Palpebral ptosis, blepharoptosis or droopy eyelids, is a condition that causes the upper eyelid to fall. This situation prevents the person from opening the affected eye well, causing fatigue and making vision difficult.
This pathology affects all ages, although, in adults, it has a higher incidence. When it occurs in children, called infantile eyelid ptosis, it can cause amblyopia (also known as lazy eye) and, as a consequence, loss of visual acuity, because the eye does not receive the visual stimulation necessary to develop normal vision.
Classification And Types Of Ptosis
Palpebral ptosis has been classified interchangeably by different authors, taking into account factors such as the time of its appearance, the cause, the function of the upper eyelid lift muscle or the degree of eyelid drooping, among others.
Congenital myogenic ptosis usually appears at birth with a clear hereditary component, specifically of the autosomal dominant type (the disorder may occur if the abnormal gene is inherited from only one of the parents) and, sometimes, is related to sex.
It can be congenital or acquired. The congenital can be, in turn, simple myogenic, and is the most common type in childhood, being a home elevator muscle dysgenesis. It manifests from birth and remains stable.
Aponeurotic ptosis is caused by an alteration of the aponeurosis (the connective membrane that covers the muscles), either congenital or acquired, by disintegration, stretching, or dehiscence (spontaneous opening) of the eyelid lift muscle.
This type of ptosis is the most common and is usually caused by the aging of the eyelid tissues; hence it also receives the name of senile ptosis.
Neurogenic ptosis occurs infrequently. They can be caused by aplasia (lack of development) of the nucleus of the III cranial nerve, due to peripheral, nuclear, or supranuclear lesions.
Although this type of ptosis (ตาตก which is the term in Thai) usually occurs in isolation, cases associated with other neurological manifestations have been described, such as ophthalmoplegic migraine, which causes headache on one side of the head or around the eye; Horner’s syndrome, which produces neurosympathetic paralysis and pupil alterations; or the Marcus-Gunn ptosis, in which the ptosis occurs before certain movements of the mouth or jaw.