Acute Angle-Closure Glaucoma Flashcards
What is acute angle-closure glaucoma?
A medical emergency caused by a sudden increase in intraocular pressure due to blockage of aqueous humour outflow.
What is the pathophysiology of acute angle-closure glaucoma?
Blockage of the trabecular meshwork by the iris prevents aqueous humour drainage, leading to a rapid rise in intraocular pressure.
What are the symptoms of acute angle-closure glaucoma?
Severe eye pain, blurred vision, headache, nausea, vomiting, and seeing halos around lights.
What are the clinical signs of acute angle-closure glaucoma?
Red eye, mid-dilated fixed pupil, corneal clouding, and a hard, tender eyeball on palpation.
What is the prevalence of acute angle-closure glaucoma?
It is less common than open-angle glaucoma but more acute and sight-threatening.
What are the risk factors for acute angle-closure glaucoma?
Age >50, hyperopia (farsightedness), female gender, family history, and Asian or Inuit ethnicity.
What are the triggers for acute angle-closure glaucoma?
Low light conditions, use of mydriatic drugs, or stress.
What investigations are used to diagnose acute angle-closure glaucoma?
Tonometry (measuring intraocular pressure), gonioscopy, and slit-lamp examination.
What intraocular pressure level is typically seen in acute angle-closure glaucoma?
Elevated intraocular pressure, often exceeding 40-50 mmHg.
What are the differential diagnoses for acute angle-closure glaucoma?
Conjunctivitis, anterior uveitis, corneal abrasion, or scleritis.
What is the first-line management of acute angle-closure glaucoma?
Lowering intraocular pressure with medications and preparing for definitive treatment, such as laser iridotomy.
What medications are used to lower intraocular pressure in acute angle-closure glaucoma?
IV acetazolamide, topical beta-blockers (e.g., timolol), and miotics (e.g., pilocarpine).
What is the role of acetazolamide in acute angle-closure glaucoma?
It reduces aqueous humour production, lowering intraocular pressure.
What is the role of pilocarpine in acute angle-closure glaucoma?
It constricts the pupil, opening the trabecular meshwork and facilitating aqueous humour drainage.
What definitive treatments are available for acute angle-closure glaucoma?
Laser peripheral iridotomy or surgical iridectomy.
What is a laser peripheral iridotomy?
A laser creates a hole in the peripheral iris to allow aqueous humour to bypass the blocked trabecular meshwork.
What are the complications of untreated acute angle-closure glaucoma?
Permanent vision loss, optic nerve damage, and blindness.
What is the prognosis for acute angle-closure glaucoma with treatment?
With prompt treatment, vision can often be preserved, but delay can result in irreversible damage.
What lifestyle advice is recommended for patients with a history of acute angle-closure glaucoma?
Avoid mydriatic drugs, regular eye exams, and educate about recognising early symptoms.
What is gonioscopy, and why is it used in acute angle-closure glaucoma?
Gonioscopy assesses the anterior chamber angle to confirm the diagnosis and evaluate the extent of closure.
What is the role of mannitol in acute angle-closure glaucoma?
Mannitol, an osmotic diuretic, reduces intraocular pressure by drawing fluid out of the eye.
What are the systemic symptoms associated with acute angle-closure glaucoma?
Nausea, vomiting, and severe headache.
Why is acute angle-closure glaucoma considered an ophthalmic emergency?
Delay in treatment can lead to rapid and permanent vision loss.
What is the role of prophylactic laser iridotomy?
It is used to prevent acute angle-closure glaucoma in the unaffected eye or in patients at high risk.
What imaging techniques are used to assess anterior chamber anatomy in acute angle-closure glaucoma?
Anterior segment optical coherence tomography (AS-OCT) or ultrasound biomicroscopy.
