Funduscopic Examination

Ovid: Field Guide to the Neurologic Examination

Authors: Lewis, Steven L.
Title: Field Guide to the Neurologic Examination, 1st Edition
> Table of Contents > Section 2
– Neurologic Examination > Cranial Nerve Examination > Chapter 11
– Funduscopic Examination

Chapter 11
Funduscopic Examination
The main purpose of optic funduscopy in the neurologic
examination is to look for swelling of the optic disc. In the clinical
context in which subarachnoid hemorrhage is a consideration, another
purpose of funduscopy is to look for retinal hemorrhages.
An attempt at visualization of the optic fundus should
be performed on all patients as part of a standard neurologic
The optic nerves are formed from the axons of retinal
neurons that converge to exit the eye and send visual information back
to the brain. The optic disc, also called the optic nerve head,
is the portion of the optic nerve that can be visualized when looking
in the optic fundus. The optic discs are located in a slightly medial
position within the retina; this is important to remember when trying
to visualize the optic disc.
The subarachnoid space that surrounds the brain and
spinal cord also extends into the optic nerves. Therefore, processes
that increase the intracranial pressure can also extend their pressure
along the optic nerves, which may be visualized as swelling of the
optic nerve head (papilledema).
An ophthalmoscope.
  • Begin by preparing the ophthalmoscope.
    Set the ophthalmoscope to 0 diopters, the optimal initial setting for
    most patients and physicians. Set the light of the ophthalmoscope so
    that it produces a white circle of light.
  • Ask the patient to look straight ahead at
    a distant spot in a dim room. It is helpful to show the patient a
    specific spot on the wall in front of the patient to fixate on (or a
    spot on the ceiling if the patient is lying in bed). Being in a dim
    room, rather than a dark room, better allows the patient to see the
    spot and helps with fixation. Ask the patient to try to keep fixating
    on that spot without moving his or her eyes.
  • Hold the ophthalmoscope to your eye. Look
    through the ophthalmoscope with your right eye to assess the patient’s
    right eye, and look through the ophthalmoscope with your left eye to
    examine the patient’s left eye.
  • While holding the ophthalmoscope to your
    eye and shining it into your patient’s pupil, bring the ophthalmoscope
    in from the temporal side of the eye so that you are aiming slightly
    toward the medial side of the retina.
  • P.40

  • Bring the ophthalmoscope in toward the
    patient as you continue to try to visualize the optic disc. Generally
    by this time you should be close to the patient. To avoid striking the
    patient’s eye with the ophthalmoscope, it is helpful to hold your index
    finger slightly outward so that this rests against the patient’s cheek,
    using your other fingers to grip the ophthalmoscope tightly.
  • Adjust the lens in the positive (black) or negative (red) direction, if needed, to bring the optic disc into focus.
Normally, the optic discs should be sharp, with reasonably well-defined margins, and have a yellowish-orange color (Fig. 11-1). There should be no hemorrhages in the retina.
Optic Disc Swelling
  • Mild swelling of the optic disc is
    manifested by obliteration of the usually sharp disc margins. Severe
    swelling of the optic disc is manifested by severe edema and
    obliteration of the disc margins (Fig. 11-2); there may also be hemorrhages around the swollen disc.
  • Swelling of the optic disc can be due to
    increased intracranial pressure (papilledema) or inflammation of the
    optic disc (papillitis). These two major causes of optic disc swelling
    cannot be differentiated through ophthalmoscopy alone. It is a useful
    general rule, however, that acute papilledema does not cause any
    significant effect on visual acuity, whereas papillitis causes vision
    loss. Papilledema does, however, cause enlargement of the physiologic
    blind spot on visual field testing, and chronic papilledema can cause
    vision loss.
Retinal Hemorrhages
Hemorrhages in the retina (subhyaloid hemorrhages) can be seen in some patients with subarachnoid hemorrhage (Fig. 11-3).
Optic Atrophy
Optic nerve head atrophy is manifested by severe pallor (whiteness) of the optic disc (Fig. 11-4). Optic atrophy is seen when there is severe chronic optic nerve dysfunction.
  • Becoming comfortable with ophthalmoscopy to visualize the optic discs requires practice, but it is not really difficult.
  • It is not reasonable for a
    nonophthalmologist to be expected to be adept at recognizing subtle
    vascular or retinal changes. Concentrate on what you really need to be
    able to assess in the neurologic examination: the optic disc. The more
    normal optic discs you evaluate, the more likely that you will
    recognize an abnormally swollen one.
  • It is not usually necessary to use
    mydriatic agents (eyedrops that dilate the pupil) to visualize the
    optic disc to assess for disc swelling in the routine neurologic
    examination. Some patients have small pupils that make visualization of
    the optic discs difficult, however. When the optic discs cannot be
    visualized and the clinical situation particularly warrants the
    examination of the discs to rule out papilledema or hemorrhages,
    mydriatic agents can be considered.
Figure 11-1 A normal optic disc.
Figure 11-2 An optic disc with severe papilledema.
Figure 11-3 Retinal (subhyaloid) hemorrhage in a patient with a subarachnoid hemorrhage.
Figure 11-4 Optic atrophy in a patient with severe chronic optic nerve dysfunction.

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