AlphaCor: Indications, Contraindications, Techniques and Outcomes
AlphaCor is a biocompatible, flexible, one-piece artificial cornea for patients whose corneal blindness is unlikely to be managed by means of standard penetrating keratoplasty. It is made from the hydrogel poly(2-hydroxyethyl methacrylate) (PHEMA) and uti
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Nada Jiraskova and Pavel Rozsival
Contents 24.1 Introduction and Background to the AlphaCor ...........................................
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24.2 Patient Selection: Indications and Contraindications ................................
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24.3 Surgical Techniques ....................................
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24.4 Routine Management ..................................
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24.5 Complications ..............................................
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24.6 Personal Experiences ..................................
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References ...............................................................
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N. Jiraskova, MD, PhD (*) • P. Rozsival, MD, PhD Department of Ophthalmology, Faculty of Medicine in Hradec Kralove, Charles University in Prague, Prague, Czech Republic e-mail: [email protected]; [email protected]
Introduction and Background to the AlphaCor
AlphaCor is an artificial cornea for patients whose corneal blindness is unlikely to be managed successfully by means of standard penetrating keratoplasty (PK) with donor corneal tissue. This device is intended to provide permanent (as defined by FDA), rather than temporary, corneal replacement. In appropriately selected patients, AlphaCor allows replacement of a diseased and opaque host cornea and allows transmission and refraction of light, with an acceptable field of view, restoring as much as possible of the patient’s full potential visual acuity. It’s design provides an acceptable cosmetic outcome. AlphaCor is a biocompatible, flexible, onepiece device made from poly(2-hydroxyethyl methacrylate) (PHEMA). The manufacture of AlphaCor utilises the different physical forms of PHEMA obtained by varying the water concentration during manufacture. The outer rim, or skirt, of the concentric core-and-skirt device comprises opaque high-water-content PHEMA sponge, with porous structure suitable for biointegration by cellular ingrowth and collagen deposition. The central core of the device is a transparent PHEMA gel, which provides the transparent optic with the required refractive power. The two concentric regions are joined by means of an interpenetration of polymers across
M. Soledad Cortina, J. de la Cruz (eds.), Keratoprostheses and Artificial Corneas: Fundamentals and Surgical Applications, DOI 10.1007/978-3-642-55179-6_24, © Springer-Verlag Berlin Heidelberg 2015
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Fig. 24.1 Photomicrographs of well-biointegrated AlphaCor explanted due to penetrating injury. Top left: overview. Top right and bottom: left side of the section, showing the cellular elements within the peripheral skirt of the device. Masson’s
trichrome stain, original magnification X20, X40, X100 and X200 (Published with permission of Liliana Werner, MD, PhD, John A. Moran Eye Center, University of Utah)
a junctional zone known as the interpenetrating polymer network (IPN) [1–3]. The entire device has a diameter of 7.0 mm, a thickness of 0.6 mm and surface curvatures that result in appropriate refractive power when implanted. The device is presently avai
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