Tissue Translocation Device for Surgical Correction of Age-Related Macular Degeneration

Abstract

Age-related macular degeneration (AMD) is the leading cause of blindness in the western world in those over age 60. While this disorder is complex, the origin of injury appears to be at the level of the retinal pigment epithelium (RPE), Bruchs membrane, and inner choroid. A potential method to replace damaged tissue in AMD is to harvest healthy donor tissue (RPE-Bruchs-Choroid) from an eye and translocate it to the injured subretinal region. Such an autograft avoids immune mediated rejection and can theoretically restore function to the neurosensory retina (light sensitive part of the retina) by restoring the damaged tissue. Such a procedure requires the design of a device that mechanically supports the integrity of the graft while inside the eye, without injuring or disrupting the tissue. This paper presents the systematic design and manufacture of a thin shape memory foil-based tissue translocation device. The selected embodiment of the design uses thermal adhesion of the tissue to the foil surfaces for tissue support. The shape memory effect enables insertion of the device into the eye via a small incision. The device is manufactured using micromachining techniques and has been tested both ex vivo and in vivo with acceptable anatomic results.