Most common cause of ptosis ?
Ans. is 'd' i.e., Congenital Ptosis Ptosis is drooping of upper eyelid. Ptosis occurs when the muscles that raise the eyelid (levator palpebrae superiors and muller's nuscles) are not strong enough to do so properly. Etiology of Ptosis may be :? A) Congenital myogenic ptosis :- It is the most common type of ptosis and is often bilateral. It is associated with maldevelopment or congenital weakness of levator palpebrae sperioris. Congenital myogenic ptosis is characterized by drooping of one or both lids at bih, with a diminished or absent lid crease and lid lag on downgaze due to tethering effect of abnormal muscle. It may occur in following forms Simple congenital ptosis :- Not associated with other anomaly Congenital ptosis with superior rectus weakness Blepharophimosis syndrome Congenital ptosis, blepharophimosis, telecanthus and epicanthus inversus. Congenital synkinetic ptosis (Marcus Gunn jaw- winking Ptosis):- Retraction of ptotic lid with jaw movement like chewing, i.e., with stimulation of ipsilateral pterygoid muscle. B) Acquird ptosis :- Depending upon the cause acquired ptosis may be Neurogenic :- It is due to paralysis of 3rd nerve, Horner's syndrome, ophthalmoplegic migraine, multiple sclerosis. Neurogenic ptosis may also occur due to lesion of sympathetic nerve) supplying muller's muscle. Myogenic :- It is due to acquired defect of LPS muscle and may be seen in myasthenia gravis, dystrophia myotonica, ocular myopathy, oculopharyngeal muscular dystrophy, thyrotoxicosis, Lambe - Eaton mysthenia syndrome Mechanical:- It is due to excessive weight on the upper lid e.g in lid tumors, multiple chalazia, lid edema. It may also occur due to scarring (cicatracial ptosis) in atients with ocular pemphigoid and trachoma. Aponeurotic ptosis :- It is due to defect of the levator aponeurosis in the presence of normal functioning muscle, e.g. involutional (senile) ptosis, post-operative ptosis.
Myasthenia gravis
Paralysis of 3rd nerve
Idiopathic
Congenital