Visual Problems due to Pituitary Tumors
Sashank Prasad, MD
Division of Neuro-Ophthalmology
Brigham and Women’s Hospital
Harvard Medical School
www.brighamandwomens.org/neuro-ophthalmology
A Patient’s Guide
Symptoms
Diagnosis
Treatment
Prognosis
Sashank Prasad, MD
Harvard Medical School
Brigham and Women’s Hospital
Division of Neuro-Ophthalmology
What kinds of visual
symptoms can be caused by
a pituitary tumor?
Symptoms
Depending on the size
of a pituitary tumor,
visual symptoms may
include:
Patients
with
small
pituitary tumors do not
typically develop visual
symptoms. However, if a
pituitary tumor has grown
larger (usually more than 1
cm), then a patient can
develop visual loss in one
or both eyes. In some
cases, based on which part
of the visual system is
affected by a growing
pituitary tumor, there can
be
reduced
peripheral
vision to both sides. When
these
changes
happen
gradually,
they
can
sometimes be difficult to
notice.
Another
important
symptom that can occur
with a pituitary tumor is
double vision, where a
person sees two images
instead of one. This occurs
because a pituitary tumor
can affect the nerves that
help the eyes move
properly. When the eyes
are not aligned correctly,
the brain will see double
images.
• Blurred vision
(in one or both
eyes)
• Loss of peripheral
vision
• Double vision
MRI scans can identify a pituitary tumor and show if it pushes
the optic nerve or optic chiasm.
In some cases,
pituitary tumors
cause
reduced
peripheral vision
on both sides.
Sashank Prasad, MD
Harvard Medical School
Brigham and Women’s Hospital
Division of Neuro-Ophthalmology
Why does a pituitary tumor
cause visual symptoms?
The pituitary gland sits
in a space called the
pituitary sella, which is
just a few centimeters
behind the eyes. In order
to see normally, we rely
on our eyes to send
information
through
cables (called the optic
nerves) that travel back to
the brain. A large pituitary
tumor can push these
cables, affecting their
ability to send visual
information
from
the
eyes.
Sometimes
a
pituitary tumor affects
the optic nerve on just
one side. In other cases, it
affects a structure known
as the “optic chiasm,”
where the optic nerves
from each eye merge
together.
When
a
pituitary tumor pushes the
optic chiasm, it causes
visual loss in both eyes.
Symptoms
A pituitary tumor can
cause visual symptoms because it sits
near important
structures in the
brain that are meant
for vision.
These include:
• The optic nerves
and optic chiasm
(which bring
vision from the
eye to the brain)
The normal pituitary gland sits beneath the optic chiasm
(which brings vision into the brain). The pituitary also lies
between important nerves that help the eyes move.
• Nerves that make
the eyes move
correctly
Sashank Prasad, MD
Harvard Medical School
Brigham and Women’s Hospital
Division of Neuro-Ophthalmology
What tests will my doctor do
to check my vision?
The doctor will perform
a number of tests to check
if a pituitary tumor is
affecting
vision.
The
examination will assess
visual acuity, color vision,
peripheral vision, eye
movements,
and
the
appearance of the retina
and optic nerve (by
looking at the back of the
eye). To check peripheral
vision, an automated test
is commonly used, in
which the patient pushes
a button every time a
flash of light is seen.
Diagnosis
To check for visual
problems, the doctor
will examine:
• Visual acuity
• Color vision
• Peripheral vision
(often using a
computerized
test)
• Eye movements
• The appearance
of the retina and
optic nerve
(in the back of
the eye)
Automated field testing is a helpful way to assess peripheral
vision. A small blind spot is normally present in each eye.
Sashank Prasad, MD
Harvard Medical School
Brigham and Women’s Hospital
Division of Neuro-Ophthalmology
If a pituitary tumor causes visual loss, the optic nerve
(arrow) may appear pale during the eye exam.
What is the treatment for
visual loss due to a
pituitary tumor?
In most cases, surgery
will be necessary to
remove as much of the
tumor
as
possible,
especially where it is
pushing on parts of the
visual system (the optic
nerves and optic chiasm).
Some types of pituitary
tumors can first be
treated with medications
that can shrink the
tumor, and surgery may
not be necessary. In some
cases radiation treatments can be used to
treat the tumor.
Can eyeglasses fix the visual
loss due to a pituitary tumor?
Eyeglasses do not correct
visual loss that occurs when
a pituitary tumor has
affected the optic nerves or
optic chiasm. Eyeglasses
are used to focus light in
front of the eye. When the
optic nerve or chiasm is
injured,
the
problem
causing loss of vision is
behind the eye. If a
patient
has
nearsightedness
or
farsightedness as a separate
problem, glasses can still
be used for that reason.
Treatment
Treatments for a
pituitary tumor that
is causing visual loss
may include:
• Surgery
• Medications to
shrink the tumor
(depending on
the
type
of
tumor cells)
• In some cases,
radiation
treatment
Unfortunately, eyeglasses do not fix
visual loss caused
by a pituitary
tumor.
Sashank Prasad, MD
Harvard Medical School
Brigham and Women’s Hospital
Division of Neuro-Ophthalmology
How can double vision
be treated?
Treatment
Double
vision
that
occurs with abnormal eye
movements
can
be
treated in several ways.
One method is to block
vision from one eye, so
that the brain will no
longer see two images.
This can be done by
wearing an eye patch or
by covering one eyeglass
lens with scotch tape. In
some cases, if the amount
of misalignment of the
eyes is very small, prisms
can
be
placed
in
eyeglasses to shift images
and reduce double vision.
Finally, if double vision has
become
a
permanent
problem (without further
improvement for about 12
months), then surgery can
be performed to adjust the
position
of
the
eye
muscles. The goal of this
surgery is to reduce double
vision
when
looking
straight ahead and down,
but double vision may still
be present when looking to
the sides.
Double vision can
occur when the normal
eye movements are
affected.
Treatments for double
vision include:
• Blocking the vision
from one eye
Normal vision
• Prisms in
eyeglasses
• Surgery on eye
muscles to correct
the alignment of
the eyes
Simulation of what a
patient with double
vision may see
Sashank Prasad, MD
Harvard Medical School
Brigham and Women’s Hospital
Division of Neuro-Ophthalmology
Will my vision improve after
the pituitary tumor
is treated?
Prognosis
been present and how
severe it is. Unfortunately,
in some cases there is
permanent
visual
loss,
despite treatments for the
pituitary tumor.
Visual
loss
can
often improve after
a pituitary tumor is
treated.
How often will I need an eye
exam or other tests?
In
some
cases,
however, if the
visual loss has been
present for a long
time or is severe,
then some visual
loss
may
be
permanent.
In many cases, loss of
vision
can
recover
considerably after surgery
or medical treatments.
However, the extent of
recovery depends on how
long the visual loss has
The frequency of eye
examinations for a patient
with a pituitary tumor will
depend on the size of the
tumor. It will also depend
on
whether
visual
symptoms have occurred,
and whether medical or
surgical treatments were
necessary. Depending on
these
factors,
some
patients will need to have
their
vision
checked
periodically, often about
every 6 to 12 months.
Some patients will also
need follow-up MRI scans
to check for growth of the
tumor.
After treatment for
a pituitary tumor,
follow-up
eye
exams
and
MRI
scans
can
be
important.
Sashank Prasad, MD
Harvard Medical School
Brigham and Women’s Hospital
Division of Neuro-Ophthalmology
What should I do if I notice a
change in my vision?
If you notice a change
in your vision, you should
tell your doctor quickly.
You may need a complete
eye exam to determine
the extent of any visual
Information
In addition to
speaking with your
doctors, there are
several excellent
online resources to
learn more about
pituitary tumors.
changes that could relate
to the tumor. This will
help
determine
what
treatments
will
be
necessary.
Where can I get more
information on pituitary
tumors?
For more information on
pituitary tumors,
consider the following
sources:
Brigham and Women's
Hospital Pituitary/Neuroendocrine Center
http://www.brighamandwo
mens.org/Departments_and
_Services/neurosurgery/Our
Services/Pituitary.aspx
Pituitary Network
Association
http://www.pituitary.org
National Institutes of Health
http://www.nlm.nih.gov/
medlineplus/ency/article/0
00704.htm
North American NeuroOphthalmology Society
http://www.nanosweb.org/
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