Acute angle-closure glaucoma and its treatment
The client has the classic picture of acute angle-closure glaucoma: sudden severe eye pain, headache, blurred vision, and vomiting that began in a dark place, with a red eye, hazy cornea, and a mid-dilated pupil that does not react to light. The goal is to lower intraocular pressure rapidly with drugs such as acetazolamide, pressure-lowering eye drops, pilocarpine once the pressure starts to fall, and mannitol if needed, followed by laser iridotomy. Timolol is a nonselective beta-blocker that is absorbed systemically from the eye and can cause bronchospasm, so the order should be questioned in a client with asthma.
Why eye drops can affect the lungs
Eye drops drain through the nasolacrimal duct into the nose, where the drug is absorbed directly into the bloodstream without first passing through the liver. A drop of timolol can therefore reach levels high enough to block beta-2 receptors in the bronchi, causing bronchospasm in a client with asthma or chronic obstructive pulmonary disease. It can also slow the heart. Pressing gently on the inner corner of the eye after instillation reduces absorption, but it does not make a nonselective beta-blocker safe in asthma.
| Order | Role in acute angle closure | Concern in this client |
|---|
| Acetazolamide IV | Reduces aqueous production | Appropriate |
| Mannitol IV | Draws fluid out of the eye if pressure stays high | Appropriate |
| Timolol 0.5% drops | Reduces aqueous production | Bronchospasm in asthma |
| Pilocarpine 2% drops | Constricts the pupil and opens the angle once pressure falls | Appropriate |
Watch out! Pilocarpine may look like the drug to question because it is withheld until the pressure starts to fall. Here the order already says once pressure falls, so it is correctly written. The safety problem is the beta-blocker in a client with asthma.
Nursing action
The nurse holds the timolol and contacts the prescriber, who may choose another pressure-lowering drop, such as an alpha agonist or a carbonic anhydrase inhibitor drop. The nurse continues to give the other ordered drugs promptly, because the optic nerve can be damaged within hours, and prepares the client for laser treatment. Key point! Question nonselective beta-blocker eye drops such as timolol in clients with asthma, because systemic absorption can cause bronchospasm.