UWORLD Chapter 38: Common Eye and Ear Conditions

What is the advantage of using topical medications for eye and ear conditions?

Adverse effects are minimized by applying medication directly to the specific location.

Why should ear drops never be used in the eyes?

Ear drops may not have an appropriate pH, may not be isotonic, and may not be sterile.

Can eye drops be used in the ear?

Yes (Sterile)

What is the volume of one drop of solution?

1 drop = 0.05 mL.

What is the correct administration technique for eye ointments?

Apply to the conjunctival sac or over lid margins.

Which ocular formulation should be shaken well before administration?

suspensions

Which ocular formulation should only be inverted and shaken once?

Gels

What is a side effect of eye ointments?

blurry vision

What is glaucoma?

A disease of the eye that results in damage to the optic nerve and loss of the visual field.

What is the normal range for intraocular pressure (IOP)?

12-22 mmHg.

What are two main forms of glaucoma?

Open-angle glaucoma and angle-closure (closed-angle) glaucoma.

What type of glaucoma is the most common?

Open-angle glaucoma.

What are the characteristics of open angle glaucoma?

often presents without symptoms and is treated with eye drops or surgery

What are the characteristics of closed angle glaucoma?

a sharp, sudden increase in IOP due to a blockage. This is a medical emergency and is treated surgically.

What are common symptoms of angle-closure glaucoma?

Eye pain, headaches, and decreased vision.

What is the goal of glaucoma treatment?

To reduce intraocular pressure (IOP).

Name a class of drugs that can increase IOP.

Anticholinergics (antihistamines, oxybutynin, scopolamine, TCAs, trihexyphenidyl, benztropine), decongestants (pseudophed), chronic steroids (especially eye drops), or topiramate.

What do glaucoma eye drops target?

the aqueous humor (fluid in the eye)

How do prostaglandin (PG) analogs affect IOP?

They are the most effective drugs at decreasing IOP by about 30%.

What is the typical dosing frequency for PG analogs?

Once daily.

What is the effect of ophthalmic beta-blockers on IOP?

They decrease IOP by approximately 22%.

Why might a beta-blocker be preferred for high IOP in one eye only?

To avoid undesirable effects like darkening of the iris and eyelash thickening from PG analogs.

What is critical for effective glaucoma treatment?

Good eye drop technique and high adherence to the treatment regimen.

What is a common mistake with the abbreviations for eye and ear prescriptions?

They can be mistaken for each other; it's safer to write them out.

What do the abbreviations OD and OS stand for?

OD stands for right eye, and OS stands for left eye.

What should patients be counseled about regarding glaucoma?

The importance of adherence to treatment since glaucoma often presents with no symptoms.

Name classes of drugs that reduces aqueous humor production.

Beta-blockers (e.g., timolol), carbonic a hydrate inhibitors (dorzolamide)

What is a common carbonic anhydrase inhibitor used in glaucoma treatment?

Dorzolamide

Which class of drugs increases aqueous humor outflow?

Prostaglandin analogs (e.g., latanoprost)

What is the dosing schedule for prostaglandin analogs?

1 drop in each eye at bedtime (QHS)

What is a potential side effect of prostaglandin analogs?

Darkening of the iris and eyelash growth, blurred vision, stinging

What is the brand name of bimatoprost used in glaucoma?

Lumigan

What is the brand name of bimatoprost used in lash lengthening?

Latisse

What are the brand names of latanoprost?

Xalatan, Xelpros

What is the brand name of travoprost?

Travatan Z

What is the contraindication for using beta-blockers in glaucoma?

Sinus bradycardia and cardiogenic shock

What is another indication for bimatoprost specifically besides glaucoma?

eyelash growth

How should latanoprost be stored before and after opening?

Before: fridge

After: room temperature

What is the dosing for Timolol in glaucoma treatment?

1 drop daily or twice daily (BID)

What are potential side effects of ophthalmic beta blockers?

Burning, stinging, bradycardia/fatigue, bronchospasm

What is the brand name of timolol?

Timoptic, Timoptic XE, Istalol

What is the brand name of timolol and dorzolamide combo product?

Cosopt or Cosopt PF

How long should you wait after eye drops administration before administering gel?

10 minutes

What is the only selective ophthalmic beta blocker?

betaxolol

What should be done before using eye drops that contain preservatives?

Remove contact lenses

What is a common side effect of cholinergic agents like pilocarpine?

Poor vision at night due to pupil constriction

What is the oral form of carbonic anhydrase inhibitor used in glaucoma?

Acetazolamide

What is oral acetazolamide used for?

Acute mountain (altitude) sickness

What is a warning with carbonic anhydrase inhibitors?

Sulfonamide allergy

What is a side effect of oral acetazolamide?

CNS effects such as ataxia and confusion

What is the role of adrenergic alpha-2 agonists in glaucoma treatment?

They increase aqueous humor outflow and reduce production

What is the dosing frequency for Brimonidine?

Three times daily (TID)

What is the mechanism of action for rho kinase inhibitors?

They increase aqueous humor outflow

What is a common symptom of conjunctivitis?

Swelling, itching, burning, and redness of the conjunctiva

What is conjunctivitis also known as?

pink eye

What are the main causes of conjunctivitis?

Virus, bacteria, allergens, or ocular irritants

What patient population does conjunctivitis occur the most in?

young children, highly contagious

What should patients with conjunctivitis do to prevent spreading the infection?

avoid Touching their eyes, sharing towels (change towels and wash clothes daily), discard eye cosmetics (mascara), wash hands thoroughly and frequently

What is a specific treatment for viral conjunctivitis?

There is no specific drug treatment

What virus usually causes viral conjunctivitis?

Adenovirus

What bacteria usually causes bacterial conjunctivitis?

Gram positive (Staphylococcus aureus, Haemophilus influenzae, Streptococcus peneumoniae, Moraxella catarrhalis). More severe cases caused by Neisseria gonorrhoeae or chlamydia.

What is the dosing for Brinzolamide in glaucoma treatment?

1 drop three times daily (TID)

What should be done with Zioptan containers after use?

Discard each single-use container after use

What should be done with Travatan Z and Xelpros regarding preservatives?

They do not contain BAK and can be used in patients with a past reaction to BAK

What is the effect of beta-blockers on aqueous humor production?

They reduce aqueous humor production

What is the primary treatment for chemical conjunctivitis?

Flushing the irritant out with saline and using NSAID or steroid eye drops to reduce inflammation.

When should contact lenses be avoided in cases of conjunctivitis?

If contact lenses caused the irritation, they should not be used until the condition clears.

What is the treatment for bacterial conjunctivitis?

Topical antibiotics such as Moxifloxacin (Vigamox), Neomycin/Polymyxin B/Dexamethasone (Maxitrol), Ofloxacin (Ocuflox), Trimethoprim/Polymyxin B (Polytrim)

What severe bacterial infections require systemic treatment in conjunctivitis?

Infections caused by Neisseria gonorrhoeae or Chlamydia.

How should azithromycin eye drops be stored and how long are they stable stored at room temperature?

store in fridge, stable for 14 days at room temperature

What are common allergens that cause allergic conjunctivitis?

Pollen, dust mites, animal dander, and molds.

What is the role of mast cell stabilizers in treating allergic conjunctivitis?

They help prevent allergic reactions by stabilizing mast cells.

What is blepharitis?

inflammation of the eyelid

What is a common treatment for blepharitis?

Application of a warm compress followed by cleaning with a warm washcloth and baby shampoo.

What are common symptoms of blepharitis?

Inflamed, irritated, and itchy eyelids.

What is the main reason eye drops cause burning sensations?

Preservatives like benzalkonium chloride (BAK) are irritating to sensitive eye tissues.

What should patients do before using eye drops if they wear contact lenses?

Remove contact lenses before using eye drops and wait 15 minutes before reinserting.

What is the purpose of artificial tears?

To alleviate dryness and provide lubrication for the eyes.

What are examples of artificial tears?

Refresh, Systane

What is the treatment for chronic dry eye?

Cyclosporine Emulsion Eye Drops (Restasis) and other lubricants.

What are some examples of medications that can cause ocular adverse effects?

Anticholinergics can cause blurry vision; PDE-5 inhibitors can cause permanent vision loss.

What is the recommended action if a patient experiences visual changes from medication?

Report the changes immediately, as damage is often reversible if the medication is stopped quickly.

What is the treatment for inflammation in the eyes?

cold compresses, Steroid eye drops (prednisolone) or NSAID (ketorlac) eye drops depending on severity.

What are some common over-the-counter treatments for eye redness?

Naphazoline, Tetrahydrozoline, and Brimonidine.

What is the significance of preservative-free eye drops?

They are formulated for patients who cannot tolerate preservatives due to irritation.

What are some examples of antihistamines used for allergic conjunctivitis?

Azelastine, Olopatadine, and Cetirizine.

What is the treatment for dry eye syndrome?

Artificial tears and medications like Lifitegrast (Xiidra).

What should be done for severe cases of conjunctivitis?

Refer for emergency care if the condition is severe or if the chemical is dangerous or unknown.

What is the role of ophthalmic decongestants in allergic conjunctivitis?

To decrease redness caused by allergic reactions.

What is a common side effect of long-term use of steroid eye drops?

Increased intraocular pressure (IOP).

What is the treatment for redness in the eyes?

Ophthalmic decongestants like Naphazoline or Brimonidine.

What drug is known to cause retinal changes or retinopathy?

Chloroquine and Hydroxychloroquine

Which drug can cause optic neuropathy and corneal deposits?

Amiodarone

Which drug can cause optic neuropathy?

Linezolid, Ethambutol, amiodarone

What syndrome causes difficulty in cataract surgery due to intraoperative floppy iris?

Alpha-blockers (e.g., tamsulosin)

What vision change can occur with digoxin toxicity?

Yellow/green vision and halos, blurriness

Which PDE-5 inhibitor can cause a greenish tinge around objects?

Sildenafil

What is a potential permanent vision loss risk associated with vigabatrin?

Permanent vision loss (high risk)

What can isotretinoin do to vision?

decreased night vision, dryness, irritation

What condition is characterized by ear wax (cerumen) impaction?

Ear blockage