Ophthalmology · Acute Angle-Closure Glaucoma
The facts most likely to be tested
Acute angle-closure glaucoma presents with a sudden onset of severe eye pain, headache, and nausea/vomiting.
Physical examination reveals a fixed, mid-dilated pupil and a steamy or cloudy cornea.
The affected eye will demonstrate increased intraocular pressure on tonometry.
Patients often report halos around lights and blurred vision due to corneal edema.
The anterior chamber is characteristically shallow on slit-lamp examination.
Avoid mydriatic agents (e.g., atropine, sympathomimetics) as they can precipitate or worsen the condition.
Definitive management is laser peripheral iridotomy after initial medical stabilization with topical beta-blockers, alpha-2 agonists, and acetazolamide.
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A 68-year-old woman presents to the emergency department with a 4-hour history of severe right-sided eye pain, nausea, and vomiting. She reports seeing halos around streetlights while driving home earlier this evening. On physical exam, the right eye is injected with a fixed, mid-dilated pupil. The cornea appears steamy and the intraocular pressure is 55 mmHg on tonometry.
What is the most appropriate initial management to lower the intraocular pressure?
Topical timolol, apraclonidine, and systemic acetazolamide
The patient presents with classic signs of acute angle-closure glaucoma; initial management requires rapid reduction of intraocular pressure using a combination of aqueous suppressants before definitive laser peripheral iridotomy.
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Etiology / Epidemiology
Common in elderly, hyperopic (farsighted) patients and those with pupillary dilation.
Clinical Manifestations
Presents with severe eye pain, halos around lights, and a fixed mid-dilated pupil.
Diagnosis
Diagnosis confirmed via gonioscopy showing a closed anterior chamber angle.
Treatment
Immediate acetazolamide IV; avoid sympathomimetics; definitive treatment is laser peripheral iridotomy.
Prognosis
Permanent vision loss occurs if untreated; requires lifelong monitoring of intraocular pressure.
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Epidemiology & Etiology
Primary angle-closure glaucoma (PACG) is most prevalent in Asian populations and individuals with shallow anterior chambers. Risk increases with age as the lens thickens and pushes the iris forward. Precipitating factors include mydriasis (pupillary dilation) from medications or dim lighting.
Pertinent Anatomy
The anterior chamber angle is formed by the junction of the cornea and the iris. Obstruction of the trabecular meshwork prevents aqueous humor outflow. A narrow angle is the critical anatomical predisposition.
Pathophysiology
The iris-lens contact creates a pupillary block, preventing aqueous humor from flowing from the posterior to the anterior chamber. This causes the iris to bow forward, physically obstructing the trabecular meshwork. The resulting rapid rise in intraocular pressure (IOP) causes ischemic damage to the optic nerve.
Clinical Manifestations
Patients present with steamy cornea, severe unilateral ocular pain, and nausea/vomiting. The physical exam reveals a fixed, mid-dilated pupil that is non-reactive to light. Red flag: Do not use topical steroids or sympathomimetics as they can worsen the angle closure.
Diagnosis
The gold standard for diagnosis is gonioscopy, which visualizes the closed angle. Tonometry typically reveals an IOP > 21 mmHg, often exceeding 50-60 mmHg during an acute attack. Optic nerve cupping may be present in chronic cases.
Treatment
Initial management includes acetazolamide to decrease aqueous humor production and topical timolol. Contraindicated: Mydriatics (e.g., atropine) will exacerbate the condition. Definitive treatment is laser peripheral iridotomy, which creates a hole in the iris to equalize pressure.
Prognosis
Untreated acute attacks lead to permanent blindness within hours to days. Patients require long-term follow-up to monitor for glaucomatous optic neuropathy. Prophylactic treatment of the contralateral eye is often indicated.
Differential Diagnosis
Uveitis: characterized by ciliary flush and cells/flare in the anterior chamber
Conjunctivitis: presents with discharge and lacks severe pain or vision changes
Corneal abrasion: history of trauma and positive fluorescein staining
Scleritis: deep, boring pain often associated with systemic autoimmune disease
Open-angle glaucoma: typically painless and presents with gradual peripheral vision loss