Pupils, nonreactive
Nonreactive (fixed) pupils fail to constrict in response to light or to dilate when the light is removed. The development of a unilateral or bilateral nonreactive response indicates an important change in the patient’s condition and may signal a life-threatening emergency and possibly brain death. It also occurs with use of certain optic drugs. (See Assessing pupillary reaction, page 552.)
A unilateral or bilateral nonreactive response indicates dysfunction of cranial nerves II and III, which mediate the pupillary light reflex. (See Innervation of direct and consensual light reflexes, page 553.)
Emergency Actions
Ifthe patient is unconscious and develops unilateral or bilateral nonreactive pupils, quickly take his vital signs. Be alert for decerebrate or decorticate posture, bradycardia, elevated systolic blood pressure, widened pulse pressure, and the development of other untoward changes in the patient’s condition. Remember, a unilateral dilated, nonreactive pupil may be an early sign of uncal brain herniation. Emergency surgery to decrease intracranial pressure (ICP) may be necessary. If the patient isn’t already being treated for increased ICP, insert an I.V. line to administer a diuretic, an osmotic, or a corticosteroid. You may also need to start the patient on controlled hyperventilation.
History
Ifthe patient is conscious, obtain a brief history. Ask him what type of eyedrops he’s using, if any, and when they were last instilled. Also ask if he’s experiencing any pain and, if so, try to determine its location, intensity, and duration.
Physical assessment
Check the patient’s visual acuity in both eyes. Then test the pupillary reaction to accommodation: Normally, both pupils constrict equally as the patient shifts his glance from a distant to a near object.
Next, hold a penlight at the side of each eye and examine the cornea and iris for any abnormalities. Measure intraocular pressure (IOP) with a tonometer, or estimate IOP by placing your second and third fingers over the patient’s closed eyelid. If the eyeball feels rock hard, suspect elevated IOP. Ophthalmoscopic and slit-lamp examinations of the eye will need to be performed. If the patient has experienced ocular trauma, don’t manipulate the affected eye. After the examination, be sure to cover the affected eye with a protective metal shield, but don’t let the shield rest on the globe.
Medical causes
Botulism
Bilateral mydriasis and nonreactive pupils usually appear 12 to 36 hours after ingestion of tainted food. Other early findings of botulism include blurred vision, diplopia, ptosis, strabismus, and extraocular muscle palsies, along with anorexia, nausea, vomiting, diarrhea, and dry mouth. Vertigo, deafness, hoarseness, nasal voice, dysarthria, and dysphagia follow. Progressive muscle weakness and absent deep tendon reflexes usually evolve over 2 to 4 days, resulting in severe constipation and paralysis of respiratory muscles with respiratory distress.
Encephalitis
As encephalitis progresses, initially sluggish pupils become dilated and nonreactive. Decreased accommodation and other symptoms of cranial nerve palsies, such as dysphagia, develop. Within 48 hours after onset, encephalitis causes a decreased level of consciousness, high fever, headache, vomiting, and nuchal rigidity. Aphasia, ataxia, nystagmus, hemiparesis, and photophobia may occur with seizures.
Glaucoma (acute angle-closure)
Acute angle-closure glaucoma is an ophthalmic emergency that upon examination reveals a moderately dilated, nonreactive pupil in the affected eye. Conjunctival injection, corneal clouding, and decreased visual acuity also occur. The patient with acute angle-closure glaucoma experiences sudden onset of blurred vision, followed by excruciating pain in and around the affected eye. He commonly reports seeing halos around white lights at night. Severely elevated IOP commonly induces nausea and vomiting.
Ocular trauma
Severe damage to the iris or optic nerve may produce a nonreactive, dilated pupil in the affected eye (traumatic iridoplegia). This sign is usually transitory but can be permanent. Slit-lamp examination commonly reveals a V-shaped notch in the pupillary rim, indicating a tear in the iris sphincter muscle. The patient usually experiences eye pain and may also develop eye edema and ecchymoses.
Oculomotor nerve palsy
Commonly, the first signs of this oculomotor ophthalmoplegia are a dilated, nonreactive pupil and loss of the accommodation reaction. These findings may occur in one eye or both, depending on whether the palsy is unilateral or bilateral. Among the causes of total third cranial nerve palsy is life-threatening brain herniation. Central herniation causes bilateral midposition nonreactive pupils, whereas uncal herniation initially causes a unilateral dilated, nonreactive pupil. Other common findings include diplopia, ptosis, outward deviation of the eye, and inability to elevate or adduct the eye. Additional findings depend on the underlying cause of the palsy.
Uveitis
In anterior uveitis, a small, nonreactive pupil appears suddenly and is accompanied by severe eye pain, conjunctival injection, and photophobia. With posterior uveitis, similar features develop insidiously, along with blurred vision and distorted pupil shape.
Wernicke’s disease
Nonreactive pupils are a late sign in Wernicke’s disease, which initially produces an intention tremor accompanied by a sluggish pupillary reaction. Other ocular findings include diplopia, gaze paralysis, nystagmus, ptosis, decreased visual acuity, and conjunctival injection. The patient may also exhibit orthostatic hypotension, tachycardia, ataxia, apathy, and confusion.
Other causes
Drugs
Instillation of a topical mydriatic and a cycloplegic may induce a temporarily nonreactive pupil in the affected eye. Opiates, such as heroin and morphine, cause pinpoint pupils with a minimal light response that can be seen only with a magnifying glass. Atropine poisoning produces widely dilated, nonreactive pupils.
Special considerations
If the patient is conscious, monitor his pupillary light reflex to detect changes. If he’s unconscious, close his eyes to prevent corneal exposure. (Use tape to secure the eyelids, if needed.)
Pediatric pointers
Children have nonreactive pupils for the same reasons as adults. The most common cause is oculomotor nerve palsy from increased ICP.
Patient counseling
Teach the patient the proper method for instilling eyedrops. If photophobia is present, suggest the patient wear dark glasses to ease discomfort. Stress the importance of follow-up care to check IOP.
Pictures
Book Source Details
- Book Title: Signs & Symptoms: A 2-in-1 Reference for Nurses
- Author(s): Springhouse
- Year of Publication: 2007
- Copyright Details: Signs & Symptoms: A 2-in-1 Reference for Nurses, Copyright © 2007 Lippincott Williams & Wilkins.
Other Book Chapters Related to Pupil symptoms
Read excerpts from these other book chapters related to Pupil symptoms:
Medical Books Excerpts
- Mydriasis
- "Handbook of Signs & Symptoms (Third Edition)" (2006)
- [ read ]
- Mydriasis
- "Professional Guide to Signs & Symptoms (Fifth Edition)" (2006)
- [ read ]
- Mydriasis
- "Signs & Symptoms: A 2-in-1 Reference for Nurses" (2007)
- [ read ]
- Mydriasis
- "Nursing: Interpreting Signs and Symptoms" (2007)
- [ read ]
Copyright Details: Signs & Symptoms: A 2-in-1 Reference for Nurses, Copyright © 2008 Williams & Wilkins.
More About Causes of Pupil symptoms
» Next page: Pupils, sluggish (Signs & Symptoms: A 2-in-1 Reference for Nurses)
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