Miragel versus silastic used as episcleral implants in rabbits. An experimental and histopathologic comparative study.
OBJECTIVE
Tissue reactions to two different biomaterials implanted on the sclera of rabbit eyes, a silicone implant (Silastic; Dow Corning) and a hydrogel (Miragel; Mira Inc.), were evaluated.


METHODS
Both materials were implanted on the scleral surface under the superior rectus to obtain a focal scleral buckling. Histopathologic examination of the 32 eyes was performed with transmission electron microscopy 5 to 8 months after implantation.


RESULTS
During the follow-up period, 6 silicone implants were extruded, compared with only one hydrogel implant. Histopathologically, both types of implants were surrounded by a newly formed fibrous capsule. Only the hydrogel implant gave rise to a granulomatous foreign body reaction against its own fragments, however.


CONCLUSIONS
The main difference between the two types of material was a superficial 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 hydrogel implant.
D'Hermies
F
F
Department of Ophthalmology, Hotel Dieu, Paris, France.
Korobelnik
J F
JF
Savoldelli
M
M
Chauvaud
D
D
Pouliquen
Y
Y
D000818:Animals; D001672:Biocompatible Materials; D005355:Fibrosis; D005500:Follow-Up Studies; D015745:Granuloma, Foreign-Body / Q000209:etiology* / Q000473:pathology; D011102:Polyhydroxyethyl Methacrylate / Q000009:adverse effects / Q000031:analogs & derivatives*; D019736:Prostheses and Implants / Q000009:adverse effects*; D011817:Rabbits; D012590:Sclera / Q000473:pathology* / Q000601:surgery; D012591:Scleral Buckling; D012826:Silicone Elastomers / Q000009:adverse effects*
D001672:Biocompatible Materials; D012826:Silicone Elastomers; C065274:Miragel; D011102:Polyhydroxyethyl Methacrylate