Fibrovascular response to retinal tacks in the rabbit and monkey eye

In order to evaluate the tissue response to metal retinal tacks experiments were carried out on 4 monkey eyes and compared to those on 4 rabbits. Non-magnetic retinal tacks (Grieshaber, Switzerland) and tacks made of 24 carat gold (our own brand) were inserted into the ocular fundus under microscopic control. The animals were kept for 3 months. In monkey eyes, histological examination disclosed a considerable fibrovascular proliferation around the retinal tack canal, including an inflammatory response, formation of collagenous tissue and glial proliferation. There was a local intra-retinal and epi-retinal neovascularization. In the rabbit retina, only a slight inflammation and thin collagenous tissue developed. Thus the tissue response was much more severe in the primate eye than in the avascular rabbit retina.