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The purpose of this study was to evaluate corneal reepithelialization and wound healing following annular excimer keratectomy. Two sets of experiments were performed on 35 rabbit eyes. In the first set of experiments, experiment I, deep Fresnel excimer keratectomy was performed, with a 6-mm outer and 3-mm inner diameter. Animals were sacrificed at 1, 5, 12, and 16 weeks, and corneas were examined by light and electron microscopy. In experiment II, the central epithelium was left intact, and superficial and deep mid-peripheral excimer annular keratectomies were performed measuring 6 mm in outer and 3 mm in inner diameter. Animals were sacrificed at 1 week, and corneas were examined by light microscopy. Following deep Fresnel excimer keratectomy (experiment I), corneas showed stromal edema in the central 3-mm zone. Intrastromal islands of epithelial cells with PAS positive basement membrane-like structures were seen histologically at 1 week. Electron microscopy showed loss of stromal collagen in areas adjacent to epithelial islands; in areas distant from the epithelial islands, the stromal collagen appeared normal. The overlying central stroma sloughed after 5 weeks. Anterior stromal scarring was observed. In experiment II (mid-peripheral annular keratectomy), intrastromal epithelial accretion was present in corneas with deep annular keratectomy but not in superficial annular keratectomy. Intrastromal epithelial accretion follows deep excimer annular keratectomy and is associated with adjacent stromal degradation.

The Collaborative Corneal Transplantation Studies (CCTS) were designed to evaluate the effect of donor-recipient histocompatibility matching and cross-matching on the survival of corneal transplants in high-risk patients. We now report on the role of symptoms in the detection of corneal allograft reactions in the CCTS and on the relationship between symptom reporting and graft survival. The 456 patients transplanted in the CCTS were followed for a minimum of 2 years or until graft failure. The follow-up protocol included 11 scheduled examinations in the first year, four examinations during the second year, and examinations every 6 months thereafter. Interim examinations were performed in response to patient-reported symptoms. At every examination, patients were asked specifically if they had redness, sensitivity to light, loss of vision, or pain (RSVP). Of the 456 patients transplanted, 62% had at least one graft reaction. Patients diagnosed with reactions at scheduled visits in the first postoperative year were 2.5 times more likely to report symptoms than those without reactions. Reports of red eye and vision loss were strongly associated with allograft reaction. However, these symptoms were neither highly sensitive nor specific for reaction (sensitivity = 46%, specificity = 70% at 6 months). The severity of reaction influenced the reporting of symptoms: 69% of patients with severe reactions reported symptoms versus 48% of patients with mild reactions (p < 0.001). The only patient characteristic associated with reliable symptom reporting was age, with younger patients with reactions being more likely to report symptoms.(ABSTRACT TRUNCATED AT 250 WORDS)

The authors describe the clinical, molecular genetic, and pathologic findings of a patient with corneal decompensation associated with the mitochondrial ophthalmoplegia plus (Kearns-Sayre) syndrome. Ultrastructurally abnormal mitochondria were observed and possibly implicate this organelle in the pathogenesis of corneal edema.

Eighteen suture abscesses that developed after penetrating keratoplasty in 15 patients were reviewed. The time from keratoplasty to the diagnosis of an abscess ranged from 1 to 53 months with a mean of 21.5 months. In 13 of the 18 cases, the patient was taking topical steroids at the time of diagnosis. All were culture-proven bacterial ulcers, except for one case that had a positive Gram's stain, but no growth on culture. The organisms cultured were Staphylococcus epidemidis (six eyes), Streptococcus pneumoniae (five eyes), Sta. aureus (four eyes), Str. viridans (two eyes), Klebsiella oxytoca (one eye), Serratia marcescens (one eye), Moraxella sp (one eye), and Escherichia coli (one eye). The offending suture was removed in all cases, and the eyes were treated with topical fortified antibiotics (cefazolin and tobramycin). After treatment, 67% (12 of 18 eyes) had clear grafts, 17% (three of 18 eyes) were scarred, and 16% (three of 19 eyes) had failed grafts. Intensive topical steroid therapy was used when a subsequent graft rejection developed. Retained sutures following corneal transplants can result in sight-threatening infections and should be considered for removal as soon as the wound is well healed.

Cornea transplantation offers the hope of restoring useful vision to millions of individuals worldwide. Yet it is widely used only in certain countries. While a lack of the necessary economic and technical infrastructure is the primary reason in many countries, the legal and social systems pose a similar obstacle in many other more prosperous countries. This article reviews the current laws governing organ and tissue donation throughout the world and distinguishes those that are most successful in obtaining tissue for transplantation.

Although epikeratoplasty (epikeratophakia) for aphakia in children has achieved a high degree of success, there remains a significant incidence of complications, some of which may result in removal of the lenticule. We report a 2-year-old child in whom epikeratoplasty was followed by an acute suppurative keratitis, necessitating removal of the epikeratoplasty lenticule. The recipient bed remained scarred following removal of the lenticule with anterior stomal fibrosis, which precluded good vision. We were able to avoid a penetrating keratoplasty by performing a superficial lamellar keratoplasty with a repeat epikeratoplasty that has remained clear.

Dextran, a high molecular weight polymer of glucose, is used as an osmotic agent in McCarey-Kaufman (MK) (corneal storage) medium. It has been proposed that Dextran may cause deleterious effects on living cells either by high molecular weight toxicity or by the induction of an immunological reaction against transplanted tissues. Prolonged retention of Dextran in transplanted corneas, therefore, may produce deleterious side effects. The efflux of Dextran from MK-stored human corneas was monitored by transferring corneas to 2 ml of fresh Krebs Ringer bicarbonate solution (BSS) containing 5.5 mM 1-13C-labeled glucose at approximately 1 h intervals for 1-24 h. Chemical shifts of 98.7, 74.5, 72.5, 71.2, 70.6, and 66.5 ppm were found for the naturally abundant 13C NMR spectrum of 40,000 molecular weight Dextran. Peak heights for the 70.6 ppm Dextran chemical shift were measured and plotted against total wash time to determine the slope for Dextran efflux from each cornea. The results of this study suggest that all of the Dextran absorbed into human corneas stored for up to 2 weeks in MK medium is eluted in about 19 h and that the rate of Dextran efflux is unaffected by donor age, time of storage in MK, or corneal viability.