when is the use of topical atropine in the eye contraindicated?
The correct answer and explanation is:
Correct Answer:
The use of topical atropine in the eye is contraindicated in patients with primary angle-closure glaucoma (narrow-angle glaucoma) or in those at risk of developing it.
300-Word Explanation:
Topical atropine is a muscarinic antagonist used in ophthalmology primarily to dilate the pupil (mydriasis) and paralyze the ciliary muscle (cycloplegia). It is commonly used for eye examinations, treatment of uveitis, and sometimes in myopia control in children. However, due to its pharmacological effects, there are specific situations where its use is contraindicated.
The main contraindication is angle-closure glaucoma, also known as narrow-angle glaucoma. In this condition, the anterior chamber angle (the space between the cornea and the iris where aqueous humor drains) is already narrow. Atropine causes pupillary dilation (mydriasis), which can push the iris forward and further narrow or completely close this angle. When the angle closes, intraocular pressure (IOP) rises dramatically, potentially causing sudden vision loss, eye pain, nausea, and headache — a medical emergency requiring immediate treatment.
Using atropine in these patients can trigger an acute angle-closure glaucoma attack, which may lead to irreversible vision loss if not promptly managed. That’s why screening patients for angle-closure risk (often with a slit-lamp or gonioscopy) before using mydriatics like atropine is critical.
Other considerations for caution or relative contraindication include:
- Hypersensitivity to atropine or its components
- Elderly patients, who are more susceptible to angle-closure
- Very young children, where systemic absorption can lead to anticholinergic toxicity
In summary, topical atropine should not be used in patients with angle-closure glaucoma or at high risk for it, as it can precipitate a dangerous rise in intraocular pressure and potential vision loss. Proper eye examination and patient history are vital before prescribing atropine.