The Maddox rod is an optometric tool used to detect heterophoria. It consists of a series of cylindrical lenses mounted in a trial frame that produces an elongated streak of light. When viewed through the Maddox rod, a point of light appears as a streak. The Maddox rod test is used to detect and measure horizontal and vertical deviations by placing the rod in front of one eye and having the patient view a fixation light. The position of the streak relative to the light indicates the type of deviation, and prisms are used to measure the degree. It is a simple and useful test to perform in office for evaluating eye alignment.

1. MADDOX ROD
OPTOM FASLU MUHAMMED

2.  It is based on the principle of dissociation
 Maddox Rod consists of a series of plano cylinder
lenses about 3mm in diameter, mounted in a trial
frame lens or in a refractor head
 A spot of light viewed through the Maddox rod
appears as an elongated streak
 The Maddox rod is often colored usually red.

5. USES
 Used to find out presence of heterophoria .
 Easy for patient to understand
 Easy to administer
 Very useful for vertical deviation
 May be done in free space

6. MADDOX ROD TEST
 Equipment required are
(1) Maddox rod
(2) Small fixation light
(3) Prism(to asses the degree of deviation)

7. PROCEDURE
 Reduce room illumination
 Maddox rod is placed in front of one eye
 Measuring horizontal deviations Maddox rod axes
are placed horizontal which produces vertical
streak
 Measuring vertical deviations Maddox rod axes are
placed vertical which produces horizontal streak
 Patient initially views with both eyes open

8. PROCEDURE FOR HORIZONTAL DIVIATION
 Maddox rod is placed horizontally(vertical streak) in
front of right eye
 With strabismics,the Maddox Rod is best placed
over the fixating eye.
 Ensure that patient can see white light and streak
simultaneously
 Ask if the streak is to the right or to the left of the
light.

10.  With Maddox Rod in front of the right eye
 If the vertical streak of line passes directly through
the centre of the spot light it indicates orthophoria
 If the vertical streak of light appears to the left of the
spot light it indicates exophoria.
 If the vertical streak of light appears to the right of
the streak light it indicates esophoria.

11.  The amount of deviation can be assessed by
placing prism bar in front of the eye.
 Place base out for eso and base in for eso
deviation.
 Keep on increasing the strength of the prism until
the streak of the light passes through the centre of
the prism.
 The strength of the prism indicates the amount of
deviation present.

12. FOR VERTICAL DIVIATION
 Same procedure is followed expect Maddox rod is
placed with its axes vertically producing horizontal
streak of light
 If the horizontal streak of light is above the fixation
light it indicates presence of hypo deviation
 If the horizontal streak of light is below the fixation
light it indicates presence of hyper deviation.