Diferencia entre revisiones de «Acute angle-closure glaucoma»
Sin resumen de edición |
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| Línea 31: | Línea 31: | ||
= Treatment = | = Treatment = | ||
Emergent | *Emergent ophthalmology consult | ||
*''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''': blocks alpha-2 adrenergic receptors | #'''apraclonidine 1% drop''': blocks alpha-2 adrenergic receptors | ||
#'''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: | |||
#'''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: | |||
#'''mannitol 1–2gm/kg IV''': if no contraindications | |||
'''Recheck IOP hourly''' | '''Recheck IOP hourly''' | ||
Revisión del 23:44 23 sep 2013
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
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
Clinical Features
- Abrupt onset of severe eye pain
- Blurred vision
- Frontal or supraorbital headache
- Nausea / vomiting / abdominal pain
Diagnosis
- Fixed, midposition pupil
- Hazy cornea
- Conjunctival injection most prominent at limbus (ciliary flush)
- Rock-hard globe
- IOP >20 mm Hg
Treatment
- Emergent ophthalmology consult
- Decrease production of aqueous humor:
- timolol 0.5% drop: blocks beta receptors on ciliary epithelium
- apraclonidine 1% drop: blocks alpha-2 adrenergic receptors
- 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:
- 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
- Reduce volume of aqueous humor:
- mannitol 1–2gm/kg IV: if no contraindications
Recheck IOP hourly
See Also
Source
Tintinalli