[Introduction of a novel video retinoscope : Application of a conventional retinoscope and video retinoscope in teaching-A comparative pilot study]. / Vorstellung eines neuartigen Videoskiaskops : Einsatz von konventionellem Skiaskop und Videoskiaskop in der Lehre ­ eine vergleichende Pilotstudie.

The video retinoscope presented here makes it possible for the first time to interactively demonstrate, discuss, evaluate and document optical phenomena with the aid of an integrated touch display. The precision in relation to the objective refraction results between the conventional retinoscope (CS) and video retinoscope (VS) is comparable (p = 0.093, Wilcoxon test). On the basis of questionnaires using visual analogue scales (0 = very unfavorable/10 = very favorable; subsequently the median/interquartile range is given) during a pilot study, 12 test persons rated the CS (VS) with respect to the feasibility of continuous light band movements with 6.9/1.3 (6.0/4.2) and the ease of use with 8.1/2.1 (8.9/1.6) out of a maximum of 10 points each and thus both retinoscopes as equivalent. In terms of weight, the subjects favored the conventional retinoscope with a rating of 8.7/2.2 (4.0/4.8).

[Interactive training using a smartphone video retinoscope : Video article]. / Interaktives Training mittels Smartphone-Videoskiaskop : Videobeitrag.

BACKGROUND: The purpose of this project is to apply and optimize a conventional streak retinoscope connected to a smartphone in order to demonstrate and record retinoscopic techniques, related phenomena, typical examination errors in a standardized environment and to use this set-up to produce instructional video clips. The videos enhance and improve the trainer-trainee interaction by instantly visualizing the optical phenomena on the integrated monitor of the retinoscope. METHODS: A smartphone (iPhone 6, Apple, Cupertino, CA, USA) is reversibly connected to a Beta 200 streak retinoscope (HEINE, Herrsching, Germany) via a coupling plate. This allows visualization of the optical phenomena on the screen of a smartphone, which can also be used for recording. To stabilize the recording conditions, the battery handle of the retinoscope is connected to a 3-axis gimbal (Zhiyun Crane Plus, Zhiyun, Guilin, China). In this way the examination unit can be rotated around all axes without any relevant changes in distance. A software-based post-processing (Adobe Premiere Pro CC 2017, Adobe Systems Software Ireland Limited, Dublin. Ireland) of the video sequences almost completely eliminates motion artefacts. RESULTS: With the aforementioned experimental set-up, the following optical phenomena have so far been documented as videos, which are available online: flashing point, with-movement and against-movement, scissors phenomenon, cataract, astigmatic ametropia and refraction scotoma. CONCLUSION: For the first time smartphone video retinoscopy allows optical phenomena to be presented to the examiner (trainee) and trainer at the same time and to produce realistic instructional videos of high quality with comparatively little effort.

Corneal topography with an aberrometry-topography system.

PURPOSE: To investigate the agreement between the central corneal radii and corneal eccentricity measurements generated by the new Wave Analyzer 700 Medica (WAV) compared to the Keratograph 4 (KER) and to test the repeatability of the instruments. METHODS: 20 subjects (10 male, mean age 29.1 years, range 21-50 years) were recruited from the students and staff of the Cologne School of Optometry. Central corneal radii for the flat (rc/fl) and steep (rc/st) meridian as well as corneal eccentricity for the nasal (enas), temporal (etemp), inferior (einf) and superior (esup) directions were measured using WAV and KER by one examiner in a randomized order. RESULTS: Central radii of the flat (rc/fl) and steep (rc/st) meridian measured with both instruments were statically significantly correlated (r = 0.945 and r = 0.951; p < 0.001). Comparison between the WAV and KER showed that rc/fl and rc/st measured with WAV were significantly steeper than those measured with KER (p < 0.001). Corneal eccentricities were statistically significantly correlated in all meridians (p < 0.05). Compared to KER, etemp and esup measured with WAV were greater (p < 0.05), while there were no statistically significant differences for enas and einf (p = 0.350 and p = 0.083). For the central radii, repeated measurements were not significantly different for the KER or WAV (p > 0.05). Limits of agreement (LoA) indicate a better repeatability for the KER compared to WAV. CONCLUSIONS: Corneal topography measurements captured with the WAV were strongly correlated with the KER. However, due to the differences in measured corneal radii and eccentricities, the devices cannot be used interchangeably. For corneal topography the KER demonstrated better repeatability.