Strabismus Measurements with Novel Video Goggles
Authors: Konrad P. Weber, Daniel Rappoport, Muriel Dysli, Tanja Schmückle Meier, Guy B. Marks, Christopher J. Bockisch, Klara Landau, Hamish G. MacDougall
Journal: Ophthalmology (2017)

PurposeTo assess the validity of a novel, simplified, noninvasive test for strabismus using video goggles.DesignCross-sectional method comparison study in which the new test, the strabismus video goggles, is compared with the existing reference standard, the Hess screen test.ParticipantsWe studied 41 adult and child patients aged ≥6 years with ocular misalignment owing to congenital or acquired paralytic or comitant strabismus and 17 healthy volunteers.MethodsAll participants were tested with binocular infrared video goggles with built-in laser target projection and liquid crystal display shutters for alternate occlusion of the eyes and the conventional Hess screen test. In both tests, ocular deviations were measured on a 9-point target grid located at 0±15° horizontal and vertical eccentricity.Main Outcome MeasuresHorizontal and vertical ocular deviations at 9 different gaze positions of each eye were measured by the strabismus video goggles and the Hess screen test. Agreement was quantified as the intraclass correlation coefficient. Secondary outcomes were the utility of the goggles in patients with visual suppression and in children.ResultsThere was good agreement between the strabismus video goggles and the Hess screen test in the measurements of horizontal and vertical deviation (intraclass correlation coefficient horizontal 0.83, 95% confidence interval [0.77, 0.88], vertical 0.76, 95% confidence interval [0.68, 0.82]). Both methods reproduced the characteristic strabismus patterns in the 9-point grid. In contrast to Hess screen testing, strabismus video goggle measurements were even possible in patients with comitant strabismus and visual suppression.ConclusionsThe new device is simple and is fast and accurate in measuring ocular deviations, and the results are closely correlated with those obtained using the conventional Hess screen test. It can even be used in patients with visual suppression who are not suitable for the Hess screen test. The device can be applied in children as young as 6 years of age. To assess the validity of a novel, simplified, noninvasive test for strabismus using video goggles. Cross-sectional method comparison study in which the new test, the strabismus video goggles, is compared with the existing reference standard, the Hess screen test. We studied 41 adult and child patients aged ≥6 years with ocular misalignment owing to congenital or acquired paralytic or comitant strabismus and 17 healthy volunteers. All participants were tested with binocular infrared video goggles with built-in laser target projection and liquid crystal display shutters for alternate occlusion of the eyes and the conventional Hess screen test. In both tests, ocular deviations were measured on a 9-point target grid located at 0±15° horizontal and vertical eccentricity. Horizontal and vertical ocular deviations at 9 different gaze positions of each eye were measured by the strabismus video goggles and the Hess screen test. Agreement was quantified as the intraclass correlation coefficient. Secondary outcomes were the utility of the goggles in patients with visual suppression and in children. There was good agreement between the strabismus video goggles and the Hess screen test in the measurements of horizontal and vertical deviation (intraclass correlation coefficient horizontal 0.83, 95% confidence interval [0.77, 0.88], vertical 0.76, 95% confidence interval [0.68, 0.82]). Both methods reproduced the characteristic strabismus patterns in the 9-point grid. In contrast to Hess screen testing, strabismus video goggle measurements were even possible in patients with comitant strabismus and visual suppression. The new device is simple and is fast and accurate in measuring ocular deviations, and the results are closely correlated with those obtained using the conventional Hess screen test. It can even be used in patients with visual suppression who are not suitable for the Hess screen test. The device can be applied in children as young as 6 years of age.