Pupillary Disorders

Sobriety Success

At Home Drug Withdrawal

Get Instant Access

PUPIL CONSTRICTION - CAUSES

Horner's syndrome

MIOSIS: the affected pupil is smaller than the opposite pupil. It does not dilate when the eye is shaded.

PTOSIS: the affected eyelid droops and may be slightly raised voluntarily. Ptosis is less marked than with a III nerve palsy.

DISTURBANCE OF SWEATING: depends on the site of the lesion. Absence of sweating occurs when the lesion is proximal to fibre separation along the internal and external carotid arteries.

Horner's syndrome may result from sympathetic damage at the following sites:

Lesion

Brain stem

- intrinsic tumour, e.g. glioma

- Vascular lesion

- Syringobulbia '

Cervical cord

- Syringomyelia

Brain stem

- intrinsic tumour, e.g. glioma

- Vascular lesion

- Syringobulbia '

- Tumour, granuloma

Internal carotid artery Trauma and occlusion/dissection

Cervical sympathetic chain Carcinoma of the apex of the lung (Pancoast syndrome)

- Tumour, granuloma

Internal carotid artery Trauma and occlusion/dissection

Cervical sympathetic chain Carcinoma of the apex of the lung (Pancoast syndrome)

Anterior roots C8, 77

- Tumour, e.g. neurofibroma

- Lower brachial plexus palsy

The congenital or familial form exists, often associated willi lack of pigmentation of die iris. The lesion site is unknown.

Distinguish peripheral and central lesions by instilling drugs, e.g. 1% cocaine in eyes.

Right sided Horner's

Preganglionic lesions

Cocaine acts at the adrenergic nerve endings and, by preventing adrenaline uptake, causes pupil dilatation when the lesion is preganglionic.

Postganglionic lesions

Right sided Horner's

When the lesion is postganglionic, cocaine has little effect because there are no nerve endings on which the drug may act.

Investigative approach: depends on associated signs. Chest X-ray is mandatory to excludc an apical lung tumour.

Was this article helpful?

0 0
Dealing With Drugs

Dealing With Drugs

Get All The Support And Guidance You Need To Be A Success At Dealing With Drugs. This Book Is One Of The Most Valuable Resources In The World When It Comes To A Parents Guide To The Drug Talk.

Get My Free Ebook


Post a comment