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Hirschberg Test
PURPOSE To determine the approximate positions of the visual axes of the two eyes under binocular conditions．This test is used to identify a strabismus when other more precise methods cannot be used．
EQUIPMENT
·Penlight．
·0ccluder.
SET-UP
·The patient removes his glasses．
·The examiner holds the penlight．
STEP-BY-STEP PROCEDURE
1. Direct the penlight toward the patient’s eyes from a distance of 50 to 100 cm．
2. Instruct patient to look at the light．
3. Occlude the patient’s left eye．
4. Place your eye directly behind the penlight and observe the location of the corneal light reflex in the right eye．There are three possible positions for the corneal reflex：
a．The center of the pil (zero angle lambda)
b．Slightly nasal to the center of the pil (positive angle lambda)
c．Slightly temporal to the center of the pil (negative angle lambda)
5．Occlude the patient’s right eye．Repeat step 4 observing the left eye．
6．Remove the occluder．Position your eye directly behind the penlight and observe the location of the corneal light reflexes in each of the patient’s eyes with both eyes open．
7．Compare the locations of the corneal reflexes in each of the two eyes relative to where they were located with each eye fixating separately：
a．If the reflexes are in the same relative positions in each of the two eyes, the patient does not have a strabismus．
b．If the reflexes are not in the same relative positions in either eye，the patient has a strabismus．Determine the direction of the deviation by observing the position of the two reflexes relative to the position of angle lambda in the fixating eye(see Table 2-5)．
c．The size of the strabismus can be determined by measuring(in mm)the distance from the position of the reflex in the deviated eye to the position where the reflex would be if the patient did not have a strabismus(see Figure 2-6)．One millimeter of deviation of the reflex is equal to 22Δ(see Figure 2-7)．
RECORDING
·If there is no strabismus, record “symmetry” or “ortho.”
·If there is a strabismus, record the eye that is deviated, the size of the deviation, and the direction of the deviation.
EXAMPLES
·Hirschberg：ortho
·Hirschberg：22 Δ LXT |
