Common appearances of the eye and retina

Horner's Syndrome

This is sympathetic interruption of one eye. It manifests as:

1. Ptosis: drooping eyelid
2. Enophthalmos: indrawing of the eye (the opposite of exophthalmos)
3. Miosis: constriction of the pupil
4. Anhydrosis: lack of tear production

Important causes to remember include: Pancoasts syndrome (lung tumour of the apex of the lung), neck trauma, surgical resection.

Optic Atrophy

Looks like a chalky white disc with sharply defined margins. There are many causes, but 3 common causes to remember include:

1. Multiple sclerosis
2. Nerve compression
3. Occlusion of the retinal artery, e.g. in Giant Cell Arteritis

Papilloedema

This is oedema of the optic disc. In some pictures the disc can look "3 dimensional," the same shape as a red blood cell. There is blurring of the disc margins, the disc may be pink or red, there may be dilatation of the veins, and flame haemorrhages may develop. Again there are many causes, but ones to remember include:

1. Increased CSF pressure, for example a space occupying lesion
2. Retinal vein obstruction
3. Optic neuritis
4. Accelerated hypertension

Nerve Palsies

The nerve innervation of the eye can be remembered by the fake chemical equation: LR6 SO4 AO3. This stands for lateral rectus cranial nerve (CN) 6, superior oblique CN 4, All Others CN 3.

CN 6 Palsy

The eye is medially deviated and cannot abduct.

CN 4 Palsy

Diplopia maximal when the eye looks downwards and inwards.

CN 3 Palsy

The eye at rest looks down and out (due to the overriding influence of the lateral rectus and superior oblique). The eye can not move upwards, downwards or inwards.