Unit 3: Pupil Abnormalities, Facial Nerve Palsy & Ptosis

Ptosis means drooping of the upper eyelid. It may be unilateral, bilateral or asymmetric.

Source: Andrewya, Wikimedia. CC Public Domain.

The eyelid is elevated by the levator muscle, which is innervated by the 3rd cranial nerve. Normally the upper eyelid covers the top 1-2mm of the cornea. Children who have a ptosis are at risk of amblyopia if the eyelid obscures the pupil.

Symptoms

Heavy eyelid
Visual field reduced if obscures pupils

Patient Assessment

Confirm that it is a true ptosis
Establish if congenital or aquired

Differential Diagnosis

The following can create the false impression of ptosis:

Enophthalmos
Dermatochalasis
Contralateral eyelid retraction
Contralateral proptosis

Amblyopia describes reduced visual acuity due to under-development of the visual system. If the brain fails to receive a clear image in the first 7 years of life it does not develop the neuronal capacity to see clearly, such that even if the ocular cause of blurred vision is treated, the vision never recovers.

Most commonly it occurs in one eye, due to underlying refractive error, squint, or less commonly, cataract. To enable the disadvantaged eye to develop, the better eye is sometimes patched, forcing the brain to use the image from the worse seeing eye.

Enophthalmos is posterior displacement of the eye.

Enophthalmos with apparent ptosis from deeper upper lid sulcus (note lid position on cornea remains the same as fellow eye, as seen by the distance between the lid and the two white corneal reflections).

Folds of skin over an old man's upper eyelids

Ophthalmic Atlas Images (EyeRounds.org, The University of Iowa) / CC BY-NC-ND 3.0.

Contributor: Andrew Doan, MD, PhD, University of Iowa.

Proptosis is a forward protrusion of the globe.

It can create the false impression of contralateral ptosis as by comparison the contralateral upper eyelid is lower.

Photo of a patient with proptosis (most common cause is thyroid eye disease)

Source: eyerounds.org Contributor: Andrew Doan, MD, PhD, University of Iowa.

The patient above has asymmetric proptosis due to thyroid eye disease - the right upper eyelid is lower than the left but is retracted rather than ptotic.

5: Ptosis

Symptoms

Patient Assessment

Differential Diagnosis

Amblyopia

Enophthalmos

Dermatochalasis

Proptosis