Difference between revisions of "Acute angle-closure glaucoma"

(Treatment)
(Treatment)
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== Treatment ==
 
== Treatment ==
*Emergent ophthalmology consult
+
#*Emergent ophthalmology consult
*Decrease production of aqueous humor:
+
#Decrease production of aqueous humor:
#'''timolol 0.5% drop''': blocks beta receptors on ciliary epithelium
+
#*'''timolol 0.5% drop''': blocks beta receptors on ciliary epithelium
#'''apraclonidine 1% drop''': alpha-2 adrenergic receptor agonist which increases trabecular outflow
+
#*'''apraclonidine 1% drop''': alpha-2 adrenergic receptor agonist which increases trabecular outflow
#'''acetazolamide 500mg IV or PO''': blocks productions of HCO3-, which draws Na+ into the eye; water follows by osmosis to form aqueous humour
+
#*'''acetazolamide 500mg IV or PO''': blocks productions of HCO3-, which draws Na+ into the eye; water follows by osmosis to form aqueous humour
*Facilitate outflow of aqueous humor:
+
#Facilitate outflow of aqueous humor:
#'''pilocarpine 1%–2% drop''': parasympatholytic alkaloid acts on muscarinic receptors found on iris sphincter muscle ==> causes muscle to contract ==> miosis
+
#*'''pilocarpine 1%–2% drop''': parasympatholytic alkaloid acts on muscarinic receptors found on iris sphincter muscle ==> causes muscle to contract ==> miosis
#*In USA - green top
+
#**In USA - green top
#*Use one drop every 15 minutes x 2 doses, then every 4 to 6 hours  
+
#**Use one drop every 15 minutes x 2 doses, then every 4 to 6 hours  
#*Only effective when IOP <40 mm Hg
+
#**Only effective when IOP <40 mm Hg
*Reduce volume of aqueous humor:
+
#Reduce volume of aqueous humor:
**'''[[mannitol]] 1–2gm/kg IV''': if no contraindications
+
#*'''[[mannitol]] 1–2gm/kg IV''': if no contraindications
*Recheck IOP hourly
+
#Recheck IOP hourly
  
 
==See Also==
 
==See Also==

Revision as of 20:35, 3 June 2015

Background

Pathophysiology

  • Obstructed aqueous outflow tract > aqueous humor builds > increased intraocular pressure (IOP) > optic nerve damage > vision loss
  • Increased posterior chamber pressure causes iris to bulge forward (iris bombé) > further obstruction of outflow tract > further increase IOP
  • Acute attack is usually precipitated by pupillary dilation

Clinical Features

  • Abrupt onset of severe eye pain
  • Blurred vision
  • Frontal or supraorbital headache
  • Nausea / vomiting / abdominal pain

Differential Diagnosis

Unilateral red eye

^Emergent diagnoses ^^Critical diagnoses

Diagnosis

  • Fixed, midposition pupil
  • Hazy cornea
  • Conjunctival injection most prominent at limbus (ciliary flush)
  • Rock-hard globe
  • IOP >20 mm Hg
  • SLIT LAMP exam shows Cell and Flare which represents visualization of individual cells in the shallow anterior chamber

Definition: 3 signs + 2 symptoms

  • At least 3 of these signs:
    • IOP >21 mm Hg
    • Conjunctival injection
    • Corneal epithelial edema
    • Mid-dilated nonreactive pupil
    • Shallow anterior chamber with occlusion
  • At least 2 of these symptoms:
    • Ocular pain
    • Nausea/vomiting
    • History of intermittent blurring of vision with halos

Treatment

    • Emergent ophthalmology consult
  1. Decrease production of aqueous humor:
    • timolol 0.5% drop: blocks beta receptors on ciliary epithelium
    • apraclonidine 1% drop: alpha-2 adrenergic receptor agonist which increases trabecular outflow
    • acetazolamide 500mg IV or PO: blocks productions of HCO3-, which draws Na+ into the eye; water follows by osmosis to form aqueous humour
  2. Facilitate outflow of aqueous humor:
    • pilocarpine 1%–2% drop: parasympatholytic alkaloid acts on muscarinic receptors found on iris sphincter muscle ==> causes muscle to contract ==> miosis
      • In USA - green top
      • Use one drop every 15 minutes x 2 doses, then every 4 to 6 hours
      • Only effective when IOP <40 mm Hg
  3. Reduce volume of aqueous humor:
    • mannitol 1–2gm/kg IV: if no contraindications
  4. Recheck IOP hourly

See Also

References