PERFORMING RELIABLE VISUAL FIELDS Heart of America Congress Presented by Jill Luebbert, CPOT, ABOC

What are “Visual Fields” A test? A view of the plains of Nebraska? “the area or extent of physical space visible to the eye in a given position

How much can we see? Monocular visual fields usually measure 60 degrees superior 75 degrees inferior 105 degrees temporal 60 degrees nasal

Making a map a.k.a. Performing Visual Fields

Meridians and Quadrants Horizontal meridian Vertical meridian Quadrants Circles of eccentricity

Two methods of presenting Visual Fields Kinetic Static

Kinetic Target in motion moved from non-seeing to seeing

Static Stationary target Threshold or suprathreshold

Terminology What are they talking about?

Terms used Perimetry Scotoma Blind Spot (natural) Isopter Decibel Visual field testing with eye located at the center of a curved instrument Campimetry Visual field testing eye located a specified distance from a flat surface Scotoma Vision entirely absent Blind Spot (natural) Approximately 15 degrees temporal to fixation (Optic Nerve) Isopter Boundary mapped for a particular stimulus size and intensity Iso = equal opter = sight Decibel Relative unit, 1/10 log unit

Threshold Suprathreshold False negative False positive Every test point is evaluated by bracketing or staircase method Suprathreshold Target value assumed to be above threshold value for all points False negative Patient does not respond when a maximally bring stimulus is present at a point previously found to be normal False positive Patient responds when no stimulus was present

Pattern Standard Deviation Grayscale To be used for patient education – Represents tested points, which have been assigned value Mean Deviation Difference in decibels between “normal” and patient’s hill of vision Pattern Standard Deviation The measurement of the degree which the shape of patient’s measured “hill” of vision departs from normal Short Term Fluctuation A measurement of the degree of variation of threshold during the test

Types of Visual Fields Confrontation Harrington Flocks (Burton) Screener Tangent Screen

Arc Perimeter Amsler Grid

Frequency Doubling Technology FDT

Goldmann introduced in 1945

Auto Perimeters Humphrey (Carl Zeiss Meditec) Octopus (Haag-Steit)

What is the “hill of vision”?

Why do we perform Visual Fields? To monitor area of vision utilized Monitor diseases Glaucoma Macular Degeneration Stroke

The technician’s responsibility To be comfortable and knowledgeable with the instrument used To perform accurate and reliable visual fields To perform repeatable visual fields To accurately gather diagnostic data To keep the patient as comfortable and relaxed as possible This is not a speed test

Setting up and Preparing Data entry can be completed before the patient sits down Choose the correct test Set variables

Setting up Choose the pre-determined test Variables Color Fluctuation Blind Spot Size Test Speed

Setting Up Enter Patient Information Spell the name same format every time All caps or upper and lower case Last name first or first name fist Middle initial with period or without period Date of Birth Vision Acuities Lens Used Pupil Size

Preparing the patient Introduce yourself Acknowledge them by their name Comfortable atmosphere Explanation of what to expect What to see or not to see How long to expect Breaks??

Ready to start Clean the instrument New chin cover sheet Give them the controller Occlude non-testing eye

Positioning Make this as comfortable as possible Adjust the instrument height Adjust the chin rest height Chin and forehead firmly in place Keep teeth clenched together Adjust lens holder Not too close or too far away

Ready??? Verify the patient is in position Give them a short test run first All OK?? Ready Set Start

Now what? MONITOR Monitor fixation Monitor attentiveness DO NOT LEAVE THE PATIENT Monitor fixation Monitor attentiveness Is the patient staying securely to forehead rest and in chin rest

Remember Restart if necessary Is the patient staying attentive It is important to achieve reliable results Is the patient staying attentive Take breaks as you judge necessary This is not a race

Finished Are you performing the same test on the other eye? Take a short break between Let the patient stretch their fingers, neck Occlude next eye Give the patient the control Any questions??? Position

Keep a watchful eye Monitor Fixation Patient attentiveness

Testing Complete Save results Return instrument control Return testing lens Return occluder Print or send results to correct station Note any observations patient restless, etc Escort patient to next station

“How did I do?” Do not share results Let the patient know they provided lots of data for the doctor to review The doctor will visit with them regarding the results

Congratulations on performing Thorough Accurate Repeatable Visual Fields

Enjoy Heart of America Experience Jill J Luebbert, CPOT, ABOC jill@jjlconsulting.com www.jjlconsulting.com Luebbert Consulting & Training