PURPOSE: To reconstruct the gradient index (GRIN) profile of human crystalline lenses ex-vivo using Optical Coherence Tomography (OCT) imaging with an optimization technique and to study the dependence of the GRIN profile with age. METHODS: Cross-sectional images of nine isolated human crystalline lenses with ages ranging from 6 to 72 (post mortem time 1 to 4 days) were obtained using a custom-made OCT system. Lenses were extracted from whole cadaver globes and placed in a measurement chamber filled with preservation medium (DMEM). Lenses were imaged with the anterior surface up and then flipped over and imaged again, to obtain posterior lens surface profiles both undistorted and distorted by the refraction through the anterior crystalline lens and GRIN. The GRIN distribution of the lens was described with three variables by means of power function, with variables being the nucleus and surface index, and a power coefficient that describes the decay of the refractive index from the nucleus to the surface. An optimization method was used to search for the parameters that produced the best match of the distorted posterior surface. RESULTS: The distorted surface was simulated with accuracy around the resolution of the OCT system (under 15 µm). The reconstructed refractive index values ranged from 1.356 to 1.388 for the surface, and from 1.396 to 1.434 for the nucleus. The power coefficient ranged between 3 and 18. The power coefficient increased significantly with age, at a rate of 0.24 per year. CONCLUSION: Optical Coherence Tomography allowed optical, non-invasive measurement of the 2-D gradient index profile of the isolated human crystalline lens ex vivo. The age-dependent variation of the changes is consistent with previous data using magnetic resonance imaging, and the progressive formation of a refractive index plateau.
PURPOSE: To reconstruct the gradient index (GRIN) profile of human crystalline lenses ex-vivo using Optical Coherence Tomography (OCT) imaging with an optimization technique and to study the dependence of the GRIN profile with age. METHODS: Cross-sectional images of nine isolated human crystalline lenses with ages ranging from 6 to 72 (post mortem time 1 to 4 days) were obtained using a custom-made OCT system. Lenses were extracted from whole cadaver globes and placed in a measurement chamber filled with preservation medium (DMEM). Lenses were imaged with the anterior surface up and then flipped over and imaged again, to obtain posterior lens surface profiles both undistorted and distorted by the refraction through the anterior crystalline lens and GRIN. The GRIN distribution of the lens was described with three variables by means of power function, with variables being the nucleus and surface index, and a power coefficient that describes the decay of the refractive index from the nucleus to the surface. An optimization method was used to search for the parameters that produced the best match of the distorted posterior surface. RESULTS: The distorted surface was simulated with accuracy around the resolution of the OCT system (under 15 µm). The reconstructed refractive index values ranged from 1.356 to 1.388 for the surface, and from 1.396 to 1.434 for the nucleus. The power coefficient ranged between 3 and 18. The power coefficient increased significantly with age, at a rate of 0.24 per year. CONCLUSION: Optical Coherence Tomography allowed optical, non-invasive measurement of the 2-D gradient index profile of the isolated human crystalline lens ex vivo. The age-dependent variation of the changes is consistent with previous data using magnetic resonance imaging, and the progressive formation of a refractive index plateau.
Authors: David Borja; Fabrice Manns; Arthur Ho; Noel Ziebarth; Alexandre M Rosen; Rakhi Jain; Adriana Amelinckx; Esdras Arrieta; Robert C Augusteyn; Jean-Marie Parel Journal: Invest Ophthalmol Vis Sci Date: 2008-03-03 Impact factor: 4.799
Authors: Raksha Urs; Fabrice Manns; Arthur Ho; David Borja; Adriana Amelinckx; Jared Smith; Rakhi Jain; Robert Augusteyn; Jean-Marie Parel Journal: Vision Res Date: 2008-11-08 Impact factor: 1.886
Authors: David Borja; Damian Siedlecki; Alberto de Castro; Stephen Uhlhorn; Sergio Ortiz; Esdras Arrieta; Jean-Marie Parel; Susana Marcos; Fabrice Manns Journal: Biomed Opt Express Date: 2010-11-08 Impact factor: 3.732
Authors: Bianca M Maceo; Fabrice Manns; David Borja; Derek Nankivil; Stephen Uhlhorn; Esdras Arrieta; Arthur Ho; Robert C Augusteyn; Jean-Marie Parel Journal: J Vis Date: 2011-11-30 Impact factor: 2.240
Authors: Damian Siedlecki; Alberto de Castro; Enrique Gambra; Sergio Ortiz; David Borja; Stephen Uhlhorn; Fabrice Manns; Susana Marcos; Jean-Marie Parel Journal: Optom Vis Sci Date: 2012-05 Impact factor: 1.973