MIRAGEL VERSUS SILASTIC USED AS EPISCLERAL IMPLANTS IN RABBITS - AN EXPERIMENTAL AND HISTOPATHOLOGIC COMPARATIVE-STUDY

Purpose: Tissue reactions to two different biomaterials implanted on t he sclera of rabbit eyes, a silicone implant (Silastic;.Dow Coming) an d a hydrogel (Miragel; Mira Inc.), were evaluated. Methods: Both mater ials were implanted on the scleral surface under the superior rectus t o obtain a focal scleral buckling. Histopathologic examination of the 32 eyes was performed with transmission electron microscopy 5 to 8 mon ths after implantation. Results: During the follow-up period, 6 silico ne implants were extruded, compared with only one hydrogel implant. Hi stopathologically, both types of implants were surrounded by a newly f ormed fibrous capsule. Only the hydrogel implant gave rise to a granul omatous foreign body reaction against its own fragments, however. Conc lusion: The main difference between the two types of material was a su perficial fragmentation of the hydrogel implants. The reason for this fragmentation is unknown, To our knowledge, this is the first reported case of foreign body giant cell granuloma that developed against a hy drogel implant.