Method and apparatus for corrective secondary saccades analysis with video oculography system
A video oculography system for calculation and display of Corrective Secondary Saccades Analysis is disclosed. A method for Objective Diagnostics of at least one of traumatic brain injury, Internuclear Opthalmopligia, Ocular Lateral Pulsion, Progressive Supernuclear Palsy And Glissades comprises the steps of using a VOG system to calculate corrective saccades. The video oculography based system for the subject is configured to collect eye images of the patient in excess of 60 hz and configured to resolve eye movements smaller than at least 3 degrees of motion. The video oculography based system collects eye movement data wherein at least one fixation target is presented to the subject in a defined position configured to yield a voluntary saccadic eye response from at least one eye of the patient. The latency, amplitude, accuracy and velocity of each respective corrective saccade and totals latency and accuracy is calculated.
1. A method of measuring ocular response in a subject comprising the steps of:
Providing a video oculography based system for the subject with the video oculography system configured to collect eye images of the patient in excess of 60 hz and configured to resolve eye movements smaller than at least 3 degrees of motion;
Collecting eye data with the video oculography based system wherein at least one fixation target is presented to the subject in a defined position configured to yield a voluntary saccadic eye response from at least one eye of the patient, wherein the initial saccadic eye response to the target is a primary saccadic response and subsequent saccadic eye responses to the target are corrective saccadic eye responses to the target;
Calculating corrective saccade measurements from the eye data including at least one of:
i) total number of corrective saccades associated with the subject's eye movement to each fixation target presented to the subject;
ii) first corrective saccade latency associated with the subject's first corrective saccade eye movement to each fixation target presented to the subject;
iii) first corrective saccade amplitude associated with the subject's first corrective saccade eye movement to each fixation target presented to the subject;
iv) first corrective saccade accuracy associated with the subject's first corrective saccade eye movement to each fixation target presented to the subject;
v) first corrective saccade velocity associated with the subject's first corrective saccade eye movement to each fixation target presented to the subject;
vi) ratio of first corrective saccade amplitude to a primary saccade amplitude associated with the subject's eye movement to each fixation target presented to the subject; and
vii) ratio of total of corrective saccade amplitudes to the primary saccade amplitude associated with the subject's eye movement to each fixation target presented to the subject.
2. The method of measuring ocular response in a subject according to claim 1 wherein the video oculography system configured to collect eye images of the patient in excess of 70 hz and configured to resolve eye movements smaller than at least 2 degrees of motion.
3. The method of measuring ocular response in a subject according to claim 1 wherein the video oculography system configured to collect eye images of the patient in excess of 100 hz and configured to resolve eye movements smaller than at least 1 degrees of motion.
4. The method of measuring ocular response in a subject according to claim 1 wherein the video oculography system configured to collect eye images of the patient in excess of 200 hz and configured to resolve eye movements smaller than at least 0.1 degrees of motion.
5. The method of measuring ocular response in a subject according to claim 1 wherein the corrective saccade measurements are calculated for the subjects left and right eyes for each fixation target presented to the subject.
6. The method of measuring ocular response in a subject according to claim 5 wherein average corrective saccade measurements are calculated for each fixation target presented to the subject based upon an average of the left and right eye responses.
7. The method of measuring ocular response in a subject according to claim 1 further comprising the step of displaying the collected eye data from each fixation target as an eye movement trace graphing angular movement of the subject eye over time relative to the position of the fixation target.
8. The method of measuring ocular response in a subject according to claim 1 wherein the corrective saccade measurements include measurements for a first corrective saccade and at least a second corrective saccade and the corrective saccade measurements for each corrective saccade includes at least one of latency, amplitude, accuracy and velocity of each respective corrective saccade.
9. The method of measuring ocular response in a subject according to claim 1 wherein the video oculography based system is a head mounted system configured to collect eye images of the patient in excess of 75 hz and configured to resolve eye movements smaller than at least 1 degrees of motion, and each fixation light is a laser configured to display a visible target at any point in the patients field of vision.
10. The method of measuring ocular response in a subject according to claim 1 wherein the video oculography based system wherein the corrective saccade measurements from the eye data is used as an objective diagnostic tool for at least one of traumatic brain injury, Internuclear Opthalmopligia, Ocular Lateral Pulsion, and Progressive Supernuclear Palsy And Glissades.