Review Biomaterials for orbital implants and ocular prostheses: Overview and future prospects Francesco Baino a,⇑ , Sergio Perero a,b , Sara Ferraris a , Marta Miola a , Cristina Balagna a , Enrica Verné a , Chiara Vitale-Brovarone a , Andrea Coggiola c , Daniela Dolcino c , Monica Ferraris a a Institute of Materials Physics and Engineering, Applied Science and Technology Department, Politecnico di Torino, Corso Duca degli Abruzzi 24, Torino, Italy b Istituto Superiore Mario Boella, Torino, Italy c S.O.C. Oculistica, Azienda Ospedaliera Nazionale SS. Antonio e Biagio e Cesare Arrigo, Via Venezia 16, Alessandria, Italy article info Article history: Received 19 July 2013 Received in revised form 29 November 2013 Accepted 9 December 2013 Available online 14 December 2013 Keywords: Orbital implant Ocular prosthesis Enucleation Porous biomaterials Antibacterial properties abstract The removal of an eye is one of the most difficult and dramatic decisions that a surgeon must consider in case of severe trauma or life-threatening diseases to the patient. The philosophy behind the design of orbital implants has evolved significantly over the last 60 years, and the use of ever more appropriate bio- materials has successfully reduced the complication rate and improved the patient’s clinical outcomes and satisfaction. This review provides a comprehensive picture of the main advances that have been made in the development of innovative biomaterials for orbital implants and ocular prostheses. Specifi- cally, the advantages, limitations and performance of the existing devices are examined and critically compared, and the potential of new, smart and suitable biomaterials are described and discussed in detail to outline a forecast for future research directions. Ó 2013 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved. 1. Introduction Dating back thousands of years, there is evidence that the Sume- rians and Egyptians were able to surgically remove the ocular globe as well as to make artificial eyes; however, it was not until the late 1500s that enucleation procedures were reported in detail in the medical literature [1]. The advances in this field progressed rela- tively slowly, and only in 1885 was the use of a well-defined orbital implant, a glass sphere, to restore the socket volume documented [2]. Improvements in surgical techniques, anesthesia, implant materials and design over the last decades have significantly im- proved clinical outcomes and patient satisfaction. Furthermore, the ability to more effectively deal with the long-term complica- tions of the anophthalmic socket, such as enophthalmos, exposure and lower lid laxity (ectropion), have greatly improved. Today, most patients can confidently return to their daily activities with good cosmetic results following the removal of an eye. This article chronicles the evolution of orbital implants and ocu- lar prostheses, gives a comprehensive overview of the current state of the art and provides a picture for prospective research. Other de- vices used in oculo-orbital surgery, such as the biomaterials for orbital floor repair, have been recently reviewed elsewhere [3–5] and are not included in the present work. Medical details are often given, so that the reader can well understand the key problems related to the use and applications of the described devices, the suitability and limitations of existing solutions, and the potential of some novel approaches suggested at the end of the article. This review is divided into three parts, devoted to presenting an essential medical background, a comprehensive materials/im- plants review, and some indications for prospective research and future challenges, respectively. The first part, Section 2, gives the reader a concise overview of the surgical approaches that can be adopted to remove a diseased eye, as well as the basic information related to orbital implants and ocular prostheses. In this context, Table 1 provides a short glossary of the medical terms that are not explained directly in the text and which may be unclear or un- known to non-specialist readers. In the second part, the different types of biomaterials and devices used as orbital implants (Sec- tion 3) and ocular prostheses (Section 4) are extensively reviewed. At the end of Section 3, an organized and critical comparison among the several existing types of orbital implants is provided. The third part, Section 5, presents the future challenges in the field and particularly highlights the potential of new experimental bio- materials with advanced properties (e.g. angiogenetic ability, con- trolled resorption, antiseptic functionality). 1742-7061/$ - see front matter Ó 2013 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved. http://dx.doi.org/10.1016/j.actbio.2013.12.014 ⇑ Corresponding author. Tel.: +39 011 090 4668; fax: +39 011 090 4624. E-mail address: francesco.baino@polito.it (F. Baino). Acta Biomaterialia 10 (2014) 1064–1087 Contents lists available at ScienceDirect Acta Biomaterialia journal homepage: www.elsevier.com/locate/actabiomat