and European populations in the central geometric and full shape properties of human lenses. Two custom-developed spectral domain optical coherence tomography systems were used to acquire the crystalline lens geometry: one in India (69 lenses from 59 donors) and the other in Spain (24 lenses from 19 donors). The steps for obtaining accurate 3-D models from optical coherence tomography raw images comprised of image segmentation, fan and optical distortion correction, tilt removal and registration. The outcome variables were lens equatorial diameter, lens thickness, anterior and posterior lens thicknesses and their ratio, central radius of curvature of the anterior and posterior lens surfaces, lens volume and lens surface area. A mixed effects model by maximum likelihood estimation was used to evaluate the effect of age, population and their interaction (age*population) on lens parameters. After adjusting for age, there were no population differences observed in anterior and posterior radii of curvature, equatorial diameter, lens thickness, anterior and posterior lens thicknesses and their ratio, volume and surface area (all p ≥ 0.08). There was also no effect of the interaction term on anterior and posterior radii of curvature, equatorial diameter, lens thickness, anterior and posterior lens thicknesses and their ratio, volume and surface area (all p ≥ 0.06). All central geometric and full shape parameters appeared to be comparable between the European and Indian populations. This is the first study to compare geometric and full shape lens parameters between different populations in vitro.This work was supported by the National Institutes of Health/National Eye Institute [Grants 2R01EY021834 and P30EY14801 (Center Grant)]; the Hyderabad Eye Research Foundation; Ministerio de Educacion y Ciencia, Spain (FIS2017- 84753-R), European Research Council (ERC-2018-AdG-833106) and IMCUSTOMEYE Ref. 779960 (H2020- ICT- 2017-1) to S. Marcos, and European Research Council (ERC) under European Union’s Horizon 2020 research and innovation programme H2020-MSCA COFUND-2015 FP-713694, MULTIPLY(AdC), CSIC ICoop Program, Florida Lions Eye Bank and the Beauty of Sight Foundation, an unrestricted grant from Research to Prevent Blindness to the Department of Ophthalmology, University of Miami and the Henri and Flore Lesieur Foundation (J-M. Parel)

3D OCT-based geometrical changes of human crystalline lenses during simulated accommodation in a lens stretcher

This is a 2020 ARVO Annual Meeting abstract.Support European Project MyFUN H2020-MSCA-ITN-2015 Ref. 675137, European Project IMCUSTOMEYE H2020-ICT-2017 Ref. 779960​, European Project SILKEYE H2020-ERC-2018-ADG Ref. 833106, European Project COFUND Multiply H-2020-MSCA-COFUND-2015 Ref. 713694, Spanish government grant FIS2017-84753-R, NEI Grants: R01EY021834, F31EY021444 (Maceo), P30EY14801 (Center Grant); the Florida Lions Eye Bank; Research to Prevent Blindness; Drs. KR Olsen and ME Hildebrandt, Drs. Raksha Urs and Aaron Furtado, the Henri and Flore Lesieur Foundation (JMP); Hyderabad Eye Research Foundation.Peer reviewe

Quantifying crystalline lens geometry and optical properties by combined optical coherence tomography & laser ray tracing

This is an abstract that was submitted for the 2017 ARVO Annual Meeting, held in Baltimore, MD, May 7-11, 2017Support NIH R01EY021834, R01EY014225 and P30EY14801, the Australian Federal Government CRC Scheme through the Vision Cooperative Research Centre, Florida Lions Eye Bank, Research to Prevent Blindness, Drs KR Olsen and ME Hildebrandt, Drs Raksha Urs and Aaron Furtado, Henri and Flore Lesieur Foundation (JMP), Hyderabad Eye Research Foundation, European Research Council ERC-AdG 294099 and CSIC iCoop ProgramPeer reviewe

Full shape crystalline lens geometrical changes with age from 3-D OCT images in vivo and ex vivo

This is an abstract that was submitted for the 2018 ARVO Annual Meeting, held in Honolulu, Hawaii, April 29 - May 3, 2018Support NEI Grants: R01EY021834, F31EY021444 (Maceo), P30EY14801 (Center Grant); the Florida Lions Eye Bank; Research to Prevent Blindness; Australian Federal Government CRC Program (Vision CRC); Drs. KR Olsen and ME Hildebrandt, Drs. Raksha Urs and Aaron Furtado, the Henri and Flore Lesieur Foundation (JMP); Hyderabad Eye Research Foundation, European Research Council ERC-AdG 294099, FIS2014-56643-R and CSIC iCoop Program.Peer reviewe

Isolated human crystalline lens spherical aberration: Experimental measurements and predictions from OCT-based geometry

ARVO Annual Meeting Abstract (2019)Support National Eye Institute Grants 1F30EY027162, 2R01EY021834, P30EY14801 (Center Grant); the Australian Federal Government CRC Scheme through the Vision Cooperative Research Centre; the Hyderabad Eye Research Foundation; Florida Lions Eye Bank and the Beauty of Sight Foundation; the Henri and Flore Lesieur Foundation (JMP); an unrestricted grant from Research to Prevent Blindness, European Research Council ERC-AdG 294099 and CSIC iCoop Program.Peer reviewe