Glaucoma
last authored: June 2012, David LaPierre
last reviewed:
Introduction
Acute-angle closure occurs wirh
Can have tremendously variable and confusing presentation; it should be on the differential for anyone with a red eye or
The Case of...
a simple case introducing clincial presentation and calling for a differential diagnosis to get students thinking.
Causes and Risk Factors
Acute-angle closure occurs most commonly in:
- female > male
- 6th and 7th decades of life
- Inuit and Asian
Risk factors for acute angle closure include:
- hyperopia
- cataracts
- older age
- shallow anterior chamber
- positive family history
- small cornea
- iris cysts
- medications
- anticholinergics
- antihistamines
- antidepressants: SSRIs, TCAs)
- sulfa drugs
- topiramate
- ACE inhibitors
- warfarin
- adrenergic drugs, eg salmbutamol
Medications, changes in light
Most common in middle-aged or seniors who are far-sighted.
Pupillary dilation
Pathophysiology
Acute angle glaucoma is associated with increased intraocular pressure following obstruction of the outflow of aqueous humor. This occurs when the space between the iris and the trabecular network narrows.
Optic neuropathy due to . Canals of schlemm
Signs and Symptoms
- history
- physical exam
History
Acute glaucoma can cause:
- severe headache, often unilateral, characterized by throbbing
- vision changes, often intermittent, and often with halo
- photophobia
- pain with eye movement
- nausea and vomiting
Past medical history
- previous attacks of a similar nature
Family history of glaucoma
Medications, including over the counter medications
Physical Exam
Perform the following testing in an undilated eye:
- external examination
- fundal exam
- visual acuity
- visual field testing
- ocular motility
- pupil size, reactivity
- slit-lamp microscopy
- tonometry - measurement of the pressure
- gonioscopy - measurement of the angle
Acute-angle closure can lead to:
- injected conjunctiva, classically in a peri-limbic pattern
- increased intro-ocular pressure (>21mmHg)
- corneal haze, with epithelial edema
- fixed, dilated pupil
- firmness with gentle palpation
- blepharospasm
Chronic glaucoma can lead to:
- normal or increased intraocular pressure
- multiple peripheral synechiae
- increased cup-to-disc ratio
Investigations
Measure intraocular pressure (normal is less than 20-30)
Differential Diagnosis
The differential diagnosis of glaucoma includes:
- conjunctivitis
- episcleritis
- corneal abrasion
- herpes zoster
- iritis
- uveitis
- orbital infection
- subconjunctival hemorrhage
- compartment syndrome
- traumatic hyphema
Treatments
Acute treatment of acute-angle closure is established with oral mannitol or glycerin to decrease pressure within the eye.
Maintain the patient supine. Provide analgesia and anti-emetic therapy. Consult an ophthalmologist.
Medical management
Pilocarpine, a miotic drop, can be used to constrict the pupil and relieve pressure by allowing aqueous outflow.
Other treatments include:
- topical carbonic anhydrase inhibitor (eg acetazolamide)
- topical beta-blocker (eg timolol)
- topical steroid (prenisolone)
- topical alpha- agonist (eg apraclonidine)
- topical prostaglandin analogues (eg Lumigan, Xalatan)
Surgical management
Peripheral iridotomy may be done to reduce IOP, either through laser or incision.
Education
Following an attack, patients should be advised to return if their symptoms do. Offending medications should be avoided. Teaching on eyedrops should be provided.
Consequences and Course
Glaucoma can lead to permanent vision loss if not treated quickly and effectively.
Other consequences can include:
- recurrence, including in opposite eye
- cataract
- optic nerve atrophy
- central retinal artery occlusion
- chronic corneal edema and fibrosis
Resources and References
Topic Development
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