Nontraumatic corneal perforation.

PURPOSE: To study the predisposing conditions, treatments, and visual outcomes of nontraumatic corneal perforations. METHODS: A retrospective chart review was conducted of all nontraumatic corneal perforations seen between January 1992 and December 1998, with > or = 3 months of follow-up, at the Cornea Service Wills Eye Hospital. RESULTS: A total of 40 nontraumatic corneal perforations was analyzed. Sixty-two percent of the cases were female. At presentation, 35 of 40 eyes (87.5%) had best corrected visual acuity of 20/200 or worse. The most common diseases associated with perforations were keratoconjunctivitis sicca (12 eyes, 30%), bacterial keratitis (6 eyes, 15%), exposure keratopathy (5 eyes, 12.5%), and herpes simplex virus (HSV) keratitis (4 eyes, 10%). Visual acuity improved > or = 2 Snellen lines in 3 of 8 eyes (37.5%) treated with penetrating keratoplasty, 5 of 14 eyes (35.7%) treated with tissue adhesive, and 1 of 12 eyes (8.3%) given medical treatment. After allowing for the different levels of presenting vision, treatment modality was not significantly related to final visual outcome. CONCLUSION: Keratoconjunctivitis sicca is the most common underlying disease associated with nontraumatic corneal perforation. Corneal perforations were managed successfully using tissue adhesive, medical therapy, or penetrating keratoplasty. Treatment depended on the characteristics of the perforation and on the visual potential of the eye.

CxGELSIX: a novel preparation of type VI collagen with possible use as a biomaterial.

PURPOSE: This study was initiated to evaluate tissue acceptance and stability of a novel type VI collagen preparation (CxGelsix) as a biomaterial in the rabbit corneal stroma. We hypothesized that CxGelsix, embedded intrastromally, does not have any adverse affect on surrounding corneal tissues, and remains intact in the presence of an acute inflammatory reaction during corneal wound healing. METHODS: Type VI collagen was extracted and purified from rabbit corneal stroma under nondenaturing conditions. This preparation, Gelsix, was concentrated and cross-linked with polyethylene glycol to produce a transparent film (CxGelsix). Discs of CxGelsix, 4.0-mm diameter, 9- to 35-microm thick were implanted intrastromally and clinically examined periodically for 4 months. In another experiment, implantation of CxGelsix, 2.0-mm-diameter, was followed by corneal wounding adjacent to the implant and examined clinically for 30 weeks. At the end of these periods, the tissues from these experiments were processed for light and transmission electron microscopy. RESULTS: An intralamellar 4.0-mm-diameter disc of CxGelsix does not alter the structure of corneal epithelium above the implant, suggesting normal transport of nutrients through CxGelsix. Moreover, no structural abnormalities were seen in the rest of the cornea, and the cornea remains transparent. Although the cornea accepts the presence of CxGelsix disc as judged by clinical criteria, gradual degradation of the implant is seen ultrastructurally. CxGelsix is remarkably stable despite its exposure to endogenous enzymes during inflammation and wound healing. Partial degradation of the implant occurs only after many months, and it is gradually replaced with bundles of fine collagen fibrils reminiscent of normal cornea. CONCLUSION: The results of this study suggest that CxGelsix is potentially useful as a biomaterial.