title: Electron microscopic study of intrastromal hydrogel implants in primates.
abstract: Three corneas with intrastromal hydrogel implants (surfilcon A) were removed from Green monkey eyes by penetrating keratoplasty and examined by light microscopy, as well as scanning and transmission electron microscopy, in order to assess the tolerance of the primate cornea for this type of synthetic plastic. Placement of these implants in the posterior cornea appears to increase the amount of protrusion into the anterior chamber, which can also be seen clinically on slit-lamp biomicroscopy. Some physiological stress to the cornea was indicated by abnormalities above and below the implant, including thinned epithelium, irregular cell shapes, and vacuolations. It appears that a basement-membrane-like material is produced by keratocytes adjacent to the implant-stroma interface, and that this material fills the spaces and provides some physical continuity between the plastic and the corneal tissue. No inflammatory reaction was seen around the implants, but further long-term studies are necessary to ensure compatibility between the cornea and the implant.
mesh_terms: D000818:Animals; D002522:Chlorocebus aethiops; D003315:Cornea / Q000187:drug effects*; D004848:Epithelium / Q000187:drug effects; D020136:Hydrogel, Polyethylene Glycol Dimethacrylate; D007910:Lenses, Intraocular / Q000009:adverse effects*; D008768:Methylmethacrylates / Q000633:toxicity*; D008854:Microscopy, Electron; D011092:Polyethylene Glycols / Q000633:toxicity*; D011205:Povidone / Q000633:toxicity*
chemical_list: D008768:Methylmethacrylates; D020136:Hydrogel, Polyethylene Glycol Dimethacrylate; C043896:Duragel 75; D011092:Polyethylene Glycols; D011205:Povidone