Usability issues in developing a Web-based consumer health site.

ClinicalTrials.gov is a Web-based system intended for a diverse audience, including patients, family members and other members of the public. Throughout the system design and development process, our decisions have been driven by usability concerns. We first describe the overall design of the site, including the home page, which provides a site overview and rapid access to the information contained within it. Next we discuss the data presentation format which has been standardized in spite of data coming to us from many different sources. We provide a detailed description of the search and browse features that are intended to simplify the complexities of medical terminology and support information discovery. We conclude with a review of our evaluation activities and future plans.

Central lamellar keratoplasty for optical indications.

PURPOSE: This study aims to evaluate the results of lamellar keratoplasty (LKP) for optical (nontectonic) indications over the past 19 years at our institution, noting the advantages and pitfalls of the procedure. METHODS: The study is a retrospective review of 52 central LKPs in 37 patients. Snellen visual acuity, preoperative clinical indications, and postoperative status of the cornea (donor graft, graft-host interface, and recipient cornea) were assessed. RESULTS: Postoperative follow-up ranged from 3 months to 18 years (median, 3 years). In descending order of frequency, corneal dystrophies, aniridic keratopathy, corneal scars, and keratoconus were the most common indications for surgery. After surgery, 38% of the eyes were able to achieve 20/50 or better visual acuity. The two most common causes of poor visual acuity were (1) opacification and/or blood vessel growth in the graft-host interface or on the graft surface and (2) high astigmatism. Persistent epithelial defects occurred in 21% of the eyes after LKP. CONCLUSION: Although LKP provides a safer alternative to penetrating keratoplasty, it is limited by vision-reducing graft-host interface problems, astigmatism, and difficult surgical technique. We postulate that the current results of LKP may be improved by (1) removing as much recipient corneal stroma as possible (e.g., dissecting down to Descemet's membrane) or, alternatively, using an automated microkeratome and (2) raising the currently used qualitative eyebank standards for accepting LKP donor tissue.