Titanium retinal tacks with pneumatic insertion. Histologic evaluation in rabbits.

Titanium retinal tacks were implanted through the formed vitreous into the posterior retinas of rabbits and evaluated by electroretinographic testing and by light microscopy at intervals after implantation. Tritiated thymidine autoradiography was used to evaluate the proliferation of ocular tissues in response to tack insertion. Within one month after implantation, the retinal tacks were surrounded by scar tissue produced by the proliferation of retinal glial cells and choroidal and scleral connective tissue cells. The tissue response was focal and there was no excessive fibrous tissue or vascular proliferation or any indication of iris neovascularization for six months. The observations of firm retinal adherence and low tissue reactivity suggest that titanium tacks can be used to secure the retina during retinal attachment surgery and can remain permanently in the eye.