Ophthalmology

Question 1

Identify the different anatomical parts of the eye

Answer 1

Cornea: primary abs site
Conjunctiva: thin mucus membrane that covers the sclera
Ciliary body: makes aq humor
Nasolacrimal duct: drug can drain from eye to nasal cavity

Question 2

Outline steps for proper administration of ocular medications

Answer 2

Local delivery: eye drops, ointments, gels
Systemic delivery: injections, oral meds

Question 3

Classify conjunctivitis as bacterial, viral, or allergic based on pt specific characteristics and provide tx options for each type

Answer 3

Bacterial:
Presentation:
- Redness, purulent discharge
- Eye stuck shut in the morning
- Unilateral
Causes (contagious):
- Bacteria
Tx:
- Non-pcol: no sharing linen, remove contacts
- Pcol: Topical antibiotics, ointment/drops
- 1st line: polymyxin B, erythromycin (alt tobramycin, aminoglycosides)
- Second line: fluorouinolones, azithromycin

Viral:
Presentation:
- Watery, burning, sandy feeling eyes
- Bilateral eventually
Causes (contagious):
- Adenovirus
Tx:
- Non-pcol: no sharing linen, avoid contacts
- Sx relief: warm/cool compress, topical decongestant (naphazoline, tetrahydrozoline)

Allergic:
Presentation:
- Red, watery, itchy eyes
- Always bilateral, often w other allergy sx
Causes:
- Airborne allergens
Types:
- Acute: sudden onset by environment
- Seasonal: response to seasonal changes
- Perennial: mild, chronic, year-round response
Pathophysiology:
- Mast cells -> histamine release
Tx:
- Non-pcol: don’t rub eyes, cool compress
- Pcol: antihistamine, mast cell stabilizer
Acute tx:
- Artificial tears
- Topical antihistamine + decongestant
- Topical antihistamine + mast cell stabilizer
Seasonal/perennial tx:
- Topical antihistamine + mast cell stabilizer (ketotifen, olopatadine)

Question 4

Categorize ocular corticosteroids as low, intermediate, or high potency

Answer 4

Low:
- Dexamethasone 0.05 - 0.1%
- Medrysone 1%

Intermediate:
- Dexamethasone alc 0.1%
- Difluprednate 0.05%
- Fluorometholone 0.1 - 0.25%
- Loteprednol 0.2 - 0.5%
- Prednisolone acetate 0.12%
- Prednisolone Na phosphate 0.125 - 1%

High:
- Fluorometholone acetate 0.1%
- Prednisolone acetate 1%
- Rimexolone 1%

Question 5

Summarize uveitis tx strategies and side effects

Answer 5

Uveitis: intraocular inflammation

Presentation: patterned redness + dilated pupil, photosensitivity

Tx: topical glucocorticoids, mydriatic/cycloplegic
- Refer to ophthalmologist/optometrist
- Tx lasts 4-6 weeks
Be aware of:
- Ophthalmic steroid toxicity
- Increase in intraocular pressure (IOP)

Question 6

Differentiate between dry and wet macular degeneration and their respective tx options

Answer 6

Dry:
- Common > 50 years old
- 90% of MD cases
- Bilateral
- Gradual loss of vision
- Tx: beta carotene supplements

Wet:
- Advanced MD
- Rapid vision loss due to abnormal growth of new blood vessels
- Tx: VEGF inhibitors

Question 7

Recommend both pcol and non-pcol tx for dry eyes

Answer 7

Step 1:
- Tear supplements
- Warm compress
- Address any environmental/med factors
Step 2:
- Topical tx (liftegrast, cyclosporine)
- In-office procedures
Step 3:
- Oral drug tx (antioxidants, omega 3 FAs)
- Sclera contact lenses
- Surgery or investigative drugs

Non-pcol:
- Increase blinking
- Warm compress, humidifiers
- Protective eyewear

Question 8

Recognize medications that may cause drug-induced ophthalmic disorders

Answer 8

Dry eyes causes:
- a-1 antagonists
- a-2 agonists
- Antihistamines
- Antipsychotics
- B-agonists and antagonists
- Cannabinoids
- Decongestants
- Diuretics
- Oral contraceptives

Cataracts causes:
- Corticosteroids, phenothiazine, statins

Floppy iris syndrome causes:
- a-1 antagonists
**irreversible

Optic neuropathy causes:
- Aminodarone, ethambutol, PDE-5 inhibitors

Retinopathy causes:
- Aminoquinolones, antiestrogens, phenothiazines, retinoids