Binocular eye tracking with the Tracking Scanning Laser Ophthalmoscope.

The development of high magnification retinal imaging has brought with it the ability to track eye motion with a precision of less than an arc minute. Previously these systems have provided only monocular records. Here we describe a modification to the Tracking Scanning Laser Ophthalmoscope (Sheehy et al., 2012) that splits the optical path in a way that slows the left and right retinas to be scanned almost simultaneously by a single system. A mirror placed at a retinal conjugate point redirects half of each horizontal scan line to the fellow eye. The collected video is a split image with left and right retinas appearing side by side in each frame. Analysis of the retinal motion in the recorded video provides an eye movement trace with very high temporal and spatial resolution. Results are presented from scans of subjects with normal ocular motility that fixated steadily on a green laser dot. The retinas were scanned at 4° eccentricity with a 2° square field. Eye position was extracted offline from recorded videos with an FFT based image analysis program written in Matlab. The noise level of the tracking was estimated to range from 0.25 to 0.5arcmin SD for three subjects. In the binocular recordings, the left eye/right eye difference was 1-2arcmin SD for vertical motion and 10-15arcmin SD for horizontal motion, in agreement with published values from other tracking techniques.

The quality of health services research in medical practice in the United Kingdom.

STUDY OBJECTIVE: The aim was to determine the scope and quality of published health services research concerned with medical practice in the United Kingdom. DESIGN: Scope of health services research was reviewed in articles published in 41 medical and public health journals in 1985. In random sample of 60 papers stratified by study design, 18 key research parameters were assessed for the quality of reporting and application in the studies. MAIN RESULTS: Over 80% of the research described in 246 articles was carried out by clinicians, mostly without acknowledged epidemiological or statistical assistance. More than half the studies were descriptive and only 17% were trials. In studies of hospital services, 4% covered long term care, in contrast to 67% concerned with inpatient care. One third of studies were conducted in general practice but only 10% of these included an assessment of clinical outcome. Important research parameters were often not reported; for example, response rates were missing in 52% of the studies, and comparability of cases and controls was not stated in 42% of relevant studies. Major inadequacies were found in the conduct of research, particularly in the selection of controls, allowance for confounding factors, objectivity of measurements, application of statistical tests, and conclusions reached. CONCLUSIONS: Published health services research concerned with medical practice in the United Kingdom is often conducted by clinicians without expert assistance. The quality of reporting and methods employed are deficient in many respects. Short training courses and other initiatives are required to enhance the quality of health services research in medical practice.