What are atropine eye drops used for?

Uses of Atropine Eye Drops

Atropine sulfate ophthalmic solution is primarily indicated for mydriasis (pupil dilation), cycloplegia (paralysis of accommodation), and penalization of the healthy eye in the treatment of amblyopia. 1

Primary Clinical Indications

• Mydriasis: Atropine causes pupillary dilation, which facilitates examination of the optic disc, macula, retina, vessels, and choroid during comprehensive eye examinations 2, 3

• Cycloplegia: Atropine paralyzes the ciliary muscle accommodation, which is necessary for accurate retinoscopy and refraction assessment, particularly in children who have increased accommodative tone compared to adults 3

• Amblyopia Treatment: Atropine is used for penalization of the healthy eye in amblyopia treatment, where it blurs vision in the non-amblyopic eye to encourage use of the amblyopic eye 3

• Myopia Control: Low-concentration atropine eye drops (0.01%-0.05%) are used to slow the progression of myopia in children 3, 4

Mechanism of Action

• Atropine is a muscarinic antagonist that blocks the action of acetylcholine at muscarinic receptors 1
• When applied to the eye, it causes:
  • Pupil dilation (mydriasis) by blocking cholinergic stimulation of the iris sphincter muscle 2
  • Paralysis of accommodation (cycloplegia) by blocking ciliary muscle contraction 3, 5

Dosing Considerations

• For mydriasis and cycloplegia: 1 drop of 1% solution topically to the conjunctival sac, 40 minutes prior to intended maximal dilation time 1
• For amblyopia treatment:
  • Daily application is typically recommended as the penalization effect lasts approximately 48 hours 5
  • The degree of penalization depends on the uncorrected hyperopic refractive error 5
• For myopia control:
  • Lower concentrations (0.01%-0.05%) are typically used 3, 4
  • 0.05% atropine has been shown to be the optimal concentration for balancing efficacy and side effects in myopia control 4

Side Effects and Precautions

• Ocular side effects:

  • Photophobia and blurred vision due to pupil dilation and cycloplegia may last up to 2 weeks 1
  • Light sensitivity (reported in 18% of children) 3
  • Conjunctival irritation (reported in 4% of children) 3
  • Risk of reverse amblyopia when used for amblyopia treatment 3

• Systemic side effects:

  • Increased heart rate and blood pressure from systemic absorption 1
  • Dryness of mouth and skin, fever, delirium, and tachycardia 3, 2
  • Children younger than 3 years may be more susceptible to systemic side effects 3

• Important precautions:

  • Applying direct digital pressure over the lacrimal sac and puncta can reduce systemic absorption and toxicity 3
  • Atropine can precipitate acute angle-closure glaucoma in susceptible individuals with narrow iridocorneal angles 2
  • Use with caution in patients taking monoamine oxidase inhibitors (MAOIs) due to potential for hypertensive crisis 1

Special Considerations

• For amblyopia treatment, atropine 1% appears to be as effective as occlusion therapy (patching) 3
• Twice-weekly dosing of atropine 1% has been shown to be as effective as daily dosing for moderate amblyopia 3
• For myopia control, concentration-dependent responses have been observed with both efficacy and side effects 4
• Atropine eye drops have demonstrated physical, chemical, and microbiological stability for up to six months when properly prepared and stored 6