Methods for Eye Movement Observation and Clinical Motility

Question 1

Eye movements should be developed in which order-

Answer 1

Horizontal
Vertical 
Diagonal 
Z axis (ficks y axis) such as convergence and combos
Stop/start
Change speed

Question 2

Type of tracking in stages from early, middle, and late

Answer 2

Early tracking:
Wont even notice it- no relation. Infant.
Whole body moves to look at target
Upper body moves to look at target

Middle: Head and eyes

Late: eyes only

Question 3

By the age of ____, the person should have learned to use the eyes free of the rest of the body.

Answer 3

5.5-6.5
Very important
If not differentiated, this may affect the ability to know where they are in space, where the object is in space, or the ability to sustain visual attention.

Question 4

Electro-oculography: Eye is a natural dipole. More + where? More - where?

Answer 4

(+) towards cornea, (-) towards retina.

Question 5

3 types of RESEARCH tools to track eye movement

Answer 5

1. Electro-oculography. Use dipole of eyes. (+) towards cornea, (-) towards retina.
2. Search coils use CL with magnets to track movements.
3. Video capture system (not IR).

Question 6

Research tool: Search coils. How do these work? What law is this idea based on?

Answer 6

Coils are embedded into a contact lens. Through electromagnetic induction, electric currents are generated in the coils. The polarity and amplitude of the current generated varies based on the direction and angular displacement of the eye.

Based on Faraday’s Law of Induction.

Question 7

Research tool: Video capture system. (NOT IR) Different methods?

Answer 7

1. Some can track reflection (purkinje image)
2. Some prevent head movement so pt can only move their eyes. This is good for research.
3. Single eye vs binocular studies.
4. Video pupil tracking

Question 8

The 5 types of clinical motility tests

Answer 8

1. King Devick
2. Developmental eye movements. DEM.
3. Groffman
4. Readalyzer
5. Right Eye

Question 9

King Devick Clinical motility test. How does it work, what are the benefits, and disadvantages?

Answer 9

Comprised of 3 separate tests with early exit points if needed.

Each test is horizontal lines.

Match age to the norm value to see if they are within range.
This is good for sports vision/concussions. Can quickly do this after a player might have had a concussion and see if value worsened.

Question 10

DEM clinical motility test. How does it work?

Answer 10

3 separate tests (A, B, and C) that you must finish in order to get results. No early exit points.

A and B are both vertical letters that the patient will read. These two tests measure automaticity of language. The score of A and B will be added together and compared to C. Test C is horizontal letters. This measures automaticity of language AND saccades.

In order to find time of saccades, you can divide.

Norms are based on age. Kids or adults up to 36.

Question 11

Groffman clinical motility test. How does it work?

Answer 11

pt is asked to start at letter A, follow the line until it reaches a number. The goal is to reach the right number at the bottom as quickly as possible. More points are given the faster you go. However, if you get the answer wrong, you get no points.

The score is matched to the age.
Easily repeatable throughout VT.

Question 12

Readlyzer clinical motility test. How does it work?

Answer 12

Highly portable. No power necessary, USB Connections. Uses IR sensors to track where the iris is moving.

The patient will be asked to read a paragraph, silently, of 100 words (10 words per line). After they read, they will be asked 10 yes/no questions. Pt must score a 7/10 in order to proceed.

First, computer will show you raw data. This data will demonstrate the yoked nature of movements and shows when the pt blinked.

After computer cleans up data, you will see lines that demonstrate how the patients eye moved during the reading.

Vertical lines indicate fixation
Horizontal line indicates saccade.
Sweep from 1 line down and to another is when the pt started reading a new row.
Left line is a short regression. This is normal to an extent.

Good test to do before/after Vt.

Question 13

Right eye clinical motility test. What is it?

Answer 13

Pretty new. Tracks where your eyes are moving/focusing. Tracks fixation, pursuits, and H/V saccades. Shows on chart where eyes are looking and how much they moved or if they could stay steady/follow a target.