348 Week 2- Sensory Perception Alterations

3 layers of the eye

• Fibrous: sclera + cornea

• Vascular: iris + choroid + ciliary body

• Neural: retina + optic nerve

Rods

Responsible for low-light and peripheral vision.

Memory: RODS = Really good in the dark

Cones

Allow color differentiation.

CONES = COLOR

Function of Aqueous humor

It helps maintain intraocular pressure (IOP).

Aqueous humor is the clear watery fluid; filling front part of eye between the cornea and lens.

Disrupted = High-pressure (Increased Fluid) Glaucoma

What does the vitreous chamber contain?

Gel-like substance that maintains the shape of the eye and transmits light.

Vitreous chamber= largest space inside the eye.

Structures are found in the middle ear?

• Tympanic membrane

• Malleus

• Incus

• Stapes

• Eustachian tube

Memory: MIST = Malleus → Incus → Stapes→ Tympanic membrane

What does the cochlea control?

Hearing

CN Vlll vestibulocochlear = hearing/balance

What do the semicircular canals control?

Balance

CN Vlll vestibulocochlear = hearing/balance

Glaucoma

A progressive optic neuropathy involving degeneration of retinal ganglion cells and their axons.

What is the normal IOP (Intra ocular pressure) range?

10–21 mmHg.

What happens in Primary Open-Angle Glaucoma (POAG)?

The drainage angle remains open, but the trabecular meshwork becomes clogged, causing a gradual increase in IOP.

Visual manifestation: Loss of peripheral vision → tunnel vision.

Is POAG usually sudden or gradual?

Gradual and often asymptomatic.

physical finding: Optic disc cupping, with possible headache and mild eye pain + halos around lights.

Cataract

An opacity (blurring/cloudiness) of the lens caused by clumping of lens proteins and fiber breakdown.

Obstructs light transmission to the retina.

Physical findings with cataracts

• Diplopia (Double vision)

• White/gray pupils

• Absent red reflex

Type of vision that is primarily affected by Age-related Macular Degeneration(AMD)

Central vision.

Memory: MACULA = Middle/central vision

Drusen

Accumulations of photoreceptor waste (fatty proteins and lipids) under the retina.

Difference between dry and wet AMD

Dry AMD:

• Most common

• Gradual progression

• Retinal capillary blockage

• Ischemia and necrosis of the macula

Wet AMD:

• Less common

• Faster onset

• Fragile new blood vessels

• Blood/fluid leakage

• Scarring

Metamorphopsia

PT Seeing wavy/distorted lines, associated with AMD.

Amsler Grid

Assess it monitors macular degeneration.

What should a patient report when using an Amsler Grid?

Wavy lines, because this may indicate a significant change requiring attention.

Retinal detachment

Separation of the retina from the underlying epithelium.

Sudden, painless "curtain" over the visual field.

Memory: RETINAL DETACHMENT = CURTAIN

Visual symptoms are associated with retinal detachment

Floaters and flashing lights.

What causes acute otitis media?

Infection causing pressure and exudate (fluid) in the middle ear.

What does the tympanic membrane look like with acute otitis media?

Bulging/red, with a displaced or obscured light reflex.

Otosclerosis

Fusion of the middle-ear ossicles, causing conductive hearing loss.

Ménière’s disease

Accumulation of endolymphatic fluid in the inner ear.

Symptoms:

• Vertigo (Spinning/whirling sensation)

• Tinnitus

• Unilateral sensorineural hearing loss

• Ear fullness/pressure

• Nausea/vomiting

What is labyrinthitis associated with?

• Sudden severe vertigo

• Tinnitus

• Hearing loss

• Nausea/vomiting

• Nystagmus

How should the nurse pull the auricle when performing otoscopy on an adult?

Up and back.

*Child = Down and back.*

Memory:
Adult = UP
Child = DOWN

What does a normal tympanic membrane look like?

Pearly gray and intact.

Where should the normal light reflex be seen?

Right ear: 5 o'clock

Left ear: 7 o'clock

What test measures visual acuity?

Snellen chart

What test measures IOP?

Tonometry

What test evaluates the drainage angle of the eye?

Gonioscopy

What test examines the optic disc and retina?

Ophthalmoscopy/Fundoscopy

What tests evaluate hearing?

• Audiometry

• Tympanometry

• Weber test

• Rinne test

Where should eye drops be placed?

In the lower conjunctival sac, NOT directly onto the cornea.

Tip: Have PT keep eyes closed for 3 mins

How long should the nurse wait between different eye drops?

5–10 minutes.

Should eye drops or eye ointment be administered first?

Eye drops first, ointment second.

Punctal occlusion

Applying pressure to the inner corner of the eye over the lacrimal punctum for 2–3 minutes after administering eye medication.

Tip: To reduce systemic absorption of ocular medication.

Timolol Medication

It is a beta-blocker that decreases aqueous humor (fluid) production.

Tip: lowers intraocular pressure (IOP) and helps prevent further damage from glaucoma.

Major adverse effects/concerns with timolol

• Bradycardia

• Hypotension

• Bronchoconstriction (narrows airways)

NOT for patients with asthma, COPD, or bradycardia.

Pilocarpine Medication

It is a cholinergic miotic that constricts the pupil and improves drainage.

Adverse Affect: Dim-light visual impairment. (Fall risk)

What should the nurse check before administering acetazolamide?

Sulfa allergy.

How does latanoprost work?

It is a prostaglandin analog that increases aqueous humor (fluid) drainage.

Notable Effects:

• Permanent darkening of the iris/eyelid

• Increased eyelash growth

What medication can rapidly decrease IOP during an acute angle-closure glaucoma emergency?

IV mannitol.

What is meclizine used for?

Treatment of vertigo; it has antihistamine/anticholinergic effects.

NURSE→ PT teaching point: Causes Sedation, which increases fall risk.

Which medications used for vertigo are contraindicated in closed-angle glaucoma?

Scopolamine and diazepam. (can worsen IOP)

What medication may be given before cataract surgery?

Atropine — a mydriatic/cycloplegic.

Dilates (widens) the pupil and temporarily relaxes the eye’s focusing muscle

What is the major post-op priority after cataract surgery?

Prevent increased IOP.

What activities should a patient avoid after cataract surgery?

Avoid:

• Bending

• Coughing

• Sneezing

• Straining/Valsalva

• Lifting more than 10 lb

• Water in the eye up to 1 week

When is the best vision expected after cataract surgery?

Approximately 4–6 weeks.

About a month

Trabeculectomy

Glaucoma surgery that creates a drainage flap.

What should the nurse monitor for after a trabeculectomy?

A bleb, which is a fluid collection area under the eyelid.

What is a stapedectomy used to treat?

Otosclerosis

The stapes is replaced during surgery

Avoid:

• Air travel 2-3 weeks

• Blowing nose aggressively with mouth closed

How should the ear be protected while showering after stapedectomy?

Keep it dry; use a cotton ball with petroleum jelly.

What cranial nerve complication should be reported after stapedectomy?

Facial nerve (CN VII) damage.

Cochlear implants are used for what type of hearing loss?

Sensorineural hearing loss.

When is a cochlear implant typically programmed?

2–6 weeks after surgery.

What imaging procedure is contraindicated with cochlear implants according to the study guide?

MRI

What environmental changes help protect patients with sensory impairment?

• Remove area rugs

• Remove clutter

• Install grab bars

• Use bright overhead lighting

• Color-code medication labels

• Avoid open flames

Why are fall-prevention measures particularly important for patients with visual alterations?

Visual alterations significantly increase the risk of falls and hip fractures.

What diet is recommended for AMD?

A Mediterranean diet.

Ex: dark leafy greens, fatty fish, and colorful fruits and vegetables

Supplements: AREDS2, containing lutein and zeaxanthin.

What dietary changes are recommended for ?

• Restrict salt/sodium

• Avoid MSG

• Avoid caffeine

• Avoid alcohol

• Space fluid intake evenly throughout the day