Page 24 - BOAF Journal 1 2012:2707

Behavioral Optometry
BOAF
Volume1 Number1 2012
movement. There is no shaking or wiggling of the test object. Also, do not begin the move- ment of the test object too far from the expected nerve-head outline as it will allow time for the patient to fatigue.
For visible to invisible (cae- canometry) chartings in making an initial investigation for a smaller than normal plotted physiological blind spot, use the 1.59 millimeter diameter test object. Take the four principal meridians as numbered in Fig- ure No.1 and in the direction indicated. DO NOT record the findings found in the four prin- cipal meridians the first time you make these excursions. This procedure gives the patient an opportunity to practice what he is to do and the doctor now has an idea as to the approxi- mate size and location of the nerve-head to be plotted. Re- take the four principal meridians and mark each findings directly under the test object with a very sharp white or silver lead pencil making a very minute mark. Continue the charting by taking the other meridians as num- bered in Figure No.1.
Figure No.1 shows the di- rection of movement of the test object when running a cae- canometry charting for focal infection.
Fig.1
As each meridian is charted, it is wise to instruct the patient again by saying, „Keep- ing your eye and mind on the yellow light, say ,now‘ when the silver ball disappears again.“
If the plotting does not have a symmetrical oval shape, more than the eight points listed in Figure No.1 may be plotted to define the area in question. If a patient should become fatigued before the charting is com- pleted, have them rest by stay- ing in position but closing their eyes.
There is a tendency on the part of the doctor to rest the hand holding the marking pencil on the edge of the chart table. The hand creates an area of distraction in the peripheral field which increases the difficulty of maintaining fixation and con- centrating on the task. There- fore, it is essential to always remove the hand after marking each finding on the chart.
Lapse of concentration on the part of the patient will cause the test object not to disappear as will the same thing happen if the patient is fixating on the test object instead of the fixation light. The doctor who does not make pencil marks on the chart as very tiny dots may cause his patient considerable difficulty in that the large mark may be mis- taken for the test object and the patient will believe he is still seeing the test object even when it is not present. In addi- tion, large marks reduce the accuracy of the plotting. The degree marks reduce the accu-
racy of the plotting The degree of toxicity is in terms of millime- ters between points so one can readily see the necessity for tiny markings.
As soon as the nerve-head of the dominant eye has been charted, the occluder is placed over this eye, the test object is moved to the side of the chart in front of the non-dominant eye, fixation is acquired, and the entire process is repeated.
Interpretation
When the nerve-heads have been charted, the outline may be filled in or left as eight dots. Since no particular purpose is served by filling in the outline, most doctors do not do so. At this point, when the chart is re- moved from the instrument, the doctor must fill in the ledger if he has not done so previously. In addition to the patient‘s name, it is essential that the date and the time of day be re- corded. For ease of reference and completeness of records, it is also advisable to enter symp- toms and other pertinent infor- mation directly on the chart.
Example of Ledger
R-20% L- 14%
Date:2-25-64 Time: 9:15 AM
Name: John Doe RXN0: .
Basal -Non-Basal T.0.1.59 1.00 0.50 0.79 m/m
(circle one)
Level of Illumination:
(circle one)
(circle one)
LO MED HI
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