Know Your Eye Medications
By Damian Baalmann, MD and Margaret Reynolds, MD
Emergency departments in the United States provide a large amount of eye care, the majority of which is for conditions other than trauma. While emergency medicine physicians often are comfortable with eye pathology, there is a certain amount of discomfort with medications beyond anesthetics. This blog post attempts to outline/summarize the different classes of emergent ophthalmological medications.
Similar to local anesthetics, there are two types of anesthetics: esters and amides. The most common anesthetics are esters are proparacaine (0.5%) and tetracaine (0.5%). Tetracaine lasts about 30 minutes in comparison to proparacaine which lasts 15 minutes but is slightly more irritating and slower in onset.
|MOA||Sodium channel blocker-->decreased
depolarization-->decreased action potential
|Indications||· Used to facilitate eye exams and procedures
· Used to help diagnose corneal causes of eye pain versus other causes
· Used to treat pain from corneal abrasions in outpatient setting 
|Special Considerations||Dogma is to never use topical anesthetics in outpatient use, but recent study RCT in 2014 by Waldman et al. demonstrates increased patient satisfaction with local anesthetics within 24 hour period and no evidence of difference in corneal healing|
Mydriatics and Cycloplegics
Mydriatics and cycloplegics dilate the eye. Mydriatic agents accomplish this by paralyzing the iris sphincter only causing dilation without affecting accommodation while cycloplegics paralyze both the iris sphincter and the ciliary muscles (hence cycloplegia). Dare to dilate the eye. A common mydriatic agent is phenylephrine (2.5%) which takes about 15 minutes to work and lasts for 3-4 hours. Cycloplegics are used for inflammation of the eye. Acute inflammation is often treated by agents with several hours of action. Common cycloplegics include:
|MOA||Mydriatic: sympathomimetic agent that paralyzes the iris sphincter
Cycloplegic: parasympatholytic agent that paralyzes the iris sphincter and the ciliary muscles
|Indications||· Evaluation of painless monocular vision
· Treatment of ciliary spasms in iritis and deep corneal abrasions
|Special Considerations||Contraindicated in patients with suspicion for increased IOP due to acute angle closure glaucoma, presence of shallow anterior chamber or concern for ruptured globe. Blue-eyed individuals are more sensitive than brown-eyed individuals to mydriatics and cycloplegics.|
In the setting of the emergency department, the most common use for miotic agents is acute angle closure glaucoma and the most common miotic is pilocarpine (2%) which facilitates drainage of the aqueous humor by pulling the iris back from its anterior position.
|MOA||Constricts the pupil, pulling the iris back from its anterior position|
|Indications||· Acute Closure Glaucoma|
|Special Considerations||Do not expect any effect until IOP<40
Also consider that if patients have had cataract surgery or have atypical causes of their acute angle closure glaucoma, it may be better to dilate the eye. Consider running it by your ophthalmologist.
Topical antibiotics are indicated for a number of ophthalmic indications including bacterial conjunctivitis, corneal ulcers, and blepharitis. Antibiotics are administered as either drops (solutions) or ointments. Ointments have longer duration, require less frequent administration but do cause blurred vision when on the eye. Drops are rapidly absorbed and require frequent instillation.
|Macrolides||Erythromycin 0.5%||· Only available as ointment
· Gram-positive and Chlamydia trachomatis coverage
· Safe in infants and newborns
|· Excellent gram-negative and Streptococcal coverage|
4th Gen Quinolones
|· Early generation quinolones have high resistance
· 4th gen. quinolones (gatifloxacin, moxifloxacin, & besifloxacin) have gram-negative and pseudomonal coverage and poor Streptococci coverage
o Very expensive
o Often used in monotherapy for corneal ulcers
|Other||Sulfacetamide||· Works by inhibiting folic acid production
· Good for blepharitis
|Bacitracin||· Gram-positive coverage|
|Polymixin B/ trimethoprim||· Good for pediatric population
· Broad coverage including Haemophilus
Topical antivirals (vidarabine and trifluridine) are used for treatment of herpes simplex keratitis but should not be given without consultation with ophthalmologist.
Topic steroids (prednisolone acetate, fluorometholone, and dexamethasone) are indicated for iritis to reduce inflammation and contraindicated in herpes simplex keratoconjunctivitis. These too should not be given without ophthalmologist consultation.
Topical adrenergic agents include beta-antagonists (timolol, betaxolol) and alpha2-agonists (apraclonidine, brimonidine).
|MOA||Reduce intraocular pressure by decreasing secretion of aqueous humor by the ciliary body|
|Indications||· Acute Angle Closure Glaucoma|
|Special Considerations||Be wary of cardiopulmonary effects including hypotension, syncope, heart block and worsening of asthma|
Damian Baalmann is a PGY-3 resident at Mayo Clinic Emergency Medicine Program in Rochester, MN
Margaret Reynolds is a PGY-2 resident at Mayo Clinic Ophthalmology Program in Rochester, MN