3. Hirschberg
Cover test (CT)
Ocular motility test (OMT)
Prism Cover test/ Krimsky test
Amplitude of accommodation (AA)
Near point convergence (NPC)
4. Purpose:
To determine the approximate positions of the
visual axes of the two eyes under binocular
conditions
Used to identify a strabismus when other more
precise methods cannot be used.
6. 1) Direct the penlight toward the patient’s eye from a
distance of 50 to 100 cm.
2) Instruct patient to look at the light.
3) Place your eye directly behind the penlight and observe
the location of the corneal light reflexes in each of the
patient’s eyes.
4) Compare the locations of the eyes’ corneal reflexes:
1) If the two reflexes are in the SAME relative positions in each of
the two eyes-pt does not have strabismus.
2) If the two reflexes are NOT in the same relative positions in
the two eyes, the patient has a strabismus. Determine the
direction of the deviation by observing the position of the two
reflexes relative to the position of angle kappa in the fixating
eye.
7. Position of the corneal reflex relative to
the position of angle Kappa in the
fixating eye
Type of deviation
Nasal Exo
Temporal Eso
Above Hypo
Below Hyper
RECORDING
If there is no strabismus, record “Symmetry” or
“Orthophoria “.
If there is a strabismus, record the eye that is deviated, the
size of the deviation, and the direction of the deviation.
Eg: RE corneal reflection displaced 15°/30°/45° temporally
8.
9. Purposes:
Objective test used to detect a squint
All diagnosis of squint is based on the
results of the cover test
10. Fixation targets
33cm – spotlight, detailed target, small picture or a
Snellens letter
6m – spotlight, small toy or picture or Snellens letter
>20m – easily seen landmark at eye level
Occluder
Black paddle
Spielman
Card
11. One eye is covered
Watch the movement of the uncovered eye to take up
fixation
If no movement of the eye is noted cover the other
eye and watch the uncovered eye.
If no movement has been seen repeat the test but
this time watch the movement of the covered eye
when the occluder is removed.
12.
13. MANIFEST - OBVIOUS SQUINT
Look for movement
of the uncovered eye
Cover the straight
eye
Cover the eye with
the best visual acuity
or the lowest
refractive error
LATENT – HIDDEN SQUINT
Movement of the
covered eye
14. RE moderate esotropia
LE moderate exotropia
1. With or without glasses
2. Distance (at 6m/at 33cm)
3. Rate of recovery for phoria
4. Note if diplopia is present upon remoal of cover (if present indicates poor recovery
or control)
5. Note laterality of deviation (RE, LE or alternating)
6. Constancy of the deviation (contant/intermittent)
7. Note characteristic of deviaion whether there is any change from phoria to tropia
16. 1. Patient head must be straight and ask to remove spectacles.
2. Ask patient to follow the light with their eyes without moving their
head.Ask pt to report any diplopia or pain during the test.
3. Place the torch at pt’s eye level ~50cm away.
4. Note the corneal reflex.
5. Move the target to the 9 position of gaze (Broad H or Union jack)
pattern can be used.
6. Carefully look for any misalignment of the eyes as well as lid position.
7. Determine whether the movement of the eyes is smooth (pursuit) and
accurate.
8. Perform cover test at all position of gaze (if necessary).
9. Duction test must be performed if underaction of any muscle is
observed.
17.
18. Underaction (u/a)
Overaction (o/a)
Jerky movement or nystagmus at any
position
Pain or diplopia