EYES AND EARS

OUTER LAYER, MIDDLE LAYER, AND INNER LAYER

Layers of the eyes

CORNEA AND SCLERA

Parts of the OUTER layer of the eye

CHOROID, CILIARY BODY, IRIS, AND LENS

Parts of the MIDDLE layer of the eye

RETINA, MACULA, FOVEA, AND OPTIC NERVE

Parts of the INNER layer of the eye

AQUEOUS HUMAR, VITREOUS HUMOR, CANAL OF SCHLEMM

other parts of the eye

OUTER LAYER

"Fibrous layer", hard layer

CORNEA

- transparent

- no blood vessels FOCUSES the light into the retina

SCLERA

- white part

- place of attachment of the EOMs

CHOROID

- contains blood vessels

- supplies nutrients to the retina

CILIARY BODY

- controls the thickness of the lens

- secretes aqueous and vitreous humor

IRIS

- colored portion

- has central aperture called PUPILS

- CONTROLS THE AMT of light entering through the pupils

LENS

- controlled by CILIARY BODY

- helps refract and focus light to the retina

- capable to adjust its thickness

RETINA

- light sensitive portion

- send nerve signals to the optic nerve

- contains photoreceptors

CONES AND RODS

2 types of photoreceptors

CONES

bright light, day vision

RODS

dim light, night vision

MACULA

- central area of the retina

- highly pigmented (dark)

- process sharp and detailed vision

FOVEA

- small depression w/in the macula

- sharp and detailed vision (sharpest)

OPTIC NERVE (CN 8)

- carries neural impulses from the retina to the brain

AQUEOUS HUMOR

- clear, watery fluid that fills anterior and posterior chambers

- drains into the canal of schlemm

ANTERIOR CHAMBER

b/n the cornea and iris

POSTERIOR CHAMBER

b/n the iris and the lens

VITREOUS HUMOR

- thick, clear gel-like substance

- located b/n the lens and the retina

- transports nutrients to the retina

- MAINTAINS THE SHAPE OF THE EYE

CANAL OF SCHLEMM

- "scleral venous sinus"

- location: corneosacral junction

- opening: trabecular meshwork

- drainage canal of the aqueuous humor

12-20 mmHg (Nsg. 10-21 mmHg)

normal IOP

ERRORS OF REFRACTION

problems with the SHAPE of the LENS

MYOPIA

- nearsightedness

- lens is too bulge

- light is in front of the retina

1. BICONCAVE LENS

2. LENS

interventions for myopia

LASIK

- laser-assisted in situ keratomileusis

- surgical correction for all types of refractive surgery

HYPEROPIA

- farsightedness

- lens is too thin

- light is behind the lens

1. BICONVEXLENS

2. LENS

interventions for hyperopia

PRESBYOPIA

- loss of lens flexibility d/t aging

- acquired

- light is behind the retina

1. BIFOCAL LENS/DOUBLE VISTA

2. LASIK

interventions for presbyopia

ANTIMETROPIA

- combination of myopia (one eye) and hyperopia (other eye)

ASTIGMATISM

- irregular shape of the cornea/lens

- image focuses @ 2 different points

EYE STRAIN, BLURRY VISSION @ DISTANCES, AND HEADACHE

s/sx of astigmatism

1. CORRECTIVE LENSES/GLASSES

2. LASIK

interventions for astigmatism

CATARACT

- opacity/cloudiness of the lens

- can l/t decreased vision

1. AGING (MOST COMMON)

2. CLUMPING OF LENS PROTEIN (D/T RADIATION)

3. CORTICOSTEROID

4. RADIATION

5. SMOKING

causes of cataract (5) ACCRS

1. BLURRING OF VISION/CLOUDED VISION (PAINLESS)

2. DIMMED VISION

3. ABSENCE OF RED REFLEX

4. GRADUAL LOSS OF VISION

assessments for cataract

ABSENCE OF RED REFLEX

also known as leukocoria, refers to the lack of the normal reddish-orange reflection from the back of the eye (retina) when light is shone into it

1. SLIT LAMP EXAMINATION

2. FUNDOSCOPY/OPTHALMOSCOPY

diagnostics for cataract

1. DARKEN THE ROOM

2. DILATE THE PUPILS

3. ADVISE PT TO LOOK FORWARD (EAR LEVEL)

preparation for the diagnostic tests for cataract

1. PHARMACOEMULSIFICATION

2. EXTRACAPSULAR CATARACT EXTRACTION

interventions for catract

PHARMACOEMULSIFICATION

- 3 mm incision

- lens is emulsification with an ultrasonic energy

- small pieces are aspirated

- new intraocular lens (IOL) is implanted

- irrigation of balanced salt solution

EXTRACAPSULAR CATARACT EXTRACTION (ECCE)

- 10 mm incision

- lens is removed and replaced with new IOL implant

NOTE LNG

cataract surgery is done 1 eye @ a time (1 month interval)

PRE-OP INTERVENTION FOR CATARACT SURG

- withhold

NSAIDs (3-5 days)

aspirin (5-7 days)

warfarin (until PT 1.5 is reached)

- administer dilating drop (mydriatics)

4 doses in 1 hr before surgery

EX: atropine sulfate, tropicamide, phenylephrine

POST-OP INTERVENTIONS FOR CATARACT SURG

- eye patch 24 hrs after surgery

- use eyeglass (daytime)

- use metal shield (nighttime) x 1-4 WKs

- Elevate НOВ 30-45 degrees

- Avoid sleeping into operative side ⭐

- position belongings into non- operative side

- Orient to environment

- Wipe drainage from inner to outer canthus

AFTER CATARACT SURG REPORT IF

- visual changes (inc. IOP -> compression of optic nerve)

- flashes of light

- redness

- swelling

- pain

- inc. eye discharge

- eye injury

DONT'S AFTER CATARACT SURG

- eye straining

- rubbing of the eyes

- rapid movements

- sneezing

- coughing

- bending over

- vomiting

- lifitn heavy objects (>15 lbs)

RETINAL DETACHMENT

- retina separates from the choroid

- can l/t deprivation of retinal oxygen

1. AGING (COMMON)

2. TRAUMA

3. CHOROID TUMOR (RARE)

causes of retinal detachment

1. FLASHES OF LIGHT (PHOTOPSIA)

2. FLOATERS/BALCK SPOTS (SIGNS OF BLEEDING)

3. FEELING OF CURTAIN BEING DRAWN OVER THE EYES (CURTAIN VISION LOSS)

4. FIELD OF VISION LOSS

4 Fs of retinal detachment assessment

1. SLIT LAMP EXAMINATION

2. FUNDOSCOPY/OPTHALMOSCOPY

diagnostic tests for retinal detachment

1. DARKEN THE ROOM

2. DILATE THE PUPILS

3. ADVISE PT TO LOOK FORWARD (EAR LEVEL)

preparation for diagnostic tests for retinal detachment

INTERVENTIONS FOR RETINAL DETACHMENT

- bed rest ⭐⭐

- apply bilateral eye patches ⭐

- to prevent further detachment

- avoid jerky head movements

- safety precaution

SCLERAL BULKING

surgery for retinal detachment

SCLERAL BULKING

- attachment of silicone or a sponge onto the sclera @ the spot of retinal tear

- holds the retina and choroid together

- scar tissues form

MACULAR DEGENERATION

deterioration of the macula (central visual area of the retina)

1. DRY MD

2. WET MD

2 types of macular degeneration

DRY MD

- non-exudative

- most common, less severe

- accumulation of DRUSEN (fatty deposits)

- no cure

WET MD

- exudative

- less common, more severe

- leakage of blood vessels

ANTI-VEGF

tx for wet MD

RISK FACTORS FOR MD

1. aging (most common)

2. smoking

3. HPN

4. overweight

5. levothyroxine

6. HCTZ

ASSESSMENTS FOR MD

1. central vision loss ⭐⭐⭐

2. dark empty areas in central vision

3. sudden onset of decreased vision

4. distortion of lines (ansler's grid)

5. trouble recognizing faces

1. ANSLER GRID TEST

2. DILATED EYE EXAM

diagnostic tests for MD

ANSLER GRID TEST

identifies central vision problems

DILATED EYE EXAM

- done via

1. slit lamp exam

2. fundoscopy/opthalmoscopy

- mottled appearance in the macula (dry)

INTERVENTIONS FOR MD

- anti-VEGF

- most effective mgt. for wet MD

- intravitreal injection

- maximize remaining vision

- ensure safety of patient

GLAUCOMA

increased intraocular pressure results in damage to the retina and optic nerve with loss of vision

1. OPEN-ANGLE

2. ANGLE-CLOSURE

2 types of glaucoma

OPEN-ANGLE GLAUCOMA

- clogging of the drainage canals (defective trabecular meshwork)

- chronic, progressive

- painless

- most common ⭐⭐⭐

ANGLE-CLOSURE GLAUCOMA

- closed/narrow angle b/n the iris and cornea

- iris is squeezed against the cornea

- acute, sudden

- painful

- painful

- symptomatic

- less common

- medical emergency

1. MYDRIATICS

2. ANTICHOLINERGIC DRUGS

3. STEROIDS

4. DM AND HPN

causes of glaucoma

PATHPHYSIOLOGY OF GLAUCOMA

blockage/obstruction -> disrupted normal outflow of aqueous humor -> inc. IOP -> GLAUCOMA -> compression of the optic nerve -> blindness

ASSESSMENT FFOR GLAUCOMA

1. tunnel-like vision ⭐⭐⭐ (peripheral vision loss)

2. halos around lights (also present in cataract)

3. blurred vision

4. ocular erythema

5. hazy/cloudy cornea

6. OPTIC DISK CUPPING

TONOMETRY

diagnostic tests for glaucoma

TONOMETRY

- measure IOP of the eyes

- best test for glaucoma

1. INC. DRAINAGE/OUTFLOW

2. DEC. PRODUCTION OF A.H.

2 goals of the intervention for glaucoma

INTERVENTIONS TO INC. DRAINAGE/OUTFLOW

to induce miosis (constriction)

1. CHOLINOMIMETICS (pilocarpine, carbachol)

2. PROSTAGLANDIN ANALOGUE (latanoprost, bimatoprost)

INTERVENTIONS TO DEC. PRODUCTION OF A.H.

1. BETA BLOCKER (timolol, betaxolol)

2. CARBONIC ANHYDRASE INHIBITORS (acetazolamide)

3. ALPHA 2 AGONIST (brimonidine, apraclonidine)

TRABECULECTOMY

surgical intervention for OAG

IRIDECTOMY

surgical intervention for ACG

PINNA AND EXTERNAL AUDITORY CANAL

parts of the outer ear

TYMPANIC MEMBRANE AND OSSICLE

part of the middle ear

MALLEUS, INCUS, STAPES

parts of the ossicle

COCHLEAR, VESTIBULE, SEMICIRCULAR CANALS

parts of the inner ear

PINNA

collects soundwaves

EXTERNAL AUDITORY CANAL

moves soundwaves to the TM

TYMPANIC MEMBRANE

vibrates and transfer the soundwaves to osicles

MALLEUS (HAMMER)

transmits vibration to incus

INCUS (ANVIL)

transmits to stapes

STAPES (STIRRUPS)

- smallest bone in the body

-transmits to inner ear

COCHLEAR

convert vibration into neural signs

VESTIBULE

maintains balance and equilibrium

SEMICIRCULAR CANALS

- fluid filled tubes

- detects movements and motion

PRESBYCUSIS

S/sx

- other people's speech sounds mumbled/slurred

- trouble hearing high-pitched sounds

- gradual hearing loss

COCHLEAR IMPLANTS

intervention for presbycusis

OTOSCLEROSIS

ABNORMAL BONE remodeling/abn growth of the stapes