Acute angle-closure glaucoma
Revision as of 01:02, 3 August 2015 by Ostermayer (talk | contribs) (→TreatmentCare of the Patient with Primary Angle Closure Glaucoma. Optometric Clinical Practice Guideline. American Optometric Association. PDF Accessed 06/17/15)
Background
Pathophysiology
- Obstructed aqueous outflow tract → aqueous humor builds up → 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 (usually unilateral) eye pain
- Blurred vision
- Frontal or supraorbital headache
- Nausea / vomiting / abdominal pain
Differential Diagnosis
Unilateral red eye
- Nontraumatic
- Acute angle-closure glaucoma^
- Anterior uveitis
- Conjunctivitis
- Corneal erosion
- Corneal ulcer^
- Endophthalmitis^
- Episcleritis
- Herpes zoster ophthalmicus
- Inflamed pinguecula
- Inflamed pterygium
- Keratoconjunctivitis
- Keratoconus
- Nontraumatic iritis
- Scleritis^
- Subconjunctival hemorrhage
- Orbital trauma
- Caustic keratoconjunctivitis^^
- Corneal abrasion, Corneal laceration
- Conjunctival hemorrhage
- Conjunctival laceration
- Globe rupture^
- Hemorrhagic chemosis
- Lens dislocation
- Ocular foreign body
- Posterior vitreous detachment
- Retinal detachment
- Retrobulbar hemorrhage
- Traumatic hyphema
- Traumatic iritis
- Traumatic mydriasis
- Traumatic optic neuropathy
- Vitreous detachment
- Vitreous hemorrhage
- Ultraviolet keratitis
^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 shallow anterior chamber and Cell and Flare (visualization of individual cells in the 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[1]
Goal of medical therapy is to 'break the attack' in order to prepare the patient for laser iridotomy.[2]
- Emergent ophthalmology consult
- Decrease production of aqueous humor:
- timolol 0.5%: Blocks beta receptors on ciliary epithelium
- 1 drop in affected eye, repeat in 1 hour if needed.
- acetazolamide: blocks productions of HCO3-, which draws Na+ into the eye; water follows by osmosis to form aqueous humour
- 500mg IV or PO (PO preferred unless pt is nauseated)
- Can substitute methazolamide 100mg if pt has renal failure.
- Dorzolamide (Trusopt) 2%: topical carbonic anhydrase inhibitor
- 1 drop in affected eye
- Brimonidine (Alphagan) 0.2% OR Apraclonidine 1%: alpha-2 agonist, which also increases trabecular outflow
- 1 drop in affected eye
- timolol 0.5%: Blocks beta receptors on ciliary epithelium
- Facilitate outflow of aqueous humor:
- pilocarpine 1%–2%: parasympatholytic alkaloid acts on muscarinic receptors found on iris sphincter muscle → causes muscle to contract → miosis → pulls iris away from trabecular network
- 1 drop in affected eye every 15 minutes x 2-4 doses, then every 4 to 6 hours
- Likely does not work until IOP drops below 40-50 mmHg, but still give immediately upon diagnosis
- pilocarpine 1%–2%: parasympatholytic alkaloid acts on muscarinic receptors found on iris sphincter muscle → causes muscle to contract → miosis → pulls iris away from trabecular network
- Reduce volume of aqueous humor:
- Hyperosmotic agents: Single most effective treatment, but watch for contraindications (e.g. renal failure) and systemic effects.
- mannitol: 1-2 g/kg IV (most common)
- 50% glycerin (Osmoglyn) OR 45% isosorbide (Ismotic): 1.5 mL/kg PO (rarely used)
- May need to give repeat doses
- Hyperosmotic agents: Single most effective treatment, but watch for contraindications (e.g. renal failure) and systemic effects.
- Recheck IOP at least hourly
Topical steroids not indicated during acute attack, but may help inflammation after IOP under control.
See Also
References
- ↑ Care of the Patient with Primary Angle Closure Glaucoma. Optometric Clinical Practice Guideline. American Optometric Association. PDF Accessed 06/17/15
- ↑ Primary Angle Closure Preferred Practice Pattern Guideline. American Academy of Ophthalmology. Angle Closure PPP Accessed 06/17/15.