CLE 162.2 Optometric Procedures
Notetaker: Kyle Reuter
Date: 1/14/13 1st Hour
Page 1
Class #14: Pupil Testing Abnormalities
Student questions concerning practical exam
- Is it possible to have different color deficiencies in both eyes?
o Yes, if acquired they could be different due to the extent/location
of trauma that caused the color vision loss. Congenital color
deficiencies are usually the same in both eyes
- When pupil testing in dim illumination, how do you see the pupil?
o You CAN turn on the stand lamp with the room lights off and
indirectly light the patient. For testing accommodation pupil
response, use stand lamp to illuminate the near target but keep the
room lights off.
o It is often easier to notice the pupil dilation when the patient looks
at distance rather than to notice the constriction when looking at
near.
A Review of Afferent vs. Efferent Pathways
- When OD is lit and both pupils are constricted, but when OS is lit both
pupils dilate. What is this called?
o (+) APD OS – direct response of OS < consensual response induced
by OD
o Afferent pathway – pathway to brain – is damaged on left side
before chiasm
 Brain interprets that light in OD is brighter than the light in
OS – even though it is the same light
o Cataracts do NOT cause APD
 Look at eye that you are shining light into and if it dilates
under direct illumination, there is something wrong with
the nerve or retina
Worksheet – Example #1
- Light shined in OD (3x) and there was no pupillary response from OD but
there was constriction in OS. Light was shined in OS (3x) and pupil
constriction occurred in both OD and OS.
Worksheet – Example #2
- Light is shined in OD (3x) and no pupillary response occurs in OD but
there is constriction in OS. Then light is shined in OS (3x) and there is
constriction of OS pupil, but no reaction in OD.
Worksheet – Example #3
- Light is shined in OD and there is no direct pupillary response, but there
is a consensual response in OS. Began alternating between OD/OS
(Marcus Gunn test) and there was no direct or consensual response from
OD but there was constant constriction present in OS.
Worksheet – Example #4
- Light is shined in OD and there is no direct or consensual response of
either eye. When light is shined in OS, both pupils constrict.
CLE 162.2 Optometric Procedures
Notetaker: Kyle Reuter
Date: 1/14/13 1st Hour
Page 2
Explanations to worksheet examples:
- Examples 1 & 4 go together
o Light in OD: No direct response OD; No consensual response OS
o Light in OS: Intact direct response in OS; Intact consensual
response OD
 What does this tell us?
 The afferent pathway is damaged in the right eye
(before chiasm)
 The brain is not receiving the message from the OD
 The efferent pathway is intact because when light is
shined in the OS, we see constriction of both OD and
OS.
o Brain can send messages to OD and OS
 If pupil does not respond to light at all, but there is an intact
efferent pathway, the eye is blind (Amaurotic pupil).
 Amaurosis means that there is a total loss of vision
 Eye cannot perceive any light at all (NLP)
 An amaurotic eye will not produce any direct or
consensual response
 Amaurotic eye will cause dilation when directly
stimulated during swing test
o **The amaurotic pupil is the APD by which
all others are measured**
 If there is any detectible direct response (even if very
slight), the eye will have some vision – even if only LP
o Will a patient with a blind eye due to optic nerve damage have
anisocoria?
 No, because there is a consensual response and both eyes
will have equal pupil sizes.
o IMPORTANT: An eye with an APD does have a direct response to
light
 The only time you won’t is if the eye is blind (NLP)
 The amaurotic eye has the ultimate APD since it has no
direct response to light, but an intact efferent pathway
- Examples 2 & 3
o Light in OD: No direct response OD; Intact consensual response OS
o Light in OS: Intact direct response OS; Absent consensual response
OD
 What does this tell us?
 The afferent pathway is intact in OD because the OS
responds to light (when light is shined in OD)
 The efferent pathway is damaged because the OD
does not respond to the direct or consensual
CLE 162.2 Optometric Procedures
Notetaker: Kyle Reuter
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Date: 1/14/13 1st Hour
Page 3
APD
o As you swing light, both pupils dilate – the eye with the light has
the APD
o Consensual response to light > direct response to light
What if efferent pathway is damaged?
o 3 things you could see (See 46:05 of lecture recording for moving
diagrams):
 No APD; the direct response OS = consensual response OS
 APD OS; The direct response OS is less than the consensual
response induced by OD
 APD OD (by reverse testing); The direct response of OS is
greater than the consensual response induced by OD