How Do Ophthalmic Anticholinergic Agents Work?

Ophthalmic anticholinergic agents block the activity of a chemical substance known as acetylcholine which activates the contraction of muscles inside the eye. Acetylcholine is a neurotransmitter that motor nerve cells (neurons) in neuromuscular junctions release to activate muscles. Blocking acetylcholine release in the eye muscles results in their temporary inactivation.

Ophthalmic anticholinergic agents paralyze the sphincter and ciliary muscles in the eye. The sphincter muscle in the eye encircles the pupil and functions to constrict the pupil in bright light. The ciliary muscle adjusts the lens shape and thickness to enable us to focus on near and far objects. The inactivation of these two muscles results in dilation of the pupil and inability to focus.

Ophthalmic anticholinergic agents are ointments or solutions administered in the eye:

• To dilate the eyes for examination and diagnosis
• As part of the treatment for uveitis (inflammation of uvea, the middle layer of the eye) to:
  • Relieve pain by preventing movement of the iris
  • Prevent the iris from adhering to the lens
  • Prevent further flare-up of inflammation

Side effects of ophthalmic anticholinergic agents may include:

• Irritation and burning sensation in the eye
• Blurred vision
• Light sensitivity
• Conjunctivitis (inflammation and swelling of the conjunctiva which includes the whites of the eye and the inner surface of eyelids)
• Conjunctival hyperemia (dilation of blood vessels in the conjunctiva)
• Eye edema
• Eye discharge
• Vascular congestion (congestion in the blood vessels of the eye)
• Increase in intraocular pressure (pressure inside the eye)
• Tachycardia (rapid heart rate)
• Drowsiness
• Hyperreactive response in children with Down's syndrome
• Dermatitis
• Anticholinergic toxicity

The information contained herein is not intended to cover all possible side effects, precautions, warnings, drug interactions, allergic reactions, or adverse effects. Check with your doctor or pharmacist to make sure these drugs do not cause any harm when you take them along with other medicines. Never stop taking your medication and never change your dose or frequency without consulting your doctor.

Generic and brand names of some ophthalmic anticholinergic agents include:

• Ophthalmic atropine (IsoptoAtropine)
• Cyclopentolate (Cyclogyl, AK-Pentolate)