Neuro lecture 11 part 1

Overview of Eye Disorders

• Introduction: Focus on sensory disorders related to the eyes and ears, starting with eye disorders.

• Objectives for Learning:

  • Explain normal physiological processes of vision and hearing.

  • Describe inflammatory conditions of the eyes and ears along with medical management.

  • Outline various surgeries involving the eye and nursing interventions with prognosis.

  • Recognize communication differences with clients suffering from visual and hearing impairments.

Anatomy of the Eye

External Structures

• Key components:

  • Eyebrows

  • Eyelashes

  • Eyelids

  • Lacrimal apparatus

  • Extraocular muscles

• Functions:

  • Primary role is protection.

• Extraocular muscles:

  • Control eye movement via:

  • Cranial nerve III (Oculomotor nerve)

  • Cranial nerve IV (Trochlear nerve)

  • Cranial nerve VI (Abducens nerve)

Lacrimal Apparatus

• Function: Manufactures and drains tears to keep the eyes moist and remove debris.

• Location: Lacrimal glands are superior and lateral to each eye.

Conjunctiva

• Definition: Transparent mucous membrane lining the eyelids’ inner aspect.

• Clinical Note: The lower conjunctiva is where eye drops/ointments are administered.

Internal Structures

• Sclera: Provides shape to the eye.

• Cornea: Lets light enter; highly sensitive and innervated by cranial nerve V (Trigeminal nerve).

• Aqueous Humor: Watery fluid in front of the eye.

• Iris: Pigmented part with a central opening (pupil).

• Choroid: Thin dark membrane lining the inner sclera.

• Retina: Innermost layer that receives images and transmits impulses via the optic nerve to the brain.

Nursing Assessment for Visual Complications

Key Assessment Questions

• Does the patient have eye pain?

• Is there redness or tearing?

• Is there uncontrolled tearing or unusual dryness in the eye?

• Are floaters or light flashes present?

• Are there halos around lights, diplopia (double vision), or eye discharge?

• Are there blind spots or are they able to visualize colors?

• Has there been nystagmus (involuntary eye movement)?

• What medications are taken daily, and are there side effects impacting vision?

• Do they wear glasses or contacts? Last eye exam date? Previous surgeries or injuries?

• How is their depth perception and peripheral vision? Do they have frequent headaches? Any allergies?

Diagnostic Exams for Eye Disorders

Tools and Tests

• Snellen Chart:

  • Used to assess visual acuity at 15-20 feet; shapes or pictures are used for children.

• Refraction: Measures the bending of light as it enters the retina, assessing for refractive errors.

  • Common errors include:

  • Astigmatism

  • Esotropia (eyes turn toward nose)

  • Exotropia (eyes turn outward)

  • Hyperopia (farsightedness)

  • Myopia (nearsightedness)

  • Strabismus (cross-eyed)

• Automated Perimetry Test: Assesses visual fields with a button response to flashes of light.

• Slit Lamp Examination: Magnifies eyelids, sclera, iris, conjunctiva, and cornea; detects glaucoma with dilating drops (mydriatics).

• Fluorescein Angiogram:

  • Invasive procedure requiring informed consent; injected dye can change urine color temporarily.

  • Used to diagnose retinal detachment or macular degeneration.

• Tonometry: Measures intraocular pressure using a puff of air.

Common Eye Infections

• Chalazion: Infection of a sebaceous gland producing a stye; presents as an acute infection.

• Chalazion (Inflammatory Cyst): Results from a complication of a stye.

• Blepharitis: Inflammation of the eyelid at the lash line, may require anti-infectives (e.g., cephalexin, erythromycin).

Conjunctivitis (Pink Eye)

• Definition: Inflammation with or without infection.

• Ophthalmia Neonatorum: Preventable by antibiotic drops at birth.

• Common causes: Allergies and infections, with the condition being highly contagious.

• Symptoms: Redness, itching, burning, photophobia, yellow crusty discharge; often linked to respiratory infections.

Interventions for Conjunctivitis

• Teach warm compress applications to alleviate pain.

• Antiinfective prescription may be needed.

• Instruct handwashing before eye drops.

• Recommend avoiding rubbing eyes and touching affected areas.

• Avoid contact lenses and separate towels/washcloths during the infection.

• Warn of blindness risk without treatment.

Corneal Inflammation

Keratitis

• Definition: Inflammation of the cornea.

• Causes: Injury, allergies, bacterial, viral, or fungal infections.

• Symptoms: Acute severe pain, photophobia, excessive tearing, edema, visual disturbances.

• Pseudomonas: Most common bacterial cause; herpes simplex is the most common viral cause.

• Treatment: Topical antibiotics; corticosteroids contraindicated due to prolonged courses and complications.

Non-Infectious Eye Disorders

Dry Eye Disorder

• Characterized by decreased tear secretion.

• Cause: Lacrimal gland dysfunction; often autoimmune.

• Symptoms: Red eyes, stringy mucus.

• Schirmer's Test: Evaluates moisture after placing filter paper in the lower eye.

  • Normal: 10-15 mm wet paper in 5 minutes.

• Treatment: Artificial tears; corticosteroids for inflammation.

Ectropion and Entropion

• Ectropion: Outward turning of the eyelid margin.

• Entropion: Inward turning of the eyelid.

• Diagnosis and control often through surgical intervention; can arise from birth defects, trauma, or burns.

Cataracts

• Definition: Crystalline opacity/clouding of the lens.

• Prevalence: 50% of seniors aged 65-74 have some degree of cataract formation.

• Causes: Aging, trauma, UV light exposure, congenital conditions, secondary due to other diseases (e.g., diabetes).

• Symptoms: Painless blurred vision, diplopia, photosensitivity, gradual vision loss.

• Surgical Management: Extracapsular extraction is common with rapid healing.

• Post-operative care includes antibiotic/corticosteroid use for 1-2 weeks, patient education on activity restrictions and eye protection.

Diabetic Retinopathy

• Occurs after 15 years of diabetes, with near-universal retinal disease and accompanying neuropathy.

• Symptoms: Vision diminishment, potential for full retinal detachment.

• Diagnosis via slit lamp; characterized by microaneurysms and floaters.

• Management: Photocoagulation, cryotherapy, and VEGF inhibitors for preventing new vessel growth.

Macular Degeneration

Types

1. Wet Type: Sudden new vessel growth leading to scarring; 10% of cases.

2. Dry Type: Slow lipid deposits with atrophy; 90% of cases.

Risk Factors

• Family history, UV exposure, smoking, being female, obesity, race, and light-colored eyes.

• Dietary supplements may slow down progression.

Symptoms and Diagnosis

• Gradual loss of clear/detailed vision, visual distortion, and scotomas.

• Fluorescein angiography confirms diagnosis through vessel leakage.

Medical Management

• Includes Avastin injections, antibiotic drops for preventing infections, and photodynamic therapy for abnormal vessels.

Glaucoma

• Group of disorders characterized by increased ocular pressure due to aqueous humor obstruction.

• Etiology linked to optic nerve atrophy and progressive peripheral vision loss.

• Risk Factors: Age, genetics, infection, diabetes, and notable prevalence in African Americans.

Types of Glaucoma

• Open-Angle: Chronic; 90% of cases, gradual disease progression.

• Closed-Angle: Acute; requires immediate treatment due to rapid vision loss.

Medical Management

• Medications: Beta blockers, miotics, carbonic anhydrase inhibitors, and surgery if medications fail.

• Importance of regular screenings to prevent extensive vision impairment.

Retinal Detachment

• Definition: Separation of the retina with abrupt vision loss, usually due to trauma.

• Symptoms: Bright flashes, floaters, and possibly a dark spot in the peripheral visual field.

Medical Management

• Includes mydriatics to prevent pupil constriction, laser photocoagulation, cryotherapy, and scleral buckle procedures.

• Education on activity restrictions and urgency for treatment to avoid irreversible blindness.

Miscellaneous Medications for Eye Disorders

• Diamox (open-angle glaucoma): Watch for renal and hepatic impairment; take with food due to glucose impact.

• Betoptic (open-angle glaucoma): Monitor for systemic effects; contraindicated in pregnancy/historical heart failure.

• Dexamethasone: Monitor for blurred vision and eye pain; contraindicated for prolonged use in children.

• Gentamicin: Used for blepharitis/conjunctivitis; ensure completion of the prescription.

• Mannitol: Used for intraocular pressure; requires monitoring of electrolytes and output.

• Sulfa Drugs: Treat ocular infections; ensure patients are not allergic.

Conclusion

• Summary of common eye disorders and their medical management.

• Emphasis on the importance of regular eye exams and patient education throughout the treatment process.