Pupil - Dilated, APT, belarusian pupils object

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Sympathetic impulses dilate the pupils. Fibres in the nasociliary nerve pass to the dilator pupillae muscle. These arise from the superior cervical ganglion at C2. Sympathetic pre ganglionic fibres to the eye (and face) originate in the hypothalamus, pass uncrossed through the midbrain and lateral medulla, and emerge finally from the spinal cord at T1 (close to the lung apex) and form the superior cervical ganglion at C2. Post ganglionic fibres leave the ganglion to form a plexus around the carotid bifurcation. Fibres pass to the pupil in the nasociliary nerve from the part of this plexus surrounding the internal carotid artery. Those fibres to the face (sweating and piloerection) arise from the part of the plexus surrounding the external carotid artery. This arrangement has some clinical relevance in Horner's syndrome.

Types of Pupils

• dilated
• APT
• Albanian
• belarusian pupil
• enlarged
• adies
• unequal

A slight difference between the size of each pupil is common (physiological anisocoria) at any age. The pupil tends to become small (3-3.5 mm) and irregular in old age (senile miosis); anisocoria is more pronounced. The convergence reflex becomes sluggish with ageing and a bright light becomes necessary to demonstrate constriction.

Argyll Robertson pupil

This small, irregular (3 mm or less) pupil is fixed to light but constricts on convergence. The lesion is in the brainstem in neural tissue surrounding the aqueduct of Sylvius. The Argyll Robertson pupil is (almost) diagnostic of neurosyphilis. Similar changes are occasionally seen in diabetes mellitus.

Myotonic pupil (Holmes-Adie pupil)

This is a dilated pupil seen most commonly in young women. It is usually unilateral, and the pupil is often irregular. There is no reaction (or a very slow reaction) to bright light and also incomplete constriction to convergence. The condition is due to denervation in the ciliary ganglion, of unknown cause. The myotonic pupil is of no more pathological significance than this, but is often associated with diminished or absent tendon reflexes.

I have a 4th grade student with constant dilated pupils; his younger two siblings and his mother have the same problem. They are just beginning eye appts. to investigate. All three children had oxygen deprivation at birth and all have poor vision and motor skills. Any suggestions for a possible diagnosis or for a classroom teacher to determine need for accomodations for this academically stong child? - Diana