Goal. Relevance. Visual Optics and Biophotonics Lab. Óptica Visual y Biofotónica. Colaboran Instituto de Oftalmobiologia Aplicada, U.

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1 Curso de introduccion a la Investigacion en Optica. Abril 9 Visual Optics and Biophotonics Lab Óptica Visual y Biofotónica Susana Marcos Sergio Barbero Lourdes Llorente Carlos Dorronsoro Elena García de Patricia la Cera Rosales Carlos Meneses Susana Marcos Instituto de Optica, CSIC, Spain Sergio Ortiz Damian Siedlecki Alberto de Castro José Requejo Pablo de Gracia Lucie Sawides Daniel Pascual Alfonso Enrique Gambra Pérez-Escudero Sabine Kling Laura Remón Colaboran Instituto de Oftalmobiologia Aplicada, U. Valladolid, IQFRS, CIB, IQO, Schepens Eye Research Institute- Harvard, USA New England College of Optometry, USA University of Tuebingen, Germany University of Houston, USA De Vrije University, The Netherlands Goal Development of optical and photonic technologies in biomedicine, in particular for the non-invasive assessment of the normal and pathological eye University of Miami, USA ; State Univerity of New York USA University of Nevada, USA ; Copernicus University, Poland Relevance myopia presbyopia Aberrations Simpler case: defocus (myopia). Affects 5% of the population Affects % of the population older than 5 Causes for their development not well understood No treatment available New alternatives for correction

2 Aberrations The eye suffers from aberrations of higher order than defocus Wave aberration: phase distortions at the pupil plane μm topographic map Goal Development of optical and photonic technologies channel to understand presbyopia myopia Laser Ray Tracing: Basic Concept Pupil monitoring to evaluate/improve Compensation methods Aberrated wavefront Spot diagram LRT Aberrometry Visual Optics & Biophotonics Lab, Instituto de Optica, CSIC

3 HARTMANN-SHACK WAVEFRONT SENSOR He-Ne Laser microlens array Hartmann-Shack CCD MICROLENS ARRAY BADAL SLD 676 nm BS W ABERRATION- ABERRATED FREE EYE EYE Liang & Williams, JOSA A 998 Moreno-Barriuso, Marcos, Burns & Navarro, OVS EYE Visual Optics & Biophotonics Lab, Instituto de Optica, CSIC, García de la Cera et al. Causes of optical aberrations Crystalline lens geometry Corneal topography Alignment of ocular surfaces Gradient index distribution Tuning cornea/crystalline lens Corneal aberrations Purkinje Imaging System Corneal topography Elevation map Ray Tracing Corneal aberrations Barbero et al. 3 Visual Optics & Biophotonics Lab, Instituto de Optica, CSIC, Rosales et al. 3

4 Purkinje imaging system for Phakometry h h 3 h 4 Equivalent mirror / Merit function approaches Scheimpflug imaging Geometrical distortion Lens tilt/decentration PI = Eβ PIII PIII= Fβ + Aα + Cd PIV PI PIV = Gβ + Bα + Dd Rosales & Marcos, JOSA A 6 Optical distortion Crystalline lens curvature. Changes with accommmodation Optical Coherence Tomography Purkinje imaging Scheimpflug imaging Rosales, Dubbelman, Marcos, van der Heijde, Journal of Vision, 6 Visual Optics & Biophotonics Lab, Instituto de Optica, CSIC, Ortiz et al. OCT Images GRIN-LRT IOL, TD-OCT Cornea and crystalline lens, in vivo soct Accommodating lens, soct Light pupil reaction, soct Institute of Optics.- Madrid 4

5 Laser Ray Tracing for crystalline GRIN () HeNe 594nm Individual eye modelling Corneal topography Axial length/acd Sources of aberrations CCD Crystalline lens Lens GRIN models CCD () x-y scanner Ray deflexions () Ray impacts () Crystalline lens shape Pupil/lens tilt& decentration Test of treatments (IOLS,LASIK, CLs) OR -5 - De Castro, Barbero & Marcos, Customized modelling of eyes with IOLs Predicted Centered IOL Measured From morphology to microscopic structures Anterior cornea IOL with tilt & dec. Scheimpflug Courtesy of Nidek Tervo & Moilanen, 3 ACD & AL Total aberrations IOL geometry, tilt & dec. Rosales & Marcos, Optics Express 8 OCT In vivo confocal microscopy Structured Illumination microscopy(in vivo) Structured Illumination microscopy Tube lens Array detector Patterned illumination (D grid). Project a D sine-pattern onto the sample. Record a series of images at equidistant phases with a wide-field detector Beamsplitter 3. Compute sectioned images Isec ( I ) ( ) ( ) I + I I3 + I3 I Phase image (3 or 4) φ=3π/ φ=π Objective Wide-field conventional Wide-field sectioned Out of focus φ= φ=π/ Focal plane x = Some maths Visual Optics & Biophotonics Lab, Instituto de Optica, CSIC, Requejo et al. Out of focus Requejo, adapted from Juskaitis et al

6 Some sample questions Question.- What triggers myopia development?? What is the role of ocular aberrations in myopia? Chick model: Axial length Axial length (mm) 9,3 Occluded eye 8,8. ±. mm/day 8,3 7,8 7,3 6,8 Garcia de la Cera, Rodríguez & Marcos, Vision Res. (6) Day #.9mm Untreated eye.5 ±.3 mm/day Garcia de la Cera, Rodríguez & Marcos, Vision Res. (6) Chick model: Refraction Refraction (D) Occluded -.5±. D/day Day # Non occluded -.±.9 D/day -8D Strehl ratio Φ=.5 mm Garcia de la Cera, Rodríguez & Marcos, Vision Res. (6) Chick model: Strehl ratio,,8,6,4, Optical quality improves with development Occluded eyes Day # Myopic eyes are more degraded than normal eyes Non-Occluded eyes Myopic LASIK Total Corneal Question.- What is the optical response of the cornea after refractive surgery?? Can we improve the laser ablation algoritms? Pre Post Marcos et al., IOVS () 6

7 TOTAL aberrations RMS (μm) rd and higher order PRE-LASIK POST-LASIK Moreno-Barriuso et al. IOVS () EYE # Increase of TOTAL Spherical Aberration with LASIK Z 4 μm Tot-pre Tot-post Marcos et al. IOVS () Spherical aberration eye # Increase of CORNEAL Spherical Aberration with LASIK Z 4 μm Corn-pre Corn-post Marcos et al. IOVS () Spherical aberration eye # Why corneal spherical aberration / asphericity increases after standard LASIK? Due to the design of the profile? Marcos et al. J. Refract. Surg 3 Due to discrepancies in the laser energy delivery? Cano, Barbero & Marcos. JOSA 4 Due to corneal biomechanical effects? Dorronsoro, Cano, Merayo & Marcos, Opt. Express 6 Computational surgery Experimental PRE corneal height Using Munnerlyn algorithm and a Parabolic approximation of the Munnerlyn algorithm Munnerlyn ablation depth - = Marcos, Cano & Barbero, J.Refract Surg (3) Using actual data of R, R, D, and S for each subject Simulated POST corneal height Experimental Kα K (PMMA) Kα= Ablation profile on spheres -3 D -6 D Ablation profile on flat surfaces -3 D = Laser efficiency effects (experimental),,9,8,7,6 Kα (PMMA) Surface location (mm) -6 D Dorronsoro, Cano, Merayo, Marcos, Opt Express 6 7

8 Corneal asphericities 6 4 Clinical Experimental profile & efficiency Biomechanical effects Corneal biomechanical properties LASIK-induced changes in the posterior corneal surface Corneal deformation with increasing Intraocular Pressure Asphericity Correction (D) Dorronsoro, Cano, Merayo & Marcos, 6. Optics Express 6 Pérez-Escudero, Sawides, Dorronsoro, Merayo, Marcos, IOVS 9 Pérez-Escudero et al. 8; Kling et al 9 Comparison with visual performance Contrast sensitivity PRE & POST LASIK MTF horizontal section Contrast sensitivity 8 4 CSF undilated pupil Modulation transfer MTF 3 mm spatial frequency (c/deg) PRE Area =.5 POST Marcos. J. Refract. Surg. (). 3 spatial frequency (c/deg) PRE Area =.38 POST Question 3. Can we improve optical quality of patients after cataract surgery with new intraocular lens designs? Total, corneal & internal aberrations POST CATARACT surgery Total Corneal Internal Total Corneal Internal Eye #-IOL D Eye #4-IOL 3 Dp Eye #4-IOL Dp Barbero et al. JOSA (3) Eye #9-IOL 6 D 8

9 Corneal aberrations Pre-op Post-op Induced μm Spherical aberration. Spherical/Aspheric Z4 (micras),4,35,3,5,,5,,5 -,5 -, -,5 Spherical IOL Z4 (micras),6,4, -, -,4 -,6 Eye # Eye # Aspheric IOL Total Total IO Corneal Corn IO Internal Interna Barbero et al. JOSA (3) Marcos et al. J. Refract Surg (5) Marcos et al. JCRS 6 Φ= mm, centered at corneal reflex Close loop adaptive optics correction Correct wavefront using deformable optics Calculate control parameters AO loop Measure residual wavefront using a sensor Question 4. Can we improve vision by correcting ocular aberrations? Courtesy of Nicolas Chateau, Imagine eyes Adaptive optics system Imagine Eyes Haso 3 3 x 3 microlenses AO-correction of ocular aberrations SLD : 86 nm Wavefront PSF Deformable mirror Shack Hartmann wavefront sensor Badal System Imagine Eyes MIRAO5d 5 actuators 5 μm stroke Eye RMS =.7 μm RMS =.39 μm Correction : 95 % Sawides, Gambra & Marcos, 7 Pupil diameter: 6.6 mm Gambra, Sawides & Marcos, 7 The 6th International Workshop on Adaptive Optics, Galway, Ireland 9

10 Visual acuity after correction of ocular aberrations,4 Influence of the ocular aberrations on accommodation, With AO Decimal visual acuity,8,6,4 Natural aberrations letras negras sin OA letras negras conoa Improvement at all luminances Increase of VA with luminance is primarily neural, Subject LS Pupil=6 mm, Time (s) Time (s) Target luminance (cd/m) Sawides, Dorronsoro, Gambra & Marcos, JOV 8 Overview Outreach Aberrometry Psychophysical tools Optical biometry myopia LASIK IOLs presbyopia CLs High resolution imaging Animal models Basic Science Training Technology development In vitro models Measurement on patients Computer eye models Industrial Impact Clinical impact Oportunidades de Becas/Contratos Opciones de solicitud de becas (FPU, FPI, JAEpre) Contratos con cargo a proyecto