Research and Development of Biodegradable Scleral Plug for CMV Retinitis

• Main Authors: Chin Wei Wen, 溫慶偉
• Other Authors: S. J. Liu
• Format: Others
• Published: 2009
• Online Access: http://ndltd.ncl.edu.tw/handle/84611882922082225101

碩士 === 長庚大學 === 醫療機電工程研究所 === 97 === Cytomegalovirus (CMV) retinitis is a frequent opportunistic ocular infection in immune-compromised patients, especially in AIDS patients. Before the widely use of highly active antiretroviral therapy (HAART), lifelong anti-CMV therapy was demanded for such patients. In the HAART era, cessation of specific anti-CMV therapy may be possible if immune recovery is achieved after introduction of HAART. Ganciclovir was widely used as the first line therapy for the CMV retinitis for a long time. But CMV retinitis that is resistant to ganciclovir mono-therapy is frequently encountered. Combined therapy with ganciclovir and foscarnet has been reported with good response in resistant cases. Although the anti-CMV therapy may be discontinued after a period of immune recovery, the maintenance of intraocular pharmaceutical level of anti-CMV drugs for a certain period was still required at acute infection stage. Previously, repeated intravitreal injections, usually twice a week, were commonly performed, but repeated injections contributed to the potential risk of secondary intraocular infection and rhegmatogenous retinal detachment. A ganciclovir device implantation is another alternative, which provides prolong release of ganciclovir monothearpy. But the implantation procedure needs large sclerotomy incision and makes possible of related complications. We develop a sintering process which incorporating both ganciclovir and foscarnet with polylactide-polyglycolide at low temperature into a biodegradable scleral plug. The plug provides sustained release of both ganciclovir and foscarnet for an extended period both in vitro and in vivo, besides, the biodegradable nature prevents the necessity of secondary explantation. The biocompatibility of the plugs was further evaluated by histopathology study and electroretinogram (ERG) in an experimental rabbit animal model. In conclusion, this study aims at development of biodegradable scleral plugs which provide sustained release of combination therapy for CMV retintis. The biocompatibility and release profile of the plug were thoroughly evaluated. Keyword: Cytomegalovirus(CMV) retintis, biodegradable scleral plug, polylactide-polyglycolide, ganciclovir, foscarnet, in vitro, in vivo, biocompatibility, histopathology, electroretinogram (ERG)