Ptosis is one of the common functional and aesthetic problems in the field of ophthalmology and plastic surgery. It involves the abnormal drooping of the upper eyelid margin, partially or completely blocking the pupil, affecting vision and causing changes in appearance. This article will systematically explore the common causes of ptosis, focusing on whether genetic factors constitute one of the causative factors . Combined with clinical cases and related research, it provides a reference for medical practice and patient science.
1. Definition and clinical manifestations of ptosis
Ptosis refers to the position of the upper eyelid margin being lower than the normal anatomical baseline when the eyes are naturally open. Its severity can be measured by the height of the palpebral fissure, the range of cornea covered by the upper eyelid, and the strength of the levator palpebrae superioris muscle.
Common clinical manifestations include:
① The palpebral fissure becomes narrower, and the upper eyelid covers part or all of the pupil;
② Limited vision, especially the upper vision;
③. Compensatory eyebrow raising or head tilting back;
④. Long-term incomplete eyelid closure can cause dry eyes or corneal lesions.
Ptosis can be divided into two categories according to its cause: congenital and acquired, which are further divided into subtypes such as neurogenic, myogenic, aponeurotic, mechanical and traumatic.
2. Common causes of ptosis
1. Congenital causes
Congenital ptosis is caused by poor development of the levator palpebrae superioris muscles or abnormal innervation at birth, including:
①, Hypoplasia of the levator palpebrae superioris muscle;
②, congenital malformation of the oculomotor nerve;
③. Congenital manifestations of Horner syndrome;
④. Hereditary ptosis syndrome.
Bilateral or unilateral asymmetry of the palpebral fissures can usually be observed in these patients at birth, and some cases have obvious familial clustering, suggesting the involvement of genetic factors .
2. The role of genetic factors
Genetic factors are one of the important mechanisms leading to certain types of ptosis, which is particularly evident in familial cases. Clinical observations have shown that some patients have no obvious history of trauma or neuropathological changes, but similar manifestations exist in their immediate relatives, suggesting that the disease may be inherited in an autosomal dominant or recessive manner.
Related genetic diseases include:
Autosomal dominant congenital levator palpebrae superioris hypoplasia ;
Chronic progressive external ophthalmoplegia (CPEO) : caused by mitochondrial disease;
Congenital muscular dystrophy-related syndromes ;
Oculopharyngeal muscular dystrophy (OPMD) : Commonly presents in late middle age with a strong family history.
Studies have found that some gene mutations related to muscle function, such as PABPN1 (oculopharyngeal muscular dystrophy) and MT-TL1 (mitochondrial disease), may be closely related to sagging symptoms.
3. Analysis of the causes of acquired ptosis
Compared with congenital ptosis, acquired ptosis can occur at any age and has more complex and diverse causes.
1. Aponeurosis (senile)
It is the most common type in adults , mainly due to degeneration, relaxation or dislocation of the levator palpebrae superioris aponeurosis. It is common in the elderly and manifests as gradual drooping of the eyelids without other nerve or muscle lesions.
2. Neurogenic ptosis
It is caused by oculomotor nerve damage, brainstem lesions, myasthenia gravis, etc., and manifests as the inability to lift the eyelids, accompanied by eye movement disorders or diplopia. Neurogenic ptosis requires a comprehensive diagnosis based on imaging and neurological examination.
3. Myogenic ptosis
Including myasthenia gravis, muscular dystrophy, mitochondrial myopathy, etc. These patients often show symmetrical bilateral ptosis accompanied by systemic muscle weakness.
4. Traumatic and mechanical
Eyelid trauma, surgical injury, tumor compression, etc. can cause damage to the levator palpebrae superioris muscle or oculomotor nerve, leading to functional disorders. Some patients have difficulty lifting their eyelids due to mechanical resistance caused by tumors or inflammation in the eye socket.
4. Diagnostic process and identification points of ptosis
In clinical practice, the cause should be determined comprehensively based on medical history, family history, physical examination, and auxiliary examinations, with the focus on:
Assessment of palpebral fissure height and levator muscle strength ;
Ice test (used to diagnose myasthenia gravis) ;
Electromyography and genetic testing (to identify myogenic lesions) ;
Head MRI or CT (to exclude central nervous system disease) .
If the patient has a family history or multiple relatives have similar manifestations, the possibility of genetic factors should be considered, and genetic testing and genetic counseling should be recommended.
5. Treatment Strategies and Prognosis
Treatment of ptosis requires individualized management based on the cause. The following are common strategies:
1. Surgery
Suitable for patients with insufficient muscle strength but no active lesions. Common surgeries include:
①. Levator muscle advancement surgery;
②, frontal muscle sling surgery (for patients with severe muscle weakness);
③. Aponeurosis reduction surgery (senile ptosis).
2. Medication
If the disease is neurological or myogenic, such as myasthenia gravis, systemic drug management (such as cholinesterase inhibitors or immunomodulators) and regular follow-up are required.
3. Genetic disease intervention
For confirmed hereditary ptosis, family screening and genetic counseling should be conducted. Although there is currently no fundamental treatment, early identification and intervention can alleviate symptoms and improve quality of life and appearance .
Beauty Encyclopedia Tips:
The causes of ptosis are diverse, covering nerves, muscles, aponeurosis and genetic factors. Genetic factors play a key role in congenital and some adult-onset ptosis . Especially for patients with similar symptoms in the family, more attention should be paid to its identification. Clinically, it is necessary to accurately diagnose the type of cause in order to develop the most appropriate intervention plan. In terms of facial aesthetics, the normal position of the eyelids directly affects the facial expression and temperament. Scientific treatment and early intervention not only help to restore visual function, but also enhance the patient's self-identity and satisfaction with appearance.