Acute Angle Closure in a Patient on Multiple Systemic Medications
A 68-year-old hyperopic woman presents with 2 hours of severe right eye pain, nausea, blurred vision and colored halos. Right acuity is 20/200, intraocular pressure 54 mmHg, with diffuse microcystic corneal edema, a mid-dilated fixed pupil and a very shallow anterior chamber; the angle cannot be seen. Left acuity is 20/20, pressure 16 mmHg, van Herick grade 1, and gonioscopy shows appositional closure over 270 degrees. She takes inhaled ipratropium, oxybutynin for urgency and amitriptyline 25 mg nightly; topiramate 50 mg twice daily was started 2 weeks ago for migraine. Blood pressure is 150/90 mmHg. She has a moderate cataract in the right eye and no previous glaucoma diagnosis or laser treatment. She asks whether the topiramate is responsible and whether both eyes need laser treatment.
1. Differentiate the likely mechanisms of this attack and outline immediate medical management, including drugs to avoid.
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Mechanisms. The leading diagnosis is acute primary angle closure in a hyperopic eye with a shallow chamber and appositional closure in the fellow eye. Topiramate can cause secondary angle closure through ciliary body effusion and anterior rotation of the iris, typically within 2 weeks of starting, often bilateral, with myopic shift. This attack is unilateral and the fellow eye shows occludable angles, which favors primary angle closure; topiramate may still have precipitated it.
Immediate management. Lower IOP with topical timolol, brimonidine, and dorzolamide, plus systemic acetazolamide 500 mg (IV or oral). If IOP remains above 40 mmHg or the patient is vomiting, add intravenous mannitol 20% at 1–2 g/kg. Apply glycerin to clear the cornea. Once the cornea clears, start pilocarpine 2% every 15 minutes for 1 hour, then four times daily. Give topical steroid and antiemetic. Stop topiramate and any anticholinergic burden where possible.
Avoid. Do not use atropine or other mydriatics, antihistamines, or additional anticholinergics in presumed primary angle closure. Avoid pilocarpine before the cornea clears and in topiramate-induced closure, where it may worsen ciliary spasm. Do not give topical prostaglandins acutely. Recheck IOP hourly until stable.
2. What definitive management would you recommend for each eye, and how does the topiramate alter your plan?
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If primary angle closure is confirmed. Perform laser peripheral iridotomy in the right eye as soon as the cornea is clear enough; do not wait for the pressure to normalize completely. Treat the left eye with prophylactic iridotomy once the right eye is stable, because more than half of fellow eyes with appositional closure will progress. If the pressure remains uncontrolled or the lens is clearly contributing, proceed to phacoemulsification, which is often definitive in an eye with cataract. Continue topical steroid and taper.
If topiramate-induced closure is confirmed. Stop topiramate permanently and manage medically; iridotomy is not reliably effective because the mechanism is ciliary body effusion. Use ultrasound biomicroscopy to look for effusions and anterior rotation. Once the effusion resolves, reassess the angle; if the angle remains occludable, iridotomy may still be needed. Avoid re-challenging with topiramate.
Counseling. Explain that the fellow eye is at high risk and that laser is preventive, not cosmetic. She should avoid over-the-counter cold remedies and anticholinergics, and tell any doctor about the attack. Arrange cataract surgery planning and follow-up IOP.