Lecture 19: Ophthalmic & Otic Disorders Flashcards
Ophthalmic Disorders
- Dry eye (keratoconjunctivitis sicca)
- Allergic conjunctivitis
- Corneal edema
- Foreign substance
- Chemical burn
- Contact dermatitis
Epidemiology: •Dry Eye
Most common eye disorder
• Appropriate for self-care
• Exacerbated by environmental conditions and low humidity
Epidemiology: Allergic Conjunctivitis
- Occurs in up to 40% of US population
- Variable causes - geography, seasonal
- Appropriate for self-care
Eye Anatomy
- Protective barriers
- Nasolacrimal system
- Cornea
Protective barriers
Eyelid, eyelashes
• Non-stimulated tears (make up the tear layer)
Nasolacrimal system
• Drainage from punctum to the to nose
Cornea
Trilaminar barrier facilitates drug absorption
• Outer epithelial layer - lipophilic (fat soluble drugs)
• Middle stromal layer - hydrophilic (water soluble drugs)
• Inner epithelial layer
What pharmacokinetic issue would you expect to most commonly occur with ocular drug administration? A) Drug dilution B) Excessive ocular penetration C) Retinal damage D) Pupillary constriction
A) Drug dilution
Ophthalmic Pharmacokinetics Absorption
- Increased by: increased time in cul-de-sac
* Decreased by: dilution and nasolacrimal drainage
Ophthalmic Pharmacokinetics Distribution
Typically local; may have systemic absorption via nasolacrimal
system
Ophthalmic Pharmacokinetics Metabolsim
Locally by enzymes and proteins
• Systemically by standard drug metabolism
Ophthalmic Pharmacokinetics Excretion
Nasolacrimal → systemic vasculature → standard elimination
Dry Eye Pathophysiology
- Etiology
- Decreased tear production
- Increased tear evaporation (stability)
- Mixed
Dry Eye -• Precipitating event
- Stress to ocular surface → inflammatory process
- Ocular damage
- Decreased blink rate
Dry Eye -Chief Complaint
- Redness
- Burning, stinging
- Foreign body sensation
- Gritty, sandy
- Pruritus
- Photophobia
- Visual changes
Dry Eye Disease: Risk is increased by
- Older age
- Female sex
- Hormonal changes
- Medications / comorbidities
- Activities: computer / TV / reading
- Ocular surgeries
- Vitamin A deficiency
- Environmental factors
Medications contributing to Dry Eye
- Anticholinergic
- Antihistamines (systemic)
- Antipsychotics
- Decongestants
- Diuretics
- Beta-blockers
Dry Eye Exclusions to Self-care
- Symptoms
- Eye pain (irritation is appropriate for self-care)
- Blurry vision
- Photophobia
- > 72 hours symptoms
- History
- Contact lenses
- Blunt trauma
- Chemical / heat exposure
Approach to Treatment
1) Symptoms
2) Onset / Duration / Severity
3) Location / Time of day (diurnal)
4) Exacerbating / Mitigating
5) Previous treatments
6) Comorbidities / Medications
7) Allergies
Dry Eye Classification-Mild
- Itching / irritation
* Intermittent visual changes (vision fatigue)
Dry Eye Classification-Moderate
- More frequent symptoms
* Impacts activities of daily living (ADLs)
Dry Eye Classification-Severe
- Constant symptoms
* Disabling
Dry Eye Non-pharmacologic: Avoidance
- Cigarette smoke
- Dry heating and air-conditioning
- Computer / TV / reading
- Environmental exposures / dust
Dry Eye Non-pharmacologic Treatments
- Humidifier
- Goggles/glasses
- Eyelid hygiene
- D/C or limit exacerbating medications
Artificial Tears MOA
- Increase tear film stability
* Decrease ocular surface stress
Artificial Tears Treatment
Improves symptoms and vision ability
• Prevents ocular damage
Artificial Tears Consider
- Preservatives
- Present in multi-dose products
- Viscosity
- ↑viscosity = ↓ evaporation / ↑ retention time
- pH / Tonicity
- Similar to physiological
Artificial Tears Adverse Effects
- Preservatives
- Irritation
- Ocular damage
- Visual changes
• Infection
- Inappropriate use / storage
Preservatives Role
- Bactericidal
* Included in multi-dose containers
Preservatives
May have a toxic effect on the tear film and cornea
• Long term use can lead to ocular damage
• Many preservatives are available
• Chlorhexidine is preferred to benzalkonium chloride (BAK) → less toxic
• Preservative-free/disappearing preservative options
• Single use
• More expensive
Ophthalmic Ointments: Non-medicated Products
- Petrolatum
- Mineral oil
- Lanolin
Ophthalmic Ointments: Severe disease
• ↑ viscosity = tear film stability / ↑ retention time
Ophthalmic Ointments: Adverse effects
• Blurry vision - apply at bedtime
Dry Eye Treatment Approach-Mild
- Low viscosity agent
* Drops 1-2 times per day
Dry Eye Treatment Approach- Moderate
- Low viscosity
* Drops 3-4 times per day
Dry Eye Treatment Approach-Severe
- Non-preservative low viscosity – applied every hour as needed
- Ophthalmic ointment at bedtime
No relief in 72 hours?
Refer to provider
Dry Eye Additional Therapies
-Medications (RX) • Anti-inflammatory • Systemic omega-3 • Cyclosporine • Systemic agents
- Interventions
• Punctal plugs
• Corrective surgery
• Corrective lenses
Allergic Conjunctivitis Chief Complaint
- Redness
- Watery discharge
- Pruritus
- “Allergic shiners”
- Visual changes = atypical
- Seasonal allergic rhinitis
Allergic Conjunctivitis Pathophysiology- Allergen contact
IgE mediated immune reaction
Allergic Conjunctivitis Pathophysiology- • Mast cell degranulation
histamine release
Allergic Conjunctivitis Pathophysiology-Histamine
vasodilation and itching
Allergic Conjunctivitis Risk factors
- Spring / summer
- Geographical location
- Environmental factors
- Seasonal allergic rhinitis
- Topical preparations
Allergic Conjunctivitis : Exclusions to Self-care
Symptoms • Eye pain (vs. irritation) • Blurry vision • Photophobia • >72 hours • Mucus discharge •History • Contact lenses – don’t use contacts until AC is resolved • Blunt trauma • Chemical / heat exposure
Allergic Conjunctivitis NON-Pharm treatments
- Cold compress 3-4 times / day
- Environmental changes
- Close doors/windows
- Use air conditioning
- Use air filters
- Monitor pollen counts
- Avoid rubbing
Allergic Conjunctivitis Pharm treatments
First line - artificial tears
• Second line - topical antihistamines, mast cell stabilizers,
decongestants
Antihistamines MOA
- Antagonize histamine at H1 / H2 receptors
* Primary mast cell mediator
Antihistamines Products
- Pheniramine, antazoline, olopatadine (Pataday®) - use 3-4 x day
- Ketotifen (antihistamine / mast cell stabilizer) - use 2-3 x day
Antihistamines Adverse Effects
- Burning /stinging
- Discomfort
- Pupil dilation
Antihistamines Contraindications
Closed angle glaucoma
Mast Cell Stabilizers-Mechanism
Prevent mast cell degranulation
• Inhibit eosinophils (late reaction)
Mast Cell Stabilizers-Products
- Ketotifen (antihistamine / mast cell stabilizer)
- Immediate relief
- 12 hour duration
- Safest and most effective
Decongestants MOA
α – agonist properties cause vasoconstriction
• Decreases red-eye, edema, congestion
Decongestants Products
ducts
• Phenylephrine
• Imidazolines = oxymetazoline / tetrahydrozoline / naphazoline
• 1-2 drops q 4-6 hours
Decongestants caution
Rebound toxicity (>72 hours) • Hyperemia • Allergic conjunctivitis • Blepharitis • Congestion
CAD/hypertension, Diabetes, Hyperthyroidism
Decongestants Adverse Effects
- Rebound toxicity (>72 hours)
- Hyperemia
- Allergic conjunctivitis
- Blepharitis
- Congestion
Pediatric Toxicity
Ingestion of ophthalmic decongestants:
• Hypotension and bradycardia
• CNS depression
• Respiratory depression
Allergic Conjunctivitis Treatment Strategy
1st line = non-pharmacological treatment
2nd line = artificial tears
3rd line = Antihistamine / mast cell stabilizer (alone or combo product)
Alternatives = decongestant, oral antihistamine
Corneal Edema Pathophysiology
Corneal swelling leading to visual changes (starbursts, halo around light)
Diagnosis required from HCP before OTC treatment
Corneal Edema Etiology
- Over-wearing contact lens
- Surgical damage
- Inherited corneal dystrophy
Corneal Edema treatment
- Draw fluid from cornea
* OTC agents = Sodium Chloride (NaCl) solutions / ointment
Corneal Edema Treatment Strategy
1: 2% NaCl solution 4 times daily
2: add 5% ointment at bedtime
3: Increase to 5% NaCl solution
Corneal Edema Adverse effects
5% NaCl = burning / stinging
Foreign Substance Treatment
- Irrigation
- Use saline solution, irrigation fluid, water
- DO NOT use eye cup
- Ointment at bedtime
Foreign Substance Refer
- Visual changes
- Pain
- Persistent redness
- Wood or metal in eye
Chemical Burn-Products
- Acids / alkalis
- Detergents
- Solvents
Chemical Burn-Emergent irrigation
- Saline solution / water
* Immediate transfer to ED
Cerumen Impaction Epidemiology
- More common in pediatric and geriatric patients
- 10% peds
- 30% nursing home patients
Cerumen Impaction Self-Treatment
• OTC options for external ear disorders
Cerumen Impaction- Clincial Presentation
- Fullness / pressure in ear
- Reduced hearing ability
- Dull pain
- Tinnitus
- Vertigo
Cerumen Impaction-Pathophysiology
- Excess cerumen
- Damage EAC which is a pathogen risk
- Causes
- Narrow or misshapen EAC
- Excess hair
- Overactive ceruminous glands
- Hearing aids, ear plugs
Cerumen Impaction exclusions to Self-care
- Infection
- Pain with discharge
- Bleeding, trauma
- Ruptured tympanic membrane
- Recent surgery (<6 weeks)
- Tympanostomy tubes
- <12 years old
Cerumen Impaction Non-Pharm treatment
- Wet washcloth
- Only for outermost portion of EAC
- Otic bulb to administer warm water
- Cotton swabs
- NOT recommended
Cerumen Impaction Pharm-Treatment
Carbamide Peroxide
Carbamide Peroxide MOA
- Exposure to O2 → effervescence + urea
- Effervescence helps to loosen and soften cerumen
- Urea aids in tissue debridement
Carbamide Peroxide Directions of Use
- Twice daily for 4 days, then refer
* Rinse with warm water with otic bulb after dose
Ear Anatomy-External ear
- Auricle
- External auditory canal (EAC)
- Tympanic membrane
Ear Anatomy-Cerumen
- Lubricates EAC, traps dust, prevents pathogens
- Collects dead skin
- Travels outward to end of EAC
Water-clogged Ears Causes
- Altered external auditory canal
- Excess cerumen
- Hot and humid environment (excess sweating)
- Swimming / bathing
- Poor hygiene
Water-clogged Ears External Otitis (Swimmer’s ear)
• Not amenable to self-care
Water-clogged Ears Clincial Presentation
- Feeling of wetness / fullness
* Reduced hearing ability
Water-clogged Ears treatement goals
- Prevent maceration
- Reduce itching, pain, infection risk
- Dry with safe and effective agent
Water-clogged Ears Exclusions to Self-care
- Infection
- Pain with discharge
- Bleeding, trauma
- Ruptured tympanic membrane
- Recent surgery (<6 weeks)
- Tympanostomy tubes
- <12 years old
Water-clogged Ears Non-Pharmacologic treatment
- Head tilt + auricle manipulation
- Hair dryer
- Water absorbing ear plugs
Water-clogged Ears Pharmacologic Treatments
- Isopropyl alcohol / glycerin
* Half and half mixture = 50% vinegar / 50% isopropyl alcohol (95%)
