Acute Angle-Closure Glaucoma

Aka: Acute Angle-Closure Glaucoma, Narrow Angle Glaucoma, Primary Angle-Closure Glaucoma, PACG

1. See Also
   1. Glaucoma
   2. Open Angle Glaucoma
2. Epidemiology
   1. Relatively rare compared with Open Angle Glaucoma
3. Risk factors
   1. Increasing age
   2. Hyperopia (Far-sightedness)
   3. Family History of Glaucoma
   4. Angle closure Glaucoma in contralateral eye
   5. Pupillary dilation
   6. Anatomic variant with shallow anterior chamber
   7. Female gender (2.4 Relative Risk)
4. Causes: Precipitating Factors
   1. Dim lighting (results in Mydriasis of the pupil)
   2. Eye Dilating Drops (Mydriatics)
   3. Ophthalmic Anticholinergic Agents
   4. Systemic medications (cause ciliary body edema)
      1. Antidepressants
      2. Sulfa-based medications
      3. Topiramate
5. Pathophysiology
   1. Drainage obstruction of aqueous from anterior chamber
      1. Physical blockage of outflow tract by iris
      2. Narrowing of anterior chamber angle
   2. Increased aqueous production
6. Symptoms
   1. Acute (Usual presentation)
      1. Decreased Visual Acuity, blurred vision
         1. Severe Vision Loss in hours to days
      2. Visual halos or rainbows may occur around streetlights from Corneal edema
      3. Photophobia
      4. Headache
      5. Extreme Eye Pain
      6. Nausea and Vomiting
      7. Abdominal discomfort
   2. Sub-acute
      1. Mild Eye Pain
      2. Visual changes
         1. Colored halos or rainbows seen around streetlights (results from Corneal edema)
         2. Visual changes less pronounced with Miosis (well-lit room, on awakening)
         3. Tunnel vision
      3. Headache
7. Signs
   1. Shallow Anterior Chamber Depth
   2. Decreased Visual Acuity
   3. Pupil mildly dilated and sluggishly reactive
   4. Globe feels firm or rock-hard on palpation through lid
   5. Increased Intraocular Pressure = 25 - 50 mmHg
   6. Eye Redness
   7. Conjunctival edema (Chemosis)
   8. Corneal edema
      1. Cornea cloudy, "steamy", hazy
   9. Ciliary Flush
   10. Fundoscopy
       1. See Open Angle Glaucoma
       2. See Fundoscopy
       3. Optic disc cupping
8. Differential Diagnosis
   1. Open Angle Glaucoma
   2. Narrow Angle Glaucoma often misdiagnosed as:
      1. Migraine Headache
      2. Gastroenteritis
9. Management
   1. Immediate ophthalmology referral
   2. Treat both eyes (typically progresses to involve both eyes)
   3. Temporizing measures
      1. Give Acetazolamide 500 mg orally or IV AND
      2. Administer all 3 ophthalmic medications (repeated every 5 minutes for 3 doses)
         1. Timolol maleate 0.5% (Timoptic) AND
         2. Apraclonidine 1% (Iopidine) given 1 minute after Timolol AND
         3. Pilocarpine 2% (Isoptocarpine) given 1 minute after Apraclonidine
            1. Pilocarpine is only effective after lowering eye pressure with Timolol (due to ischemic paralysis of the iris)
      3. Monitor Intraocular Pressure hourly until patient is seen by ophthalmology
   4. Surgery (definitive treatment)
      1. Laser iridotomy
      2. Iridectomy
10. References
    1. Gupta (2016) Am Fam Physician 93(8):668-74 [PubMed]
    2. Sharma (2000) Can Fam Physician 46:303-12 [PubMed]
    3. Pokhrel (2007) Am Fam Physician 76:829-36 [PubMed]