糖尿病与圆锥角膜是否具有相关性

Purpose: To examine whether there is an association between diabetes mellitus (DM) and keratoconus. Design: A retrospective comparison of the proportion of keratoconus patients with DM versus the proportion of overall patients with DM,and a retrospective cross-sectional study of a cohort consisting of all diabetic keratoconus patients and randomly selected keratoconus patients without DM at a single center. Participants: Patients seen at theWilmer Eye Institute from January 1,1995,through March 18,2004. Methods: Review of billing data and clinic charts. Eligibility criteria for the cross-sectional study were 1 or more clinic visits,lack of other eye pathologic features (excluding cataract and diabetic retinopathy),and absence of bilateral penetrating keratoplasty (PK) at presentation. Application of novel keratoconus severity index was based on best-corrected visual acuity (BCVA) in the better eye at last visit and defined as: grade 1 (least severe),spectacle wear with BCVA of 20/40 or better; grade 2 (intermediate),spectacle wear with BCVA worse than 20/40 or rigid gas permeable lens wear; grade 3 (most severe),PK. Main Outcome Measures: Prevalence of DM in keratoconus patients and those without keratoconus,odds ratio of having DM on a diagnosis of more severe keratoconus,and prevalence of DM in keratoconus patients and those without keratoconus who underwent corneal transplantation. Results: There was no difference in the prevalence of DM in keratoconus patients and those without keratoconus,and there was no difference in the prevalence of DM in keratoconus patients and those without keratoconus undergoing PK. However,our results suggest a negative association between DM and severity of keratoconus (P=0.03,Fisher exact test). The odds of being in the most severe group as opposed to the least severe group were lower in DM patients than in those without DM(P=0.01; odds ratio OR=0.20; 95% confidence interval CI,0.05-0.70). Compared with those without DM,DM patients also had lower odds of being in the intermediate group than in the least severe group (P=0.02; OR=0.25; 95% CI,0.08-0.80). After adjustment for age,gender,and race,these differences remained statistically significant. Conclusions: We found that DM is not associated with a diagnosis of keratoconus,but having DM decreases the odds of having more severe keratoconus.

组织黏合剂在改良的显微角膜刀辅助的后板层角膜移植术中的应用

Objective: To compare graft stability and astigmatic change using suture vs tissue adhesive in an experimental model of microkeratome-assisted posterior lamellar keratoplasty. Methods: A 300-μ m-thick partial flap keratectomy was performed in human donor corneoscleral rims using an artificial anterior chamber and a manual microkeratome. The flap stopped at the left central opening border,providing a wide hinge to add stability. After flap reflection,a 6.25-mm trephination was performed to obtain a disc of posterior stroma,Descemet membrane,and endothelium. The disc was positioned in a sutureless fashion,and the flap secured with either 5 interrupted sutures or a chondroitin-sulfate-aldehyde-based adhesive. Increasing intrachamber pressures were created to detect graft stability. Videokeratographic data were recorded to evaluate astigmatic change. Results: The mean (SD) astigmatic change was 3.08 (0.84) diopters (D) in the sutured group and 1.13 (0.55) D in the glued group (P=.008). Mean (SD) resisted pressures were 95.68 (27.38) mm Hg and 82.45 (18.40) mm Hg in the sutured and glued groups,respectively (P=.97). Conclusion: This modified technique of microkeratome-assisted posterior lamellar keratoplasty showed excellent graft stability in both groups. Flaps sealed with the novel tissue adhesive had reduced astigmatic changes in our experimental model. Clinical Relevance: Sutureless microkeratome-assisted posterior lamellar keratoplasty using tissue adhesive may become a new alternative in the surgical treatment of corneal endothelial disorders.