Pathophysiology - Cataract

CATARACTS – opacity of the eye’s normally clear, transparent crystalline lens

Causes

• Aging process
• Inherited
• Injury
• Endocrine disorders

Sign and Symptoms

• Gradual, painless blurring or loss of vision
• Photophobia
• Opaque or cloudy white pupil
• Decreasing visual acuity
• Progressive nearsightedness

Diagnostic Study

• Snellen visual acuity test – used to asses for vision
• Opthalmoscopy– examination of the fundus or interior of the eye
• Slit lamp examination – examination of the structures and fluid in the anterior segment of the eye using binocular microscope that magnifies the surface of the eye

Surgical management

• Intracapsular cataract extraction (ICCE)
• Extracapsular cataract extraction (ECCE)
• Phacoemulsification

Pathophysiology - Conjunctivitis

CONJUNCTIVITIS – inflammation of the conjunctiva, commonly called “pink eye”

Causes

• Allergy
• Bacterial, viral, or chlamydial infection
• Physical or chemical trauma

Signs and Symptoms

• Redness
• Pain
• Swelling
• Excessive tearing
• Burning or itching
• Purulent discharge from one or both eyes
• Lesions on or near the lid margins
• Enlarged lymph nodes in the neck or throat area

Medical management

• Anitibiotic
• Warm soaks or sterile saline irrigations
• Antihistamine and decongestants

Pathophysiology - Glaucoma

Glaucoma

• is optic nerve damage, often associated with increased eye pressure
• it leads to progressive, irreversible loss of vision

Types

• Chronic open angle glaucoma
• Primary/simple/chronic
• Signs and symptoms
• No early signs and symptoms
• Insidious visual impairment
• Diminished accommodation and loss of peripheral vision
• Halos around lights 
• Chronic closed angle glaucoma
• Acute closed angle/ narrow angle glaucoma
• Obstruction to outflow or closure of the irido-corneal angle
• Signs and symptoms
• Transitory attacks of diminished visual acuity
• Colored halos around lights
• Excruciating pain
• Headache nausea and vomiting
• Blurred, cloudy vision
• Congenital glaucoma
• Secondary glaucoma

Pathophysiology - Hearing Impairment

HEARING IMPAIRMENT

Hearing Impairment – described as mild, moderate, severe, or profound depending on the intensity of sound required for a person to hear it

Results from

• Conducting hearing loss – mechanical problem in the external ear canal or middle ear that blocks the conduction of sound
• Sensorineural hearing loss – damage to the sensory structures (hair cells) of the inner ear, auditory nerve pathways in the brain

Causes

• Sensorineural hearing loss
• aging- prebycusis
• Conductive hearing loss
• Choleastoma – non cancerous tumor caused by ear infection
• Chronic middle ear fluid – otitis media with effusion
• Middle ear infection – otitis media
• Obstruction of External ear canal – obstruction is caused either by a wax, tumor or pus from an infection
• Otosclerosis – bony growth of the ossicles

Prevention

• Age related hearing loss and most other causes of hearing loss are not preventable
• Noised induced hearing loss – can be prevented by
• Limiting exposure to loud noise
• The volume through headphones should always be kept at a reasonable level
• Use of glycerin filled muffs or ear plugs – for occupational and firearm exposure

Pathophysiology - Mastoiditis

MASTOIDITIS

• is a bacterial infection in the mastoid process, the prominent behind the ear
• generally occurs secondary to otitis media
• a collection of pus (abscess) may form in the bone

Symptoms

• Fever
• Anorexia
• Vertigo
• Headache and ear pain
• Discharge from the ear
• Tenderness over the mastoid

Therapeutic management

• Antibiotics – eardrops or systemic cleaning of the ear
• Surgical intervention – mastoidectomy,  tympanoplasty

Nursing Management

• Obtain specimen of exudates if present for culture and sensitivity
• Instruct client to seek treatment for ear infections
• Administer prescribed antibiotics
• Instruct client on how to administer eardrops

Pathophysiology - Meniere's Disease

MENIERE’S DISEASE

• term given to the episodic symptoms created by fluctuation in the production or reabsorption of fluid in the ear

Cause

• Unknown

Signs and symptoms

• Vertigo
• Nausea
• Tinnitus
• Headache
• Sensory hearing loss, usually unilateral
• Nystagmus during attacks

Treatment

• Specific drugs may include the following
• Meclizine (Antivert) – antihistamine, suppresses the vestibular system
• Diazepam or other tranquilizers – to help control vertigo in acute episodes
• Promethazine (Phenergan) – anti vertigo effect
• Low sodium diet
• Bed rest during acute attacks
• Surgical procedures – indicated for incapacitated clients
• Labyrinthectomy
• Transtympanic gentamycin treatment
• Vestibular nerve section

Pathophysiology - Otitis Media

OTITIS MEDIA

• inflammation or infection in the middle ear
• clients may have acute or chronic forms of either serous otitis, or the purulent or suppurative type

Causes

• Serous otitis media
• a collection of pathogen-free fluid behind the tympanic membrane
• results from irritation associated with respiratory allergies and enlarged adenoids
• Purulent otitis media
• results from the spread of microorganisms from the Eustachian tube to the middle ear during respiratory infections

Potential complications

• Mastoiditis
• Labyrinthinitis
• Brain abscess

Clinical findings

• History of upper respiratory tract infection or seasonal allergies
• Tinnitus
• Fever
• Sever earache
• Diminished hearing
• Bulging or perforation of the eardrum

Pathophysiology - Otosclerosis

OTOSCLEROSIS

• is the result of the bony overgrowth of the stapes
• common cause of hearing impairments among adults
• fixation of the stapes occur gradually many years

Etiology

• Underlying cause unknown
• Most common in women
• Most clients have a family history of the diseases which indicates a possible hereditary relationship

Signs and Symptoms

• Loss of hearing
• Ringing or buzzing in the ears
• Presence of spongy bone in the labyrinth
• Bone conduction better than air conduction

Diagnostic Evaluation

• Audiometric tests – reveal the type of hearing loss
• CT scan – demonstrates the extent and location of excessive bone growth

Therapeutic intervention

• Hearing aids – to amplify sounds
• Stapedectomy – removal of the portion of the stapes and replacement with a prosthetic implant and to conduct vibrations from the middle ear to the inner ear

Pathophysiology - Refractive Errors

REFRACTIVE ERRORS

Emmetropia (normal vision) – means that light rays are bent to focus on the retina

In refractive errors, vision is impaired because the light rays are not sharply focused on the retina

Refractive Errors include

1. Myopia – occurs in people with elongated eyeballs, because of the excessive length of the eye, light rays focus in the vitreous body before they reach the retina
2. Hyperopia – results when the eyeball is shorter than normal, causing the light rays to focus at a theoretical point behind the retina
3. Astigmatism – results from unequal curvatures in the shape of the cornea
4. Presbyopia – occurs because of degenerative changes. Caused by the gradual loss of elasticity of the lens, which leads to decreased ability to accommodate, or focus, for near vision. The loss of accommodation progresses gradually.

Diagnostic Evaluations

• Visual acuity – snellen chart
• Retinoscopy – vision of myopes improves when concave trial lenses correct the focusing power of the eyes
• Hypropes experience improvement when convex lenses are used

Treatment

• Eyeglasses or contact lenses
• Myopia – concave lenses
• Hyperopia – convex lenses
• Astigmatism – cylindrical lenses
• Prebyopia – prescription lenses

Pathophysiology - Retinal Detachment

RETINAL DETACHMENT – is separation of the retina from the underlying layer of blood vessels

Causes

• Trauma
• Retinal degeneration
• Tumor in the eye
• Haemorrhage
• Cataract surgery
• Myopia

Signs and Symptoms

• Painless blurring of vision
• Shadows falling across the visual field
• Floating spots
• Flashes of lights before the eyes

Diagnostic study

• Opthalmoscopic examination

Management

• Provide bed rest
• Cover both eyes
• Speak before approaching
• Position head as prescribed
• Protect from injury

Pathophysiology - Eye Tumors: Retinoblastoma and Melanoma

TUMORS OF THE EYE

• may be benign or malignant, can form in or metastasize to the eye

1. Retinoblastoma – a congenital malignant neoplasm found in children
• Spreads easily by extension to the brain or bone marrow
2. Melanoma – common in the iris and choroid
• Grows slowly but metastasizes to the liver and lungs

Signs and Symptoms

• Subjective
• Headache
• Visual complaints
• Objective
• Decreased vision
• Increased intra ocular pressure
• White pupils
• Strabismus – in retinoblastoma

Treatment

• Chemotherapy – such as cyclophosphamide, vincristine, carbotin
• Radiation therapy – has significant consequences such as cataracts, chronic dry eye
• Enucleation – surgical removal of the eye

Pathophysiology - Uveitis

UVEITIS 

• is an inflammation of the uveal tract which consists of iris, ciliary body and choroids

Causes

• May develop following eye trauma or surgery
• In association with disease which affect other organs such as ankylosing spondylitis, sarcaidosis and wide spread infections

Symptoms

• Blurred vision
• Eye pain
• Photophobia
• Eye appears red and congested
• Pupils react poorly to light

Medical management

• Oral and topical antibiotics
• Mydriatic eye drops such as atropine – to relieve discomfort caused by contraction of the ciliary muscles
• Antibiotic eye drops
• Analgesics for pain
• Sunglasses reduce the discomfort of photophobia

Pathophysiology - Burns

BURNS

Etiology

• Thermal
• Electrical
• Chemical
• Radiation

Assessment

• History
• Causative agent
• Temperature of burning agent
• Duration of contact
• Thickness of skin

Types

• Superficial burns (1^st Degree)
• Involves epidermis only
• Local pain and erythema; may or may not have blisters
• Rapid healing without scarring
• Discomforts last about 48hours
• Pain eased by cooling
• Partial-thickness burns (2^nd Degree)
• Involves the epidermis and part of the dermis
• Painful, red to pale ivory moist skin with blisters
• Intact tactile and pain sensors
• Healing: 21-28 days with variable scarring