pupils abnormal

Description

Pupils may be abnormal in terms of size, shape or reactions; or the normal cat’s eye red reflex may be lost.

Clinical features

The pupils may not be identical in size due to natural physiological variation.

Abnormally large pupils are seen in Holmes-Adie syndrome (one eye, fails to contract to light), with third cranial nerve palsy (usually with associated double vision and/or ptosis, fails to contract to light), eye-drops, or drugs such as cocaine.

Abnormally small pupils are seen with Horner’s syndrome (one eye, often with slight ptosis), eye-drops (eg pilocarpine for glaucoma), drugs such as morphine or, rarely, stroke.

Misshapen pupils are seen due to adhesions to the lens following intra-ocular inflammation (synechiae), trauma, congenital abnormalities such as coloboma or aniridia, or iris tumours.

The eye may lose its normal cat’s eye red reflex due to cataract, retinal detachment, or blood or other abnormalities within the eye

A white pupil is seen in advanced cataract and a range of serious conditions of the vitreous or retina

Management

Abnormalities of the pupils often indicate potentially serious underlying problems and should be assessed by an ophthalmologist. Urgent referral is indicated for abnormalities in children, those of sudden onset or progressing, and those with associated pain or loss of vision.