Phaco-Ersatz: Cataract surgery designed to preserve accommodation

Parel, Jean Marie; Gelender, Henry; Trefers, W. F.; Norton, Edward W.D.

doi:10.1007/bf02141492

Cited by 131 publications

(51 citation statements)

References 9 publications

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“…Applications of corrected Scheimpfl ug crystalline lens/IOL in vivo imaging include customized eye modeling, 18,19 studies of quantitative changes of crystalline lens morphology with accommodation, 11,[20][21][22] aging, 6,23 or disease, 24 and assessment of new intraocular implants and surgical approaches for the correction of presbyopia. 25 …”

Section: Discussionmentioning

confidence: 99%

Pentacam Scheimpflug Quantitative Imaging of the Crystalline Lens and Intraocular Lens

Rosales¹,

Marcos²

2009

J Refract Surg

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PURPOSE: To implement geometrical and optical distortion correction methods for anterior segment Scheimpfl ug images obtained with a commercially available system (Pentacam, Oculus Optikgeräte GmbH). METHODS:Ray tracing algorithms were implemented to obtain corrected ocular surface geometry from the original images captured by the Pentacam's CCD camera. As details of the optical layout were not fully provided by the manufacturer, an iterative procedure (based on imaging of calibrated spheres) was developed to estimate the camera lens specifi cations. The correction procedure was tested on Scheimpfl ug images of a physical water cell model eye (with polymethylmethacrylate cornea and a commercial IOL of known dimensions) and of a normal human eye previously measured with a corrected optical and geometrical distortion Scheimpfl ug camera (Topcon SL-45 [Topcon Medical Systems Inc] from the Vrije University, Amsterdam, Holland). RESULTS:Uncorrected Scheimpfl ug images show fl atter surfaces and thinner lenses than in reality. The application of geometrical and optical distortion correction algorithms improves the accuracy of the estimated anterior lens radii of curvature by 30% to 40% and of the estimated posterior lens by 50% to 100%. The average error in the retrieved radii was 0.37 and 0.46 mm for the anterior and posterior lens radii of curvature, respectively, and 0.048 mm for lens thickness. CONCLUSIONS:The Pentacam Scheimpfl ug system can be used to obtain quantitative information on the geometry of the crystalline lens, provided that geometrical and optical distortion correction algorithms are applied, within the accuracy of state-of-the art phakometry and biometry. The techniques could improve with exact knowledge of the technical specifi cations of the instrument, improved edge detection algorithms, consideration of aspheric and non-rotationally symmetrical surfaces, and introduction of a crystalline gradient index.

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Section: Discussionmentioning

confidence: 99%

Pentacam Scheimpflug Quantitative Imaging of the Crystalline Lens and Intraocular Lens

Rosales¹,

Marcos²

2009

J Refract Surg

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“…A "Phaco-Ersatz" or "lens refilling" method was proposed more than twenty years ago for use in ophthalmic surgery, whose purpose is the aspiration of the lens and subsequent refilling of the capsule with a biocompatible polymer that simulates the optical and mechanical properties of the young lens tissue, thereby restoring the transparency and accommodation function of the healthy lens [38,39]. This approach may find numerous applications in the treatment of some of the most common ocular disorders, such as presbyopia and lens opacification (cataract).…”

Section: Perspectives On New Welding Techniques: Laser Closure Of Thementioning

confidence: 99%

Laser tissue welding in ophthalmic surgery

Rossi¹,

Matteini²,

Ratto³

et al. 2008

Journal of Biophotonics

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Laser welding of ocular tissues is an alternative technique or adjunct to conventional suturing in ophthalmic surgery. It is based on the photothermal interaction of laser light with the main components of the extracellular matrix of connective tissues. The advantages of the welding procedure with respect to standard suturing and stapling are reduced operation times, lesser inflammation, faster healing and increased ability to induce tissue regeneration. The procedure we set up is based on the use of an infrared diode laser in association with the topical application of the chromophore Indocyanine Green. Laser light may be delivered either continuously or in pulses, thus identifying two different techniques that have been applied clinically in various types of transplants of the cornea.

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“…The result coming from this research was the world's first, commercially viable, AG-IOL technology, patented and published in June 2016, as aw orld patent. [22] Professor Jean-Marie Parel [81] from the University of Miami's-Bascom Palmer Eye Institute(BPEI) introduced and popularised the Phaco-Ersatz accommodating gel (AG) IOL concept, in conference papers, during 1981 and 1982 [82] before publishing this work in 1986 [83] plus other manuscripts]. [84][85][86] The concepti sw idely accepted.…”

Section: Accommodating Gel-intraocularl Ensmentioning

confidence: 99%

“…Figure 43 shows at ypicalh ealthy eye, and most importantly the lens, which can deteriorate with age, leading firstlyt opresbyopia and ultimately cataract blindness Figure 44 demonstratest he effects of presbyopia, also associated with cataract blindness, which alters the focus of light Parel discussed some research outcomes investigating Ersatz silicone materials for his "Phaco-Ersatz" procedure. Reported were room temperature vulcanised( RTV) silicone polymers and two-partL ow Temperature Vulcanised (LTV) silicones, [83,94,95] Norbby [96] published ap atentf or injectables ilicone polymers for intraocular lens use [97] and published ap atent for photocurable siliconeg el IOL [98] Koopmans published his PhD thesis [99][100][101][102] in 2006, investigating the "Phaco-Ersatz" procedure, but focussing on epithelial cell proliferation following AG IOL cataracts urgery.K oopmans used ac onfidential two-parth ydrosilylation platinum cured silicone polymer gel, assumed to have been provided for his research by Norrby. [103] Following Parel'sm anuscripts, many research teams attempted to produce aw orkable Phaco-Ersatz AG-IOL, but all failed.K nowing of BHVI'ss uccess, developing the world's first long-wearing, oxygen permeable, silicon-hydrogel contact lens, Parel formed ap artnership with BHVI in the 1990s.…”

Section: Accommodating Gel-intraocularl Ensmentioning

confidence: 99%

Advanced Silicon Chemistry in Australia: Forming Strong Links with Asia

Clarke¹,

Nguyen

Markovic³

et al. 2017

Chemistry An Asian Journal

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This paper details Australianc ommercial and academic silicon research. Areas of interest include silicon metal, polysiloxane polymers, copolymers, cyclics, emulsions, microemulsions, silanes, silane coupling agents, sol-gel chemistry and water-treatments, porouss ilicon, polysiloxane degradation, silicon hydrogel contact lenses, silanolate synthesis, siloxanei nterfacial polymerisation, hydrosilylation, polysiloxanee lectrolytes forl ithium ion batteries, silanes for PBX materials, octafunctionalized polyhedralo ligomeric silsesquioxanes (POSS), POSS hybrids, sol-gel hydrogenation catalysts, silane modification of silica, sol-gel energy storage, silicate grout stabilisation,G eoPolymer concretes, aerogel insulatingfoams,"Phaco-Ersatz"A ccommodating Gel-Intraocular Lens technologies. Strong collaborative opportunities, in silicon, with Asia, exist with organisationss uch as:1 )The Asian Silicon Society and 2) The Agency for the Assessment and Application of Technology (BPPT) Indonesia. General OverviewHigh-cost, specialised silicon materials, including silicone polymers, have reduced in price, over the years and,i nm any instances, are now competitive in cost and application,w ith counterpart petrochemical derived, organic materials and polymers. Clarson has identified the growth of silicon options, from a2 5% increase in annual demandf or silicon used in solar panel applications,w hichh as been the drivingf orce, pushing down the cost of many silicon applications. [1] Silicon materials have been used for aw ide variety of applications,a nd Australia has played ak een role in the development of many new silicon materials. Siliconm aterials are used for aw ide variety of applications including:s olar panelsf or electricale nergy;a pplicationsi ns pecialist materials;p hotonics;e nvironmental applications;m etallurgicala pplicationsa nd surfacemodification.[2]

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Phaco-Ersatz: Cataract surgery designed to preserve accommodation

Cited by 131 publications

References 9 publications

Pentacam Scheimpflug Quantitative Imaging of the Crystalline Lens and Intraocular Lens

Pentacam Scheimpflug Quantitative Imaging of the Crystalline Lens and Intraocular Lens

Laser tissue welding in ophthalmic surgery

Advanced Silicon Chemistry in Australia: Forming Strong Links with Asia

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