Constantin E. Uhlig

Efficiencies of Internet-Based Digital and Paper-Based Scientific Surveys and the Estimated Costs and Time for Different-Sized Cohorts

Aims To evaluate the relative efficiencies of five Internet-based digital and three paper-based scientific surveys and to estimate the costs for different-sized cohorts. Methods Invitations to participate in a survey were distributed via e-mail to employees of two university hospitals (E1 and E2) and to members of a medical association (E3), as a link placed in a special text on the municipal homepage regularly read by the administrative employees of two cities (H1 and H2), and paper-based to workers at an automobile enterprise (P1) and college (P2) and senior (P3) students. The main parameters analyzed included the numbers of invited and actual participants, and the time and cost to complete the survey. Statistical analysis was descriptive, except for the Kruskal-Wallis-H-test, which was used to compare the three recruitment methods. Cost efficiencies were compared and extrapolated to different-sized cohorts. Results The ratios of completely answered questionnaires to distributed questionnaires were between 81.5% (E1) and 97.4% (P2). Between 6.4% (P1) and 57.0% (P2) of the invited participants completely answered the questionnaires. The costs per completely answered questionnaire were

A dummy orbit for training in diagnostic procedures and laser surgery with enucleated eyes

0.57–

Intravitreal recombinant tissue plasminogen activator without and with additional gas injection in patients with submacular haemorrhage associated with age-related macular degeneration

1.41 (E1–3),

Long-term efficacy of glycerine-processed amniotic membrane transplantation in patients with corneal ulcer

1.70 and

Fibrin sealing improves stability of corneal prostheses during vitreoretinal procedures.

0.80 for H1 and H2, respectively, and

Morphological and histopathological changes in gelatinous drop-like corneal dystrophy during a 15-year follow-up

3.36–

Ergebnisse einer internetbasierten Umfrage zur Hornhautspendebereitschaft bei DOG-Mitgliedern

4.21 (P1–3). Based on our results, electronic surveys with 10, 20, 30, or 42 questions would be estimated to be most cost (and time) efficient if more than 101.6–225.9 (128.2–391.7), 139.8–229.2 (93.8–193.6), 165.8–230.6 (68.7–115.7), or 188.2–231.5 (44.4–72.7) participants were required, respectively. Conclusions The study efficiency depended on the technical modalities of the survey methods and engagement of the participants. Depending on our study design, our results suggest that in similar projects that will certainly have more than two to three hundred required participants, the most efficient way of conducting a questionnaire-based survey is likely via the Internet with a digital questionnaire, specifically via a centralized e-mail.

Development and evaluation of a device for sutureless and repeated application of amniotic membrane overlays.

PURPOSE A dummy orbit for enucleated eyes was developed for training residents in diagnostic and surgical procedures. METHODS Porcine eyes were used to construct the model. The device is made of black anodized metal. The final prototype was tested for ease of use and optical quality. Principal elements are an adjustable eye support, a cylinder, and a removable ring. RESULTS The dummy orbit and enucleated eye allow direct and indirect ophthalmoscopy; inspection with contact lenses, including gonioscopy; and retinal laser coagulation using contact lenses. Laser trabeculoplasty, argon laser trabeculotomy, Nd:YAG laser iridectomy, and Nd:YAG laser capsulectomy are possible, as well as training in tonometry and ultrasonography techniques. CONCLUSION The dummy orbit is a valuable aid for teaching and training in diagnostic and laser surgery procedures with nondissected enucleated eyes.

Development of Microelectronic Visual Implants

Purpose:  To compare intravitreal recombinant tissue plasminogen activator (rt‐PA) treatment with and without gas injection in patients with submacular haemorrhage associated with age‐related macular degeneration.

Combined Excimer Laser Photoablation and Amniotic Membrane Overlay for Relief of Symptomatic Discomfort in Gelatinous Drop-like Corneal Dystrophy.

The aim of this study was to determine the long‐term treatment efficacy of glycerine‐preserved human amniotic membrane transplantation in patients suffering from corneal ulcers.