Fakhruddin Aliasger

MADDOX ROD

Aliasger Fakhruddin Lecturer , SPIO ( a unit of Dr. Agarwal’s eye hospital )

Fakhruddin Aliasger

It is based on the principle of dissociation Maddox Rod consists of a series of plano

cylinder lenses about 3 mm 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

Fakhruddin Aliasger

Fakhruddin Aliasger

Fakhruddin Aliasger

Uses

Used to find out presence of heterophoria or heterotropia

Easy for patient to understand Easy to administer Very useful for vertical deviations. May be done in free space

Fakhruddin Aliasger

Maddox rod test

Equipment required are 1. Maddox rod 2. Small fixation light 3. Prisms ( to asses the degree of

deviation )

Fakhruddin Aliasger

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

Fakhruddin Aliasger

Procedure for horizontal deviation 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

Fakhruddin Aliasger

Fakhruddin Aliasger

With maddox rod infront of 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

Fakhruddin Aliasger

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 exo 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

Fakhruddin Aliasger

For vertical deviations

Same procedure is followed except 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