Overview
Ptosis is the partial or total inability to lift the upper eyelid due to incomplete or lost function of the levator muscle, or other causes that obscure part or all of the pupil.
Classification of ptosis
1. Congenital ptosis, which accounts for about 80% of all classifications, is caused by abnormal development of the levator muscle, resulting in its weakening or even loss of function;
2. Acquired ptosis, which is caused by paralysis of the motoneurotic nerve or myasthenia gravis;
3. Pseudopelvic ptosis is a condition in which the upper eyelid is drooping in appearance, but the function of the levator muscle is normal and the true position of the upper eyelid is normal on objective examination, commonly due to laxity of the upper eyelid skin, lack of upper eyelid support, and idiopathic blepharospasm.
Symptoms of ptosis
(i) Congenital: often bilateral, but not always symmetrical on both sides.
②Acquired: most often with a history of related conditions or with other symptoms, such as actinic nerve palsy that may be accompanied by paralysis of other extraocular muscles; a history of trauma to the levator muscle; sympathetic nerve damage with Horner syndrome; ptosis due to myasthenia gravis is characterized by morning lightness and nighttime heaviness, which is significantly reduced after neostigmine injection.
This disease is usually due to weakness of the spleen and qi and weakness in lifting, or to weakness of the spleen and stomach, lack of transformation of water and grain, lack of essence and blood, loss of harmony in the veins and collaterals, opening of the skin and couples, and loss of warmth in the lids due to wind and evil in the lids; or to trauma to the lids, loss of harmony between the camp and the body, and loss of nourishment in the lids. It is characterized by ptosis of the upper eyelid in one or both eyes. In mild cases, the upper eyelid half covers the black eye and the pupil, while in severe cases, the upper eyelid covers the black eye and cannot be opened. In severe cases, it can be difficult to swallow, and in severe cases, it can be difficult to see one or two eyes and can be bedridden.
Causes and symptoms of ptosis
(a) Congenital. The majority of cases are due to hypoplasia or deficiency of the levator muscle, or a deficiency of the nerve innervating the levator muscle. It is a congenital developmental malformation, mostly bilateral, sometimes unilateral, and can be autosomal dominant or recessive. It is often associated with impaired upward eye movement. In patients with more pronounced bilateral ptosis, the eyelid skin is smooth, thin, and wrinkle-free. If the pupil is obscured by the eyelid, the patient tries to overcome the visual impairment by tightening the frontalis muscle, forming deeper transverse skin wrinkles that pull the eyebrows upward in an arch-like projection, thereby raising the position of the upper lid margin, or the patient tilts the head to see.
(ii) Acquired. There are four causes: traumatic, neurogenic, myogenic, and mechanical. Myogenic causes are most often caused by myasthenia gravis.
1. Paralytic ptosis: This is caused by paralysis of the oculomotor nerve. It is mostly monocular and is often combined with paralysis of other extraocular or intraocular muscles innervated by the motoneurotic nerve.
2. Sympathetic ptosis: This is caused by dysfunction of the Müller muscle or by damage to the cervical sympathetic nerve; in the latter case, it is accompanied by ipsilateral pupillary narrowing, inversion of the eye, flushing of the face, and absence of sweating, called Horner syndrome.
3. Myogenic ptosis: This is most often seen in myasthenia gravis and is often accompanied by generalized fatigue of the random muscles. However, there are also cases that appear solely in the extraocular muscles and do not progress to other muscles over time. This type of ptosis is characterized by improvement after rest, immediate aggravation during continuous transients, light in the morning and heavy in the afternoon, and temporary relief of symptoms after subcutaneous or intramuscular injection of neostigmine 0,3 to 1,5 mg for 15 to 30 minutes.
4.Other
(1) Traumatic injury to the actinic nerve or the levator muscle, Müller muscle, can cause traumatic ptosis.
(2) Diseases of the eyelid itself, such as severe trachoma and lid tumors, increase the weight of the eyelid and cause mechanical ptosis.
(3) Anophthalmia, microphthalmia, ocular atrophy, and various causes of reduced orbital fat or orbital contents can cause pseudopelvic ptosis.
(3) Hysterical ptosis. This is caused by hysteria, where both upper lids suddenly droop or are accompanied by hysterical pupillary dilatation, and sometimes compression of the supraorbital nerve can cause the droop to suddenly disappear.
(iv) Unusual combined eyelid movements: refers to eyelid movements associated with jaw, facial and ocular movements
1. Marcus Gunn jaw-winking: A congenital abnormal connection between the nucleus accumbens and the motor nucleus of the trigeminal nerve, resulting in a joint movement of the external pterygoid muscle and the levator muscle, with symptoms such as lifting of the upper eyelid by opening the mouth or swinging the jaw, and, in some cases, a transient movement with chewing while eating.
2. Martin Amat phenomenon, once known as the anti-Marcus Gunn phenomenon: abnormal joint movements occur after regenerative recovery from facial nerve damage, with contraction of the orbicularis oculi during movement of the lower facial muscles and eyelid closure.
3. Combined upper eyelid movement occurs with damage to the dynamic eye nerve.
Preoperative examination of ptosis
In normal individuals, the upper eyelid margin covers 2 mm of the superior cornea and the average width of the lid fissure is approximately 7.5 mm. To estimate the function of the levator muscle, the position of the upper eyelid margin can be measured when the eye is looking extremely upward and downward, respectively, with the frontalis muscle contraction force offset. In normal individuals, the difference should be more than 8 mm. If the difference is less than 4 mm between the front and back, this indicates severe insufficiency of the levator muscle.
Treatment of Ptosis
The main goal is to prevent vision loss and improve appearance, and should be treated for the cause. Congenital ptosis should be corrected with early surgery. This is especially true if the pupil is obscured unilaterally to prevent amblyopia. In myogenic or paralytic ptosis, adenosine triphosphate, vitamin B1, or neostigmine can be used to improve muscle function. Surgery should be carefully considered when prolonged treatment is not effective.
Surgical options for ptosis include.
① Enhance the strength of the levator muscle, such as shortening or migrating the anterior muscle.
②Opening the lid fissure with the help of the traction of the frontalis or superior rectus muscle. The surgical procedure can be chosen according to the condition and the strength of each muscle.
Ptosis correction points
Comparison of upper lid ptosis correction surgery
1. Choose a good surgical procedure: frontalis flap stop down suspension is suitable for any type of ptosis, especially for patients with severe ptosis, but the patient’s frontalis muscle should be functionally present. Mild to moderate ptosis can be corrected with an upper eyelid lift shortening procedure.
2. Adjust the height of the lid fissure: Regardless of which method is used to correct ptosis, the height of the lid fissure should be adjusted. If it is too wide, the postoperative exposure keratitis will be severe, and if it is too narrow, the correction will be unsatisfactory.
3. When using the frontalis flap stop for downward transfer suspension, the entire frontalis flap that is peeled and shaped (including the part that is transferred to the upper lid) retains good contraction, which is the basis for successful surgery.
If the midline point is too low, the upper lid will be lifted excessively and a “triangle eye” will form, while if it is too high, the upper lid will not be lifted enough and the ptosis will not be corrected satisfactorily.
5. After unilateral ptosis correction, the healthy side should be made into a double eyelid so that both sides are basically symmetrical.
6. Before surgery, the patient should be carefully examined to make a good differential diagnosis. Choose the appropriate surgical method.
Purpose of ptosis surgery
The fundamental purpose of ptosis correction surgery is to raise the drooping upper lid, restore the normal height of the lid fissure, expose the pupil, expand the visual field, prevent amblyopia, correct abnormal morphology, and improve facial appearance. In short, it is important to achieve both functional restoration and cosmetic purposes.
Requirements for postoperative results of ptosis
The ideal and perfect post-operative corrective result should have the following.
(1) Morphology: The upper lid ptosis is corrected, and both sides of the heavy lid crease, the height and width of the lid fissure, the shape of the lid margin, and the distance between the eyebrow margins are symmetrically coordinated.
②Functionally: normal eyelid opening and closing and transient movements are maintained, the lid movements are coordinated when the eye moves to all sides, and the lid fissure closes well during sleep.
③In terms of complications: as far as possible, no complications such as strabismus, diplopia, or rabbit eyes are produced.
Ptosis – efficacy evaluation
1. Cure: The wound heals and the upper lid margin does not cover the upper cornea by more than 3mm in bilateral cases; in unilateral cases, the upper lid position of the operated eye and the healthy eye are basically symmetrical or do not differ by more than 2mm.
2. Improved: The wound healed and the ptosis was partially corrected but did not meet the above criteria.
3. Failure to heal: Wound healing with secondary infection, failure of ptosis correction, or uncorrected ptosis.
Tip: The lid can be opened easily and freely in normal people.
Normal people can open their eyelids and see what is in front of them easily and freely. Because the ptosis blocks the view, the contraction of the frontalis muscle is used to lift the upper lid and raise the head, commonly referred to as “looking at the antennae”, which affects the appearance of the face. Congenital ptosis can usually be corrected surgically to remove the visual obstruction, prevent amblyopia, and improve facial appearance. For acquired ptosis, treatment is directed at the cause of the condition and is done in conjunction with neurological diagnosis and medication. Early treatment can be expected to cure or improve the condition. Alternatively, surgery may be considered only after six months or more of treatment without improvement.