|
PURPOSE To screen for previously unnoted visual field defects．This technique is generally effective only for substantial field losses．
EQUIPMENT
·Overhead lamp．
·Target(white sphere，3 mm or less in diameter，mounted on matte black wand)．
·0ccluder．
SET-UP
·Instruct the patient to remove his glasses．
·The examiner faces the patient at eye level, about 50 cm away．
·The space between the patient and the examiner should be brightly illuminated, but 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．
·The patient holds the occluder．
STEP-BY-STEP PROCEDURE
1．Hold a finger in front of the eye being tested at a distance of 40 to 60 cm．Instruct the patient to maintain fixation on the tip of your finger throughout the test．
2．Show the target to the patient．
3．Tell him that you are going to bring the target into his side vision．Instruct the patient to tell you as soon as he sees it．Repeat the instruction to keep looking at the tip of your finger．
4．Instruct the patient to cover his left eye with the occluder．
5．Throughout the test，the target should remain 1 to 2 inches from the patient’s facial structures(see Figure 2-l0)．
6．Place the target where the patient cannot see it; then slowly move it toward his line of sight, noting the location at which he first reports seeing it．Note that since the target is close to the patient’s face, even small movements cover large angles and rapid movements will cover large angles quickly．
Note：As you perform this test, try to visualize where the limits of the patient’s field ought to be．In this test you are comparing where the patient sees the target to where，in your judgment，he ought to be able to see it．
7．Test the appropriate eight locations in the field, on each side of the four visual field meridian (see Figure 2-11)．
8．When you have mapped the field for the right eye，instruct the patient to occlude his right eye and repeat steps 6 and 7 on the left eye．
9．Throughout the test，monitor the patient’s fixation and keep reminding him to maintain fixation on your fingertip．
RECORDING
·Record the results for each eye separately．
·If the field is normal．Write “full．”
·If the field is abnormal，write “restricted” followed by the location of the restriction．
EXAMPLES
·VF：OD full
OS full
·VF：full OD，restricted temporally OS
·VF：restricted per right quadrant OD and OS
EXPECTED FINDINGS
Right eye full and left eye full. |
