From the Research
Monocular ptosis and one and a half syndrome are distinct conditions with different etiologies and management approaches, and their treatment should prioritize addressing the underlying cause to improve morbidity, mortality, and quality of life. Monocular ptosis (drooping of one eyelid) is commonly caused by myasthenia gravis, third nerve palsy, Horner's syndrome, aponeurotic dehiscence, or mechanical factors, as noted in studies such as 1. Management depends on the underlying cause, with options including anticholinesterase medications like pyridostigmine for myasthenia gravis, addressing vascular or compressive causes for third nerve palsy, and surgical correction for aponeurotic ptosis.
One and a half syndrome, characterized by a conjugate horizontal gaze palsy in one direction and internuclear ophthalmoplegia in the other, typically results from a lesion in the pontine paramedian reticular formation and medial longitudinal fasciculus, with common causes including stroke, multiple sclerosis, tumors, or infections, as discussed in 2 and 3. Management focuses on treating the underlying condition, with approaches such as antiplatelet therapy or anticoagulation for stroke, immunomodulatory treatments for multiple sclerosis, and surgical intervention for tumors.
Both conditions require thorough neurological evaluation, including imaging (MRI brain) and possibly additional testing such as acetylcholine receptor antibodies for myasthenia gravis or lumbar puncture for inflammatory conditions, as emphasized in 4 and 5. Symptomatic management may include prism glasses for diplopia in one and a half syndrome or temporary measures like ptosis crutches while awaiting definitive treatment for ptosis.
Key considerations in managing these conditions include:
- Identifying the underlying cause to guide treatment
- Conducting thorough neurological evaluation
- Considering symptomatic management options
- Prioritizing treatment of the underlying condition to improve outcomes. Given the most recent and highest quality evidence, the management of monocular ptosis and one and a half syndrome should focus on addressing the underlying cause and utilizing a multidisciplinary approach to improve patient outcomes, as supported by studies such as 1 which highlights the importance of keeping up to date on diagnostic and therapeutic contributions for ptosis.