Definition
A.Acute angle-closure glaucoma is an ocular emergency caused by elevations in intraocular pressure (IOP) that damage the optic nerve, leading to loss of peripheral fields of vision; this leads to loss of central vision, resulting in blindness.
Incidence
A.Acute angle-closure glaucoma is the second leading cause of blindness in the United States (other leading causes include diabetic retinopathy [1st cause], age-related macular degeneration, cataract). Ten percent of glaucoma cases are due to angle-closure glaucoma. Approximately 5% to 15% of the patient population develops some form of glaucoma.
Pathogenesis
A.The essential pathophysiologic feature of glaucoma is an IOP that is too high for the optic nerve. Increased IOP increases vascular resistance, causing decreased vascular perfusion of the optic nerve and ischemia. Light dilates (?) the pupil, causing the iris to relax and bow forward. As the iris bows forward, it comes into contact with the trabecular mesh-work and occludes the outflow of aqueous humor, resulting in increased IOP.
Predisposing Factors
A.Narrow anterior ocular chamber.
B.Prolonged periods of darkness.
C.Drugs that dilate the pupils (i.e., anticholinergics).
D.Advancing age.
E.African American heritage.
F.Family history.
G.Trauma.
H.Neoplasm.
I.Corticosteroid therapy.
J.Neovascularization.
K.Female gender.
L.Hyperopia (farsightedness).
Common Complaints
A.Ocular pain.
B.Blurred vision, decreased visual acuity, cloudiness
of vision.
C.Halos
around lights at night.
D.Neurologic complaints (headache, nausea, or vomiting).
Other Signs and Symptoms
A.Red eye with ciliary flush. Ciliary flush is a red or purple ring that surrounds the cornea which expands beyond the ring.
B.Silent blinder
is a nickname used for glaucoma. It causes extensive damage before the patient is aware of visual loss.
C.Dilated pupil.
D.Hard orbital globe.
E.No pupillary response to light.
F.Increased IOP (normal IOP is 10–20 mmHg).
Subjective Data
A.Review the onset, course, and duration of symptoms; note visual changes in one or both eyes. Do symptoms get worse in early evening?
B.Review medical history and medications, including over-the-counter (OTC) products.
C.Review family history of glaucoma.
D.Determine whether there has been any difficulty with peripheral vision, any headache photophobia, or any visual blurring.
E.Rule out presence of any chemical, trauma, or foreign bodies in the eye.
F.Review any recent history of herpes outbreak.
G.Ask the patient whether this has ever occurred before, and if so, how it was treated.
H.Determine if IOP has been measured in the past.
Physical Examination
A.Blood pressure.
B.Inspect:
1.Examine both eyes.
2.Rule out foreign body.
3.Inspect for redness, inflammation, and discharge.
4.Check pupillary response to light.
5.Redness noted around iris, pupil is dilated, and cornea appears cloudy.
6.Inspect anterior chamber of eye by holding penlight laterally and direct toward nasal area. Shallow chamber will cast a shadow on the nasal side of the iris.
7.Facial symmetry.
8.Cranial nerves.
9.Strength of upper/lower extremities.
C.Palpate: Palpate the globe of the eye, which will feel firm on palpation.
D.Funduscopic exam: This may reveal notching of the cup and a difference in cup-to-disk ratio between the two eyes.
Diagnostic Tests
A.Check visual acuity and peripheral fields of vision.
B.Measure IOP with a tonometer. Normal level is 10 to 21 mmHg; acute angle-closure glaucoma IOP is greater than 50 mmHg. Tonometer exam is not recommended if external infection is present.
C.Slit-lamp exam: Edematous and/or cloudy cornea.
D.Gonioscopy (gold standard) using a slit lamp. Exam typically performed by optometrist or ophthalmologist.
Differential Diagnoses
A.Acute angle-closure glaucoma.
B.Acute iritis.
C.Acute bacterial conjunctivitis.
D.Iridocyclitis.
E.Corneal injury.
F.Foreign body.
G.Herpetic keratitis.
H.Cerebrovascular accident (CVA).
Plan
A.General interventions:
1.Severe attacks can cause blindness in 2 to 3 days. Same-day referral is critical if angle-closure glaucoma is suspected. Seek medical attention immediately to prevent permanent vision loss.
2.Frequency of attacks is unpredictable.
B. 
See Section III: Patient Teaching Guide How to Administer Eye Medications.
C.Pharmaceutical therapy: Management must be instituted by an ophthalmologist. If evaluation and treatment by an ophthalmologist is projected to be greater than 1 hour, initial treatment to lower pressures should be considered with:
1.Timolol maleate 0.5%.
2.Pilocarpine (Pilocar) 2%.
3.Apraclonidine 1%.
D.Surgical intervention:
1.Surgery is indicated if IOP is not maintained within normal limits with medications or if there is progressive visual field loss with optic nerve damage.
2.Surgical treatment of choice is peripheral iridectomy—excision of a small portion of the iris whereby the aqueous humor can bypass the pupil.
E.Laser peripheral iridotomy—creates on opening in the peripheral iris to reduce pressures against the optic nerve.
Follow-Up
A.Annual eye exams by an ophthalmologist are necessary to monitor IOP and treatment efficacy.
Consultation/Referral
A.All patients should be referred to an ophthalmologist immediately for measurement of IOP, acute management, and possible surgical intervention (laser peripheral iridectomy).
Individual Considerations
A.Adults:
1.Women normally have slightly higher IOPs than men.
2.Asians may have higher IOPs than African Americans and Caucasians.
3.Individuals older than age 40 should have their IOP measured periodically. Every 3 to 5 years is sufficient after a stable baseline is established for the patient.
B.Geriatrics:
1.Incidence increases with age, usually in those older than 60.
2.Medications that have anticholinergic properties may adversely affect patients with narrow-angle glaucoma. These medications are used to treat diseases such as:
a.Asthma/COPD: Atrovent (ipratroprium bromide) or Spiriva (tiotropium bromide).
b.Incontinence/overactive bladder: Detrol (tolterodine) and Ditropan (oxybutynin).
c.Gastrointestinal problems: Tagamet (cimetidine) and Zantac (ranitidine).
d.Muscle spasms: Norflex (orphenadrine) and Artane (trihexyphenidyl).
e.Depression: Selective serotonin reuptake inhibitors (SSRIs) such as Prozac (fluoxetine) and Paxil (paroxetine), tricyclic antidepressants such as Elavil (amitryptiline) and Tofranil (imipramine).
f.Allergies: Antihistimines OTC that contain diphenhydramine.
g.Nausea: Phenergan (promethazine).
h.Anxiety: Vistaril (hydroxyzine).
i.Colds: Medications containing ephedrine.
j.Use caution when using medications containing sulfonamide-containing drugs, such as Topamax (topiramate), Diamox (acetazolamide), Qualaquin (quinine), Sumycin (tetracycline), and Bactrim (trimethoprim/sulfamethoxazole).
3.Chronic use of oral steroids may affect open-angle glaucoma and should be avoided if possible.
4.Long-term use of steroids also may increase the risk of developing cataracts.