Comparison of the efficiency, MTF and chromatic properties of four diffractive bifocal intraocular lens designs

International audienceThe aim of this paper is to compare the properties of four different profiles which can be used as multifocal intraocular lens. The Hankel transform based on the theory of scalar diffraction is applied to a binary profile, a parabolic one, a parabolic profile with holes, and finally a sinusoidal one. This enables to study the various distributions of the diffractive efficiencies and the axial chromatism. The image quality is evaluated by means of simulations of the MTFs with Zemax®. Finally we propose a new way to graphically synthesize all the properties of these lenses, using a radar graph

Comparison of the efficiency, MTF and chromatic properties of four diffractive bifocal intraocular lens designs

International audienceThe aim of this paper is to compare the properties of four different profiles which can be used as multifocal intraocular lens. The Hankel transform based on the theory of scalar diffraction is applied to a binary profile, a parabolic one, a parabolic profile with holes, and finally a sinusoidal one. This enables to study the various distributions of the diffractive efficiencies and the axial chromatism. The image quality is evaluated by means of simulations of the MTFs with Zemax®. Finally we propose a new way to graphically synthesize all the properties of these lenses, using a radar graph

Shack-Hartmann multiple spots with diffractive lenses

International audienceIn this Letter we aim to bring an understanding to the apparition of multiple spots when using a Shack-Hartmann (SH) wavefront sensor behind diffractive lenses. In contrast to previous work, this phenomenon is described in terms of diffractive orders. It is illustrated with Zemax simulations, where three kinds of diffractive lenses (monofocal, bifocal, and trifocal) are set behind a microlens array. The presence of multiple spots is related to the phase jump of the diffractive profile and also to the number of steps seen through the microlens pupil. The possibility of assessing the optical quality of such lenses using SH measurements is discussed, in particular within the field of ophthalmology, where the need for precautions is underline

Optical metrology for immersed diffractive multifocal ophthalmic intracorneal lenses

This paper deals with the optical characterization of diffractive multifocal Intra-Corneal Lenses (ICLs) that we have developed in order to correct presbyopia. These diffractive multifocal lenses are made of a very soft material (permeable to oxygen and nutrients), with a thickness smaller than 100 µm and require liquid immersion. As a consequence, most of the conventional metrology methods are unsuited for their characterization. We developed specific setups to measure diffractive efficiencies and Modulation Transfer Function (MTF) adapted to such components. Experimental results are in good agreement with Zemax® simulations. For the best of our knowledge, it is the first time that optical characterization is devoted to the ICLs. Furthermore, most of the IOL’s optical characterizations are focused on far vision MTF and don’t assess the near vision MTF, which we study in this paper

Through-focus response of multifocal intraocular lenses evaluated with a spatial light modulator

A new testing technique based on the use of a liquid crystal spatial light modulator (SLM) is proposed to analyze the optical quality of multifocal intraocular lenses (MIOLs). Different vergences and decentrations of the incident beam can be programmed onto the SLM in order to record the point spread function (PSF) for different object positions. From these axial PSFs, the through-focus modulation transfer function is computed. Because there are no moving parts in the experimental setup, this method is fast and versatile to assess MIOLs. Experimental results confirm the potential of the proposed method.We acknowledge the financial support from Ministerio de Ciencia e Innovacion (grants FIS2011-23175 and TRA2009-0215), Generalitat Valenciana (grant PROMETEO2009-077), and Universitat Politecnica de Valencia (PAID-05-11), Spain. L. Remon acknowledges a fellowship of "Fundacion Cajamurcia," Spain.Remón Martín, L.; Arias, A.; Calatayud Calatayud, A.; Furlan, WD.; Monsoriu Serra, JA. (2012). Through-focus response of multifocal intraocular lenses evaluated with a spatial light modulator. Applied optics. 36(51):8594-8598. https://doi.org/10.1364/AO.51.008594S859485983651Portney, V. (1992). Optical testing and inspection methodology for modern intraocular lenses. Journal of Cataract & Refractive Surgery, 18(6), 607-613. doi:10.1016/s0886-3350(13)80453-1Rawer, R., Stork, W., Spraul, C. W., & Lingenfelder, C. (2005). Imaging quality of intraocular lenses. Journal of Cataract & Refractive Surgery, 31(8), 1618-1631. doi:10.1016/j.jcrs.2005.01.033Barbero, S., Marcos, S., & Jiménez-Alfaro, I. (2003). Optical aberrations of intraocular lenses measured in vivo and in vitro. Journal of the Optical Society of America A, 20(10), 1841. doi:10.1364/josaa.20.001841Schwiegerling, J., & DeHoog, E. (2010). Problems testing diffractive intraocular lenses with Shack-Hartmann sensors. Applied Optics, 49(16), D62. doi:10.1364/ao.49.000d62Schwiegerling, J. (2007). Analysis of the Optical Performance of Presbyopia Treatments With the Defocus Transfer Function. Journal of Refractive Surgery, 23(9), 965-971. doi:10.3928/1081-597x-20071101-19ATCHISON, D. A. (1989). Optical Design of Intraocular Lenses. III. On-Axis Performance in the Presence of Lens Displacement. Optometry and Vision Science, 66(10), 671-681. doi:10.1097/00006324-198910000-00003Taketani, F., Matuura, T., Yukawa, E., & Hara, Y. (2004). Influence of intraocular lens tilt and decentration on wavefront aberrations. Journal of Cataract & Refractive Surgery, 30(10), 2158-2162. doi:10.1016/j.jcrs.2004.02.072Altmann, G. E., Nichamin, L. D., Lane, S. S., & Pepose, J. S. (2005). Optical performance of 3 intraocular lens designs in the presence of decentration. Journal of Cataract & Refractive Surgery, 31(3), 574-585. doi:10.1016/j.jcrs.2004.09.024Phillips, P., Rosskothen, H. D., Pérez-Emmanuelli, J., & Koester, C. J. (1988). Measurement of intraocular lens decentration and tilt in vivo. Journal of Cataract & Refractive Surgery, 14(2), 129-135. doi:10.1016/s0886-3350(88)80086-5De Castro, A., Rosales, P., & Marcos, S. (2007). Tilt and decentration of intraocular lenses in vivo from Purkinje and Scheimpflug imaging. Journal of Cataract & Refractive Surgery, 33(3), 418-429. doi:10.1016/j.jcrs.2006.10.054Sasaki, K., Sakamoto, Y., Shibata, T., Nakaizumi, H., & Emori, Y. (1989). Measurement of postoperative intraocular lens tilting and decentration using Scheimpflug images. Journal of Cataract & Refractive Surgery, 15(4), 454-457. doi:10.1016/s0886-3350(89)80071-9Eppig, T., Scholz, K., Löffler, A., Meßner, A., & Langenbucher, A. (2009). Effect of decentration and tilt on the image quality of aspheric intraocular lens designs in a model eye. Journal of Cataract & Refractive Surgery, 35(6), 1091-1100. doi:10.1016/j.jcrs.2009.01.034Calatayud, A., Rodrigo, J. A., Remón, L., Furlan, W. D., Cristóbal, G., & Monsoriu, J. A. (2012). Experimental generation and characterization of Devil’s vortex-lenses. Applied Physics B, 106(4), 915-919. doi:10.1007/s00340-012-4913-0Simpson, M. J. (1992). Diffractive multifocal intraocular lens image quality. Applied Optics, 31(19), 3621. doi:10.1364/ao.31.003621ATCHISON, D. A., YE, M., BRADLEY, A., COLLINS, M. J., ZHANG, X., RAHMAN, H. A., & THIBOS, L. N. (1992). Chromatic Aberration and Optical Power of a Diffractive Bifocal Contact Lens. Optometry and Vision Science, 69(10), 797-804. doi:10.1097/00006324-199210000-00009Portney, V. (2011). Light distribution in diffractive multifocal optics and its optimization. Journal of Cataract & Refractive Surgery, 37(11), 2053-2059. doi:10.1016/j.jcrs.2011.04.038Castignoles, F., Flury, M., & Lepine, T. (2010). Comparison of the efficiency, MTF and chromatic properties of four diffractive bifocal intraocular lens designs. Optics Express, 18(5), 5245. doi:10.1364/oe.18.00524

Design, elaboration and implementation of a diffractive bifocal intracorneal implant to correct presbyopia

Actuellement, la presbytie peut être corrigée chirurgicalement à l’aide d’implants intraoculaires réfractifs ou diffractifs multifocaux (chirurgie endoculaire invasive et irréversible) ou en intracornéen avec une correction multifocale réfractive (correction laser irréversible, ou insertion d’un implant dans le stroma). L’objectif de ce travail est de développer un nouvel implant permettant de corriger la presbytie, qui allie l’innocuité et la réversibilité d’une correction intracornéenne, à l’efficacité du diffractif. Le design des profils optiques bifocaux a été permis grâce au développement d’outils de simulation optique. Les efficacités de diffraction sont calculées à partir de la propagation du champ électrique par spectre angulaire. La qualité optique est déterminée d’après les simulations de Fonction de Transfert de Modulation obtenues sous Zemax. Des simulations de rendu d’images permettent de visualiser les effets de différents profils envisagés. Les paramètres critiques du design optique sont déterminés. Le choix du matériau dépend des contraintes de biocompatibilité de l’implant et des techniques de fabrication. La solution retenue est un hydrogel à forte teneur en eau, couplé à une nouvelle architecture de l’implant. L’hydrogel est obtenu par polymérisation radicalaire de macromonomères difonctionnels de poly(éthylène glycol) de masses molaires de l’ordre de 8000 g.mol‐1 qui conduisent à des propriétés mécaniques et une perméabilité aux nutriments compatibles avec l’application. La réalisation, la stérilisation et la caractérisation optique de prototypes ont abouti à la preuve du concept d’un implant bifocal diffractif intracornéenPresbyopia can be corrected with surgery by means of refractive or diffractive multifocal intraocular lenses (which imply an irreversible and invasive endocular surgery) or by intracorneal multifocal refractive correction (irreversible laser correction, or insertion of an intrastromal implant). This work aims at developing a new implant to correct presbyopia, which takes advantage of both the harmlessness and the reversibility of an intracorneal correction, and the efficiency of diffractive optics. The design of the bifocal optical profiles was based on the development of optical simulation tools. The diffractive efficiencies are calculated from the distribution of the electric field with the method of angular spectrum. The optical quality is determined according to the simulations of Modulation Transfer Function obtained with Zemax. Images simulations show the effects of the different profiles studied. The critical parameters of the optical design are also determined. The choice of the material depends on several constraints such as biocompatibility and techniques of manufacturing. The adopted solution relies on the used of an hydrogel with high water content and the design of a new implant architecture. The hydrogel is obtained by radical polymerization of difunctional macromonomers of poly(ethylene glycol) with molar masses around 8000 g.mol‐1, allowing mechanical properties and permeability to nutriments compatible with the application. The realization, the sterilization and the characterization of prototypes showed the proof of the concept of a diffractive bifocal intracorneal implan

Conception, réalisation et évaluation d'un implant diffractif bifocal intracornéen pour la correction de la presbytie

Actuellement, la presbytie peut être corrigée chirurgicalement à l aide d implants intraoculaires réfractifs ou diffractifs multifocaux (chirurgie endoculaire invasive et irréversible) ou en intracornéen avec une correction multifocale réfractive (correction laser irréversible, ou insertion d un implant dans le stroma). L objectif de ce travail est de développer un nouvel implant permettant de corriger la presbytie, qui allie l innocuité et la réversibilité d une correction intracornéenne, à l efficacité du diffractif. Le design des profils optiques bifocaux a été permis grâce au développement d outils de simulation optique. Les efficacités de diffraction sont calculées à partir de la propagation du champ électrique par spectre angulaire. La qualité optique est déterminée d après les simulations de Fonction de Transfert de Modulation obtenues sous Zemax. Des simulations de rendu d images permettent de visualiser les effets de différents profils envisagés. Les paramètres critiques du design optique sont déterminés. Le choix du matériau dépend des contraintes de biocompatibilité de l implant et des techniques de fabrication. La solution retenue est un hydrogel à forte teneur en eau, couplé à une nouvelle architecture de l implant. L hydrogel est obtenu par polymérisation radicalaire de macromonomères difonctionnels de poly(éthylène glycol) de masses molaires de l ordre de 8000 g.mol 1 qui conduisent à des propriétés mécaniques et une perméabilité aux nutriments compatibles avec l application. La réalisation, la stérilisation et la caractérisation optique de prototypes ont abouti à la preuve du concept d un implant bifocal diffractif intracornéenPresbyopia can be corrected with surgery by means of refractive or diffractive multifocal intraocular lenses (which imply an irreversible and invasive endocular surgery) or by intracorneal multifocal refractive correction (irreversible laser correction, or insertion of an intrastromal implant). This work aims at developing a new implant to correct presbyopia, which takes advantage of both the harmlessness and the reversibility of an intracorneal correction, and the efficiency of diffractive optics. The design of the bifocal optical profiles was based on the development of optical simulation tools. The diffractive efficiencies are calculated from the distribution of the electric field with the method of angular spectrum. The optical quality is determined according to the simulations of Modulation Transfer Function obtained with Zemax. Images simulations show the effects of the different profiles studied. The critical parameters of the optical design are also determined. The choice of the material depends on several constraints such as biocompatibility and techniques of manufacturing. The adopted solution relies on the used of an hydrogel with high water content and the design of a new implant architecture. The hydrogel is obtained by radical polymerization of difunctional macromonomers of poly(ethylene glycol) with molar masses around 8000 g.mol 1, allowing mechanical properties and permeability to nutriments compatible with the application. The realization, the sterilization and the characterization of prototypes showed the proof of the concept of a diffractive bifocal intracorneal implantST ETIENNE-Bib. électronique (422189901) / SudocSudocFranceF

Optical metrology for immersed diffractive multifocal ophthalmic intracorneal lenses

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