Nonreactive (fixed) pupils fail to constrict in response to light or dilate when the light is removed. The development of a unilateral or bilateral nonreactive pupil indicates an important change in a patient’s condition and may signal a life-threatening emergency, including possible brain death. Certain ophthalmic drugs can also produce this finding.

Evaluation of pupillary response involves:

1. Direct light reflex: Shine a bright penlight into one eye while covering the other. A normal pupil constricts promptly.

2. Consensual light reflex: Shine light into one eye while observing the opposite pupil. Both pupils should constrict.

A unilateral or bilateral nonreactive response indicates dysfunction of cranial nerves II (optic) and III (oculomotor), which mediate the pupillary light reflex.

Emergency interventions

• For unconscious patients, promptly assess vital signs.

• Watch for decerebrate or decorticate posturing, bradycardia, elevated systolic blood pressure, widened pulse pressure, and other signs of deterioration.

• A unilateral dilated, nonreactive pupil may indicate early uncal brain herniation. Emergency interventions may include:

  • Surgery to reduce intracranial pressure (ICP).

  • I.V. administration of diuretics, osmotics, or corticosteroids.

  • Controlled hyperventilation, if indicated.

History and Physical Examination

• If conscious, ask about: eye drops, pain type and location, onset, and intensity.

• Assess visual acuity and pupillary reaction to accommodation (constriction when focusing on a near object).

• Examine cornea, iris, and intraocular pressure (IOP) using a tonometer or by palpation. Rock-hard eyeball suggests elevated IOP.

• Ophthalmoscopic and slit-lamp exams may be required.

• Avoid manipulating eyes with trauma; protect with a metal shield.

Examination Tip: Innervation of Direct and Consensual Light Reflexes

• Direct reflex: Light in one eye causes constriction in that eye.

• Consensual reflex: The opposite eye constricts simultaneously.

• Afferent arc: CN II (optic nerve)

• Efferent arc: CN III (oculomotor nerve)

• Sluggish or absent reflex indicates cranial nerve dysfunction or CNS disease.

Medical Causes

Other causes

Drugs: topical mydriatics, cycloplegics, opiates (pinpoint pupils), atropine poisoning (widely dilated).

Special considerations

• Monitor pupillary light reflex in conscious patients.

• For unconscious patients, protect eyes from exposure using tape or shields.

Patient counseling

• Teach proper eye drop instillation techniques.

• Advise on photophobia protection and emphasize the importance of follow-up care to monitor IOP and ocular health.

Pediatric pointers

• Nonreactive pupils in children usually result from the same causes as adults.

• The most common pediatric cause is oculomotor nerve palsy due to increased ICP.

References

1. Biswas J, Krishnakumar S, Ahuja S. Manual of ocular pathology. New Delhi, India: Jaypee—Highlights Medical Publishers; 2010.

2. Eagle RC Jr. Eye pathology: An atlas and text. Philadelphia (PA): Lippincott Williams & Wilkins; 2011.

3. Gerstenblith AT, Rabinowitz MP. The Wills Eye Manual. Philadelphia (PA): Lippincott Williams & Wilkins; 2012.

4. Roy FH. Ocular differential diagnosis. Clayton, Panama: Jaypee—Highlights Medical Publishers, Inc.; 2012.

5. Buttaro TM, Tybulski J, Bailey PP, Sandberg-Cook J. Primary care: A collaborative practice. St. Louis (MO): Mosby Elsevier; 2008.

6. Sommers MS, Brunner LS. Pocket diseases. Philadelphia (PA): F.A. Davis; 2012.

7. Roy FH. Ocular Differential Diagnosis. Clayton, Panama: Jaypee—Highlights Medical Publishers; 2012.