Reliability and Reproducibility of Automated Angular Measurement in Strabismus

Overview

Angular measurement of deviation is an essential element in the clinical evaluation of strabic patients. It is performed by orthoptic methods. However, studies show that the same patient presents a great variability of his angular measurement between 2 consultations, and between 2 observers. Automated angle measurement is a recent concept that aims to overcome the defects of subjective angle measurement by alternate occlusion test and prismatic bar. Improvements made by these devices would provide reliable, objective and reproducible measurements of the angle of deviation by increasing the accuracy of strabal angle assessment, improving decision making and surgical follow-up, decreasing inter-examiner variability and variability over time, and facilitating data comparison to improve scientific publication possibilities. The Gazelab® device is a video-oculograph combined with a laser projection system and an infrared camera. It allows an objective angular evaluation, in non-dissociating physiological conditions, possible even in the absence of binocular vision and allows an analysis of the deviation in all positions. There is extremely little data in the literature on automated measuring devices. The Gazelab tool is still little known in the strabology discipline and seems to have a number of advantages over other devices. The interest of this examination towards this pathology led the ophthalmology department to use it in the current practice, and since recently it is an act nomenclaturé.

The objective of this work is to evaluate the reliability and reproducibility of the automated angular measurement by the Gazelab® (ES12/13127) apparatus, compared to the standard gold which is the angular measurement by alternate occlusion test and prismatic bar, in horizontal strabisms (converging and diverging). Indeed in our daily practice the 2 examinations are carried out. To compare with the standard gold which denotes a strong inter-observer variability, the investigator will compare the results of the Gazelab to the alternate occlusion by prism bar (standard gold) 2 times with 2 trained examiners

Conditions