The Eye ppt

8/9/2019 The Eye ppt

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The EyePresented by 4E


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Definition of terms

Vision: passage ray of light from an object through the

cornea, aqueous humor, lens, & vitreous humor to the

retina its appreciation in the cerebral cortex.

Emmetropia: normal vision (20/20)

Ametropia: abnormal vision

Myopia: nearsightedness

Hyperopia: farsightedness


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Definition of terms

Accomoda

tion: focusing apparatus of the eye adjusts toobject at different distances by means of increasing the

convexity of the lens.

Prebyopia: elasticty of the lens decreases with increase age

Astigmatism: uneven curvature of the cornea causing the

patient to be unable to focus horizontal and vertical rays

of light on the retina at the same time.


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Common Abbreviation

OD(oculous dexter): R eye

OS (oculus sinister): L eye

OU (oculus unitas): both eyes

IOP: intarocular pressure

IOL: inraocular lens

EOL: extraocular lens


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Eye Specialists O

phthal

mologis

ts: medical doctor specialist indiagnosing and treating the eye.

Optometrist: examine, diagnose, and manage visualproblems and diseases; does not performsurgery

Optician: fits, adjusts, and give eyeglasses asprescribe.

Ocularist: technicians who makes ophthalmicprostheses.


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Anatomy and Physiology

(An Overview) Eyeball: it is a protective bony structure known as the

orbit.

Line with muscle and connective adipose

tissue

4 sided pyramid surrounded on 3 sides of

Eyelids: composed of thin elastic skin that covers striated

and smooth muscles

Protect the anterior portion of the eye

Contain multiple glands (sebaceous, sweat, &

accessory lacrimal glands)

Upper lid, covers the uppermost portion of iris and

is innerviated by oculomotor nerve (CN III)


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Eyelids: triangular spaces (inner/medial canthus &

outer/lateral canthus)

With every blink of the eyes, the lid wash the

cornea and conjunctiva.

Lacrimal Gland: form TEARS; secreted in response to reflex

or emotional stimuli.

Conjunctiva: a mucous membrane, provides a barrier to the

external environment and nourishes the eye.

Goblet cells (secrete lubricating mucus)

Bulbar conjunctiva covers sclera

Palpebral conjunctiva lines the inner surface of the

upper and lower eyelids.

Fornix, junction of the 2 portions


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Sclera: white eye; dense, fibrous structure that makes

up the posterior five sixthes of the eye.Helps maintain the shape of the eyeball and protect

intraocular contents from traumaLimbus, outermost edge of the iris (conjunctiva &

cornea meets)

Cornea: transparent, avascular, dome like structure, forms

the most anterior part portion of the eyeball.Main refracting surface of the eye5 Layers:

Epithelium

Bowmans membrane

Stroma

Descemets membraneEndothelium


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Anteriorchamber: filled with continually replenished

supply of clear aqueous humor (nourishes the

cornea)

Produced by cleary bodyProduction r/t the IOP

N.V. IOP 10-12 mmHg

Uvea: iris, ciliary body, & choroid

Iris: colored part of the eye; highly vascularized,pigmented collection of fibers surrounding the

pupil.

Pupil: space that dilatyes and constricts in response to

light.Normal: round & constrict symmetrically when a

bright light shines on themDilation & Constriction: controlled by the sphincter

& dilator pupillae muscle


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Lens: behind the pupil & irisColorless, biconvex structure held in position by

zonular fibers

Avascular & has no nerve or pain fiberResponsible for accomodation

Posteriorchamber: small spaces between the vitreous and

the iris

Choroid: lies between the retina and the scleraAvascular tissue, supply blood to the closest

position of retina

Ocular Fundus: largest chamber of the eyeContains vitreous humor (clear, gelationous

substance that mostly of H2O & encapsulated by aheploid membrane & helps maintain the shape of

the eye.


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Retina: neural tissueLandmarks:

Optic Disc: point of entrance of the optic

nerve; pink-oval/circular formRetinal Vessels: emanating inside the

physiologic depression

Macula: responsible for central vision

2Layes:

Retinal pigment epithelium

Sensory retina


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DIAGNOSTICEVALUATION: Direct Opthalmoscopy: Hand-held instruments with variousplus and minus

lenses.

Indirect Opthalmoscopy: Used by the opthalmologist to see larger areas of the

retina, although in an unmagnified state.

Slit- Lamp Examination: Binocular microscope mouted ona table with a

magnification of 10-40 times the real image.

Color Vision: ability to differentiate colors has a dramatic effect on the activities

of daily living.

Amsler Grid: Used for patients with macular problems, such as macular

degeneration.

Ultrasonography: is a ver valuable diagnostic technique, especially when the

view of the retina is obscured by opaque media such as cataract or hemorrhage.


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OptiacalCoherence Tomography: emerging technology that involves low

coherence interferometry.

Fluorescein Angioraphy: clinically significant macular edema, documents

macular capillary non perfusion and identifies retinal and choroidal

neovascularization in age-related macular degeneration.

Indocyanine Green Angiography: Used to evaluate abnormalities in the

choroidal vasculature.

Tonometry: Measures IOP by determining the amount of force of

pressure necessary to indent or flatten a small anterior area of the global

of the eye.

Perimetry Testing: evaluates the field of vision.


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CATARACT

Derived from the greek word cataractos, whichmeans running water.

Lens opacity or cloudiness.

Changes in the clarity of the natural lens inside the

eye that gradually degrade visual quality.


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CATARACT:PATHOPHYSIOLOGY

Cataract formation is characterized chemically by the

reduction in oxygen uptake and an initial increase in water

content followed by dehydration of the lens. Sodium and

calcium contents are increased: potassium, ascorbic acid and

protein content decreased. The protein in the lens undergoes

numerous age- related changes, including yellowing fromformation of fluorescent compounds molecular change. These

change, along with photoabsorption of violet radiation

throughout life, suggest that cataract maybe caused by photo

chemical process.


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CATARACT:STAGE OF DEVELOPMENT

Imma

tu

reCa

ta

rac

t- incomplete opaque, and somelight is transmitted through them, allowing useful

vision.

MatureCataract completely opaque

IntumescentCataract

the lens absorbs water andincreases size.


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CATARACT: TYPES CongenitalCataractsorinfantile occurs at birth

NuclearCataract the central portion of the lens is mostly

affected

CorticalCataract- Opacities at the lens cortex ( outside of

the lens.)

SubcapsularCataract- Opacity develops immediately to the

lens capsule(common in posterior portion.)

SenileCataract- commonly occurs with aging

Aphakia - absence of crystalline lens


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CATARACT:RISK FACTORS Aging: Loss of lens transparency, Clumping or aggregation of the

lens, Accumulation of yellow

brown pigment due to the

breakdown of the lens protein, Decrease oxygen uptake, Increase

in sodium and calcium, Decrease in levels of Vit. C, protein and

glutathione.

Associated OcularConditions: Retinitis pigmentosa, Myopia,

Retinal detachment and retinal surgery, Infection

Toxic Factors: Corticosteroids, especially at high doses and in long

term use, Alkaline chemical eye burns, positioning, Cigarette

smoking, Calcium. Copper, iron, gold and mercury, which tent to

deposit in the papillary area of the lens


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Nutritional Factor: Reduced levels of antioxidants, Poor

nutrition, Obesity

Physical Factors: Dehydration associated with chronic

diarrhea, use of purgatives in anorexia nervosa, and use of

hyperbaric oxygenation, Blunt trauma, perforation of the lens

with a sharp object or foreign body, electric shock,ultraviolent radiation in sunlight and x-ray.

Systemic Diseaseand Syndromes: DM, Down Syndrome. d/o

r/t lipid metabolism, Renal d/o, Musculoskeletal d/o.


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CATARACT:CLINICAL MANIFESTATION

Painless, blurry vision

Person perceives that surroundings are dimmer, as if his or her glasses

need cleaning.

Light scattering

Reduced contrast sensiitvity

Sensitivity to glare

Reduces visual acuity

Myopic shift

Astigmatism

Monocular diplolia

Brunescens


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CATARACT: COMPLICATION

Secondary Glaucoma Postoperative Infections

Bleeding

Macular edema

Wound leaks


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CATARACT: ASSESSMENT ANDDIAGNOSTIC FINDINGS

Decreased visual acuity

DIANOSTICEVALUATION:

Slit-lamp exam

Tonometry

Direct and indirect opthalmoscopy

Perimetry


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CATARACT:NSG. DX & PLANNING

Disturbed visual secondary perception r/t altered sensory

reception, status of sense organs and therapeutically

restricted.

Risk for injury: Risk factor may include poor vision, reduced

hand/ eye coordination.

Planning:The client will gain improved vision and will adapt

to change in visual correction.


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CATARACT: INTERVENTIONS SurgicalInterventions:

IntracapsularCataractExtraction: Entire lens is removed

and fined sutures are used to close the incision.

ExtracapsularCataractExtraction: Involves smaller

incisional wounds and maintains the posterior capsule of

the lens.

Phacoemulsification: Method of extracapsular surgery

uses an ultrasonic device that liquefies the nucleas and

cortex, which are then suctioned out through tubing.

LensReplacements


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CATARACT: INTERVENTIONS Nursing Interventions:

Administer dilating drops every 10 min for 4 doses atleast1 hour before surgery.

Antibiotic, corticosteriod and anti-inflammatory drops amy

be administered prophylactically to prevent postoperative

infection and inflammations. After the surgery the patient receives verbal and written

instruction about how to protect eye, administer

medications, recognize complications and obtain

emergency care.


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The nurse also explains that there should be minimal discomfort

after surgery.

Instruct patient self care to prevent accidental rubbing of the

eye.

Teach patient self care to prevent accidental rubbing of the eye.

Patient should wear a protective eye patch for 24 hours aftersurgery, followed by eyeglasses worn during the day and a

metal shield worn at night for 1 to 4 weeks.

Teach client eye patch is removed after first follow up

appointment.


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CATARACT: EVALUATION

Adaption to restored normal vision is usually rapid.

Adaption to limited vision requires more time based

on individual variations.


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RETINAL DETACHMENT a medical emergency requiring prompt surgical treatment to

preserve vision.

The retina is the light-sensitive tissue that lines the inside

back wall of your eye. In retinal detachment, the retina is

pulled away from the underlying choroid a thing layer of

blood vessels that supplies oxygen and nutrients to the retina. Retinal detachment leaves retinal cells deprived of oxygen.

The longer the retina and choroid remain separated, the

greater the risk of permanent vision loss in the affected eye.


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RETINAL DETACHMENT:SYMPTOMS

Retinal detachment is painless, but visual symptoms almost

always appear before it occurs. Warning signs of retinal

detachment include:

1. The sudden appearance of many floaters small bits of

debris in your field of vision that look like spots, hairs or

string and seem to float before your eyes2. Sudden flashes of light in one or both eyes

3. A shadow or curtain over a portion of your visual field

4. A sudden blur in your vision


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RETINAL DETACHMENT:CAUSES

1. Trauma

2. Advanced diabetes

3. An inflammatory disorder, such as sarcoidosis or

cytomegalovirus retinitis

4. Sagging or shrinkage of the jelly-like vitreous thatfills the inside of your eye


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RETINAL DETACHMENT:PATHOPHYSIOLOGY

Retinal detachment occurs when vitreous liquid (vitreous humor)

leaks through a retinal tear and accumulates underneath the retina.

Leakage can also occur through tiny holes where the retina has

thinned due to aging or other retinal disorders. Less commonly,

fluid can leak directly underneath the retina, without a tear or

break. As liquid collects underneath it, the retina can peel away

from the underlying layer of blood vessels (choroid). Over timethese detachment areas may expand, like wallpaper that, once

torn, slowly peels off a wall. The areas where the retina is detached

lose their blood supply and stop functioning, leading to loss of

vision.


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RETINAL DETACHMENT:RISK FACTORS

Aging retinal detachment is more common in people older than age 40

Previous retinal detachment in one eye

A family history of retinal detachment

Extreme nearsightedness (myopia)

Previous eye surgery, such as cataract removal

Previous severe eye injury or trauma Weak areas on the sides (periphery) of your retina


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RETINAL DETACHMENT:TEST AND DIAGNOSIS

An ophthalmologist may be able to see a retinal hole, tear or

detachment by looking at the retina with an ophthalmoscope.

If blood in your vitreous cavity blocks the view of your retina,

ultrasound examination may be useful.

Photocoagulation a light beam is passed through the pupil,

causing a small beam and producing an exudates between thepigments epithelium and retina.


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RETINAL DETACHMENT:NURSING DIAGNOSIS

A

nxiety r/t visual deficit and surgical outcome Risk for injury r/t eye surgery


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RETINAL DETACHMENT:TREATMENTS AND DRUGS

Surgery is the only effective therapy for a retinal tear, hole or

detachment.

Pneumaticretinopexy for a relatively uncomplicated

detachment with the tear located in the upper half of the

retina; usually done under local anesthesia.

Scleralbuckling

this is one of the most common surgeriesfor repairing retinal detachment.


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RETINAL DETACHMENT:TREATMENTS AND DRUGS

Vitrectomy - removing portions of the vitreous itself is

occasionally necessary when vitreous clouding blocks the

surgeons view of the detached retina or retinal scarring limits

the effectiveness of pneumatic retinopexy or scleral buckling.

Electrodiathermy an electrode needle is passed through the

sclera to allow subretinal fluid to escape Retinalcryopexy supercooled porbe is touched to the

sclera.


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RETINAL DETACHMENT:NURSING MANAGEMENT

Provide supportive care

Promote comfort

Teach about complication

Sedation, bed rest, and eye patch to restrict eye

movements

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