Ophthalmoscopy
is a test that allows a health
professional to see inside the back
of the eye (called the fundus) and
other structures using a magnifying
instrument (ophthalmoscope) and a
light source. It is done as part of
an eye examination and may be done
as part of a routine physical
examination.
The fundus contains a lining of
nerve cells (the retina), which
detects images seen by the clear,
outer covering of the eye (cornea).
The fundus also contains blood
vessels and the optic nerve. See a
picture of the structures of the
eye.
There are two types of
ophthalmoscopy.
- Direct
ophthalmoscopy.
Your health professional uses an
instrument about the size of a
small flashlight with several
lenses that can magnify up to
about 15 times. This type of
ophthalmoscopy is most commonly
done during a routine physical
examination.
- Indirect ophthalmoscopy.
Your health professional wears a
light attached to a headband and
uses a small handheld lens.
Indirect ophthalmoscopy provides
a wider view of the inside of
the eye and allows a better view
of the fundus even if the lens
is clouded by cataracts.
Why It Is Done
Ophthalmoscopy is done to:
- Detect problems or diseases
of the eye, such as retina
problems.
- Help diagnose other
conditions or diseases that
damage the eye.
- Evaluate symptoms, such as
headaches.
- Detect other problems or
diseases, such as head injuries
or brain tumors.
How To Prepare
No special preparation is needed
before having this test.
Your health professional may use
eyedrops to widen (dilate) your
pupils. This makes it easier to see
the back of the eye. The eyedrops
take about 15 to 20 minutes to
dilate the pupil fully. Your health
professional may also use eyedrops
to numb the surface of your eyes.
Tell your health professional if:
- You or anyone else in your
family has glaucoma.
- You are allergic to dilating
or anesthetic eyedrops.
You may have
trouble focusing your eyes for
several hours after the test. You
may wish to arrange to have someone
drive you home after the test. You
also will need to wear sunglasses
when you go outside or into a
brightly lit room.
How It Is Done
Direct
ophthalmoscopy
This is the
most common type of examination to
look at structures inside the eye.
- Your eyes may be dilated,
and you will be seated in a
darkened room and asked to stare
straight ahead at some distant
spot in the room.
- Looking through the
ophthalmoscope, your health
professional will move very
close to your face and shine a
bright light into one of your
eyes. Each eye is examined
separately.
- Try to hold your eyes steady
without blinking.
This examination
takes 3 to 5 minutes. See a picture
of a direct ophthalmoscopic
examination.
Indirect
ophthalmoscopy
This type of
ophthalmoscopic examination gives a
more complete view of the retina
than direct ophthalmoscopy. It is
usually done by an ophthalmologist.
- Your eyes will be dilated,
and you will be asked to sit in
a reclining or semi-reclining
position in a darkened room.
- Your health professional
will hold your eye open, shine a
very bright light into it, and
examine it through a special
lens.
- Your health professional may
ask you to look in different
directions and may apply
pressure to your eyeball through
the skin of your eyelids with a
small, blunt instrument to help
bring the edges of your fundus
into view.
This examination
takes between 5 and 10 minutes. See
a picture of an indirect
ophthalmoscopic examination.
How It Feels
Direct
ophthalmoscopy
During direct
ophthalmoscopy, you may hear a
clicking sound as the instrument is
adjusted to focus on different
structures in the eye. The light is
sometimes very intense, and you may
see spots for a short time following
the examination. Some people report
seeing light spots or branching
images. These are actually the
outlines of the blood vessels of the
retina.
Indirect
ophthalmoscopy
With indirect
ophthalmoscopy, the light is much
more intense and may be somewhat
uncomfortable. Pressure applied to
your eyeball with the blunt
instrument also may be
uncomfortable. After-images are
common with this test. If the test
is painful, let the health
professional know.
When dilating
eyedrops are used
Dilating drops
may make your eyes sting and cause a
medicine taste in your mouth. You
will have difficulty focusing your
eyes for up to 6 hours after your
eyes have been dilated. Your
distance vision usually is not
affected as much as your near
vision, though your eyes may be very
sensitive to light. Do not drive for
several hours after your eyes have
been dilated. Wearing sunglasses may
make you more comfortable until the
effect of the drops wears off.
Risks
In some people, the dilating or
anesthetic eyedrops can cause:
- Brief episodes of nausea,
vomiting, dry mouth, flushing,
and dizziness.
- An allergic reaction.
- A sudden increase in
pressure inside the eyeball
(closed-angle glaucoma).
Call your health
professional immediately if you have
severe and sudden eye pain, vision
problems (halos may appear around
light), or loss of vision after the
examination.
Results
Ophthalmoscopy is a test that
allows a health professional to see
inside the back of the eye (called
the fundus) and other structures
using a magnifying instrument
(ophthalmoscope) and a light source.
Ophthalmoscopy
Normal: |
- All
of the structures inside
the eye appear normal.
See a picture of a
normal retina as seen
through an
ophthalmoscope.
|
Abnormal: |
- The retina is
detached.
- Swelling of the
optic nerve (papilledema)
is found.
- Optic nerve damage
caused by glaucoma is
found.
- Changes in the
retina (such as hard,
white deposits beneath
the retina called drusen,
or broken blood vessels
called hemorrhages)
indicate macular
degeneration.
- Damaged blood
vessels or bleeding in
the back of the eye is
seen. This could be
caused by diseases such
as high blood pressure
or diabetes.
- Cataracts are found.
|
What Affects the
Test
Factors that can interfere with
your test or the accuracy of the
results include:
- The inability to remain
still during the exam.
- Eye problems, such as
incomplete pupil dilation,
cataracts, or cloudiness of the
liquid inside the eyeball.
What To Think
About
- Other
eye tests may be done routinely
along with ophthalmoscopy,
including vision testing and
tonometry testing for glaucoma.
For more information, see the
medical tests Vision Tests and
Tonometry.
- Direct ophthalmoscopy is
done more frequently than
indirect ophthalmoscopy.
Indirect ophthalmoscopy is a
more difficult procedure and
requires greater skill and more
specialized equipment than
direct ophthalmology, so it is
generally done by
ophthalmologists and
optometrists.
- Indirect ophthalmoscopy has
several advantages over direct
ophthalmoscopy:
- It allows better
visualization of the inside
of the eye when a cataract
is present.
- It provides a
three-dimensional (3-D) view
of the back of the eye,
allowing a more detailed
view of certain eye
conditions (such as growths,
optic nerve swelling, or
retinal detachment).
- It allows a wider view
of the back of the eye than
direct ophthalmoscopy.
If your
health professional suspects a
problem with the blood vessels
in your eye, a test called eye
angiography may be done. This
test uses fluorescein dye and a
camera to photograph blood
vessels in the eye. For more
information, see the medical
test Eye Angiogram.