How can bioactive glasses be useful in ocular surgery?

In the last few decades, the introduction of bioactive glasses (BGs), a special class of bioceramics that are able to bond to living tissues stimulating new tissue growth, has improved both treatment procedures via reconstructive surgery and the quality of life of rehabilitated patients in orthopedics and dentistry. While BGs have been extensively investigated for applications in these two surgical fields, there has been relatively little research on their use in other medical areas. Glass has been used for centuries to produce external refractive lenses and the intraocular implantation of small glass disks to correct visual deficiencies has been documented since the mid 1700s. Moreover, some evidences reported in the recent literature seem to demonstrate that the success of three specific types of ophthalmic devices, that is, synthetic grafts for eye orbit bone repair, orbital implants replacing the whole ocular globe and keratoprostheses (artificial cornea), could significantly benefit by the use of BG. A prospective view as well as a state-of-the-art review on this topic are currently lacking in the literature. The present article aims to give a comprehensive picture of the BG-based implants that have been developed in the context of ocular surgery; the strengths and shortcomings of the existing devices are outlined in order to provide useful stimuli for future research. Promising research directions are also proposed, emphasizing the added values that BGs could carry in ophthalmology in the light of recent findings in tissue engineering and regenerative medicine.