What are the symptoms and treatment options for a patient with acute angle-closure glaucoma experiencing severe eye pain, headache, and blurred vision?

Pain in Acute Angle-Closure Glaucoma

Severe eye pain in acute angle-closure glaucoma (AACG) is a medical emergency requiring immediate IOP-lowering therapy followed by definitive laser peripheral iridotomy to prevent permanent vision loss and blindness. 1, 2

Clinical Presentation of Pain in AACG

The pain associated with acute angle-closure crisis is characteristically severe and multifaceted:

• Eye pain is typically intense and localized to the affected eye, resulting from the sudden, marked elevation in intraocular pressure (often >40 mmHg) 3, 2
• Severe headache frequently accompanies the eye pain and may radiate beyond the periocular region 3, 4
• Nausea and vomiting are common systemic manifestations of the acute IOP spike, reflecting the severity of the pressure elevation 3, 2, 5
• Blurred vision and halos around lights occur from pressure-induced corneal edema, creating the characteristic "steamy" corneal appearance 3, 2, 5

Important Clinical Caveat

Not all angle-closure presents with pain. Painless acute angle-closure glaucoma can occur and may mimic amaurosis fugax, making diagnosis more challenging 6. Patients may present with only transient visual symptoms without accompanying pain, yet still be at risk for vision-threatening complications 6.

Diagnostic Features Beyond Pain

When evaluating a patient with suspected AACG, look for these specific examination findings:

• Mid-dilated, poorly reactive or fixed pupil (may appear oval or asymmetric) in the affected eye 3, 2, 5
• Conjunctival and episcleral hyperemia (red eye) from vascular congestion 3, 2, 7
• Corneal edema with a cloudy, "steamy" appearance 3, 8
• Rock-hard globe on gentle palpation 8
• Shallow anterior chamber on slit-lamp examination 3, 5
• Markedly elevated IOP measured by Goldmann applanation tonometry 3, 1

Immediate Treatment Algorithm for Pain and IOP Control

Step 1: Medical Therapy (Initiate Immediately)

The American Academy of Ophthalmology recommends aggressive medical therapy to rapidly lower IOP 1, 2:

• Topical beta-blockers (e.g., timolol) - first-line agent 1, 2, 7
• Topical alpha-2 agonists (e.g., brimonidine) 1, 2, 7
• Topical carbonic anhydrase inhibitors 1, 2, 7
• Oral or intravenous carbonic anhydrase inhibitors (e.g., acetazolamide) for systemic effect 7
• Oral or intravenous hyperosmotic agents (e.g., mannitol) to rapidly reduce IOP 1, 2, 7
• Topical parasympathomimetics (pilocarpine) to constrict the pupil once corneal clarity improves 7

Critical Pitfall: Timolol and other beta-blockers have little to no effect on pupil size and should NOT be used alone in angle-closure glaucoma 9. The immediate objective is to reopen the angle, which requires pupillary constriction 9.

Step 2: Definitive Treatment (Once IOP Controlled)

• Laser peripheral iridotomy (LPI) in the affected eye is the definitive treatment 1, 2, 5
• Prophylactic LPI in the fellow eye must be performed, as untreated fellow eyes have a 50% risk of acute attack within 5 years 1, 5

Step 3: Post-Treatment Monitoring

• Verify iridotomy patency after LPI 2
• Monitor for persistent IOP elevation - some patients have plateau iris configuration that persists after iridotomy and may require additional intervention 1, 2
• Perform gonioscopy to assess for peripheral anterior synechiae (PAS) 2

Prognostic Implications of Delayed Treatment

The natural history of untreated AACG is devastating for both pain control and vision preservation:

• 18% of eyes become blind within 4-10 years following an untreated AACC event (50% of blindness from glaucoma) 3, 2, 5
• 48% develop glaucomatous optic neuropathy 3, 5
• 58% have visual acuity worse than 20/40 3
• Rapid optic nerve damage can occur within hours to days if IOP remains elevated 1, 5

Critical Pitfalls to Avoid

• Do not delay treatment waiting for ophthalmology consultation if AACG is suspected - initiate medical therapy immediately 5
• Do not dismiss transient symptoms (intermittent blurred vision, halos, mild eye discomfort) as benign - these represent warning episodes before potentially blinding acute attacks 1, 5
• Do not dilate the pupil in patients with suspected narrow angles or intermittent angle-closure symptoms until after LPI is performed, as dilation can precipitate acute crisis 5
• Do not forget the fellow eye - prophylactic treatment is essential as acute attacks can occur within days 1

Risk Factors for AACG

Identify patients at high risk who may develop painful acute episodes:

• Asian descent (highest prevalence) 2
• Hyperopia 3, 2
• Age >50 years 3, 2
• Female gender 2
• Shallow anterior chamber depth 3, 2
• Short axial length 3, 2
• Thick, anteriorly positioned crystalline lens 3, 2
• Family history of angle-closure glaucoma 3, 2
• Medications with anticholinergic or adrenergic effects (e.g., topiramate, ipratropium, phenothiazines) 3