From the Guidelines
The absence of a papillary reflex is most commonly caused by damage to the neural pathways controlling pupil constriction and dilation, with common causes including third nerve palsy, brain injury, stroke, and increased intracranial pressure, as noted in the 2020 adult strabismus preferred practice pattern 1.
Causes of Papillary Reflex Absence
The causes of papillary reflex absence can be diverse, ranging from neurological conditions to structural damage to the eye or iris.
- Third nerve palsy, as discussed in the adult strabismus preferred practice pattern 1, is a significant cause, where the pupil may be involved, indicating a potential compressive lesion that requires urgent evaluation.
- Brain injury, stroke, and increased intracranial pressure are other critical causes that can lead to the absence of a papillary reflex, often signaling serious neurological dysfunction.
- Certain medications, such as anticholinergics, opioid overdose, alcohol intoxication, and neurological conditions like Adie's tonic pupil, can also prevent normal pupillary responses.
Clinical Significance
The absence of a papillary reflex is clinically significant because it indicates dysfunction in the cranial nerves II (optic) and III (oculomotor) that control the pupillary light reflex.
- In emergency settings, fixed and dilated pupils may signal life-threatening conditions like brain herniation, emphasizing the importance of prompt evaluation and management.
- The reflex normally involves light stimulation causing pupil constriction to protect the retina and optimize vision, so its absence disrupts these protective mechanisms and can affect visual function.
Evaluation and Management
Evaluation of the absence of a papillary reflex should include a comprehensive eye examination, with particular attention to sensorimotor exam, evidence of ptosis and anisocoria, and pupillary responses in bright and dim illumination, as recommended in the adult strabismus preferred practice pattern 1.
- Neuroimaging, including MRI with gadolinium and magnetic resonance angiography (MRA) or computed tomography angiography (CTA), may be necessary to rule out compressive lesions, especially in cases of pupil-involving third nerve palsy.
- The prognosis and management should consider the underlying cause, with the absence of pupillary reflex to light at 72 hours or more after cardiac arrest being a predictor of poor neurologic outcome, as noted in the 2015 American Heart Association guidelines update for cardiopulmonary resuscitation and emergency cardiovascular care 1.
From the Research
Papillary Reflex Absence Causes
The absence of a papillary reflex can be caused by various factors, including nerve damage or compression.
- Carotid artery dissection is a known cause of ischemic stroke among young and middle-aged patients, and it can also lead to nerve damage or compression, potentially affecting the papillary reflex 2, 3, 4, 5.
- The studies suggest that carotid artery dissection can cause Horner syndrome, which is characterized by ptosis, miosis, and anhidrosis, and can also lead to lower cranial nerve palsy 3, 4, 5.
- However, there is no direct evidence in the provided studies that specifically links papillary reflex absence to carotid artery dissection or other causes.
- The provided studies focus on the relationship between carotid artery dissection and Horner syndrome, as well as lower cranial nerve palsy, but do not directly address the causes of papillary reflex absence 2, 3, 4, 5.