Crystalline lens gradient refractive index distribution in the guinea pig.
crystalline lens
gradient refractive index
guinea pig
myopia
Journal
Ophthalmic & physiological optics : the journal of the British College of Ophthalmic Opticians (Optometrists)
ISSN: 1475-1313
Titre abrégé: Ophthalmic Physiol Opt
Pays: England
ID NLM: 8208839
Informations de publication
Date de publication:
05 2020
05 2020
Historique:
received:
20
09
2019
accepted:
04
12
2019
entrez:
28
4
2020
pubmed:
28
4
2020
medline:
22
7
2021
Statut:
ppublish
Résumé
The crystalline lens undergoes morphological and functional changes with age and may also play a role in eye emmetropisation. Both the geometry and the gradient index of refraction (GRIN) distribution contribute to the lens optical properties. We studied the lens GRIN in the guinea pig, a common animal model to study myopia. Lenses were extracted from guinea pigs (Cavia porcellus) at 18 days of age (n = 4, three monolaterally treated with negative lenses and one untreated) and 39 days of age (n = 4, all untreated). Treated eyes were myopic (-2.07 D on average) and untreated eyes hyperopic (+3.3 D), as revealed using streak retinoscopy in the live and cyclopeged animals. A custom 3D spectral domain optical coherence tomography (OCT) system (λ = 840 nm, Δλ = 50 nm) was used to image the enucleated crystalline lens at two orientations. Custom algorithms were used to estimate the lens shape and GRIN was modelled with four variables that were reconstructed using the OCT data and a minimisation algorithm. Ray tracing was used to calculate the optical power and spherical aberration assuming a homogeneous refractive index or the estimated GRIN. Guinea pig lenses exhibited nearly parabolic GRIN profiles. When comparing the two age groups (18- and 39 day-old) there was a significant increase in the central thickness (from 3.61 to 3.74 mm), and in the refractive index of the surface (from 1.362 to 1.366) and the nucleus (from 1.443 to 1.454). The presence of GRIN shifted the spherical aberration (-4.1 µm on average) of the lens towards negative values. The guinea pig lens exhibits a GRIN profile with surface and nucleus refractive indices that increase slightly during the first days of life. GRIN plays a major role in the lens optical properties and should be incorporated into computational guinea pig eye models to study emmetropisation, myopia development and ageing.
Types de publication
Journal Article
Research Support, Non-U.S. Gov't
Langues
eng
Sous-ensembles de citation
IM
Pagination
308-315Informations de copyright
© 2020 The Authors Ophthalmic & Physiological Optics © 2020 The College of Optometrists.
Références
Garner LF, Yap M & Scott R. Crystalline lens power in myopia. Optom Vis Sci 1992; 69: 863-865.
Mutti DO, Mitchell GL, Sinnott LT et al. Corneal and crystalline lens dimensions before and after myopia onset. Optom Vis Sci 2012; 89: 251-262.
Muralidharan G, Martinez-Enriquez E, Birkenfeld J, Velasco-Ocana M, Pérez-Merino P & Marcos S. Morphological changes of human crystalline lens in myopia. Biomed Opt Express 2019; 10: 6084-6095.
Howlett MHC & McFadden SA. Form-deprivation myopia in the guinea pig (Cavia porcellus). Vision Res 2006; 46: 267-283.
Howlett MHC & McFadden SA. Spectacle lens compensation in the pigmented guinea pig. Vision Res 2009; 49: 219-227.
Ortiz S, Pérez-Merino P, Gambra E, de Castro A & Marcos S. In vivo human crystalline lens topography. Biomed Opt Express 2012; 3: 2471-2488.
Martinez-Enriquez E, Sun M, Velasco-Ocana M, Birkenfeld J, Pérez-Merino P & Marcos S. Optical coherence tomography based estimates of crystalline lens volume, equatorial diameter, and plane position. Invest Ophthalmol Vis Sci 2016; 57: 600-610.
de Castro A, Ortiz S, Gambra E, Siedlecki D & Marcos S. Three-dimensional reconstruction of the crystalline lens gradient index distribution from OCT imaging. Opt Express 2010; 18: 21905-21917.
de Castro A, Birkenfield J, Maceo B et al. Influence of shape and gradient refractive index in the accommodative chnges of spherical aberration in nonhuman primate crystalline lenses. Invest Ophthalmol Vis Sci 2013; 54: 6197-6207.
de Castro A, Birkenfield J, Heilman BM et al. Off-axis optical coherence tomography imaging of the crystalline lens to reconstruct the gradient refractive index using optical methods. Biomed Opt Express 2019; 10: 3622-3634.
de Castro A, Siedlecki D, Borja D et al. Age-dependent variation of the Gradient Index profile in human crystalline lenses. J Mod Opt 2011; 58: 1781-1787.
Birkenfeld J, de Castro A & Marcos S. Contribution of shape and gradient refractive index to the spherical aberration of isolated human lenses. Invest Ophthalmol Vis Sci 2014; 55: 2599-2607.
Howlett MH & McFadden SA. Emmetropization and schematic eye models in developing pigmented guinea pigs. Vision Res 2007; 47: 1178-1190.
Pérez-Merino P, Velasco-Ocana M, Martinez-Enriquez E et al. Three-dimensional OCT based guinea pig eye model: relating morphology and optics. Biomed Opt Express 2017; 8: 2173-2184.
Martinez-Enriquez E, Pérez-Merino P, Velasco-Ocana M & Marcos S. OCT-based full crystalline lens shape change during accommodation in vivo. Biomed Opt Express 2017; 8: 918-933.
Uhlhorn SR, Borja D & Parel JM. Refractive index measurement of the isolated crystalline lens using optical coherence tomography. Vision Res 2008; 48: 2732-2738.
Rosen AM, Denham DB, Fernandez V et al. In vitro dimensions and curvatures of human lenses. Vision Res 2006; 46: 1002-1009.
Stavroudis OO. The Optics of Rays, Wavefronts and Caustics, Academic Press: New York, 1972.
Sharma A, Kumar DV & Ghatak AK. Tracing rays through graded-index media - a new method. Appl Optics 1982; 21: 984-987.
Stone BD & Forbes GW. Optimal interpolants for Runge-Kutta ray tracing in inhomogeneous-media. J Opt Soc Am A 1990; 7: 248-254.
de Castro A, Barbero S & Marcos S. Accuracy of the reconstruction of the crystalline lens gradient index with optimization methods from ray tracing and Optical Coherence Tomography data. Opt Express 2011; 19: 19265-19279.
Pierscionek B. Species variations in the refractive index of the eye lens and patterns of change with ageing. In: Focus on Eye Research, OR Ioseliani, (ed.). Nova Science Publishers, Inc. New York, 2005; pp. 91-115.
Campbell MC. Measurement of refractive index in an intact crystalline lens. Vision Res 1984; 24: 409-415.
Atchison DA & Smith G. Chromatic dispersions of the ocular media of human eyes. J Opt Soc Am A Opt Image Sci Vis 2005; 22: 29-37.
Daimon M, Masumura A. Measurement of the refractive index of distilled water from the near-infrared region to the ultraviolet region. Appl Optics 2007; 46: 3811-3820.
Dubbelman M & Van der Heijde GL. The shape of the aging human lens: curvature, equivalent refractive index and the lens paradox. Vision Res 2001; 41: 1867-1877.
Moffat BA, Atchison DA & Pope JM. Explanation of the lens paradox. Optom Vis Sci 2002; 79: 148-150.
Sheil CJ & Goncharov AV. Crystalline lens paradoxes revisited: significance of age-related restructuring of the GRIN. Biomed Opt Express 2017; 8: 4172-4180.
Siedlecki D, de Castro A, Gambra E et al. Distortion correction of OCT images of the crystalline lens: gradient index approach. Optom Vis Sci 2012; 89: E709-E718.
Borja D, Siedlecki D, de Castro A et al. Distortions of the posterior surface in optical coherence tomography images of the isolated crystalline lens: effect of the lens index gradient. Biomed Opt Express 2010; 1: 1331-1340.