Ptosis refers to the upper eyelid margin being lower than the normal anatomical position, blocking part of the pupil and, in severe cases, the entire pupil area. This pathological phenomenon not only affects the appearance, but also interferes with normal visual function and even leads to compensatory lesions of other eye organs. Its formation mechanism, clinical manifestations and functional damage deserve great attention in the fields of ophthalmology and plastic surgery.
Types and causes of ptosis
Ptosis can be divided into two categories according to the cause: congenital and acquired.
Congenital ptosis is mostly caused by poor development or absence of the levator palpebrae superioris muscle, with the upper eyelid positioned low from birth and often unilateral. Some cases are combined with levator palpebrae superioris muscle insufficiency or abnormal development of the extraocular muscles, which affect eye movement.
Acquired ptosis is caused by neurological, myogenic, mechanical or traumatic factors. Common causes include:
③. Oculomotor nerve palsy
④Myasthenia gravis
⑤. Scar contraction after trauma
⑥ Relaxation of the levator palpebrae superioris aponeurosis
Abnormal innervation and muscle structure of the levator palpebrae superioris muscle are the key pathological basis for ptosis . The levator palpebrae superioris muscle is mainly innervated by the oculomotor nerve. Damage or dysfunction of this nerve can cause a decrease in the muscle's contraction ability, manifesting as ptosis. In addition, with age, the relaxation and decrease in elasticity of the aponeurosis can also cause "senile ptosis."
Effects of ptosis on visual function
1. Visual impairment
The most direct functional impact is the limited upper visual field . When the upper eyelid margin covers part or all of the pupil, the eyeball is difficult to be fully exposed, resulting in a narrowing of the visual field. Especially when walking, reading or looking upward, the patient needs to maintain the visual field through compensatory actions such as tilting the head back or raising the eyebrows. This is more obvious in childhood and may affect the development of the cervical spine in the long run.
2. Strabismus and amblyopia formation
Congenital severe ptosis often leads to limited monocular vision. In order to compensate for the loss of vision, the child may only use the healthy eye, resulting in monocular dominance , which in turn causes strabismus or amblyopia . Such patients do not gain binocular vision experience during the critical visual development period and may develop persistent visual development disorders.
3. Limited eye movement and visual fatigue
Under the action of the compensatory mechanism, patients habitually overuse the frontalis muscle or superior rectus muscle to maintain the position of the upper eyelid, resulting in increased tension in the extraocular muscles . If this continues for a long time, it may develop into incoordination of eye movements or visual fatigue, affecting work and study efficiency, especially in situations that require long periods of staring.
4. Decreased light regulation ability
The eyelids play a shielding and protective role in regulating light intensity. When the movement of the upper eyelid is restricted, the blinking frequency decreases, which may lead to uneven tear film distribution and worsening corneal dryness symptoms . In addition, since the upper eyelid cannot be lifted normally, the light incident path is reduced, and the retina's ability to receive light decreases, affecting the ability to adapt to light.
Mental and psychological effects
Although ptosis is mainly an anatomical and functional problem, its change in appearance may cause a significant psychological burden . Patients often feel inferior and anxious due to the gaze of others in social situations. Child patients may receive strange looks from their peers, which has a negative impact on their psychological development. Some patients even have their career choices and social interactions affected by their "tired" and "lifeless" faces.
Compensatory mechanism and secondary damage of ptosis
1. Increased compensatory activity of the frontalis muscle
Due to the decreased function of the levator palpebrae superioris muscle, patients often unconsciously raise their eyebrows to lift the upper eyelid. Long-term excessive contraction of the frontalis muscle can easily lead to deepening of forehead wrinkles , sagging of the upper eyelid skin, and even affect the soft tissue structure of the forehead, resulting in "brow-raising headache."
2. Abnormal head position
Especially in children, in order to maintain a clear vision, they often need to continuously tilt their neck back . This abnormal posture will have long-term adverse effects on the development of the cervical spine and spinal alignment, and may even develop into abnormal cervical curvature, shoulder and neck muscle strain, etc.
3. Asymmetric palpebral fissures and blinking disorders
Long-term ptosis can lead to changes in the width of the palpebral fissure and inconsistent eyelid tension , affecting normal eye closure and tear drainage function, and may be complicated by dry eyes, chronic conjunctivitis or meibomian gland dysfunction.
Diagnosis and assessment tools
The diagnosis of ptosis requires a combination of clinical manifestations, eyelid mobility tests, and neurological function assessments. Common indicators include:
Upper eyelid margin-corneal reflex point distance (MRD1)
Measurement of levator palpebrae superioris muscle activity
Frontalis muscle compensation strength test
Imaging tests (eg, MRI to exclude neuropathic lesions)
Comprehensive evaluation of the impact of ptosis on function will help develop more scientific treatment strategies , such as whether surgical correction is needed and whether combined amblyopia training should be performed.
Treatment and intervention recommendations
Treatment of ptosis should take into account both functional recovery and aesthetic improvement. For those whose visual function is affected, surgical treatment should be given priority , such as levator palpebrae superioris muscle shortening and frontalis muscle suspension. Childhood patients need early intervention to prevent the formation of amblyopia. For middle-aged and elderly people, the risk of complications and the ability of eyelid closure after surgery need to be evaluated to avoid the risk of corneal exposure.
Non-surgical measures such as eye muscle training and neuronutrition are suitable for mild ptosis or preoperative evaluation stage. Psychological counseling should not be ignored to help patients establish positive self-cognition.
Beauty Encyclopedia Tips:
Although ptosis is a common eyelid disease, its comprehensive impact on visual function, psychological state and quality of life cannot be ignored. The cause should be identified early, the degree of functional impairment should be reasonably assessed, and the appropriate intervention method should be selected. Parents should pay special attention to child patients to prevent permanent visual impairment caused by damage to key functions during the visual development period. In daily life, eye fatigue should be avoided and attention should be paid to eye hygiene to slow down the rate of eyelid muscle degeneration. Scientific treatment combined with standardized follow-up can significantly improve function and appearance, and enhance patients' quality of life and social confidence.