IT is better to undertake a large task and get it half done than to undertake nothing and get it all done.

W. Marshall Craig

On the following slide you will see a picture of the eye. The structures of the eye are numbered. These numbers correlate to your outline.

On your outline you will list (as we proceed) the function of the structure along with common problems associated with that structure.

Eyes and Ears

4 3 5 1 2 5a 6

 Function?

 Common problems?

  protection fluid distribution    Hordeolum (sty)  Infection of sebaceous (oil) glands by Staph. Advise to apply warm, moist compresses.

Chalazion  Chronic inflammation of sebaceous gland. Treat same as sty.

Blepharitis  lid margins inflammed due to Staph. Itching/burning present. Treat w/antibiotic ointment.

1- Eyelids & Eyelashes

This is a sty – it is tender and develops rapidly. Moist compresses help reduce the swelling and can be used till resolved. If reoccurrence is frequent antibiotic ointment or drops can be used.

Function?

 Lines inner lids  Secretion of mucus and tears – Lubrication!

Problems?

   PINK EYE – common in kids due to poor hand hygiene. Is Bacterial – can be Staph, Strep, or Haemophilus influenzae Is self-limiting but can use a antibiotic drops.

2- Conjuctiva

 Viral  Adenovirus from swimming pools  antiviral drops non-effective  Chlamydial:  major cause of blindness – preventable!

 transmitted via hands and flies  Allergic –  Defining symptom: itching!  avoid allergen if known – can use artificial tears to dilute allergen.

Conjunctivits - continues

CORNEA – • avascular (no blood supply) • main job is bending or refraction of light. • When we get to refractive problems remember this is the structure involved.

3- Cornea

 Bacterial – variety of bugs – treat w/topical antibiotics  Viral • Herpes simplex – leading cause of corneal blinding in western hemisphere – causes corneal ulceration. Antivirals effective.

• Varicella- zoster: (shingles on the cornea) – antivirals effective  Fungus – • not too common but can occur following trauma to the eye in an outdoor (soil) environment.

Keratitis

Corneal ulcer: can result from an infection – very painful, feels like a foreign body in the eye. If left untreated will result in scaring or perforation.

 What is this?

• Lacrimal system  Why Important?

• PROVIDES O2/NUTRIENTS TO THE CORNEA! • Remember the cornea is avascular

 Lacrimal problem?

• DRY EYES – • can use artificial tears • can apply warm compresses to eye • can have canals ‘plugged’

4- Lacrimal duct dysfunction

 Function?

• bend light so it falls on the retina.

• Accommodation when the person looks at a near object, the CILIARY BODY ( 5a when a person needs bifocals.

) contracts – changing the shape of the lens.

-this is what weakens  Problem?

CATARACT – • • • • Opacity in the lens – cloudy 50% of those over 65 Nearly 100% over 70 clearly age related Other causes: TRAUMA, maternal rubella, UV light, long-term use of corticosteroids, diabetics get them at younger age.

• Mydriatics are used to dilate the pupil during interocular lens replacement.

5- LENS

Function?

• Innermost layer, extends and forms the optic nerve • Rods and cones are photoreceptors • rods – black/white/grays, cone –color) • Center of retina is fovea – composed only of densely packed cones – sharpest visual acuity. • Around fovea is macula – relatively free of blood vessels, high density of cones.

6- Retina

• What does this mean?

• leading cause of blindness in diabetics.

• Vessels burst due to microaneurysms

Diabetic retinopathy

• Hypertensive retinopathy – slow…… eventually causes retinal hemorrhages and macular swelling. Untreated leads to sudden visual loss.

• Retinal detachment – separation of the retina from supporting epithelium. Causes: aging, trauma, idiopathic…. Pt sees flashes of light, floaters, cobwebs.

• Macular Degeneration – irreversible central vision loss usually due to aging - Cells atrophy.

Additional retinal problems

• Group of disorders due to increase in intraocular pressure. • Leads to: optic nerve atrophy, peripheral vision loss. • Second leading cause of blindness. 2 million have it and 50% are unaware. • Balance btwn inflow and outflow is cause. • Outflow occurs at the ‘angle’. • Open angle means the fiberous meshwork natural to the eye overgrows and clogs the “pipe”. • Closed angle means the angle is closed from the lens bulging.

GLAUCOMA

Normal Glaucoma – note vessels drop into optic cup Treated with drugs and surgery. Drugs are drops but be aware that they can have side affects on other systems.

GLAUCOMA

A candle that lights another loses no light itself.

Anonymous

• Refraction means eyes ability to bend the light so it falls on the retina. • Myopia = Near sightedness • Hyperopia = Far sightedness • Astigmatism = Uneven cornea – visual distortion • Presbyopia = Loss of accommodation

Refractory problems

• 6.5 million over 65 are unable to read newsprint even with glasses.

• Total blindness = no light perception • Functional blindness = some light but no usable vision • Legally blind = best correction is 20/200, visual field no greater than 20 degrees

Uncorrectable refractory

Nursing diagnosis?

• Disturbed sensory perception related to visual deficit • Risk for injury • Self-care deficits • Fear • Grieving

What does it mean to your patient?

1 2 3

• • Functions?

Problems?

Catch sound waves and direct them to the tympanic membrane Fine hairs, sebaceous (oil) and ceruminous (wax) glands helps lubricate canal, trap debris, and kill bacteria.

• • Trauma – bruising, cuts… blow to ear can break tympanic membrane and/or disrupt ossicles (bones) causing conductive hearing loss.

External Otitis – swimmers ear – infection of the epithelium of the canal. Pain especially w/chewing, muffled sounds.

1- External Ear

Functions?

Problems?

• SOUND CONDUCTION • tympanic membrane vibrates ossicles (malleus, incus, stapes) – vibrates oval window moves fluid in inner ear which stimulates receptors. • Acute Otitis Media – infection of the ossicles, pushes on the tympanic membrane: red, bulging, painful (can break). • Common in children as their auditory tube is flatter and narrower than adults. Tube drains fluid from the middle ear. • IF CHRONIC they do a MYRINGOPLASTY (tympanoplasty) • TEACH : avoid putting the head under water.

2- Middle Ear

Problems continue: • Otosclerosis – hereditary – spongy bones grow around ossicles – what does this do for vibration?

• Can surgically replace stapes which helps. Also hearing aids help amplify sounds.

Middle Ear

 Functions: • Bony labyrinth – fluid filled maze – maintains balance • Cochlea – coiled structure that converts sound waves to electrochemical impulses sent to temporal lobe of brain via CN VIII (vestbulocochlear nerve) for sound interpretation.

3- Inner Ear

 Problems: • Meniere’s Disease: episodic vertigo, tinnitus, fluctuating sensorineural hearing loss. Significant disability as vertigo causes N/V, sweating, pallor. Onset btwn 30 and 60 – cause unknown.

Inner Ear

 CONDUCTIVE:  SENSORINEURAL: • • • Where?

 Outer or middle ear Why?

  transmission of sound impaired to inner ear (something in the way or not working) Wax, otosclerosis, burst tympanic membrane.

• • Where?

  inner ear vestibulocochlear nerve Why?

     congenital/hereditary noise trauma presbycusis Meniere’s ototoxicity What do you “see”?

 patient speaks softly and can hear better in a noisy environment.

• What do you “see”?

 Pt. can hear sound but not understand speech.

HEARING LOSS

      Concerts!

immediate!

Heavy traffic/subway/trains 80 Decibels if exposure is longer than 8 hours Shop tools/lawn mower no longer than 8 hours Chain saw/snow mobile less than 2 hours Gunshot/jet plan immediate!

Rocket launching inevitable - irreversible 120 Decibels 90 Decibels 100 Decibels 140 Decibels 180 Decibels

Hazardous Zones for EARS

Protect them – they’re all you’ve got!

Next Week: Chapters 40 & 41