The document discusses the Maddox rod test, used to assess various types of heterophoria by utilizing a glass rod that converts a light source into a streak of light, measuring deviations in eye alignment. It outlines the methodology for testing both horizontal and vertical deviations, including the types of prisms used for correction and the characteristics of different phorias. Additionally, it addresses the advantages and disadvantages of the test, emphasizing its applicability in clinical settings for detecting eye muscle balance issues.

1. Maddox Rod Test
Md.Azizul Islam
Junior Optometrist(Oculoplasty Dept)
Ispahani Islamia Eye Institute & Hospital
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2. Declaration
I have no financial interest by
presenting this presentation
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3. Lay out of Presentation
To know about Maddox Rod
 Use of Maddox Rod
Method of Assessment MR
Double MR Test procedure
Recording procedure of MR Test
 To know about Heterophoria, Cyclophoria,
Esophoria,Exophoria,Hyperphoria,Hypophoria
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4.  A glass rod (or a series of parallel glass rods) that
converts the image of a light source into a streak of
light perpendicular to the axis of the rod. The
position of this streak in relation to the image of
the light source seen by the fellow eye indicates the
presence and amount of heterophoria.
Red,White or Green parallel plano convex cylinder
lens, which refracts light rays so that a point source
of light is seen as a line or streak of light. Due to the
optical properties.
The test is based on the principle of diplopic
projection.
Maddox rod
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5. The Maddox rod test should be used in cases of:
 The Maddox rod test can be used to subjectively
detect and measure a latent, manifest,
horizontal or vertical deviation for near and
distance.
Small to moderate (i.e..<25 pd) vertical
deviations where there is simultaneous
perception and normal retinal correspondence
(NRC)
Decompensated phorias.
Acquired strabismus (rather than congenital or
early onset).
Indication of use MR
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6. Maddox rod
Light source (Pen
Torch ) at near
33 cm, (Fixed
target light ) at
distance 6m
Base in, base
out, base up, base
down prisms bar.
Trial frames
Equipment required in
MR Testing..
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7. Method of assessment
Method for measuring horizontal deviations:
When performing the clinical test, the room lights
should be dimmed and only one light source should be
visible.
When testing at near, the patient is to fixate on light
source at 33 cm, which is held at eye level. When testing
at distance, the patient is to fixate on a light source at
6m.
Patient is instructed to fixate on the light source with
both eyes opened.
The Maddox rod is then placed over the fixating eye.
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8. To measure the horizontal deviation, the Maddox
rod is placed in front of the right eye( making the red
line will be vertical.)
The patient is then asked whether the white light is
superimposed on the red line, or if it is to the left or
right of the red line.
If the patient saw a red line to the left and white light
to the right, they are said to have exotropia or
Exophoria (crossed diplopia) in which base in (BI)
prisms.
If the patient saw a red line to the right and white
light to the left, they are said to have esotropia or
Esophoria (uncrossed diplopia) in which base out
(BO) prisms.
CONTD…...
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9. Orthophoria
Esophoria
Exophoria
Method of assessment
R/E L/E
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10. Esophoria (uncrossed
diplopia) in which base
out (BO) prisms are
used measure and
correct the deviation.
Exophoria (crossed
diplopia) in which base
in (BI) prisms are used
measure and correct the
deviation.
Prism @ Horizontal deviation
I

11.  The patient is held for granted to hold the Maddox Rod in front
of their right with the cylinders vertical, making the red line
horizontal.
The patient is then asked whether the white light is
superimposed on the red line or if it appears above or below the
red line.
If the line appears below the light, there will be a hyper-
deviation in which base down prisms are used to measure and
correct the deviation.
If the line appears above the light, there will be a hypo-
deviation and base up prisms are used measure and correct the
deviation.
If the white light is superimposed on the red line, there are no
vertical deviations present
Method for measuring vertical deviations:
Method of assessment
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12. Method of assessment
R/E L/E
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13. Hyper-deviation in
which base down (BD)
prisms are used to
measure and correct
the deviation.
Hypo-deviation in
which base up(BU)
prisms are used
measure and correct
the deviation.
Prism @ Vertical deviation
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14. Double Maddox rod test
The double Maddox rod test can also be used to
assement of yclophoria.
The room lights should be dimmed and only one light source
should be visible
Maddox rods are placed into the trial frames, one before each eye
Cylinders are placed into trial frame vertically, making the two
red lines horizontal.
Vertical prism ( base-up, or base-down) can also be added into the
trial frames to separate the two red lines.The degree of deviation
and the direction (incyclo or excyclo).
The amount of cyclodeviation is measured in degrees, utilised
from the scale on the trial frame .
 Fixate on light source at 33 cm, which is held at eye level. When
testing at distance, fixate on a light source at 6m .
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15. Method of assessment
Double MR Test
Can be determined
by the angle of
rotation that causes
the line images to
appear horizontal and
parallel.
The amount of
cyclodeviation is
measured in degrees,
utilised from the scale
on the trial frame.
Orthophoria
Incyclophoria
Excyclophoria
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16. Examples of recordings are
shown below:
MR: sc (F) L/R 5∆ eso 8∆ (FR)
MR: sc (F) R/L 5∆ eso 8∆ (FR)
MR: sc (F) 5∆ BD 8∆ BO (FR)
sc: without correction
- F: far
- N: near
- FR: fixing right
- FL: fixing left
- BD: base down prisms
- BU: base up prisms
- BO: base out prisms
BI: base in prisms
- eso: esotropia
- exo: exotropias
- L/R: left hypertropia or
right hypotropia
- R/L: right hypertropia
or left hypotropia
Recording MR Test Report
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17. Advantages &Disadvantages MR test
Advantages
Subjective test
Can easily be performed
Simple and fast technique
Can be used on children
Can be used to test eye muscle balance
Disadvantage
Cannot be done when there are sensory anomalies
present.
Cannot be performed if a patient has suppression, as
they are unable to see the light.
Cannot be performed if there is Abnormal Retinal
Correspondence (ARC), as the angle of separation of the
images will not correspond to the angle of deviation.
Cannot differentiate between tropias and phorias
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18. Phoria:The relative directions assumed by the eyes
during binocular fixation of a given object in the
absence of an adequate fusion stimulus.
Orthophoria: A state of perfect alignment of the two
eyes even when they are deprived of the assistance of
the binocular reflexes that maintain alignment.
Exophoria: In which there is deviation of the visual
axis of an eye away from that of the other eye in the
absence of visual fusional stimuli.
Esophoria :In which there is deviation of the visual
axis of one eye toward that of the other eye in the
absence of visual fusional stimuli.
Phoria / Heterophoria
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19. Hyperphoria :In which there is
permanent upward deviation of the visual
axis of an eye in the absence of visual
stimuli.
Hypophoria: In which there is
permanent downward deviation of the
visual axis of an eye in the absence of
visual stimuli.
Cyclophoria :In which there is deviation
of the eye from the anteroposterior axis in
the absence of visual fusional stimuli.
Phoria / Heterophoria
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20. Take Home Messages
 MR Used only for detect
Phoria
 Thickest part is the
Base of prism
 Exo: =BI prism & Eso: =
BO prism
 Hyper: = BD prism &
Hypo: = BU prism
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21. References
www.wikiVisually.com
 Maddox rod. (n.d.) Millodot: Dictionary of
Optometry and Visual Science, 7th edition. (2009).
 The Maddox Rod Test" (PDF). Jomtonline.com.
Retrieved 13 October 2014
http://medical-
dictionary.thefreedictionary.com/Maddox+rod
Picture: Me ,Google.
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