October 13th, 2015

Know Your Eye Medications

By Damian Baalmann, M.D.

Know Your Eye Medications

By Damian Baalmann, MD and Margaret Reynolds, MD

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Emergency departments in the United States provide a large amount of eye care, the majority of which is for conditions other than trauma.[1] 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.

Anesthetics

White Caps

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[2]

·         Used to treat pain from corneal abrasions in outpatient setting [3]

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

Red Caps

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:

  • Cyclopentolate: onset 30-60 minutes with duration of ~24 hours
  • Tropicamide: onset 15-20 minutes with duration of ~6 hours
  • Homatropine and atropine have days to week in duration and probably have no role in the emergency department
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.

 

Miotics

Green Caps

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.

 

Antimicrobials

Tan Caps

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

Aminoglycosides Tobramycin 0.3%

Gentamicin 0.3%

·         Excellent gram-negative and Streptococcal coverage
Fluoroquinolones Ciprofloxacin 0.3%

Ofloxacin 0.3%

Levofloxacin 1.5%

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.

Steroids

Pink Caps

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.

Adrenergic Agents

Blue Caps

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

 

Systemic Medications

  • Hyperosmotic agents
    • IV mannitol (20%)
    • Decrease intraocular pressure by decreasing the volume of fluid in the eye
    • Indicated in acute angle closure glaucoma
  • Carbonic anhydrase inhibitor
    • IV acetazolamide
    • Decrease intraocular pressure by decreasing secretion of aqueous humor by the ciliary body
    • Indicated in acute angle closure glaucoma and refractory retinal artery occlusion
    • Contraindications include sickle cell disease! pH change can increase sickling of RBCs in anterior chamber which decrease aqueous outflow and increases IOP. Use caution in chronic kidney disease as it may worsen.

 

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

 

  1. Nash, E.A. and C.E. Margo, Patterns of emergency department visits for disorders of the eye and ocular adnexa. Arch Ophthalmol, 1998. 116(9): p. 1222-6.
  2. Sklar, D.P., J.E. Lauth, and D.R. Johnson, Topical anesthesia of the eye as a diagnostic test. Annals of emergency medicine, 1989. 18(11): p. 1209-11.
  3. Waldman, N., I.K. Densie, and P. Herbison, Topical tetracaine used for 24 hours is safe and rated highly effective by patients for the treatment of pain caused by corneal abrasions: a double-blind, randomized clinical trial. Academic emergency medicine : official journal of the Society for Academic Emergency Medicine, 2014. 21(4): p. 374-82.

 

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