DESCRIPTION 
Disease characterized by elevation of intraocular pressure, optic neuropathy, and progressive loss of vision.
ETIOLOGY
- Primary glaucoma:
- Open-angle glaucoma:
- Normal anterior chamber angle
- Insidious onset with persistent rise in intraocular pressure
- Most common type accounting for 90% of glaucomas in US
- Leading cause of blindness in African Americans
- Risk factors include African American, age > 40 yr, family history, myopia, diabetes, and HTN
- Acute angle-closure glaucoma:
- Narrowing or closing of anterior chamber angle precluding natural flow of aqueous humor from posterior to anterior chamber of eye and through its filtering portion of trabecular meshwork
- Usually abrupt onset with sudden increase in intraocular pressure
- Risk factors include Asians and Eskimos, hyperopia, family history, increased age, and female gender
- Secondary glaucoma occurs from other diseases, including diseases of eye, trauma, and drugs:
[Outline]
SIGNS AND SYMPTOMS
Classic descriptions:
- Open angle:
- Painless and gradual loss of vision
- Closed angle:
- Painful loss of vision with fixed midsized pupil
History
- Primary open-angle glaucoma:
- Gradual reduction in peripheral vision or night blindness
- Typically bilateral
- Painless
- Primary angle-closure glaucoma:
- Severe deep eye pain and ipsilateral headache often associated with nausea and vomiting
- Decrease in visual acuity often described as visual clouding with halos surrounding light sources
- Associated abdominal pain, which may misdirect diagnosis
- Concurrent exposure to dimly lit environment such as movie theater
- Use of precipitating medications:
Physical Exam
- Primary open-angle glaucoma:
- Primary angle-closure glaucoma:
- Decreased visual acuity
- Pupil is mid-dilated and nonreactive.
- Corneal edema with hazy appearance
- Conjunctival injection, ciliary flush
- Firm globe to palpation
ESSENTIAL WORKUP
- Detailed ocular exam
- Visual acuity:
- Hand movements typically all that is seen
- Tonometry:
- Normal pressures are 10–21 mm Hg.
- Primary open-angle glaucoma:
- Degree of elevation can vary, but 25–30% of patients may have normal intraocular pressures.
- Primary angle-closure glaucoma:
- Any elevation is abnormal, but usually seen in ranges > 40 mm Hg.
- Slit-lamp exam:
- Evaluation of anterior chamber angle
- Used to eliminate other possibilities in differential including corneal abrasion and foreign body
DIAGNOSIS TESTS & INTERPRETATION
Lab
Directed toward workup of differential
Imaging
Directed toward workup of differential
Diagnostic Procedures/Surgery
Gonioscopy:
- This is direct measurement of the angle of closure
DIFFERENTIAL DIAGNOSIS
[Outline]
PRE-HOSPITAL
- No specific interventions need occur prior to arrival at the hospital in regard to the eye:
- Pain control may be necessary
- In traumatic etiologies, stabilize other injuries
INITIAL STABILIZATION/THERAPY
- Initiate steps to lower intraocular pressure in acute closed-angle glaucoma:
- Address other effects of trauma if this was the etiology
- Discontinue inciting medication when involved
ED TREATMENT/PROCEDURES
- Primary open-angle glaucoma:
- Recognition and prompt ophthalmologic referral
- Patients maintained on topical β-blockers or prostaglandin analogs to decrease IOP
- Primary angle-closure glaucoma (ophthalmologic emergency):
- Intraocular pressure reduction:
- Topical β-blocker, timolol maleate, to decrease aqueous humor production
- Topical α2-agonist, apraclonidine, to decrease aqueous humor production
- Carbonic anhydrase inhibitor, acetazolamide, for reduction of formation of aqueous humor
- Hyperosmotic agent, mannitol, to draw aqueous humor from vitreous cavity into blood (indicated for severe attacks).
- Movement of iris away from trabecular meshwork:
- Topical parasympathomimetic, pilocarpine hydrochloride, to constrict pupil once intraocular pressure is < 40 mm Hg
- Reduction of inflammation:
- Emergent ophthalmology consultation for possible definitive surgical treatment, laser iridectomy, if no improvement with medical management
- Adequate narcotic analgesia and antiemetics as needed
MEDICATION
- Acetazolamide: 500 mg IV or PO
- Mannitol 20%: 1–2 g/kg IV over 30–60 min
- Pilocarpine hydrochloride 1–2% solution: 1 drop q15–30min until pupillary constriction occurs, then 1 drop q2–3h
- Prednisolone acetate 1% solution: 1 drop q15–30min for total of 4 doses
First Line
- β-Agonists:
- Timolol maleate 0.25 or 0.5%:
- 1 drop to affected eye BID
- Levobunolol 0.25 or 0.5%:
- 1 drop to affected eye BID
- Carteolol HCL 1%:
- 1 drop to affected eye BID
- Betaxolol 0.25 or 0.5%:
- 1–2 drop(s) to affected eye BID
Second Line
- Adrenergic agonists:
- Apraclonidine 0.5%, 1%:
- 1–2 drop(s) to affected eye BID
- Brimonidine:
- 1 drop to affected eye TID
- Carbonic anhydrase inhibitors:
- Prostaglandin analogs:
Considerations in Prescribing
- Prostaglandin analogs have become standard of care for open-angle glaucoma due to an improved side-effect profile
- Due to cost, topical β-blockers are often still used primarily
[Outline]
DISPOSITION
Admission Criteria
- Severe pain, nausea, or vomiting
- Patients receiving parenteral medications should be observed for side effects.
- Patients without improvement of symptoms or intraocular pressures should be admitted for continued monitoring of intraocular pressure, medical treatment, and possible definitive surgical management:
- Laser intervention is more likely than operative
Discharge Criteria
Patients with minor symptoms and significant improvement of intraocular pressure may be safely discharged once seen by ophthalmology and with close, < 24-hr follow-up.
Issues for Referral
If no ophthalmologist is available, treatment should be initiated and patient transferred to nearest hospital with ophthalmologic consultation.
FOLLOW-UP RECOMMENDATIONS
- Open-angle glaucoma patients need urgent ophthalmology follow-up to optimize medical management
- Closed-angle glaucoma patients need immediate intervention
[Outline]
- Chew P, Sng C, Aquino MC, et al. Surgical treatment of angle-closure glaucoma. Dev Ophthalmol. 2012;50:137–145.
- Dargin JM, Lowenstein RA. The painful eye. Emerg Med Clin North Am. 2008;26(1):199–216.
- Marx JA, Hockberger RS, Walls RM, et al. Rosen's Emergency Medicine: Concepts and Clinical Practice. 7th ed. St. Louis, MO: Mosby; 2010.
- Müskens RP, Wolfs RC, Witteman JC, et al. Topical beta-blockers and mortality. Ophthalmology. 2008;115(11):2037–2043.
- Nongpiur ME, Ku JY, Aung T. Angle closure glaucoma: A mechanistic review. Curr Opin Ophthalmol. 2011;22(2):96–101.
- Tse DM, Titchener AG, Sarkies N, et al. Acute angle closure glaucoma following head and orbital trauma. Emerg Med J. 2009;26(12):913.
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