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Anatomy of the eye

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The front part of the eye

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Anatomy of the Eye

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1. Assessment of the eye and vision
Subjective data-includes complaints of altered vision or other symptoms,
associated lifestyle and other factors, and recent and past
health history
Presenting symptoms
• Any blurred vision, double vision, and loss of vision or a portion of the visual
field?
• Is there pain, headache, foreign body sensation, photophobia, redness,
itchiness, lacrimation?
• Is there difficulty in functioning such as driving or reading due to visual
problem?
Associated factors
• Does the patient wear contact lenses or glasses?
• What is the patient’s occupation?
• How long have there been symptoms?
History
• Any eye injury or accident
• Any recent infections
• Any ocular history, such as previous injury, surgery, or use of medication
• Medical history such as diabetes, and hypertension

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A. Tests of visual acuity/Snellen chart/
Visual acuity is a measure of the resolving power of
eye. It can be for the near or distant vision.
Nurse’s responsibility
• Assessment of near vision is to ask client to read
printed materials under adequate light
• If the client is unable to read, the nurse uses an E-
chart or one picture of familiar objects
• The client is instructed to hold the material at a
distance of 5 to 6 cm from the eyes
• If the patient has a complaint of visual problems at
near, and for all patients 40 years of age or older,
the nurse tests the near visual acuity
Examination, investigation, and nursing responsibilities

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Snellen chart

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Continued…Tests of visual acuity/Snellen chart/
• Assessment of distant vision requires use of Snellen chart
(paper chart). The chart should be well lighted
• The nurse has the client to sit or stand 20 feet/6 meter/ away
from the chart and try to read all of the letters beginning at any
line with both eyes open and then with each eye separately
(with the opposite eye covered)
• When covering the eye, the client shouldn’t apply pressure to
the eye
• If the patient reads the line with two or fewer errors the
examiner instructs the patient to read the next lower line

Continued…Tests of visual acuity/Snellen chart/
• The nurse notes the smallest line the patient
can read with two or fewer errors, and records
the standard of 20 feet (6 meters) and then the
distance in feet on the line of the Snellen chart
the patient read successfully
• The test is repeated with the client wearing
corrective lenses
• The nurse does the test rapidly enough that
the client doesn’t memorize the chart
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Continued…Tests of visual acuity/Snellen chart/
• The nurse records visual acuity as with out correction (sc) or
with correction (cc) depending on whether or not the client
wears glasses or contact lenses
• The nurse then asks the patient to cover the other eye and
the processes is repeated
• If the patient cannot read letters, the examiner can use an eye
chart with pictures, numbers, letter E in four different
directions (the examiner asks the patient to point the direction
of the E)
• If the patient is unable to see the 20/400 letter, the nurse
holds up a number of fingers 3 to 5 feet (0.9 to 1.5 meters) in
front of the patient and asks the patient to count them
• If the patient is unable to count the fingers, the nurse holds up
a different number of fingers at successively close distance
up to 1 feet and again asks the patient to count them
• If the patient could count the number of fingers at 2 feet (0.6
meters) the nurse records the acuity as FC or CF (Finger
Count or Count Fingers) at 2 feet (0.6 metes)

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Continued…Tests of visual acuity/Snellen chart/
• If the patient can not count fingers, the nurse asks the patient to
indicate if moving the hand is seen in front of the face, the level
of visual acuity is HM (Hand Motion)
• The abbreviation LP (Light Perception) is used for patients with
visual acuity of only light can be seen
– If client note when the light is turned on or off, light perception is intact
• The abbreviation NLP (No Light Perception) is used for patients
with visual acuity of unable to identify light perception
• The Snellen chart has standardized number at the end of each
line of the chart. The numerator is the number 20, or the
distance the client stands from the chart. The denominator is
the distance from which the normal eye can read the chart
• The largest the denominator, the poorer the clients visual acuity
• The nurse records the visual acuities using ophthalmic
abbreviations
• A normal person is able to read letters at a distance of 20 feet/6
meters/, there fore the normal vision is 20/20

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2. Ophthalmoscopic examination
Ophthalmoscope is a hand held instrument with a light
source and magnifying lenses that is held close to the
patients eye to visualize the posterior part of the eye
• The ophthalmoscope is used to inspect the cornea,
lens, and the fundus (retina, choroids, optic nerve)
• There is no pain or discomfort associated with these
examinations
• As a rule the patient sits and the examiner stands
facing each other with their eyes at the same height
• When the right eye is examined the examiner holds
the ophthamoscope on the right hand and stands on
the right side of the patient
• The examination requires dark room

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Ophthalmoscope

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Ophthalmoscopic examination…continued
• The client removes eye glasses, but contact lenses
may be left in place
• The examiner’s right hand and eye are used to
examine the client’s right eye, and the left hand and
eye are used to examine the client’s left eye
• The ophtalmoscope is held comfortably against the
examiner’s face
• As the client gazes, straight a head with both eyes
open, the examiner, at a distance of approximately
25 cm from the client and 25 degrees lateral to the
client’s central line of vision shines the light on the
pupil
• The light from the ophthalmoscope causes the pupil
to constrict
• The nurse must relax and keep both eyes open

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Pupil constricted/dilated

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Ophthalmoscopic examination…continued
• The examiner inspects the size, color, and
clarity of the disk; checks the integrity of the
vessels, looks for the presence of retinal
lesions; and assesses the appearance of the
macula and fovea
• Normally the following structures are observed:
– A clear, yellow optic nerve disc
– Reddish pink retina (whites) or darkened retina
(African-Americans)
– Light red arteries and dark red veins
– The avascular macula

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Normal eye

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Normal fundus/whites

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Normal fundus/blacks

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3. Measurement of intraocular pressure
Intraocular pressure is the pressure of the eye
• Intraocular pressure is measured by using an instrument called
Tonometer (Schiotz’s tonometry)
• Use of the intraocular pressure measurement is to determine
the intraocular pressure
Procedure
• The patient lies supine and both eyes are anesthetized by using
tetracaine/amitocaine
• Ask the patient to place his thumb far from his forehead
• As the patient stare directly upward to his own thumb finger, the
lids are opened wider, the foot of the tonometer is set lightly but
firmly on the center of the cornea
• A reading is quickly taken, while the shaft of the tonometer is
held absolutely vertical
• The normal intraocular pressure is between10-21 mmHg

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Tonometer

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3. Measurement of intraocular pressure…continued
Nurse’s responsibility
• Clean the tonometer before each use by
carefully wiping the foot plate with a moist
sterile cotton swab and sterilize the instrument
once a day (dry heat)
• Wash hands on each patients exam
• Make sure that the tonometer is very clean and
dry, even a tiny speck of dirt, or grease or
moisture can cause friction in the plunger and
so give an inaccurate readings
• Measurement of intraocular pressure in
patient’s with corneal ulcer should be done in
great care

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Slit lamp with aplanation tonometer

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4. Estimation of the visual field
Visual field-useful in detecting decreased peripheral
vision
Procedure
• Patient is seated 18 to 24 inches in front of the
examiner
• One eye is covered while the patient focuses with
the other eye on a spot about 1 feet from the eye
• A test object is brought in from the side at 15
degree intervals, through complete 360 degrees
• The patient signals when he or she sees the test
object and again when the object disappears
through the 360 degrees

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Refraction errors/Ametropia
Refraction error is a pathological condition where parallel rays
of light are not brought to focus on retina, because of defect
in refractive media that is the cornea and lens
• Refraction is the ability of the eye to bend light rays so that
they fall on to the retina
• In the normal eye, parallel light rays are focused through the
lens in to a sharp image on the retina, this condition is
termed as emmetropia and it is to mean that light is focused
exactly on the retina, not in front of it or behind it
• When the light does not focus properly, it is called a
refractive error
Refractive errors can be:
• Myopia
• Hypermetropia
• Astigmatism
• Presbyopia
• Aphakia

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A. Myopia/Near sightedness/
• The individual with this condition see near objects
clearly (near sightedness/short sightedness), but
objects at a distance are blurred
• This condition occurs when an image is focused in
front of the retina, because the eye is too
long, or because there is excessive refracting
power (cornea or lens have excessive refractive
power)
• A concave lens/minus/ is used to correct the light
refraction so that objects seen in the distance are
focused clearly on the retina (bends light ray
outward)

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Myopia/Near sightedness/

Vision in Myopia
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B. Hypermetropia/farsightedness
• The individual with this condition see distant
objects clearly (farsightedness/long
sightedness), but close objects are blurred
• This condition occurs when an image is
focused behind the retina, either because
the eye is too short, or because there is
inadequate refracting power (cornea or lens
have inadequate refractive power)
• A convex lens/plus/ is used to correct the
refraction (lens bends light ray in ward)

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Hypermetropia/farsightedness

Vision in Hypermetropia
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C. Astigmatism
• Is caused by unevenness in the
corneal or lenticular curvature
causing horizontal and vertical rays
to be focused at two different points
on the retina, which results in visual
distortion (blurred vision)
• It can be myopic or hypermetropic
in nature in relation to where the
image falls

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Astigmatism

Vision in Astigmatism
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D. Presbyopia
• Is a form of hypermetropia that occurs as a
normal process of aging, usually around the
age of 40
• As the lens ages and becomes less elastic,
it loses its refractive power, and the eye can
no longer accommodate for near vision
• As with hypermetropia, convex lenses are
used to correct the light refraction so that
the presbyopic individual can see clearly to
read and accomplish other near vision
tasks by reading glass /bifocals/ or
pogressive lense

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E. Aphakia
• Is the absence of the crystalline lens
• The lens may be absent congenitally,
or it may be removed during cataract
surgery or due to trauma
• Eye loses approximately 30% of its
refractive power and no near vision
• Currently correction is by implanting
intraocular lens (IOL)

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Matured cataract

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Cataract

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1. Hordeolum/sty/
Hordeolum (sty) is an acute suppurative infection of the
sebaceous glands in the eye lid margin
Etiology/cause
• Staphylococcus aureus
Clinical manifestation
• The lid becomes red and edematous
• Small collection of pus in the form of an abscess
• Pain
Management
• Warm and moist compress application 3-4 times a day for 10
to 15 minutes
• If condition is not improved after 48 hours, incision and
drainage may be indicated
• Application of topical antibiotics may be prescribed there
after
External ocular disease

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Hordeolum/sty/

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2. Chalazion
Chalazion- is blockage of the meibomian gland in the
lids
Etiology/cause
• Obstruction of the meibomian gland
Clinical manifestation
• Painless swelling that is firm
• Reddened area
• The swelling is at some distance from the lid margin
Management
• Warm and moist compress application 3-4 times a
day for 10-15 minutes, especially in the early stage
• Most often surgical excision is indicated
• Corticosteroid injection to the chalazion lesion

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Chalazion

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Chalazion

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Chalazion

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3. Blepharitis
Blepharitis is inflammation of both eye lid
margins
It can take the form of:
• Staphylococcal blepharitis
• Seborrheic blepharitis
1. Staphylococcal blepharitis
• Is usually ulcerative and is more serious due
to involvement of the base of hair follicle
• Permanent scaring can result
2. Seborrheic blepharitis
• Is chronic and usually resistant to treatment,
but the milder cases may respond to lid
hygiene

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Blepharitis

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Blepharitis

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Blepharitis
Clinical manifestation
• The lids are red rimmed with many scales
or crusts on the lid margins and lashes
• Itching
• Burning, irritation, and photophobia
• Conjunctivitis may occur simultaneously
Management
• Staphylococcal blepharitis requires topical
antibiotics
• Instruction on lid hygiene (to keep the lid
margins clean and free of exudates) are
given to the patient for both staphylococcal
and seborrheic

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Disease of the conjunctiva
1. Conjunctivitis/pink eye/
Conjunctivitis is inflammation of the conjunctiva
• It is the most common ocular disease world wide
• It is characterized by a pink appearance (hence the
common term “pink eye”), because of
subconjunctival blood vessel hemorrhages
Etiology
• Bacteria: haemophilus influenza, staphylococcus
aureus, etc (Bacterial conjuctivitis)
• Virus: adenovirus, herpes simplex virus, etc (Viral
conjuctivitis)
• Allergy: allergy to pollens and other environmental
allergens, etc (Allergic conjunctivitis)
• Toxins: chemicals like chlorine, exposure to fumes,
smoke, hair sprays, etc (Toxic conjunctivitis)

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Conjunctivitis

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Conjunctivitis

Bacterial conjunctivitis
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Clinical manifestation
• Redness in the white of the eye or inner eye lid
• Foreign body sensation
• Scratching or burning sensation
• Itching
• Photophobia
• Discharge
• Increased amount of tears
• The infection usually starts in one eye and then
spreads to the other eye by hand contacts
Assessment and diagnostic findings
• Types of discharge: watery, mucoid, mucopurulent
or purulent
• Eye swab for culture and sensitivity test

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• Topical antibiotics, eye drops or ointment
• For viral conjunctivitis, since not responsive
to any treatment cold compress may alleviate
some symptom
• For allergic conjunctivitis, especially recurrent
type corticosteroids in ophthalmic
preparations
• Use of vasoconstrictors
• Cold compress, ice packs, and cool
ventilation usually provide comfort by
decreasing swelling
• For toxic conjunctivitis caused by chemical
irritants- eye irrigation with saline or sterile
water
Management

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• Aware the patient the contagious nature of
the disease, especially the bacterial and viral
type of conjunctivitis
– Emphasis hand washing
– Avoid sharing hand towels
– Avoid sharing face clothes
– Avoid sharing eye drops
– Tissue paper should be directly discarded in to a
trash can after use
– Using new tissue paper every time you wipe the
discharge
• All forms of tonometry must be avoided,
unless medically indicated
• Wearing dark glasses for the photophobia
Management…cont.

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2. Trachoma
Trachoma (rough eye) is a highly contagious eye disease
which may result in blindness
Etiology/cause
• Chlamidia trachomatis
Pathophysiology
• Scaring of the inside of the eye lid
• The eye lid turns inward and the lash rubs the eye ball
• Scaring of the cornea (the front eye)
• Irreversible corneal opacities and blindness
Mode of transmission
• Direct contact with eye, nose and throat secretions from
infected individuals or contact with objects such as towel,
handkerchiefs, fingers, flies, or wash clothes

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Clinical manifestations
• Swollen eye lids with pain
• Eye discharge which is slightly
mucopurulent
• Photophobia
• Conjunctival follicles and papillae ,
especially on the upper tarsal
conjunctiva
• Entropion or trichiasis of the upper lid
• Scarring of the upper tarsal conjunctiva
• Pannus blood vessels on the upper part
of the cornea
• Corneal scarring

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Mild active trachoma

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Moderate active trachoma

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Moderate active trachoma

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Severe active trachoma

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Corneal pannus

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Entropion

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Corneal vascularization and scaring

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Acute secondary bacterial infections

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Management
• Surgery: Trichiasis and entropion
• Antibiotics: TTC, Sulphonamides, Erythromycin
• Facial cleanliness: good hand and face washing
practice
• Environmental changes: address water shortage,
eradicate flies, avoid
crowded households, etc
SAFE strategy
(Global Elimination of Trachoma, GET 2020)

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Disease of the cornea
1. keratitis
Keratitis is inflammation of the cornea
Etiology
• Bacteria: Staphylococcus aureus, Streptococcus
pneumoniae, pseudomonas aeruginosa, etc
• Fungus: candidia, aspergillus, cephalosporium, etc
• Virus: herpes simplex, varicella zoster virus, etc
• Exposure: exophthalmos, lagophtalmos, etc
Clinical manifestaion
• Eye pain
• Vision loss/blurred vision
• Sensation of foreign body
• Photophobia
• Watering

3/16/2023 68

Lagophthalmos

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keratitis

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Diagnostic test
• Slit lamp examination after the eye stained
with fluorescein
Herpes simplex keratitis stained with fluorescein

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Management
• Think blink- for exposure type
• Broad spectrum antibiotic for bacterial
type (drops and systemics)
• Acyclovir for viral type
• Natamycin for fungal type
• Application of moisturizing ointment for
exposure type
• Wearing sun glass-day time
• Keratoplasty- corneal transplantation

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Corneal transplantation

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2. Corneal ulcer-ulceration of the cornea
Etiology
Bacteria
- Streptococcus pneumonia
- Pseudomonas
- Staphylococcus aureus
Fungus
- Aspergillus
- Candidia albicanus
Clinical manifestation
– Pain
– Blurred vision
– Photophobia
– Epiphoria
– The ciliary vessels around the cornea will be dilated

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A dendritic herpes simplex corneal
ulcer stained with fluorescein

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Diagnostic tests
• Visible ulcer if the ulcer is larger and deeper
• Instillation of fluorescein dye in to the conjunctiva sac
• The anterior chamber may contain an inflammatory exudates
in severe cases it may form hypopyon
• Gram stain and microscopic examination with possible
culture and sensitivity test
Management
• Treat urgently
Antibacterial
• Gentamycin eye drops
• Ciprofloxacilin eye drops
Antifungal
• Natamycin eye drops
• Econazole eye drops

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Intraocular disease
1. Cataract
Cataract is clouding or opacity of the crystalline lens
that impairs vision
• According to WHO, cataract is the leading cause of
blindness in the world (2002)
Etiology
• Aging (senile cataract)
• From birth (congenital cataract)
• Eye injury (traumatic cataract)
• Intraocular diseases like uveitis
• Drugs like corticosteroids
• Additional risk factors include: diabetes, ultraviolet
light exposure, high dose of radiation therapy, etc

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Cataract

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Clinical manifestations
• Gradual, progressive, and painless loss of vision
• Double vision/blurred vision
• Reduced light transmission
• Rainbow/haloes/
• Previously dark pupil may appear milky or white
Diagnostic assessment
• History and physical examination
• Ophthalmoscopic examination
• Slit lamp examination
Management
Surgery
• Surgical removal of the lens-usually done under local
anesthesia
• Intra Ocular Lens (IOL) are usually implanted at the time of
cataract extraction

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Vision in cataract

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Nursing
• Preoperative care/preparing the patient for surgery/
– Orient patient and explain procedures and plan of care to
decrease anxiety
– Instruct patient not to touch eyes to decrease
contamination
– Administer preoperative eye drops
• Post operative care
– Medication as prescribed
– Teach the patient to report sudden pain and restlessness
with increased pulse
– Caution patient against coughing, sneezing, rapid
movement, bending
– Encourage patient to wear shield at night to protect
operated eye from injury while sleeping

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Disease of the sclera
1. Scleritis
Scleritis-is an inflammation and swelling of the sclera
Etiology
• Associated with connective tissue disorders like
rheumatoid arthritis
Clinical manifestation
• Severe pain
• The white part of the eye may appear red, swollen
and a nodule which is painful to touch
Management
• Heavy immunosupperesion may be needed
– Systemic corticosteroids and eye drops
– Systemic NSAID’s and treating the underlining cause.

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Disease of the uveal tract
1. Uveitis
Uveitis- is inflammation of uveal tract (Iris/Iritis/, Ciliary
body/Cyclitis/, and choroids/Chorioiditis/)
Etiology
• Toxoplasmosis
• Herpes zoster and simplex virus
• Candidiasis
• Histoplasmosis
• Tuberculosis
• Syphilis
Types
1. Non granulomatous
2. Granulomatous

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Clinical manifestation: for non
granulomatous uveitis(the most common)
• Acute onset
• Pain
• Photophobia
• Conjunctival injection, especially around the cornea
• Pupil will be small or irregular
• Vision will be blurred
• In severe case hypopyon- accumulation of pus in
the anterior chamber
• Repeated attack can cause anterior synechia-
peripeheral iris adheres to the cornea and impeds
outflow of aqueous humor or
• Posterior synechia- adherence of the iris and lens

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Hypopyon

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Anterior synechia

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Clinical manifestation: for
granulomatous uveitis
• Insidious onset
• Vision is markedly and adversely affected
• Conjunctival injection is diffuse
• Vitreous clouding
• Photophobia and pain is minimal
Management
• Mydraisis (pupil dilator)- for ciliary spasm and synechia
• Cycloplegic medications- for paralysis of the iris sphincter
• Local corticosteroid drops instilled 4 to 6 times a day to
reduce inflammation
• In severe cases, systemic corticosteroids intravenously
• Wearing dark glass for the photophobia during out door stay

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Disease of the inner eye
A. Panophthalmitis
Panophthalmitis-is an inflammation of all the tissues of the eye ball
Etiology
• Bacteria
• Virus
• Fungus, etc
On assessment
• History of recent intraocular operation
• Penetrating trauma
• Common in immunocompromised patients: HIV/AIDS and diabetes
Clinical manifestation
• Severe pain
• Loss of vision
• Redness of the conjunctiva and the underlying episclera
Management
• Medications (antimicrobials + steroids)
– Topical
– Subconjunctival
– Intravitreally
– Systematically, or in a combination form
• Surgery
– Enucleation

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Injuries to the eye
1. Trauma to the eye
A. Blunt contusion- bruising of periorbital
soft tissue
Clinical manifestation
• Swelling and discoloration of the tissue
• Bleeding into the tissue and structures of
the eye
• Pain
Management
• Reduce swelling and pain
• Refer for ophthalmologist assessment

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B. Hyphema- presence of blood in the
anterior chamber
Clinical manifestation
• Pain
• Blood in the anterior chamber
• Increased intraocular pressure
Management
• Usually spontaneously recovers
• If severe bed rest, and eye shield application

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Hyphema

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C. Orbital fracture- fracture and dislocation
of walls of the orbit, orbital
margins, or both
Clinical manifestation
• May be accompanied by other signs of head injury
• Rhinorrhea
• Contusion
• Diplopia
Management
• May heal by itself, if no displacement or
infringement on other structure
• Surgery/repair the orbital floor/

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D. Foreign body- on conjunctiva, cornea
Clinical manifestation
• Sever pain with lacrimation
• Foreign body sensation
• Photophobia
• Redness
• Swelling
Management
• Consider as medical emergency
• Removal of foreign body through irrigation,
cotton tipped applicator, magnet or needle tip
• Surgical removal

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Foreign body

Foreign body: corneal, conjunctival,
sub-tarsal and intraocular
.

Removing a sub-tarsal foreign body

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Foreign body

Corneal foreign body

Removing a corneal foreign body by needle tip

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E. Laceration/perforation- cutting or
penetration of soft tissue
Clinical manifestation
• Pain
• Bleeding
• Lacrimation
• Photophobia
Management
• Consider as medical emergency
• Surgical repair-method of repair depends on the
severity of injury
• Antibiotics

Laceration/perforation
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Laceration/perforation

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F. Ruptured globe-concussive injury to globe with
tears in the ocular coats
Clinical manifestation
• Pain
• Altered intraocular pressure
• Limitation of gaze in field of rupture
• Hyphema
• Hemorrhage
Management
• Consider as medical emergency
• Surgical repair
• Antibiotics
• Steroids
• Enucleation

Hyphema

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2. Burn of the eye- is the destruction of eye
tissue by chemical, thermal, and ultraviolet ray.
• Determine the causative agent
A.Burns of chemical agent that is
caused by alkali or acids
Clinical manifestation
• Pain
• Burning
• Lacrimation
• Photophobia
Management
• Consider as medical emergency
• Copious irrigation until PH is 7
• Severe scarring may require keratoplasty
• Antibiotics

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B. Burns of thermal sources
Clinical manifestation
• Pain
• Burned skin
• Blisters
Management
• First aid- apply sterile dressing
• Pain control
• Leave fluid blebs intact
• Suture eye lids together to protect eye- if perforation
is possible
• Skin grafting with severe second and third degree
burns

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C. Burns of ultraviolet source
Clinical manifestation
• Pain
• Foreign body sensation
• Lacrimation
• Photophobia
Management
• Pain relief
• Bilateral patching with antibiotic ointment and
cycloplegics

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Other conditions of the eye
1. Glaucoma
Glaucoma-is a pathological rise in the intraocular pressure, which damages various
structures in the eye, especially the optic nerve
There are four types of glaucoma
A. Congenital glaucoma
B. Closed angle glaucoma (acute glaucoma)
C. Open angle glaucoma (chronic glaucoma)
D. Secondary glaucoma
A. Congenital glaucoma
• Is a rare condition that occurs in infants and neonates
Etiology
• The angle of the anterior chamber does not develop normally in
the embryo
Clinical manifestations
• The eye, and especially the diameter of the cornea, increases in
size
• The cornea becomes edematous

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Normal aqueous humor flow inside the eye

Normal aqueous humor flow

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Diagnostic evaluations
• Increase in IOP
Management
Medical
• Pilocarpine drops
• Acetazolamide tablet
Surgical
• Goniotomy- to incise the mesodermal
membrane in the angle of anterior chamber

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B. Closed angle glaucoma (acute glaucoma)
• It accounts for 10% of glaucoma
Etiology
• Mechanical blockage of anterior chamber angle
• Angle closure occurs because of the pupillary
dilation or forward displacement of the iris
• Results in accumulation of aqueous humor
• Within several days, scar tissue forms between the
iris and cornea, closing the angle. The iris and
ciliary body begin to atrophy, the cornea
degenerates because of edema, and the optic
nerve begins to atrophy

POAG & ACG

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Closed angle glaucoma

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Pupilary dilation in glaucoma

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Glaucoma and the iris

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Glaucoma and the optic nerve disk

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Vision in glaucoma

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Clinical manifestations
• Severe pain in and around the eye
• Nausea and vomiting
• Pupil mid-dilated and fixed
• Hazy appearing cornea due to corneal edema
• Progressive visual field loss
• It occurs suddenly with loss of vision
• Sudden elevation of intra ocular
pressure/IOP/
Diagnostic evaluations
• Tonometery-IOP usually elevated

120
Management
Medical
• Lower the IOP as quick as possible by medical means
• Miotics-used to constrict the pupil and contract the ciliary muscle, thus
the iris is drawn away from cornea; aqueous humor may drain through
lymph spaces(meshwork) in to canal of schlemm
E.g.: Pilocarpine drops 2%-4%- 1 drop every 5 minutes for an hour, and then every
hour for 12 hours topically
• Carbonic anhydrase inhibitor-restricts action of enzyme that is
necessary to produce aqueous humor
E.g.: Acetazolamide (Diamox) 250 mg 4 times a day orally
• Hyperosmotic agents-reduces intraocular pressure by promoting
diuresis
E.g.: Mannitol intravenously
Surgical
• Iridectomy- excision of a small portion of the iris whereby aqueous
humor can bypass pupil- this prevents the periphery of the iris blocking
the angle of the anterior chamber
• Trabeculectomy- partial thickness scleral resection with small part of
trabecular meshwork removed and iridectomy
• Laser iridotomy- multiple tiny laser incision to iris to create openings for
aqueous flow

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Procedures of iridectomy
Incision close to the limbus

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Prolapsed iris excised

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Operation completed

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C. Open angle glaucoma (chronic glaucoma)
• Makes up 90% of primary glaucoma cases
• Its incidence increases with age
Etiology
• Degenerative changes occur in the trabecullar meshwork and
canal of schlemm
• This causes microscopic obstruction
• Aqueous fluid can not emptied from the anterior chamber
Risk factors
• Age
• Familial history of glaucoma
• Diabetes
• Hypertension
Clinical manifestations
• Mild, bilateral discomfort (tired feeling in eyes, foggy vision)
• Slowly developing impairment of peripheral vision with dilated pupil
• Progressive loss of visual field
• No pain or inflammation

POAG & ACG

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Open angle glaucoma

127
Diagnostic tests
• A rise in IOP
• Optic nerve atrophy
• Paleness of the optic disk
Management
Medical
• Reduce the IOP by medication-the medication should be
continued for the rest of patient’s life
– Pilocarpine drops 2%-4% 4 times a day
– Adrenaline drops 1% 2 times a day
– Timolol/Timoptol/ drops 0.25%-0.5% 2 times a day
Surgery
– Iridencleisis- an opening is created between anterior chamber and
space beneath the conjunctiva ; this by passes the blocked meshwork,
and aqueous humor is absorbed in to conjunctival tissues
– Cyclodiathermy/cyclocryotherapy- destruction of ciliary body with a
high frequency electrical current or supercooled probe respectively

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A normal optic disc

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Primary optic atrophy

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Early glaucomatous optic atrophy

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Advanced glaucomatous optic atrophy

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Very advanced glaucoma

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Procedures of iridencleisis
Iris prolapsed through incision, and
transected radially

134
Operation completed

135
D. Secondary glaucoma-a type of glaucoma
caused by a specific
causes or pathologies
Etiology
• Hemorrhage
• Corticosteroid use
• Uveitis, etc
Management
• Treat the cause

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2. Diabetic retinopathy
Diabetic retinopathy-is a complication of diabetes mellitus that affects the
retinal blood vessels
Etiology
• Weakening of the walls of the micro blood vessels
• Capillary dilation
• Decreased capillary blood flow
• Retina becomes ischemic and it stimulates the growth of new blood
vessels
Clinical manifestations
• Complain of sudden, often severe loss of vision
• Bleeding to the vitreous
• Floaters
Diagnostic evaluation
• History
• Ophthalmoscopic examination
• Slit lamp microscopic examination
Management
• Photocoagulation-coagulation of the new blood vessels that bleeds
• Proper control and expert management of the diabetes mellitus

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Normal fundus of white people

138
Normal fundus of black people

139
Diabetic retinopathy

140
3. Strabismus
Strabismus/Squint/- the two eyes are looking in different
directions
Etiology
• Disorder of the vision
• Disorder of the eye movements
• Refractive errors
Clinical manifestation
• The corneal light reflex
– This is the best and simplest test of squint
– If the two eyes are straight, then the two corneal light
reflexes are central and symmetrical, but if one eye
squints, then the reflex deviates from the center of the
cornea
• Testing the ocular movements
– There are six extra ocular muscles, and each one
produces most of the movement in a particular direction

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Muscles of the eye

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Movement of the eye

143
Effect of squint
In adults
• Double vision /diplopia/
• Abnormal head posture
In children
• Amblyopia /lazy eye/
Management
• In children
– Try to correct any refractive errors and amblyopia before
straightening the squint surgically
– Patching the good eye
– Surgical correction by either weakening, strengthening or
realigning the extra ocular muscles
• In adults
– Cosmetic surgery is the only treatment

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Muscle movement
• Medial rectus (MR)
– Moves the eye inward, towards the nose (adduction)
• Lateral rectus (LR)
– Moves the eye outward, away from the nose (abduction)
• Superior rectus (SR)
– Primarily moves the eye upward (elevation)
– Secondarily rotates the top of the eye toward the nose (intorsion)
– Tertiarily moves the eye inward (adduction)
• Inferior rectus (IR)
– Primarily moves the eye downward (depression)
– Secondarily rotates the top of the eye away from the nose (extorsion)
– Tertiarily moves the eye inward (adduction)
• Superior oblique (SO)
– Primarily rotates the top of the eye toward the nose (intorsion)
– Secondarily moves the eye downward (depression)
– Tertiarily moves the eye outward (abduction)
• Inferior oblique (IO)
– Primarily rotates the top of the eye away from the nose (extorsion)
– Secondarily moves the eye upward (elevation)
– Tertiarily moves the eye outward (abduction)

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Position of the eye and the muscles

146
4. Detachment of the retina
Retinal detachment is a separation of the sensory retina and
the underlying pigment epithelium with fluid accumulation
between the two layers
Etiology
• Degenerative changes in the retina that occurs in aging
• Trauma, inflammation, or tumor
• Diabetic retinopathy
• Occurs most commonly in patients older than age 40
Clinical manifestations
• Painless loss of peripheral or central vision
• Photopsia- light flashes
• Blurred vision
• The patient notes sensation of particles moving-floaters
• A sensation of a veil like coating coming down, coming up, or
coming sideways in front of the eye: is often misinterpreted
as a drooping eyelid or elevated cheek

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Retinal detachment

148
Floaters

149
Diagnostic method
• Visual acuity measurement
• Ophthalmoscopic examination
• Slit lamp microscopic examination
Management
• Sedation, bed rest, and eye patch
• Surgery
– Photocoagulation-a light beam is passed through the
pupil, causing a small burn and producing an exudates
between the pigment epithelium and retina
– Electrodiatermy- an electrode needle is passed through
the sclera to allow subretinal fluid to escape. An exudates
forms from the pigment epithelium and adheres to the
retina
– Cryosurgery/retinal cryopexy- a supercooled probe is
touched to the sclera, causing minimal damage; as a
result of scarring, the pigment epithelium adheres to the
retina

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5. Vitamin “A” deficiency
Vitamin “A” deficiency- a disorder of the eye caused by a
deficiency of vitamin “A”
Clinical manifestation
• Night blindness
• Conjuctival xerosis/Xerophthalmia/- dry and wrinkled
appearance of the conjunctiva
• Bitoti’s spots- a small plaque/spot of material on the
surface of the bulbar conjunctiva
• Corneal xerosis-dried and lusterless appearance of
the cornea
• Corneal ulceration/Keratomalacia/- part or the whole
cornea melts away
• Corneal scaring-the healed state of the cornea

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Conjunctival xerosis- dry and wrinkled
appearance of the conjunctiva

152
Bitoti’s spot- a small plaque/spot of material
on the surface of the bulbar conjunctiva

153
Corneal xerosis- dried and lusterless
appearance of the cornea

154
Corneal xerosis with ulceration

155
Corneal and conjunctival xerosis

156
A large superficial ulcer stained
with fluorescein

157
Corneal ulceration/Keratomalacia/- part
or the whole cornea melts away

158
Corneal scaring-the healed state of the cornea

159
Management
• Vitamin “A”(Retinol/Carotene)
–<6 months of age------50,000 IU
–>6 months of age------100,000 IU
–>12 months of age-----200,000 IU
–Next day------------------same age specific
dose
–At least 2 weeks later-same age specific
dose
–Women of reproductive age group with
night blindness or Bitoti’s spots should
receive daily doses of < 25,000 IU weekly

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6. Onchocerciasis
Onchocerciasis- a disease caused by infestation with
filarial of the genus onchocerca
• The disease affects the eye, skin, and lymph node
• Is the second leading cause of infectious blindness
worldwide
Etiology
• Infection in humans begins with the deposition of
infective larvae on the skin by the bite of an infected
black fly
• The black fly vector breeds along free flowing rivers
and streams
• Both biting and disease transmission are most
intense in these locations

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Clinical manifestations
• Early findings are conjunctivitis
with photophobia
• Snowflakes/white-grey spots-due
to a reaction to the dead
microfilariae
• Sclerosing keratitis- opacity of
the cornea
• Corneal opacities
• Anterior uveal tract deformity
may cause secondary glaucoma

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Snowflake/white-grey spots

163
Early sclerosing keratitis

164
More advanced sclerosing keratitis

165
Diagnosis
• Skin snip
• Presence of microfilaria in the
anterior chamber of the eye

166
Management
• Ivermectin single dose of 150µg/kg
either yearly or semiannually
• Vector control
• Community based administration of
ivermectin every 6 to 12 months- for
endemic area
• Wearing cloths which covers most of the
skin surface