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PURPOSE To screen for previously unnoted visual field defects．This technique is generally effective only for substantial field losses．
EQUIPMENT
·Overhead lamp．
·Occluder．
SET-UP
·Instruct the patient to remove his glasses．
·The examiner faces the patient at eye level at a distance of 60 to 80 cm from the patient．
·The space between the patient and the examiner should be brightly illuminated, but the light should not shine directly into either the patient’s or the examiner’s eyes．
·The rest of the testing room should be dimly illuminated．
STEP-BY-STEP PROCEDURE
1．Instruct The patient to occlude his left eye．
2．Tell him that you are going to show him your fingers in his side vision and that you will hold one，two，or four fingers．Instruct the patient to tell you how many you are holding ．Tell him to keep looking at your left eye at all times．Avoid holding three fingers as this stimulus is too easily confused with two or four fingers．
3．Close your right eye．
4．Place your closed fist in the peripheral visual field．Your hand should be in the far periphery, but at a location where you will be able to distinguish the number of fingers exposed．Finger counting fields are actually a form of visual acuity of the peripheral visual field, so the fingers should not be moved or wiggled．In finger counting fields, the patient’s visual field is compared to the examiner’s field, which is presumed to be full．
5．Expose one，two，or four fingers，taking care that they are brightly illuminated，that the darkened exam room(not your hand or arm)provides the background，that they are not pointing toward the patient，and that the fingers are in a plane mid-way between you and the patient (see Figure 2-12)．
6．Repeat step 5 in the appropriate 8 locations in the field, on each side of the 4 visual field meridia．
7．When you have mapped the field for the right eye，have the patient occlude his right eye and repeat steps 4 through 6 on the left eye．
8．Throughout the test，monitor the patient’s fixation and keep reminding him to maintain fixation on your open eye．
RECORDING
·Record the results for each eye separately．
·Use FCF(Finger Counting Fields)to identify the procedure．
·If the field is normal．Write “full．”
·If the field is abnormal, write “restricted” followed by the location of the restriction．
EXAMPLES
·FCF：OD full, OS full
·FCF：full OD, restricted temporally OS
·FCF：restricted per right quadrant OD and OS
EXPECTED FINDINGS
Right eye full and left eye full． |
