1. The Maddox rod test uses a red or white lens with parallel cylinders to convert a point light source into a vertical streak of light, which is used to assess the type and size of strabismus. 2. The test procedure involves placing the Maddox rod in front of one eye to see a vertical streak while fixating on a distant light with both eyes. The relative position of the streak compared to the light indicates the type of strabismus. 3. The amount of strabismus is measured by adding prisms until the streak is seen passing through the light, indicating the strength of prism needed to align the eyes.

2. A red or white lens consisting of a series of parallel cylinders that converts a point
source of light into a streak of light or a line image perpendicular to the axis of
parallel cylinders.
A dissimilar image test in which a single target is artificially made dissimilar in
both eyes.

3. PRINCIPLE

4. TEST OBJECTIVE
• This test is performed to asses the type and size of a latent or manifest horizontal,
vertical or torsional strabismus for distance & near fixation subjectively.

5. EQUIPMENT REQUIRED
• Maddox rod
• Source of spotlight
• Prism bar or loose prisms
• Trial frame

6. SET UP
• Patient should weal his/her optimal refractive correction
• Patient should be explained about the test & the procedures of the test.
• Room light should be dimmed and make sure that others source of light does not
disturb the patient’s view of the streak & target spotlight.

7. PROCEDURE
1. Place the Maddox rod in front of the right eye Making sure the grooves in the
Maddox rod are absolutely horizontal so that the patient sees vertical streak.
2. Spotlight is provided at distance of 6meter using projector chart or Snellen
yellow light.
3. Ask the patient to see on the spotlight
4. Ask the patient whether s/he sees both the vertical streak & spotlight
5. If s/he finds difficulty in recognizing or seeing the streak demonstrate the
patient by alternately covering the eye.
DISTANCE HORIZONTAL
DEVIATION

8. 6. If s/he sees only streak or spot, suppression may be present.To confirm the
presence of suppression, Maddox rod is transferred to the left eye & try again and
follow up test should be performed.
7.With the Maddox rod on right eye---
a) If the patient sees streak passing through or overlapping the spotlight s/he is
orthophoric i.e. patient does not have any deviation.
b) If the patient sees streak and spot light separated; streak on right side and spot
on the left side which are uncrossed images, the patient has esodeviation
c) If the patient sees crossed images that is the streak on the left side and the
spotlight on the right side, the patient has exodeviation.

9. • 6. measurement of deviations is done by placing loose prisms or prism bar in front
of the either eye according to the type of deviation of eyes.
a. To determine the amount of esodeviation, base out prism is placed in front of
any eye until the patient sees the streak passing through the spot light.
b. To determine the amount of exodeviation, base in prism is placed in front of any
eye until the patient sees the streak passing through the spotlight.

10. Distance vertical deviation
1. Rotate the Maddox rod so that the grooves are absolutely vertical in orientation.
2. Ask the patient to see the spotlight.
3. Ask the patient if the streak is above or below the spotlight
4. With the Maddox rod on the right eye
a. If the streak passes through the spotlight then the patient has no vertical deviation.
b. If the streak is above the spotlight then, the patient has right hypodeviation or left
hyperdeviations. It is possible to specify vertical deviations with respect to other eye.
Thus, this type of deviation can also be called as left over right.
c. If the streak is below the spotlight then, the patient has right hyperdeviation or left
hypodeviation.This type of deviation can also be called as right over left.

11. • 5. to determine the amount of vertical deviations base up or base down prisms are
used:
a. If the deviation is left over right, base down prism is placed before the left eye (or
base up prism before the right eye).
b. If the deviations is right over left, base down prism is placed the right eye (or base
up prism before the left eye) until the streak passes through the spotlight.

12. NEAR HORIZONTAL &VERTICAL
DEVIATION USING MADDOX ROD
• The horizontal & vertical deviations at near can be similarly measured.
• The penlight is shone at nose bridge between the eyes at about 40cm
• The near horizontal deviation measurement with Maddox rod are considered
unreliable in young patients due to the lack of a good accommodative stimulus.
• In presbyopes near deviation should be measured with the addition.The
measurement technique is exactly the same as measurement of deviation at
distance.

13. THANKYOU