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16 pags., 7 figs. -- OCIS codes: (110.4500) Optical coherence tomography; (110.6880) Three-dimensional image acquisition; (330.7322) Visual optics, accommodation; (100.2960) Image analysis; (330.7327) Visual optics, ophthalmic instrumentation ; The full shape of the accommodating crystalline lens was estimated using custom three-dimensional (3-D) spectral OCT and image processing algorithms. Automatic segmentation and distortion correction were used to construct 3-D models of the lens region visible through the pupil. The lens peripheral region was estimated with a trained and validated parametric model. Nineteen young eyes were measured at 0-6 D accommodative demands in 1.5 D steps. Lens volume, surface area, diameter, and equatorial plane position were automatically quantified. Lens diameter & surface area correlated negatively and equatorial plane position positively with accommodation response. Lens volume remained constant and surface area decreased with accommodation, indicating that the lens material is incompressible and the capsular bag elastic. ; European Research Council under the European Union's Seventh Framework Program (FP/2007-2013) / ERC Grant Agreement (ERC-2011-AdG- 294099); Spanish Government (FIS2011-25637); Spanish Government (FIS2014-56643-R). ; Peer Reviewed

ARVO Annual Meeting Abstract (2019) ; Support a collaborative agreement with Essilor International, France. Spanish government grant FIS2014-56643-R, Spanish government grant FIS2017-84753-R, European Research Council under the European Union's Seventh Framework Programme (FP7/2007-2013) ERC-2011-AdG-294099 ; Peer reviewed

12 págs.; 9 figs.; 1 tab. ; © 2015 ARVO. We studied the role of native astigmatism and ocular aberrations on best-focus setting and its shift upon induction of astigmatism in 42 subjects (emmetropes, myopes, hyperopes, with-the-rule [WTR] and against-the-rule [ATR] myopic astigmats). Stimuli were presented in a custom-developed adaptive optics simulator, allowing correction for native aberrations and astigmatism induction (+1 D; 6-mm pupil). Best-focus search consisted on randomized-step interleaved staircase method. Each subject searched best focus for four different images, and four different conditions (with/without aberration correction, with/without astigmatism induction). The presence of aberrations induced a significant shift in subjective best focus (0.4 D; p < 0.01), significantly correlated (p = 0.005) with the best-focus shift predicted from optical simulations. The induction of astigmatism produced a statistically significant shift of the best-focus setting in all groups under natural aberrations (p = 0.001), and in emmetropes and in WTR astigmats under corrected aberrations (p < 0.0001). Best-focus shift upon induced astigmatism was significantly different across groups, both for natural aberrations and AO-correction (p < 0.0001). Best focus shifted in opposite directions in WTR and ATR astigmats upon induction of astigmatism, symmetrically with respect to the best-focus shift in nonastigmatic myopes. The shifts are consistent with a bias towards vertical and horizontal retinal blur in WTR and ATR astigmats, respectively, indicating adaptation to native astigmatism. ; The research leading to these results has received funding from the European Research Council under the European Union's Seventh Framework Programme (FP/2007-2013)/ERC Grant Agreement n. [ERC-2011- AdC 294099]. This study was supported by grants FIS2011-24637 to SM and a collaborative research project funded by Essilor International. Optometric examinations were performed in the Faculty of Optometry Clinic of the University Complutense de Madrid (Madrid, Spain). GM and MH work for Essilor International. ; Peer Reviewed

12 pags., 6 figs., 3 tabs. -- OCIS codes: (110.4500) Optical coherence tomography, (110.6880) Three-dimensional image acquisition, (100.2960) Image analysis, (330.7327) Visual optics, ophthalmic instrumentation, (330.7324) Visual optics, comparative animal models, (330.5370) Physiological optics ; Custom Spectral Optical Coherence Tomography (SOCT) provided with automatic quantification and distortion correction algorithms was used to measure the 3-D morphology in guinea pig eyes (n = 8, 30 days; n = 5, 40 days). Animals were measured awake in vivo under cyclopegia. Measurements showed low intraocular variability (<4% in corneal and anterior lens radii and <8% in the posterior lens radii, <1% interocular distances). The repeatability of the surface elevation was less than 2 µm. Surface astigmatism was the individual dominant term in all surfaces. Higher-order RMS surface elevation was largest in the posterior lens. Individual surface elevation Zernike terms correlated significantly across corneal and anterior lens surfaces. Higher-order-aberrations (except spherical aberration) were comparable with those predicted by OCT-based eye models. ; European Research Council under the European Union´s Seventh Framework Program (FP/2007-2013;) / ERC Grant Agreement [ERC-2011-AdC-294099], and Spanish Government grant FIS2011-25637; and FIS2014-56643-R to SM. ; Peer Reviewed

This abstract was presented at the 2019 ARVO Annual Meeting, held in Vancouver, Canada, April 28 - May 2, 2019 ; Support European Research Council (ERC) under European Union's Horizon 2020 research and innovation programme H2020-MSCA-COFUND-2015-FP-713694, Spanish government grant FIS2014-56643-R, European Research Council under the European Union's Seventh Framework programme ERC-2011-AdG-294099, Patent P201130685, Patent US2016 62/329,392. ; Peer reviewed

8 pags., 6 figs. ; Purpose: 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. Methods: 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. Results: 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. Conclusions: 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. ; This work was supported by European Research Council (ERC) Grant Agreement ERC-2011-AdC- 294099; ERC under the European Union's Horizon 2020 research and innovation programme (H2020-MSCA COFUND-2015 FP-713694, MULTIPLY) and under grant agreement No 779960, IMCUSTOMEYE and No 675137 (MyFUun MSCA ITN); Spanish Government Grant FIS2017-84753-R; Hunter Medical Research Institute G1400967 and the University of Newcastle (FVG 1031537 and SSP).

ARVO Annual Meeting Abstract (2019) ; Support European Research Council ERC-2011-AdG 294099; Spanish Government FIS2014-56643-R, FIS2017-84753-R; H-2020-MSCA-COFUND-2015 713694 ; Peer reviewed

In vivo three-dimensional (3-D) anterior segment biometry before and after cataract surgery was analyzed by using custom highresolution high-speed anterior segment spectral domain Optical Coherence Tomography (OCT). The system was provided with custom algorithms for denoising, segmentation, full distortion correction (fan and optical) and merging of the anterior segment volumes (cornea, iris, and crystalline lens or IOL), to provide fully quantitative data of the anterior segment of the eye. The method was tested on an in vitro artificial eye with known surfaces geometry at different orientations and demonstrated on an aging cataract patient in vivo. Biometric parameters CCT, ACD/ILP, CLT/ILT Tilt and decentration are retrieved with a very high degree of accuracy. IOL was placed 400 οm behind the natural crystalline lens, The IOL was aligned with a similar orientation of the natural lens (2.47 deg superiorly), but slightly lower amounts (0.77 deg superiorly). The IOL was decentered superiorly (0.39 mm) and nasally (0.26 mm). © 2013 Optical Society of America. ; This study has been funded by Spanish Government Grant FIS2011-25637 and European Research Council Grant ERC-2011-AdG-294099 to S. Marcos. ; Peer Reviewed

This is an abstract that was submitted for the 2018 ARVO Annual Meeting, held in Honolulu, Hawaii, April 29 - May 3, 2018 ; Support 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 reviewed