Diplopia Charting: Double Vision Test (www.healthkura.com)

Diplopia Charting: Common Method of Double Vision Test

Double Vision Test: Diplopia Charting
Effective management of diplopia or double vision is
possible only after the diagnosis of the root cause of
diplopia.
If the double vision is due to neurological cause,
then diplopia charting will help to determine which of
the extraocular muscle(s) is/are more affected.
Diplopia chart is the common double vision test.
You can Get Full Detail about Diplopia charting ON Health Kura

Diplopia charting is the subjective method of double
vision test in which the recording of the separation of
double or diplopic images is made in the primary
position as well as other cardinal gazes (nine
positions of gaze).
It is a common ophthalmic procedure employed to
helping with diagnosing ophthalmoplegia (ocular
muscle’s paresis or palsy).

 If the single extraocular muscle is affected, diplopia
charting gives an accurate result, but it may be
difficult to pinpoint the more affected paretic muscles
in the case of multiple muscle paresis or palsy.
 So, other methods of diplopia tests may be utilized
to measure the separation of the diplopic images
and to diagnose the cause of diplopia along with
diplopia charting, such as Hess charting.
 Diplopia chart gives a symbolic or pictorial record of
double vision in situations where there is a
separation of two images, that changes with change
in position of gaze.

 As it is entirely a subjective method of double vision
test, the reliability of the diplopia charting depends
on the response of the patient.
 The chart can only be plotted in patients who are
cooperative and can appreciate the diplopia and
with comitant and incomitant deviation of eyes.
 Plotting of diplopia fields is indicated in patients with
complaints of confusion or double vision.

What is the principle of diplopia
charting?
 The diplopia chart is based on the haploscopic
principle, foveal projection, Hering’s Law of Equal
Innervation, and Sherrington’s Law of Reciprocal
Innervation.
 In short, the concept is each retinal point has its own
value of direction in gazes.

Types of Double Vision Test
1.Simple method
2.Electronic devices (Quantitative measurement of
actions of extraocular muscles)
•Lancaster red-green test
•Hess charting (screen test)
•Lees screen test
•Interpretation method (new)

What are the indications for the
double vision test?
 If diplopia is due to incomitant deviation, diplopia
charting can be an aid for diagnosis and for follow
up.
 Based on the record of diplopia and separation in
different gazes, the eye doctor can determine
whether the diplopia or confusion is improving or
worsening.

Required materials for the Diplopia
Charting
 Light source (linear): linear light allows the patient to
see a distorted or tilted image if there is cyclotropia.
 A pair of red and green goggle

The procedure of diplopia charting as a
double vision test
 Before starting the test, make sure the required
materials such as linear light, R-G glasses, color
markers, diplopia chart sheet, and comfortable chair
for patient and examiner, are available.
 If the patient is cooperative, he can be given 2
pencils (or told to raise two fingers of two hands)
and asked to hold them exactly as he sees the 2
lights.

 The patient is allowed to sit comfortably on the chair
with his head erect and still throughout the
examination.
 Turn off the room light as the test is carried out in a
dark room.
 The procedure should be explained to the patient in
detail because the test is completely dependent on
the patient’s response.

 R-G glasses are fitted in such a way that the red glass is in
front of the right eye (and green to the left).
 Armstrong Goggles are preferred as these are shaped to fit
properly on the orbital margin, so that patient would be looking
only through the colored area.
 The examiner holds the linear light vertically in the primary
position at a distance of 50 cm (or 1 meter).
 The test distance should be clearly mentioned on the chart
sheet.
 The linear light can be held horizontally for the easy
assessment of diplopia if the complaint is of vertical separation
of images.

 The patient is allowed to look at the light and is
asked about the nature of diplopia.
 Ask the patient which colored image appears in front
of him and which side does he see the second
image.
 Also ask about the nature of images, whether they
are vertical, horizontal, or tilted.

Two things might happen when the examiner project
light to the primary gaze of the patient: a single
image or a double image.
If the patient comments as seeing a single image,
the examiner must find out whether it is a
suppressed or fused image.
If one image is obscured due to large image
separation or due to the size of the nose, there may
not be a comment of diplopia.

 The position in which double vision appears and is
maximal is to be noted if there is no double vision in
the primary position or gaze.
 The relative position and nature of the two images
are noted if the patient sees a double image.
Similarly, the light is projected in the remaining 8
cardinal positions of gaze and the relative
separation of images is noted.
 The area of single vision, minimum separation, and
maximum separation along with estimated
separation value is mentioned pictorially on the
chart sheet.

Interpretation of the diplopia chart
 While interpreting the diplopia chart in a double
vision test, two important points that every examiner
should consider are the positions of gaze at which
the diplopia is present and the position of gaze at
which the image separation is maximum.
 The position of maximum vertical and horizontal
separation of images and the position of maximum
torsion is noted.

 There is no diplopia if two images which are visible are joined together.
But if the red and green images are separated it confirms the presence
of diplopia.
 Among the nine cardinal gazes, the maximum separation of the two
images will be seen in the quadrant in which the muscle is restricted
because it is the direction of the action (position in which that muscle
moves the eye) of the paralyzed muscle.
 The main reason behind this is the overaction of the antagonistic
muscle and yoke muscle and the underaction of the affected muscle.

 Similarly, the image is seen displaced towards the
field of action of the paralyzed muscle. If there are
uncrossed diplopia and horizontally separated
images, it is esodeviation. In exodeviation, there will
be crossed diplopia with horizontally separated
images.
 If there are uncrossed diplopia and vertically
separated images, the oblique muscle is involved. In
paresis of the vertical rectus muscle, there will be
crossed diplopia with vertically separated images.

Diplopia charts of paralysis of the Right Lateral Rectus and
Right Medial Rectus muscles are shown in the following
figures:

Diplopia charts of paralysis of the Right Superior Rectus and
Right Inferior Rectus muscles are shown in the following
figures:

Diplopia charts of paralysis of the Right Superior Oblique and
Right Inferior Oblique muscles are shown in the following
figures:

Diplopia charts of paralysis of the Left Medial Rectus and Left
Lateral Rectus muscles are shown in the following figures:

Diplopia charts of paralysis of the Left Inferior Rectus and Left
Superior Rectus Muscles are shown in the following figures:

Diplopia charts of paralysis of Left Inferior Oblique and Left
Superior Oblique muscles are shown in the following figures:

Precautions to be followed during the procedure
 Patients shouldn’t be allowed to turn head to look in any position.
 R-G glasses must be fitted properly to the eyes.
 The light source must be moved in each direction of gaze in such a
way that it remains visible to both the eyes.
 The light source should be held at a consistent distance in every
cardinal gazes.
 Make sure that the image is not moved out of the visual field of the
patient if he says that there is a single image.
 Make sure the light is visible to both eyes in any position of gaze.
 Never judge the diplopia chart in isolation. The single method can’t
fulfill the requirement of clinical practice due to the variability of
diplopia. So, other methods of double vision tests like Hess charting
and other clinical examinations should be employed in conjunction to
come to a final decision.

How to record the result of diplopia chart?
 Although there is a practice of recording the diplopia on paper depicting the
examiner’s view (if it is done, note it in the chart), it is better to always record
the images from the patient’s view to avoid confusion and for much
reliability. So, while recording the diplopic images on the chart sheet the
right R (R) and left (L) is the patient’s right and left and not the examiner.
 Clearly label the patient’s right and left side on the chart sheet.
 Always mention the test distance-the the distance at which the examination
was done.
 Use only red and green markers to draw the findings on the chart sheet.
 Always note which eye projects the red image and green image.
 Keep a record of the image separation in each position and tilted image as
described by the patient.

Disadvantages of diplopia charting test
 It is not easy to appreciate the minor changes in the deterioration or
improvement from the records of different dates in the same patient as
the test is only qualitative.
 The most important drawback of diplopia charting is that this double
vision test can’t be performed in color-blind patients as the colors used
on the test are red and green.
 The test requires a cooperative and intelligent patient, especially to
notice and tell about the gazes with minimum and maximum
separation of diplopic images.
 Diplopia can’t be elicited in long-standing onset due to deep
suppression. So, diplopia charting is not useful in congenital palsies
and those of long-standing onset.
 The chart may give false interpretations if the paresis unmasks a latent
deviation or the patient starts maintaining fixation with the paretic eye,
especially if the paralyzed eye has better visual acuity.
 Diplopia chart is not much useful in diagnosis in case of multiple
muscle pathologies.

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Diplopia Charting: Double Vision Test (www.healthkura.com)

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Diplopia Charting: Double Vision Test (www.healthkura.com)