2. Ophthalmology: the science of the eye and its disorders
and diseases
Opthalmologist: physician who specializes in the
diagnosis and treatment of disorders and diseases of the
eye
Optometrist: is not a medical doctor, but can perform eye
examinations, diagnose vision problems and eye
diseases, and treat visual defects through corrective
lenses and eye exercises
Opticians: trained to fill prescriptions written by
ophthalmologists and optometrists for corrective lenses
by grinding the lenses and dispensing eyewear
2
4. 4
Modified from Damjanov I: Pathology for the health-related professions, Philadelphia, 1996, Saunders.
5. Visual impulse begins with light passing through the
cornea
Cornea refracts the light and passes it through the
aqueous humor and pupil into the lens
Ciliary muscle adjusts the curvature of lens to again
refract light rays
Rays pass into the retina, trigger photo-receptor cells of
rods and cones
Light energy converts into an electrical impulse and is
sent through the optic nerve to the brain
5
7. Presbyopia
o Changing the point of focus from distance to near becomes
difficult, due to age
o Difficulty seeing at reading level
Astigmatism
o Occurs when light rays entering the eye are focused irregularly
o Occurs because the cornea or the lens is not a smooth sphere,
but has an irregular shape
o Corrected with glasses, contacts, or surgery
7
12. Strabismus
o Eyes do not track together (do not look in same direction)
o In children, caused by weakness in eye muscles
Nystagmus
o Constant, involuntary movement of one/both eyes
o Accompanied by blurred vision
o Caused by an abnormal function in part of the brain that controls
eye movements
12
13. Strabismus
Eyes do not track together, do not look in the same
direction at the same time.
14.
15.
16. Hordeolum (stye): localized purulent infection of
sebaceous gland of eyelid
Chalazion: small cyst from blockage of meibomian gland
Keratitis: inflammation of cornea, results in superficial
ulcerations
Conjunctivitis: inflammation of conjunctiva caused by
irritation, allergy, or bacterial infection
Blepharitis: inflammation of glands and lash follicles
along eyelids
16
21. Corneal abrasion: caused by foreign body or direct
trauma
o Diagnosis is confirmed by fluorescein stain, highlighted by cobalt
blue light
o Foreign bodies are removed first, then treated with antibiotic
ointment and nonsteroidal antiinflammatory ophthalmic
ointments
Cataract: cloudy area blocks passage of light into retina
o Condition may result from eye injury, exposure to extreme heat
or radiation, or inherited factors, but is usually due to aging
o Blurred, dimmed vision
o Effective treatment is surgical removal of the lens
21
23. Glaucoma: common and serious, increased intraocular
pressure (IOP)
o Damages the optic nerve and causes blindness if untreated
o Tonometer and gonioscopy used to diagnose
o Miotic and beta-blocker eye drops or surgery for treatment
Macular degeneration: progressive deterioration of the
macula lutea
o Causes severe vision loss and blindness
o No cure, but antioxidants may prevent or slow progression
o Two forms: dry (90% of cases) and wet
23
30. Diabetic retinopathy is a complication of diabetes that
results from damage to the blood vessels of the light-
sensitive tissue at the back of the eye (retina). At first,
diabetic retinopathy may cause no symptoms or only
mild vision problems. Eventually, however, diabetic
retinopathy can result in blindness.
Diabetic retinopathy can develop in anyone who has
type 1 diabetes or type 2 diabetes. The longer you have
diabetes, and the less controlled your blood sugar is, the
more likely you are to develop diabetic retinopathy.
31.
32. Ophthalmoscope projects light to view interior parts of
eye and retina
Eyelids examined for edema
Pupils examined for shape, symmetry, reactivity to light,
and movement coordination
Slit lamp biomicroscope to view details of eye, requires
mydriatic eye drops
Exophthalmometer measures how far eye protrudes
beyond edge of socket
PERRLA: Pupils, Equal, Round, Reactive to Light and
Accommodation
32
33. Best single test for vision screening, used with the
Snellen alphabetical chart
Patients must be able to view the chart at eye level, from
a distance and well-lit
Gross screening of visual acuity, patients usually allowed
to use glasses or contacts
Document use of corrective lenses, result of each eye
separately and as fractions, outcomes of each test with
appropriate abbreviations
33
35. Distance Visual Acuity
Distance visual acuity is typically assessed using a
Snellen chart.
– May use E chart, pediatric picture chart, or alphabet chart
– Patient stands 20 feet from chart at eye level
– Eyes tested with corrective lenses worn
36. – Distance Visual Acuity
– Record results as fraction with 20 feet on top
– Visual acuity is expressed as a fraction. The top number
refers to the distance you stand from the chart. This is
usually 20 feet. The bottom number indicates the
distance at which a person with normal eyesight could
read the same line you correctly read. For example,
20/20 is considered normal. 20/40 indicates that the line
you correctly read at 20 feet can be read by a person
with normal vision from 40 feet away.
– Both eyes remain open during examination; no squinting or
straining
37. Abbreviations
OD-Oculus Dexter- EYE RIGHT
OS-Oculus Sinister- EYE LEFT
OU-Oculus Uterque- EYE BOTH
PERRLA: Pupils Equal, Round, Reactive to Light and
Accommodation
38. Patient holds card 14 to 16 inches from face, with
varying size font
Test each eye, other eye covered, but open
Document number at which the patient stopped reading
for each eye, whether corrective lenses were worn, and
any signs of eye strain, like squinting
38
40. Tests for defects in color vision (congenital or acquired)
Assess perception of primary colors and shades of
colors
Polychromatic plates with numbers of one color, and
background dots are different color
If the score is 10 or higher, the patient is within average
range
40
42. Eye irrigation
o Use sterile technique and equipment to avoid contamination
o Used to relieve inflammation, remove drainage, dilute chemicals,
or wash away foreign bodies
o Never attempt to remove foreign body with an applicator
Instillation of medication to treat infection, soothe
irritation, anesthetize eye, dilate pupils
o Eye drops or ointments are common
Aseptic procedures in ophthalmology
o Avoid contamination of eye medication applicators
o Sterility of medications is critical
42
44. Outer ear
o Auricle, auditory canal
Middle ear
o Tympanic cavity
Inner ear
o Called the labyrinth
o Organ of Corti
44
45. From Jarvis C: Physical examination and health assessment, ed 7, Philadelphia, 2016, Saunders.
45
46. From Applegate EJ: The anatomy and physiology learning system, ed 4, Philadelphia, 2011, Saunders.
46
47. Conductive hearing loss
o Caused by a problem that originates in the external or middle ear
Sensorineural hearing loss
o Results from an abnormality of the organ of Corti or of the
auditory nerve
47
50. Otitis externa (swimmer's ear)
o Causes: dermatologic conditions, trauma, continuous use of
earplugs/earphones, swimming
Otitis media
o Serous or suppurative
o Often associated with upper respiratory tract infection or allergic
reaction
o More common in children
50
52. 52
(From Frazier MS, Drzymkowski JW: Essentials of Human
Diseases and Conditions , ed 5, St Louis, 2013, Saunders.)
53. Cerumen: soft, yellowish, waxy substance that lubricates
the external auditory canal
o Excessive secretion can cause:
• Hearing loss
• Tinnitus
• Feeling of fullness
• Otalgia
o Impacted cerumen can cause conductive hearing loss
53
54.
55. Causes swelling and edema in the semicircular canals
Triggers episodes of recurring attacks of vertigo, tinnitus,
a sensation of pressure in the affected ear, and
advancing hearing loss
55
57. Measures hearing by air conduction and bone
conduction
To activate the fork, hold it by the stem and strike the
tines softly on the palm of the hand
Weber test used if patient reports better hearing in one
ear
Rinne test compares air conduction sound with bone
conduction sound
o In normal hearing, sound is heard twice as long by air as by
bone conduction
57
58. Measures the lowest intensity of sound an individual can
hear
Wearing headphones, the patient is exposed to sounds
and is asked to signal when a sound is heard
If initial screening indicates hearing deficit, an audiologist
may be consulted
58
62. Ear irrigation
o Done to remove excessive or impacted cerumen, to remove a
foreign body, or to treat inflamed ear with an antiseptic solution
o Administer irrigating solution with applicator tilted up, toward top
of external canal
o Always chart the treatment and its results immediately after
completion
Instilling otic medications
o Medication ordered for ear instillation is given to soften impacted
cerumen, to relieve pain, or as an antibiotic drop for an infectious
pathogen
62
63. Treatment Procedures
Ear Irrigation To Remove Excess Cerumen
Direct solution toward roof of canal
Abbreviations—
Auris dextra (AD), right
Auris sinistra (AS), left
Auris uterque (AU), both
64. Adult—pull pinna up
and back
Child under 3—pull
ear lobe down and
back
65.
66. Nasal cavity examined to test mucous membrane and
nostrils
Throat includes the larynx and the pharynx
o Seen with mirror tongue depressor/gauze square
Collection of throat specimens
66
67. Use good listening skills, appropriate nonverbal
methods, and touch to communicate empathy and
understanding
Include family members in the patient's treatment plan
Offer referrals to community resources
67
Editor's Notes
The medical assistant must be familiar with the normal anatomy and physiology of the
eyes, ears, nose, and throat.
Figure 30-1 shows the anatomy of the eye.
The eyeball consists of three layers.
What are the three layers of the eye? (The outermost layer is made up of the white sclera [protects the eyeball] and cornea [allows light to enter the eye]. The choroid is the posterior portion of the middle layer of the eye, and it contains many blood vessels that supply nutrients to the outer layers of the retina. The inner layer of the eye includes the retina in the posterior portion and the lens in the anterior portion.)
What occurs in the brain when an electrical impulse is received? (The impulse is received
in the visual cortex of the occipital lobe of the brain and is interpreted, and a picture is created.)
Figure 30-2 shows myopia (A) and hyperopia (B), along with how they are corrected.
How is presbyopia treated? (A combination corrective lens, known as a bifocal lens or a
progressive lens correction, is used to focus both distal and proximal objects directly on
the retina. Conductive keratoplasty is the new laser procedure used to treat presbyopia.)
How does astigmatism affect vision? (It is like attempting to focus on objects seen through a wavy piece of window glass.)
Surgical correction of astigmatism attempts to reshape the cornea into a more spherical or uniformly curved surface.
Hyperopia is a refractive error, which results from a disorder rather than from disease.
A refractive error means that the shape of your eye does not bend light correctly,
resulting in a blurred image.
Hyperopia is a refractive error, which results from a disorder rather than from disease.
A refractive error means that the shape of your eye does not bend light correctly,
resulting in a blurred image.
Adults can develop strabismus because of a condition or disease elsewhere in the body,
such as diabetes mellitus, muscular dystrophy, or hypertension, or as the result of a head
injury; it is caused by muscle weakness in children.
A patient with signs and symptoms of nystagmus first should undergo neurological evaluation to determine the cause of the disorder with treatment based on those findings.
Eyeglasses and contact lenses are the traditional treatments for visual acuity problems caused by refractive errors.
Problems with the shape of the lens can be corrected surgically, on an outpatient basis.
The brain and eyes have to work together to produce clear vision. If the brain favors
one eye — usually due to poor vision in the other eye — the weaker eye tends to
wander inward or outward. Eventually, the brain may ignore the signals received
from the weaker eye. This condition is sometimes referred to as lazy eye (amblyopia).
Bacterial infections are treated with antibiotic ophthalmic preparations.
Symptoms of corneal abrasion include pain, inflammation, tearing, and photophobia.
Most cataracts develop slowly and progressively as a result of the natural aging
deterioration of the lens of the eye and typically occur after age 60.
Caused by:
Something hits your eye
Something gets in your eye
Foreign body
High-speed particles (metal, wood)
Figure 37-3 shows corneal abrasion stained with fluorescein.
Figure 37-4 shows corneal abrasion stained with fluorescein and highlighted by cobalt blue light.
What are the two types of glaucoma? (The two types are chronic open-angle glaucoma
and acute closed-angle glaucoma. Chronic can be suffered for a long time without
noticing symptoms, whereas acute has more obvious symptoms, such as severe pain,
headache, and inflammation.)
How do physicians screen for glaucoma? (The ophthalmologist first uses a tonometer with a slit lamp to measure increased intraocular pressure. Gonioscopy also can be used to examine the aqueous fluid drainage system and to determine whether the glaucoma is the open- or closed-angle type.)
Figure 30-5, A shows open-angle glaucoma; B shows closed-angle glaucoma.
Glaucoma refers to a category of eye disorders often associated with a dangerous
buildup of internal eye pressure (intraocular pressure or IOP), which can damage
the eye's optic nerve that transmits visual information to the brain.
A cataract is a clouding of the eye's natural lens, which lies behind the iris and the pupil.
The lens works much like a camera lens, focusing light onto the retina at the back of
the eye. The lens also adjusts the eye's focus, letting us see things clearly both up
close and far away.
What is PERRLA? (PERRLA stands for Pupils, Equal, Round, Reactive to Light, and
Accommodation. It is charted by the physician if the pupils are reacting normally.)
How do you record the results of this test? (The numerator [top number] is the distance
of the patient from the chart [always 20 feet], and the denominator [bottom number] is
the lowest line read satisfactorily by the patient. For example, if the patient reads the 20
line at 20 feet, the fraction 20/20 is recorded for that eye. The last line the patient can read
without squinting or straining and with no more than two mistakes is the line recorded in
the patient’s chart for that eye.)
Figure 37-7 shows different types of Snellen charts.
Procedure 37-1 on p. 754 outlines the procedure for measuring distance visual
acuity with the Snellen chart.
This test frequently is given to patients initially to screen for presbyopia or hyperopia.
The patient reads the card, starting at the top, until reaching the smallest print that can be read.
Near visual acuity is tested with a near-vision acuity chart; size of type varies.
Helps with diagnosis of presbyopia
Give in well-lit room, with patient holding card 14 to 16 inches away
Given in each eye; monitor patient for squinting or straining
Figure 37-9 shows the chart for the near vision acuity test.
If the score is 7 or lower, the patient is suspected of having a color deficiency, and
the ophthalmologist performs additional assessment tests using more precise
color vision testing equipment.
Procedure 30-2 provides the protocol for assessing color acuity using the Ishihara test.
The eye is irrigated to relieve inflammation, remove drainage, dilute chemicals, or
wash away foreign bodies.
Newly opened sterile solutions should be used for each patient and should be
discarded after instillation or given to the patient for home use.
Procedure 37-3 on pp. 758-759 details how to perform eye irrigation, and
Procedure 37-4 on pp. 759-760 details how to instill eye medication
Notify the physician immediately if a patient comes into the office with something in his or her eye.
If the physician’s order is for you to remove the foreign body, do so with irrigation only.
If this technique is unsuccessful, cover both of the patient’s eyes with a gauze dressing and notify your supervisor immediately.
The auricle collects sound waves and sends them down the auditory canal.
The middle ear contains the auditory ossicles or bones: malleus, incus, and stapes.
These three tiny bones are linked by minute ligaments to form a bridge across the
space of the tympanic cavity.
The inner ear, called the labyrinth, is divided into the cochlea and the semicircular canals, which are joined by the vestibule.
The organ of Corti, which contains the receptors for sound, is located within the cochlea.
Figure 30-12 shows the anatomy of the ear.
Figure 30-13 shows the semicircular canals of the inner ear.
Describe the process of conductive hearing loss. (Conductive hearing loss is caused by
a problem that originates in the external or middle ear, which prevents sound vibrations
from passing through the external auditory canal, limits the vibration of the tympanic
membrane, or interferes with the passage of bone-conducted sound in the middle ear.)
If the sensorineural hearing loss cannot be improved by hearing aids, an option is
surgical implantation of an artificial cochlea.
Figure 30-14 shows different causes of deafness.
A cochlear implant is a small, complex electronic device that can help to provide a
sense of sound to a person who is profoundly deaf or severely hard-of-hearing.
The implant consists of an external portion that sits behind the ear and a second
portion that is surgically placed under the skin (see figure). An implant has the
following parts:
A microphone, which picks up sound from the environment.
A speech processor, which selects and arranges sounds picked up by the
microphone.
What is the difference between otitis externa and otitis media? (Otitis externa affects
the external ear canal and is called swimmer’s ear. Otitis media is an inflammation of
the normally air-filled middle ear that results in a collection of fluid behind the
tympanic membrane.)
Swimmers frequently have otitis externa, because water collects in the ears and mixes with cerumen to form an ideal culture medium for bacteria and fungus.
Figure 30-15 shows inflammation and infection of the ear and surrounding canals.
How is otitis diagnosed? (An otoscopic examination reveals that the normally pearly gray tympanic membrane is inflamed and bulging. Areas of fluid or pus may be visible through the membrane.)
A tympanogram may be done to determine the air pressure of the middle ear and
the mobility of the tympanic membrane. Figure 37-14 shows a normal tymponogram
test with a peak at normal pressure.
Figure 37-15 shows a tympanic membrane with a tympanostomy tube.
The American Academy of Pediatrics recommends an initial delay of treatment with antibiotics, giving the child's immune system a chance to fight the infection by itself. If the condition does not improve, antibiotics may be prescribed.
How is impacted cerumen removed? (This can be done by softening the wax with oily drops,
such as carbamide peroxide [Debrox], and then irrigating the ear with warm water until the
plug is removed.)
Ménière's disease is treated during active periods with medications for nausea and vomiting.
A salt-restricted diet, diuretics, and antihistamines may be prescribed to control edema in
the labyrinth.
Surgical destruction of the affected labyrinth is an option. Although this relieves symptoms,
it may also result in permanent deafness if the cochlea is damaged.
Figure 37-16 shows instruments used in otoscopic testing.
A number of tests are used to assess hearing acuity.
Remember that in bone conduction, the sound vibrates through the cranial bones to the inner ear.
Striking the tines too forcefully creates a tone that is too loud for diagnostic use.
The results are printed on a graph, called an audiogram, or the medical assistant charts
the results on a graph sheet.
An adult with normal hearing can hear tone frequencies below 25 decibels, and children
with normal hearing can hear those below 15 decibels.
Figure 30-20 shows an audiometer and how to correctly place the headphones.
Routine examination instruments should be disinfected or sterilized after each use according to office policy and stored in a clean area.
Procedure 30-5 describes the protocol for measuring hearing acuity with an audiometer.
1) Distinguishes between conductive and sensorineural hearing.
2) Strike a 512 Hz tuning fork softly
3) Place the vibrating fork on the middle of the client's head
4) Ask client if the sound is heard better in one ear or the same in both ears
Patients with ear conditions may be in considerable pain and may have difficulty hearing,
which makes health teaching a challenge.
Wait until after the procedure has been completed and the patient is more comfortable
to reinforce health behaviors.
Procedure 37-6 (pp. 767-769) outlines how to irrigate a patient's ear.
Procedure 37-7 (p. 770) provides the steps for instilling medicated ear drops.
The physician may use a nasal speculum to visualize the nostrils and examines the nasal
sinuses by palpation and transillumination.
The physician may spray the patient's throat with a topical anesthetic before the
examination to prevent the gag reflex.
Throat cultures are collected by gently swabbing the back of the throat and the surfaces
of the tonsils with a sterile swab.
Procedure 37-8 (p. 771) describes how to collect a specimen for a throat culture.
What are some modifications one can make to help patients with sensory loss?
(A person with a vision loss benefits from large-print forms and handouts, increased
levels of lighting, and verbal rather than written instructions to reinforce learning.
For an individual with a hearing deficit, printed instructions, demonstrations of how
to manage treatments, or even sign language interpretation should be available to
ensure accurate communication.)
