ENA Ocular
A funduscopic examination is used to evaluate which structure? A. Posterior chamber B. Cornea C. Conjunctiva D. Iris
Your incorrect answer: B A funduscopic examination allows visualization of the posterior chamber of the eye. An external eye examination allows the nurse to assess the cornea, conjunctiva, and iris.
Which ocular injury is the most emergent? A. Thermal burn B. Orbital blowout fracture C. Hyphema D. Chemical burn
Your incorrect answer: B Chemical burns are the most emergent of all ocular injuries and require immediate treatment with copious irrigation before assessment.
Blood in the anterior chamber indicates which injury? A. Subconjunctival hemorrhage B. Ruptured globe C. Orbital blowout fracture D. Hyphema
Your correct answer: D A hyphema (blood in the anterior chamber) usually results from blunt ocular trauma. A subconjunctival hemorrhage (bleeding between the conjunctiva and sclera) is a common benign condition. A ruptured globe typically causes a teardrop- or keyhole-shaped pupil. An orbital blowout fracture may force the orbital contents to herniate into the maxillary or ethmoid sinuses.
Which disorder is a common complication of a hyphema? A. Rebleeding B. Infection C. Eyelid spasm D. Light flashes in the visual field
Your correct answer: A The most common complication of hyphema is rebleeding, which occurs in 30 percent of affected patients usually 2 to 5 days after the initial injury. Rebleeding may result in corneal staining, secondary glaucoma, and permanent vision loss. Infection is not a complication of the hyphema but results from bacterial or viral invasion of the eye. Eyelid spasm is a sign of corneal abrasion. Classic symptoms of retinal detachment include patient reports of light flashes, floaters, or a curtain coming down over the visual field.
Which assessment finding differentiates orbital cellulitis from periorbital cellulitis? A. FeverB. PainC. Impaired extraocular movementD. Decreased vision
Your correct answer: C In orbital cellulitis, extraocular muscle movement is impaired. In periorbital cellulitis, no extraocular muscle impairment occurs. In both infections, fever, pain, and decreased vision also occur, although decreased vision is a late finding in periorbital cellulitis.
In a patient with a globe rupture, which sign or symptom is expected? A. Altered depth of the posterior chamber B. Dilated pupil C. Teardrop-shaped pupil D. Decreased pain sensation
Your correct answer: C Signs and symptoms of a globe rupture include hyphema, a teardrop-shaped pupil, altered depth of the anterior chamber, altered light perception, vitreous hemorrhage (occasionally), and minimal to severe pain.
For a patient with a hyphema, the nurse should include which discharge instruction? A. Take an antiemetic, as needed. B. Lie flat in bed. C. Take aspirin for pain management. D. Do not patch the injured eye.
Your correct answer: A A patient with a hyphema who is nauseated may require an antiemetic to decrease the risk of vomiting, which can increase intraocular pressure and lead to secondary glaucoma. The mainstay of hyphema management is head elevation. The nurse should elevate the head of the bed at least 30 to 45 degrees. To minimize the risk of rebleeding, the nurse should caution the patient to avoid aspirin and nonsteroidal anti-inflammatory medications. To improve comfort and protect the eye, the patient should wear an eye shield at all times until the hyphema resolves.
In a patient with a periorbital contusion, which disorder should you suspect? A. Subconjunctival hemorrhage B. Primary glaucoma C. Central retinal artery occlusion D. Blepharitis
Your correct answer: A Although a periorbital contusion is usually a benign ocular injury, the nurse should assess the patient for additional ocular injuries. Ocular blunt trauma can cause subconjunctival hemorrhage, orbital fractures, hyphemas, and globe disruption. Primary glaucoma is not associated with ocular trauma. Central retinal artery occlusion usually results from an embolus (carotid and cardiac), thrombosis, hypertension, or atrial fibrillation-not ocular trauma. Blepharitis is an acute or chronic inflammation of the lid margin, which is unrelated to ocular trauma.
Which ocular condition is mostly likely to cause vision loss? A. Retinal artery occlusion B. Conjunctival foreign body C. Conjunctivitis D. Corneal abrasion
Your correct answer: A Ocular conditions that can cause vision loss include retinal artery occlusion, globe rupture, chemical burns, and acute angle-closure glaucoma. Conjunctival foreign body, conjunctivitis, and corneal abrasion are not associated with significant morbidity. However, they can cause discomfort and disrupt the patient's normal routine.
Measurement of intraocular pressure by tonometry is most helpful in identifying which disorder? A. HyphemaB. Retinal detachmentC. GlaucomaD. Iritis
Your incorrect answer: B Glaucoma results from elevated intraocular pressure, and tonometry is the diagnostic tool used to identify this disorder. Although tonometry is not used to diagnose hyphema (bleeding in the anterior chamber of the eye), it may be used to detect increased intraocular pressure caused by this ocular injury. Tonometry is not used to identify retinal detachment or iritis.
What is the first step when assessing a patient with an ocular complaint? A. Obtain an accurate history. B. Remove contact lenses. C. Perform an internal eye examination. D. Assess pupillary response.
Your correct answer: A Although patient assessment may require all of these actions, it should begin with obtaining an accurate history. Pertinent data include a history of eye trauma or disease; a medical disorder that may be significant, such as sickle cell disease, hypertension, or diabetes; and tetanus immunization.
In a patient who presents with an orbital fracture and entrapment, which assessment finding is expected? A. Pupil constriction in the affected eyeB. Hearing loss and tinnitusC. Facial spasmsD. Limited upward gaze in the affected eye
Your incorrect answer: A Because of orbital entrapment of the extraocular muscles, the patient is likely to display limited upward gaze in the affected eye and normal movement in the unaffected eye. An orbital fracture may result in pupil dilation, not constriction, on the side of orbital injury. Hearing loss, tinnitus, and facial spasms are not associated with orbital fractures but may indicate other concomitant injuries.
A patient with which intraocular pressure measurement requires further treatment? A. 5 mm Hg B. 10 mm Hg C. 20 mm Hg D. 30 mm Hg
Your incorrect answer: A Intraocular pressure normally ranges from 10 to 20 mm Hg. Consultation with an ophthalmologist is recommended when the pressure exceeds 20 mm Hg, although treatment may not be indicated until the pressure reaches 30 mm Hg or higher.
Which injury should raise the suspicion of a concurrent ocular injury? A. Clavicle fracture B. Pneumothorax C. Basilar skull fracture D. Thoracic spine injury
Your incorrect answer: A Ocular injuries commonly occur with head and facial injuries, so patients with these injuries require careful evaluation for coexisting ocular injury after airway, breathing, circulation, and disability have been evaluated and stabilized. Pneumothorax, clavicle fracture, and thoracic spine injury are not closely associated with ocular injury.
Which disorder results in abnormal extraocular movements? A. Corneal ulcer B. Retinal detachment C. Orbital cellulitis D. Glaucoma
Your correct answer: C The nurse evaluates extraocular movements by testing the six cardinal fields of gaze. This assesses cranial nerves III, IV, and VI (the oculomotor, trochlear, and abducens nerves). Impaired extraocular movement may result from an entrapped muscle caused by orbital cellulitis, an orbital blowout fracture, muscular injury, or an underlying central nervous system problem. Corneal ulcer, retinal detachment, and glaucoma do not affect extraocular movement.
A patient with which disorder would benefit most from an eye shield? A. Hyphema B. Corneal abrasion C. Eye infection D. Globe rupture
Your correct answer: D An eye shield (patch) minimizes ocular stimulation by reducing movement and limiting light exposure, which is indicated for a patient with a globe rupture. A patient with hyphema (a collection of blood in the anterior chamber) would not benefit from minimizing ocular stimulation. Patching a simple corneal abrasion does not shorten healing time or decrease pain, so it is no longer routinely recommended. An eye infection contraindicates patching.
Which disorder should the nurse triage as most emergent? A. Central retinal artery occlusion B. Retinal detachment C. Herpes zoster ophthalmicus D. Hyphema
Your correct answer: A Central retinal artery occlusion produces the sudden onset of unilateral, painless vision loss and is a true ocular emergency. Retinal circulation must be restored within 60 to 120 minutes (or less) to prevent permanent vision loss. Retinal detachment requires consultation with an ophthalmologist to determine a definitive treatment, such as laser repair or scleral buckling. Herpes zoster ophthalmicus requires local wound care, administration of analgesics and antivirals, and possibly topical steroids and antibiotics. Hyphema requires consultation with an ophthalmologist.
A patient with an orbital blowout fracture is likely to have which finding? A. Pupil constriction B. Exophthalmos C. Limited downward gaze D. Subconjunctival hemorrhage
Your correct answer: D An orbital blowout fracture occurs when an orbital floor fracture increases the intraocular pressure, causing the orbital contents to herniate into the maxillary or ethmoid sinuses and trap the inferior rectus muscle. A blowout fracture is characterized by subconjunctival hemorrhage, enophthalmos (sunken eye), limited upward gaze, periorbital ecchymosis, periorbital edema, and diplopia. The fracture itself does not cause pupil constriction.
For a patient with a corneal abrasion, which discharge instruction is appropriate? A. Patch the affected eye for 24 hours. B. Administer anesthetic eye drops, as indicated. C. Avoid wearing contact lenses until follow-up is completed. D. Irrigate the affected eye four times a day.
Your correct answer: C Corneal abrasion occurs when an object, such as a contact lens, finger, dirt, or debris, scratches or abrades the epithelial lining. Wearing contact lenses may worsen the abrasion. Initially, you may administer anesthetic eye drops to decrease pain temporarily for the visual acuity assessment. The patient should not need these eye drops after discharge. If prescribed, teach the patient how to use cycloplegic eye drops to decrease ciliary muscle spasms and antibiotic eye drops to prevent secondary infection. Patching is no longer recommended. A corneal abrasion does not need irrigation.
Ocular massage is a treatment for which disorder? A. Glaucoma B. Retinal detachment C. Central retinal artery occlusion D. Uveitis
Your correct answer: C For a patient with central retinal artery occlusion, reestablish retinal perfusion as quickly as possible to prevent permanent vision loss. To do this, assist the physician with digital ocular massage and administer drugs to reduce intraocular pressure, such as acetazolamide (Diamox) and timolol (Timoptic), as prescribed. Also arrange for emergent consultation with an ophthalmologist. Glaucoma, retinal detachment, and uveitis do not respond to ocular massage.
Measurement of intraocular pressure is contraindicated when which ocular problem is suspected? A. Subconjunctival hemorrhage B. Glaucoma C. Hyphema D. Globe rupture
Your correct answer: D Intraocular pressure measurement is contraindicated in a suspected or possible globe rupture. Subconjunctival hemorrhage, glaucoma, and hyphema pose no contraindications to this measurement.
For a patient with an alkali burn of the eye, which of these marks the endpoint for continuous irrigation? A. Ocular pH of 7.1 B. Ocular pH of 7.4 C. Completion of 20 minutes of irrigation D. Administration of 1 L of fluid
Your incorrect answer: C For a patient with an alkali burn, continue irrigation until the ocular pH reaches about 7.3 or 7.4. (Normal conjunctival pH is 7.0 to 7.3.) If litmus paper is not available for pH measurement, irrigate for at least 60 minutes with 2 L of fluid. A severe chemical burn may require 2 to 4 hours of irrigation. Measure the pH periodically during and after the initial irrigation.
Which disorder is a life-threatening infection? A. Uveitis B. Orbital cellulitis C. Iritis D. Keratitis
Your incorrect answer: C Orbital cellulitis is an infection deep in the orbital septum that can be life threatening. The usual causative organisms are Streptococcus pneumoniae, Staphylococcus aureus, and Haemophilus influenzae. Uveitis, iritis, and keratitis are not life-threatening infections. Uveitis and iritis are inflammations of the uveal tract, which includes the iris, ciliary body, and choroid. When uveal inflammation affects the anterior uveal tract, it is categorized as iritis. Keratitis is a corneal inflammation caused by a corneal ulcer, bacteria, or fungus.
Which foreign bodies pose the greatest risk of infection? A. Metallic objects B. Organic objects C. High-speed projectile objects D. Inert foreign bodies
Your incorrect answer: C Organic objects, such as wood splinters, are much more likely to cause infection. Metallic objects are more likely to penetrate the posterior chamber. All foreign bodies in the eye are considered contaminated, so the patient receives treatment with antibiotic and tetanus prophylaxis, as appropriate.
Which ocular emergency requires the most emergent management? A. Radiation burnB. Chemical burnC. Acute angle-closure glaucomaD. Central retinal artery occlusion
Your incorrect answer: D A chemical burn of the eye requires the most emergent intervention to avoid permanent vision loss caused by cellular protein damage or ischemia. Acute angle-closure glaucoma and central retinal artery occlusion are time-sensitive emergencies but not as emergent as a chemical burn. A radiation burn is extremely painful but does not take priority over a chemical burn.
Which ocular emergency typically requires treatment with antiviral medication? A. Herpes zoster ophthalmicusB. ConjunctivitisC. IritisD. Orbital cellulitis
Your incorrect answer: D Standard management of herpes zoster ophthalmicus (shingles of the ophthalmic division of the trigeminal nerve) includes antivirals, analgesics, and local wound care. The patient should receive antivirals within 72 hours of any vesicular eruptions on the face or periorbital area to decrease complications such as permanent vision loss and postherpetic neuralgia. Although conjunctivitis commonly results from viral infection, it does not require antivirals but may benefit from supportive measures, such as artificial tears, cool compresses, and decongestant or antihistamine eye drops. Iritis usually is an inflammatory process, which responds to treatment with topical steroids. Orbital cellulitis is a potentially life-threatening infection deep in the orbital septum, which requires intravenous antibiotics, not antivirals.
During extraocular movement assessment, which cranial nerve is tested when the nurse asks the patient to look laterally and midline? A. Cranial nerve II (optic nerve) B. Cranial nerve III (oculomotor nerve) C. Cranial nerve IV (trochlear nerve) D. Cranial nerve VI (trochlear nerve)
Your correct answer: D Cranial nerve VI (abducens nerve) controls lateral and midline eye movement. Cranial nerve II (optic nerve) is a sensory nerve for vision. Cranial nerve III (oculomotor nerve) elevates the upper lid, constricts the pupils, and controls the ability to look up and laterally, down and laterally, and up and medially. Cranial nerve IV (trochlear nerve) controls the downward and inward movement of the eye.
When caring for an immunocompromised patient with suspected herpes zoster ophthalmicus, which interventions should the nurse anticipate? A. Hospitalization and intravenous administration of antiviral drugs B. Administration of herpes zoster vaccine (Zostavax) and application of warm compresses C. Administration of timolol (Timoptic) and pilocarpine (Isopto) D. Application of an eye shield and elevation of the head of the bed
Your correct answer: A Herpes zoster ophthalmicus is shingles that affects the ophthalmic division of the trigeminal nerve. To treat this infection, hospitalization and intravenous administration of antivirals, such as acyclovir (Zovirax), are indicated for a patient who is immunocompromised or has intracranial signs and symptoms. Herpes zoster ophthalmicus can be prevented by vaccination with the herpes zoster vaccine (Zostavax), which is indicated in patients age 60 or older who have previously had chickenpox. Warm compresses are used to treat a hordeolum (external stye) or hypopyon. Timolol (Timoptic) and pilocarpine (Isopto) are used to treat acute angle-closure glaucoma but not herpes zoster ophthalmicus. Application of an eye shield and elevation of the head of the bed are appropriate for treatment of a hyphema.
For a patient with acute angle-closure glaucoma, which topic is appropriate to include in discharge teaching? A. Instillation of timolol (Timoptic) eye drops B. Use of promethazine (Phenergan) for nausea, as needed C. Application of an eye patch for comfort D. Return to a weight-lifting exercise program
Your correct answer: A Treatment of acute angle-closure glaucoma includes identifying and lowering the intraocular pressure as quickly as possible. To do this, administer medications that decrease aqueous humor production, which include beta-blockers, such as timolol (Timoptic); alpha-agonists, such as brimonidine (Alphagan); and carbonic anhydrase inhibitors, such as dorzolamide (Trusopt). Or administer medications that increase aqueous outflow, such as pilocarpine (Isopto), which is a mainstay of treatment for this condition. Avoid anticholinergic drugs, such as atropine, ipratropium (Atrovent), and promethazine (Phenergan) because they can theoretically induce angle-closure glaucoma by narrowing the angle of the anterior chamber. Although limited use of the affected eye(s) is usually recommended, an eye patch is not indicated. A patient with increased intraocular pressure should avoid any activity that can increase intraocular pressure, such as lifting, bending, coughing, or straining.
In a patient with an ocular chemical burn, visual acuity should be assessed after which activity has been performed? A. Evaluation by an ophthalmologistB. Copious irrigationC. Application of bilateral eye patchesD. Administration of ophthalmic antibiotic ointment
Your correct answer: B A chemical burn of the eye is a vision-threatening emergency that requires immediate, copious irrigation. After irrigation, the patient should receive a thorough eye examination, including a visual acuity assessment. After irrigation and a thorough eye examination, the patient may receive topical antibiotics, cycloplegics, and steroids, as prescribed. Bilateral eye patches may be applied, as ordered.
When caring for a patient with an alkali chemical burn, the nurse should keep which factor in mind? A. No further damage occurs after the initial contact. B. The chemical continues to penetrate and cause corneal damage until it is removed. C. The burn rarely involves the globe. D. Signs and symptoms usually begin 8 to 12 hours after exposure.
Your correct answer: B Alkalis continue to penetrate and cause corneal damage until they are removed. Acid burns cause no further damage after the initial contact because the acid is neutralized on contact. Thermal burns affect the eyelids but rarely involve the globe because of reflex lid closure. Radiation burns usually cause pain, tearing, photophobia, and a foreign body sensation that begin 8 to 12 hours after exposure.
Which patient is most likely to experience an ocular injury? A. A resident, age 80, in a long-term care facility B. A high school student, age 18 C. A truck driver, age 65 D. A mother of two, age 40
Your correct answer: B Although no segment of the population escapes the risk of eye injury, most patients who experience eye injuries are young. Most eye injuries occur in people under age 30. Trauma is the most common cause of enucleation in pediatric patients over age 3.
To assess the external eye, the nurse should perform which activity? A. Have the patient identify letters or objects on a chart or card. B. Inspect and gently palpate the eyelids, lashes, and surrounding bony structures. C. Have the patient follow the nurse's fingers with his or her eyes. D. Visualize the external structures with a slit lamp.
Your correct answer: B An external eye assessment consists of the inspection and gentle palpation of the eyelids, lashes, and surrounding bony structures. Visual acuity is assessed by having the patient identify letters or objects on a chart or card. Cardinal fields of gaze are assessed by having a patient follow the nurse's fingers with his or her eyes. A slit-lamp microscope is used to help visualize the superficial structures and the anterior chamber.
When using the Snellen chart, how should the nurse interpret a finding of 20/30? A. The patient is legally blind. B. The patient can read at 20 feet what the normal eye can read at 30 feet. C. The patient can correctly identify 20 out of 30 objects on the chart. D. The patient can read at 30 feet what the normal eye can read at 20 feet.
Your correct answer: B Visual acuity is recorded as a fraction. The numerator represents the distance to the chart, and the denominator represents the distance from which a normal eye can read the line. For example, 20/30 means that the patient can read at 20 feet what a person with 20/20 vision (standard for the Snellen chart) can read at 30 feet. A patient with 20/200 vision while wearing corrective lenses is considered legally blind.
Which intervention is appropriate for a hypopyon? A. Apply an eye patch for comfort. B. Apply cool compresses. C. Obtain a specimen for culture and sensitivity testing. D. Irrigate the eye with copious fluids.
Your correct answer: C A patient with a corneal infection may develop a hypopyon (collection of pus due to white blood cells in the anterior chamber of the eye). Obtain a specimen of the hypopyon for culture and sensitivity testing to determine the specific cause of the infection. Other interventions include applying warm compresses and administering broad-spectrum antibiotics and possibly antifungal eye drops. Do not patch the eye because of the risk of Pseudomonas infection, which is a particular concern with contact lens wearers. Irrigation with copious fluids is an intervention for a chemical burn, not a hypopyon.
A patient with which intraocular pressure measurement requires further treatment? A. 5 mm Hg B. 10 mm Hg C. 20 mm Hg D. 30 mm Hg
Your correct answer: D Intraocular pressure normally ranges from 10 to 20 mm Hg. Consultation with an ophthalmologist is recommended when the pressure exceeds 20 mm Hg, although treatment may not be indicated until the pressure reaches 30 mm Hg or higher.
Which factor can cause a globe rupture? A. Decreased intraocular pressure B. Penetrating trauma C. Vomiting D. Contact lenses
Your incorrect answer: A A common mechanism of a globe rupture is penetrating trauma from an object, such as a stick, pencil, scissors, or knife. Globe rupture also may result from blunt trauma that abruptly increases intraocular pressure. Although vomiting does not cause globe rupture, it frequently results from this injury and increases intraocular pressure and the risk of expulsion of intraocular contents. Corneal damage occurs when an object, such as a contact lens, scratches or abrades the epithelial lining. Contact lenses do not cause globe rupture.
Which disorder causes blood in the anterior chamber of the eye? A. GlaucomaB. HordeolumC. HyphemaD. Iritis
Your incorrect answer: A A hyphema is characterized by blood in the anterior chamber of the eye. Glaucoma is defined by elevated intraocular pressure. A hordeolum (external stye) is an infection of the eyelash oil gland. Iritis is the inflammation of the anterior portion of the uveal tract.
Your department has an advanced triage protocol that allows the emergency nurse to administer an anesthetic eye drop before Morgan lens application. What color is the top of the container? A. RedB. WhiteC. GreenD. Yellow
Your incorrect answer: A The tops of eye drop containers are color coded by the medication's effects. White or clear caps indicate anesthetics, red caps indicate mydriatics (which dilate pupils), green caps indicate miotics (which constrict pupils), and yellow caps indicate medications that decrease aqueous humor production.
A patient presents with blunt trauma from being struck in the right eye by a baseball. The nurse notes a vitreous hemorrhage. Which intervention is most appropriate? A. Administer analgesic eye drops.B. Maintain the patient in a supine position.C. Assist with intraocular pressure measurement.D. Place a protective shield over the affected eye and patch the unaffected eye.
Your incorrect answer: A Vitreous hemorrhage suggests the patient has a ruptured globe. The nurse should place a protective device over the injured eye and should patch the unaffected eye to minimize consensual movement. If a ruptured globe is suspected, the nurse should not instill eye drops. The patient should rest in the semi-Fowler's position. Intraocular pressure measurement is not indicated at this time. Detailed examination of the ocular injury should be deferred until the ophthalmologist arrives.
When caring for an immunocompromised patient with suspected herpes zoster ophthalmicus, which interventions should the nurse anticipate? A. Hospitalization and intravenous administration of antiviral drugs B. Administration of herpes zoster vaccine (Zostavax) and application of warm compresses C. Administration of timolol (Timoptic) and pilocarpine (Isopto) D. Application of an eye shield and elevation of the head of the bed
Your incorrect answer: B Herpes zoster ophthalmicus is shingles that affects the ophthalmic division of the trigeminal nerve. To treat this infection, hospitalization and intravenous administration of antivirals, such as acyclovir (Zovirax), are indicated for a patient who is immunocompromised or has intracranial signs and symptoms. Herpes zoster ophthalmicus can be prevented by vaccination with the herpes zoster vaccine (Zostavax), which is indicated in patients age 60 or older who have previously had chickenpox. Warm compresses are used to treat a hordeolum (external stye) or hypopyon. Timolol (Timoptic) and pilocarpine (Isopto) are used to treat acute angle-closure glaucoma but not herpes zoster ophthalmicus. Application of an eye shield and elevation of the head of the bed are appropriate for treatment of a hyphema.
What is the normal intraocular pressure? A. 10 to 20 mm HgB. 20 to 30 mm HgC. 30 to 40 mm HgD. 40 to 50 mm Hg
Your incorrect answer: B Intraocular pressure normally ranges from 10 to 20 mm Hg. An intraocular pressure of 20 to 30 mm Hg is mildly elevated, 30 to 40 mm Hg is elevated, and 40 to 50 mm Hg is seriously elevated.
In a patient with a globe rupture, which sign or symptom is expected? A. Altered depth of the posterior chamber B. Dilated pupil C. Teardrop-shaped pupil D. Decreased pain sensation
Your incorrect answer: B Signs and symptoms of a globe rupture include hyphema, a teardrop-shaped pupil, altered depth of the anterior chamber, altered light perception, vitreous hemorrhage (occasionally), and minimal to severe pain.
A patient presents to triage complaining of a sudden, complete loss of vision in his left eye. He denies any injury and rates his pain as 0 on a scale of 0 to 10. Which ocular emergency should you suspect? A. Acute angle-closure glaucomaB. Central retinal artery occlusionC. Retinal detachmentD. Hyphema
Your incorrect answer: C Central retinal artery occlusion produces sudden, painless blindness, usually limited to one eye. Retinal circulation must be reestablished within 60 to 90 minutes to prevent permanent vision loss. Acute angle-closure glaucoma, retinal detachment, and hyphema present with different constellations of signs and symptoms.
