Definition: a drooping of the upper or lower eyelid – which may worsen when the patient tires. Ptosis can lead to ambylopia (abnormal development of brain due to reduced stimulation during development) or astigmatism (inability to point focus an image onto the retina – often linked to irregular eye dimensions).
Classification / type of disease and aetiology:
- Neurogenic ptosis which includes oculomotor nerve palsy, Horner’s Syndrome (miosis and anhidrosis), Marcus Gunn jaw winking syndrome, IIIrd cranial nerve misdirection.
- Myogenic ptosis which includes myasthenia gravis (uni/bilat, diurnal variance), myotonic dystrophy, ocular myopathy, simple congenital ptosis, blepharophimosis syndrome
- Aponeurotic ptosis which may be involutional or post-operative.
- Mechanical ptosis which occurs due to oedema or tumors of the upper lid
- Neurotoxic ptosis which is a classic symptom of envenomation by elapids such as cobras or kraits. Bilateral ptosis is usually accompanied by diplopia, dysphagia and/or progressive muscular paralysis. Regardless, neurotoxic ptosis is a precursor to respiratory failure and eventual suffocation caused by complete paralysis of the thoracic diaphragm. It is therefore a medical emergency and immediate treatment is required.
- pseudo ptosis due to:1-Lack of lid support:Empty socket or atrophic globe. 2-Higher lid position on the other side:
Presenting symptoms / signs: drooping upper or lower eye lid – may obstruct vision.
- Damaged 3rd CN
- Brain tumour
- Nerve abnormalities
- Inflammation or infection
- Vascular pathology
- High dose opiate use
Treatment / management:
Aponeurotic and congenital ptosis may require surgical correction if severe enough to interfere with vision or if cosmesis is a concern. Treatment depends on the type of ptosis and is usually performed by an ophthamolic plastic and reconstructive surgeon, specializing in diseases and problems of the eyelid.
Surgical procedures include:
- Levator resection
- Müller muscle resection
- Frontalis sling operation
Non-surgical modalities like the use of “crutch” glasses or special Scleral contact lenses to support the eyelid may also be used.
Ptosis that is caused by a disease will improve if the disease is treated successfully.