Anisocoria

Editor-In-Chief: Prab R Tumpati, MD
Obesity, Sleep & Internal medicine
Founder, WikiMD Wellnesspedia &
W8MD's weight loss doctor NYC
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Anisocoria
Anisocoria in a patient
Synonyms	N/A
Pronounce	N/A
Specialty	N/A
Symptoms	Unequal pupil sizes
Complications	May indicate serious underlying conditions
Onset	Can be sudden or gradual
Duration	Varies depending on cause
Types	N/A
Causes	Physiological anisocoria, Horner's syndrome, Adie syndrome, Third nerve palsy, Trauma, Medication
Risks	Head injury, Stroke, Brain tumor, Aneurysm
Diagnosis	Physical examination, Neurological examination, Imaging studies
Differential diagnosis	Horner's syndrome, Adie syndrome, Third nerve palsy
Prevention	N/A
Treatment	Depends on underlying cause
Medication	N/A
Prognosis	Varies; benign in physiological cases, serious if due to neurological causes
Frequency	Common (physiological anisocoria)
Deaths	N/A

Anisocoria is a condition characterized by an unequal size of the pupils. It is a common condition, occurring in approximately 20% of the population. Anisocoria can be a benign finding or a sign of more serious medical conditions.

Causes

Anisocoria can result from a variety of causes, which can be broadly categorized into physiological and pathological causes.

Physiological Anisocoria

Physiological anisocoria is a benign condition where the difference in pupil size is usually less than 1 mm and does not change with different lighting conditions. It is often idiopathic and does not require treatment.

Pathological Anisocoria

Pathological anisocoria can be due to:

• Horner's syndrome: A condition caused by disruption of the sympathetic nerves supplying the eye, leading to ptosis, miosis, and anhidrosis.
• Adie's tonic pupil: A neurological disorder where one pupil is larger than normal and reacts slowly to light.
• Third nerve palsy: A condition affecting the third cranial nerve, leading to ptosis, "down and out" eye position, and pupil dilation.
• Iritis or uveitis: Inflammation of the iris or uveal tract can cause anisocoria due to irregular pupil shape or size.
• Pharmacological agents: Certain medications or drugs can cause anisocoria by affecting the muscles of the iris.

Diagnosis

The diagnosis of anisocoria involves a thorough medical history and physical examination. Key steps include:

• Observation in different lighting conditions: To determine if the anisocoria is more pronounced in bright or dim light.
• Slit-lamp examination: To assess the anterior segment of the eye for any abnormalities.
• Neurological examination: To check for any associated neurological signs that might indicate a more serious underlying condition.

Treatment

Treatment of anisocoria depends on the underlying cause. Physiological anisocoria does not require treatment. Pathological anisocoria requires addressing the underlying condition, which may involve:

• Medications: For conditions like uveitis or iritis.
• Surgery: In cases of structural abnormalities or tumors.
• Observation: In cases where the cause is benign and self-limiting.

Related pages

• Pupil
• Horner's syndrome
• Adie's tonic pupil
• Third nerve palsy
• Iritis
• Uveitis