This document provides information on performing a comprehensive eye examination, including:
- Assessing visual acuity using a Snellen chart
- Examining the external structures of the eye
- Testing eye movements and cranial nerve function
- Performing diagnostic tests like ophthalmoscopy, slit lamp examination, and tonometry
- Evaluating color vision, the macula, retinal blood vessels, and intraocular pressure
The goal is to gather all relevant information to assist in diagnosing any ocular conditions.
3. HISTORY
Ocular History
• The nurse, through careful questioning, elicits
the necessary
• information that can assist in diagnosis of an
ophthalmic condition.
• . Genetics plays a role in many eye
• and vision problems; for more information,
see Chart 58-2.
4. Occular history
• What does the patient perceive to be the problem?
• Is visual acuity diminished?
• Does the patient experience blurred, double, or distorted vision?
• Is there pain; is it sharp or dull; is it worse when blinking?
• Is the discomfort an itching sensation or more of a foreign body sensation?
• Are both eyes affected?
• Is there a history of discharge? If so, inquire about color, consistency, odor.
• Describe the onset of the problem (sudden, gradual). Is it worsening?
• What is the duration of the problem?
• Is this a recurrence of a previous condition?
• How has the patient self-treated?
• What makes the symptoms improve or worsen?
• Has the condition affected performance of activities of daily living (ADLs)?
• Are there any systemic diseases? What medications are used in their treatment?
• What concurrent ophthalmic conditions does the patient have?
• Is there a history of ophthalmic surgery?
• Have other family members had the same symptoms or condition?
5. Visual Acuity
• The Snellen chart, which is composed of a series of
progressively smaller rows of letters, is used to test distance
vision.
• The fraction 20/20 is considered the standard of normal
vision. Most people can see the letters on the line designated
as 20/20 from a distance of 20 feet.
• The patient is positioned at the prescribed distance, usually
20 feet, from the chart
• Right eye is tested and recorded first.
• Completely occlude the left eye using palm
• Ask the patient to read the smallest line that he or she can
see. The patient should wear distance correction (eyeglasses
or contact lenses) if required.
• Patients should be encouraged to read more letters and to
guess, if necessary. The patient should be encouraged to read
every letter possible.
6. • If patient can not see largest snellen letters
proceed as follows
• Reduce the distance
• Ask the patient to count the fingers and then
hands
7. External Eye Examination
• After the visual acuity has been recorded, an external eye
examination is performed.
• The position of the eyelids is noted. Commonly, the
upper 2 mm of the iris are covered by the upper lid.
• The patient is examined for ptosis (drooping eyelid) and
for lid retraction (too much of the eye exposed).
• Sometimes, the upper or lower lid turns out, affecting
closure. The lid margins and lashes should have no
edema, erythema, or lesions. The examiner looks for
scaling or crusting, and the sclera is inspected.
• A normal sclera is opaque and white. Lesions on the
conjunctiva, discharge, and tearing or blinking are noted.
8. • The room should be darkened so that the pupils can be
examined. The pupillary response is checked with a
penlight to determine if the pupils are equally reactive
and regular.
• A normal pupil is black. An irregular pupil may result
from trauma, previous surgery, or a disease process.
• The patient’s eyes are observed, and any head tilt is
noted. A tilt may indicate cranial nerve palsy.
• The patient is asked to stare at a target; each eye is
covered and uncovered quickly while the examiner
looks for any shift in gaze. The examiner observes for
nystagmus (ie, oscillating movement of the eyeball).
• The extraocular movements of the eyes are tested by
having the patient follow the examiner’s finger, pencil,
or a hand light through the six cardinal directions of
gaze (ie, up, down, right, left, and both diagonals).
9. Pupillary reaction
• It should be round and equal in dm, although
less than 1 mm in equality may be normal
• Poor pupillary reaction in dim light may
indicate sympathetic nervous system
dysfunction.
• Poor pupillary reaction in bright light may
indicate para sympathetic nervous system
dysfunction.
10. Pinhole Testing:
• The pinhole testing device can determine if a problem
with acuity is the result of refractive error.
• The pinholes only allow the passage of light which is
perpendicular to the lens, and thus does not need to
be bent prior to being focused onto the retina.
• The patient is instructed to view the Snellen chart with
the pinholes up and then again with them in the down
position. If the deficit corrects with the pinholes in
place, the acuity issue is related to a refractive
problem.
11. Observation of External Structures:
• Occular Symmetry: Occasionally, one of the
muscles that controls eye movement will be
weak or foreshortened, causing one eye to
appear deviated medially or laterally
compared with the other.
12. Eye Lid Symmetry
• Both eye lids should cover approximately the
same amount of eyeball. Damage to the
nerves controlling these structures (Cranial
Nerves 3 and 7) can cause the upper or lower
lids on one side to appear lower then the
other
13. Sclera
• The normal sclera is white and surrounds the iris and pupil. In
the setting of liver or blood disorders that cause
hyperbilirubinemia, the sclera may appear yellow, referred to
as icterus. This can be easily confused with a muddy-brown
discoloration common among older African Americans that is
a variant of normal.
14. Conjunctiva
• The sclera is covered by a thin transparent membrane
known as the conjunctiva, which reflects back onto the
underside of the eyelids. Normally, it's invisible except
for the fine blood vessels that run through it. When
infected or otherwise inflamed, this layer can appear
quite red, a condition known as conjunctivitis.
Alternatively, the conjunctiva can appear pale if patient
is very anemic. By gently applying pressure and pulling
down and away on the skin below the lower lid, you
can examine the conjunctival reflection, which is the
best place to identify this finding.
15.
16. Extraocular movements and cranial
nerves
• Normally, the eyes move in concert (e.g. when the left eye moves
left, the right eye moves left to a similar degree). This coordinated
movement depends on 6 extraocular muscles that insert around
the eye balls, allowing them to move in all directions. Each muscle
is innervated by one of 3 Cranial Nerves (CNs): CNs 3 (Oculomotor),
4 (Trochlear) and 6 (Abducens).
• elevation (pupil directed upwards)
• depression (pupil directed downwards)
• adbduction (pupil directed laterally)
• adduction (pupil directed medially)
• extorsion (top of eye rotating away from the nose)
• intorsion (top of eye rotating towards the nose)
17. cranial nerve testing
• examiner can observe eye movements in all directions.
• Stand in front of the patient.
• Ask them to follow your finger with their eyes while
keeping their head in one position
• Using your finger, trace an imaginary "H" or rectangular
shape in front of them, making sure that your finger moves
far enough out and up/down so that you're able to see all
appropriate eye movements (ie lateral and up, lateral
down, medial down, medial up).
• At the end, bring your finger directly in towards the
patient's nose. This will cause the patient to look cross-
eyed and the pupils should constrict, a response referred to
as accommodation.
18. DIAGNOSTIC TESTS
Ophthalmoscope:
• Visualise lens, vitreous humor, retina, optic disc
• Priorly phenylphrine solution is instilled to dilate
the pupil thus permits better view of inner eye
• Have the patient seated comfortably
• Instruct the patient to look at a point not to move
• Begin to look at right eye about 1 foot from
patient
• Use your right eye with opthalmoscope in your
right hand
19. • Place your free hand on patients forehead or
shoulder to keep yourself steady
• Slowly come close to the patient
• Examine optic disc, retinal blood vessel,
retinal back ground
20. Slit-Lamp Examination
• The slit lamp is a binocular microscope mounted on a table.
• This instrument enables the user to examine the eye with
magnification of 10 to 40 times the real image.
• The illumination can be varied from a broad to a narrow beam
of light for different parts of the eye.
21. Color Vision Testing
• color vision test is performed using Ishihara polychromatic
plates.
• On each plate of this booklet are dots of primary colors
that are integrated into a background of secondary colors.
• The dots are arranged in simple patterns, such as numbers
• Patients with diminished color vision may be unable to
identify the hidden shapes.
• Patients with central vision conditions (eg, macular
degeneration) have more difficulty identifying colors than
those with peripheral vision conditions (eg, glaucoma)
because central vision identifies color.
22.
23. Amsler Grid
• it consists of a geometric grid of identical squares with a
central fixation point.
• Hold the Amsler grid approximately 14 to 16 inches from
your eyes.
• Cup your hand over one eye while testing the other eye.
• The grid should be viewed by the patient wearing normal
reading glasses.
• Each eye is tested separately. The patient is instructed to
stare at the central fixation spot on the grid and report any
distortion in the squares of the grid itself.
• For patients with macular problems, some of the squares
may look faded, or the lines may be wavy.
• Switch to the other eye and repeat.
24.
25. Optical Coherence Tomography
• Light is used to evaluate retinal and macular diseases as well
as anterior segment conditions.
• Series of retinal 2 D and 3 D images are taken
• This method is noninvasive and involves no physical contact
with the eye.
26. Color Fundus Photography
• The patient’s pupils are widely dilated before the procedure.
• A fundus camera or retinal camera is a specialized low power
microscope with an attached camera designed to photograph
the color image of interior surface of the eye, including the
retina, retinal vasculature, optic disc, macula, and posterior
pole (i.e. the fundus).
27. Fluorescein Angiography
• Fluorescein angiography evaluates macular edema,
documents macular capillary nonperfusion, retinal blood
supply
• It is an invasive procedure in which fluorescein dye is injected,
usually into an antecubital vein.
• Within 10 to 15 seconds, this dye can be seen coursing
through the retinal vessels.
• Over a 10-minute period, serial black-and-white photographs
are taken of the retinal vasculature.
28. Indocyanine Green Angiography
• It is used to evaluate abnormalities in the
choroidal vasculature, conditions often seen in
macular degeneration.
• Indocyanine green dye is injected intravenously,
and multiple images are captured using digital
videoangiography over a period of 30 seconds to
20 minutes.
• Left – FA
• Right - IGA
29. Tonometry
• Tonometry measures IOP
• Normal IOP 12-22 mm Hg.
• The procedure is noninvasive and usually
painless.
• A topical anesthetic eye drop is instilled in the
lower conjunctival sac.
30. Perimetry Testing
• To do the test, you sit and look inside a bowl-shaped instrument
called a perimeter.
• While you stare at the centre of the bowl, lights flash. You press
a button each time you see a flash.
• A computer records the spot of each flash and if you pressed
the button when the light flashed in that spot.