Eye and Ear Diseases and Disorders
Anatomy and Physiology of the Eye
Sensory organ located in orbit of skull.
Components:
Sclera, cornea, iris, and pupil.
Anterior and posterior chambers.
Lens (CN III), retina (CN II), choroid layer, and posterior cavity.
Muscles:
Superior and inferior rectus (CN III): move eye up and down.
Medial (CN III) and lateral rectus (CN VI): move eye toward the nose and away.
Superior (CN IV) and inferior oblique (CN III): move the eye to the right and left vertically.
Eyelids:
Cover the anterior portion of the eyeball.
Regulate light entering the eye.
Protect the eye.
Lubricate the eye (CN VII).
Conjunctivae:
Clear transparent membranes to protect the eye.
Lacrimal glands:
Clean and moisten the eye (CN VII).
Common Signs and Symptoms of Eye Disorders
Pain or burning in or around eye.
Visual acuity issues.
Seeing flashes of light.
Eye redness.
Diagnostic Tests of the Eye
Ophthalmoscopy: Exam back of eye.
Visual acuity (Snellen): Clarity.
Tonometry (air puff): Measures pressure.
Slit lamp: Examines front/back of eye.
Angiography: Blood vessels to retina.
Refractive Errors of the Eye
Visual Acuity Issues: Inability to focus images on retina.
One-third of population affected.
Types:
Myopia: Nearsightedness (reading far is difficult).
Hyperopia: Farsightedness (reading close is difficult).
Presbyopia: Age-related hyperopia.
Astigmatism: Irregularity of cornea surface, causes blurry or distorted vision.
Symptoms: squinting, blurred vision, headaches, rubbing of eyes.
Diagnosis: Snellen Chart.
Treatments
Radial keratotomy (RK): corrects Myopia (being replaced by LASIK)
Laser-assisted in-situ keratomileusis (LASIK): newest form of RK.
Automated lamellar keratoplasty (ALK): Remove part of the cornea.
Implantable contact lenses (ICL): Permanent contact (can be revised).
Monovision: Adjusts one eye to see at a distance and other stays close.
Inflammation and Infection of the Eye
Conjunctivitis
Inflammation of conjunctiva (pink membrane lining inner eyelid).
Cause: wind, sun, heat, and cold.
Symptoms: Excessive tearing, itching, burning, and pain.
Acute bacterial (Pink Eye).
Treatment:
Warm compresses
Anti-inflammatories
Analgesics
Perhaps antibiotic ointment
Prevention: Good hygiene.
Blepharitis
Inflammation of edge of eyelid, eyelash follicles, and glands.
Causes:
Bacterial infection, Allergic reaction, Seborrhea.
Symptoms:
itching and burning, red/swollen/crusted eyelids.
Diagnosis: slit lamp microscope.
Treatment: remove cause.
Prevention: Good Hygiene.
Keratitis
Inflammation of cornea caused by trauma or infection.
Usually Unilateral
Cause: herpes simplex, allergies, contacts.
Symptoms:
Photophobia, Pain, Excessive tearing.
Diagnosis: Slit lamp microscope.
Treatment:
Antibiotic ointment or drops
Analgesics
Eye patch
Stye: Also known as hordeolum
Inflammatory infection of sebaceous gland of eyelid
Resembles pimple
Usually caused by Staphylococcus bacteria
Treatment:
Warm compresses
Topical or systemic antibiotics
Some cases: drain
Cataract
Clouding of lens
Causes:
Change in metabolism and nutrition in lens
Can be caused by trauma, birth defects, diabetes
Common with aging (60% of those > 70)
Symptoms: Decreased visual acuity
Treatment: Lens replacement surgery
Glaucoma
Characterized by excessive eye pressure
Slow progression with or without symptoms (rare <40 yo)
Permanent damage can occur before symptomatic
Symptoms: Damage of optic nerve and blindness
Diagnosis: Tonometry
Treatment: Eye drops, Surgery
Prevention: Regular eye exams
Nystagmus
Constant, involuntary movement of eyes that may affect one or both eyes
Causes: Brain tumors, Disease, Alcohol abuse, Congenital defects
Symptoms: Abnormal eye movement
Diagnosis: Hard to diagnose cause
CT scan, MRI, myelogram, angiogram, spinal tap
Treatment: Correct underlying cause
Strabismus
Eyes fail to focus in the same direction simultaneously
Cause: muscle weakness in one or both eyes (amblyopia in affected eye)
Can occur after stroke
Symptoms: Diplopia (double vision)
Diagnosis: Cover test (cover one eye)
Treatment: Cover normal eye to train affected eye to function
Eye exercises, Corrective lenses, Surgery
Macular Degeneration
Degeneration of macular area of retina
Cause: Most commonly age-related disease (>50 yo)
Risk Factors: Farsightedness, light eye color, smoking
Symptoms:
Loss of central vision
Reading and detailed vision difficult
Diagnosis: angiogram
Treatment:
Laser surgery to improve vision
Diabetic Retinopathy
Vascular changes in retina leading to decreased visual acuity
Leading cause of blindness in United States
Cause: Diabetes (Type I and II) if sugar is not controlled
Symptoms: retinal scarring (dec visual acuity), both eyes, can cause blindness
Diagnosis: Dilated Eye Exam
Treatment: Laser photocoagulation
Conditions can recur
Prevention: Controlling blood sugar
Color Blindness
Also called color vision deficiency (CVD)
Causes: Ability to see color diminishes with age due to yellowing of lens
Inherited (1 in 10 males, rare in females)
Symptoms: Most commonly affects ability to distinguish between red and green
Diagnose: Color Pattern Charts
Treatment: No cure, good at seeing camouflage
Red/green colorblind glasses
Trauma
Corneal Abrasion
Causes:
Obstruction trapped between eyelid and cornea
Ill-fitting or worn contact lenses
Accidentally poking finger in eye
Extreme light
E.g., welding
Symptoms: occur 12-18 hours after trauma
Severe pain, tearing, and photophobia
Treatment:
Remove obstruction
Antibiotic ointment or analgesics
Pressure dressing to prevent eye movement
Reduce photophobia pain
Retinal Detachment: When retina peels away from underlying tissue
Cause: Often occurs with trauma, diabetes, and other retinopathies
Symptoms:
Blurred vision
Flashes of light
Floating spots
Painless disorder, but needs attention
Treatment:
Surgery
Rare Diseases
Retinoblastoma
Hereditary malignant tumor of eye occurring during infancy and childhood
Fatal if untreated, otherwise 90% survival
Usually Both eyes affected
Diagnosis: “cat’s eye”
White light reflex
Treatment: radiation, chemo, enucleation (eyeball removal)
Effects of Aging on the Eye
Changes in ability to focus on near objects (especially with middle age), color perception, some sensitivity to light, and decreased visual acuity
Average visual acuity at 65 is 20/70
Glaucoma and Cataracts
Arcus Senilis
Anatomy and Physiology of the Ear
External Ear
Pinna and auditory canal
External and middle ear separated by tympanic membrane
Middle Ear
Also known as tympanic cavity
Malleus, stapes, and incus bones
Inner Ear
Most sophisticated
Vestibule, semicircular canals, round window, and cochlea
Responsible for hearing and equilibrium
Cochlea
Organ of hearing
Common Signs and Symptoms of Disorders of the Ear
Otalgia (ear pain)
Deafness
Vertigo (dizziness)
Tinnitus (ringing in ears)
Otitis Media (middle ear infection)
Diagnostic Tests of the Ear
Otoscopy
Examine external ear canal and tympanic membrane
Audiometry
Test hearing sounds of different frequencies and intensities
Infection of the Ear
Otitis Media: Inflammation in middle ear
Usually affects infants and young children
Types:
Serous – clear fluid build up in middle ear
Suppurative – fluid pus due to bacteria
Caused by URI
Symptoms: Otalgia, nausea, fever, chills, vertigo
Diagnosis: otoscopy reveals bulging eardrum
Treatment:
Analgesics, Decongestants, Antibiotics
Tympanostomy tubes (fall out on own)
Otitis Externa: Also known as swimmer’s ear
Inflammation of external ear canal caused by bacterial or fungal infection
Cause: extended periods in water, trauma, contaminated water
Symptoms:
Extreme pain, Fever, Pruritus (itching)
Purulent fluid
Diagnosis: Otoscopy and culture
Treatment: Keep ear canal clean and dry, antibiotics
Prevention: earplugs
Mastoiditis: Inflammation of mastoid bone or process (porous)
Acute mastoiditis usually result of middle ear infection, common in children
Prior to antibiotics it was the leading cause of death in children
Symptoms: Tinnitus (ringing), Otalgia (pain), fever, headache
Diagnosis: otoscopy
X-ray, culture, CT scan
Treatment:
Antibiotics
Mastoidectomy
Deafness
Affects more than 25 million people
Conductive vs Sensory
Conductive
Caused by external or middle ear disorders that stop sound conduction
E.g., impacted cerumen, otosclerosis, ruptured eardrum
Sensory
Cochlear or auditory nerve damage preventing sound to be carried to brain
Cause related to damaging noise levels and ototoxic medications
Impacted Cerumen
Cerumen: Soft, yellow-brown secretion (earwax)
Causes: Skin dryness, Excessive hair, Narrow ear canal, Excessive dust (construction workers)
Symptoms: partial hearing loss, tinnitus, pain
Treatment: Ear irrigation
Prevention: 3-4 drops of mineral oil weekly
Otosclerosis
Bony fixation of middle ear bones that do not allow vibrations from eardrum to inner ear
Cause: unknown, may be hereditary
Symptoms: slow hearing loss that continues to worsen
Treatment:
Stapedectomy – stapes removed
replaced with prosthesis
Sensorineural Deafness
Sensory deafness due to damage to cochlea or auditory deafness
Damage may be due to exposure to loud noise
Can also be caused by tumors, strokes, trauma, and infections
Damage often permanent
Symptoms: gradual hearing loss
Diagnosis: Audiometry
Treatment: Hearing aids or cochlear implant
Prevention: Avoiding causes
Presbycusis: Progressive sensory deafness related to aging
Symptoms: usually begin after age 50
Lower tones more difficult to hear
Treatment: Use of hearing aid
Amplify sounds
Prevention: Avoid causative factors
Motion Sickness
Experiencing nausea when traveling by car, boat, or airplane
Symptoms:
Nausea and vomiting, Diaphoresis (sweating), Vertigo
Diagnosis: History (no testing needed)
Treatment:
Anti-motion sickness medication
Rest
Closing of eyes
Prevention: Prescribed medication
Transderm Scop®
Trauma
Ruptured Tympanic Membrane
Causes:
Middle ear infection
Sticking sharp object in ear canal
Symptoms:
Pain
Partial loss of hearing
Bloody or purulent discharge
Treatment:
Antibiotics
Surgical patching of membrane with tissue graft
Rare Diseases
Meniérè’s Disease: Affects individuals 40-60 years old
Chronic disease of inner ear
Cause: unknown
Symptoms: Tinnitus, Vertigo, progressive Hearing loss, fullness
Treatment: low-salt diet, diuretics, antihistamine, stop smoking
Surgery if no response to treatment (Can lead to permanent deafness)
Otitis Interna: aka Labyrinthitis (Inflammation of the inner ear)
Cause: many causes (viral, stress, allergies, Meniere’ disease, autoimmune)
Symptoms: vertigo, hearing loss, tinnitis
Diagnosis: Ruling out others
Treatment: Based on cause
Physical therapy
Anti-inflammatories
Effects of Aging on the Ear
Hearing loss affect the ability to perceive what is heard and might affect behavior, personality, and attitudes.
Interferes with social life and independence
Thinner and less flexible tympanic membrane does not conduct sound as well
Degenerative changes in neurons (CN VIII), bones of middle ear, and cochlea à Presbycusis (men > women)