Background
Upper eyelid ptosis is a drooping of the upper eyelid margin in relation to superior limbus. This problem can have significant functional and aesthetic implications. Because it can be a difficult problem to correct, a variety of procedures have been developed to address ptosis. [1, 2]
The image below depicts a procedure used to correct upper eyelid ptosis.
History of the Procedure
Treatment of ptosis dates back well prior to 200 years ago. Until the early 1800s, management was limited to simple excision of skin from the upper lid. Von Graefe described a technique that resected a strip of orbicularis muscle with the skin excision. Bowman described a transconjunctival resection of the levator. [3] Fansella and Servat reported resection and plication of the conjunctiva, tarsus, and levator to address mild ptosis with good levator function. [4] Beard proposed a modification that used a continuous running suture rather than interrupted horizontal sutures. [5]
The use of fascial slings to suspend the upper lid from the frontalis muscle was originated by Payr [6] and Lexer [7] and later adapted by Risdon. [8] Tillett and Tillett [9] and McCord and Shore [10] suspended the ptotic lid in a similar fashion but employed silastic strips rather than fascia.
Anterior approaches to the levator using a blepharoplasty-type incision allow resection of a portion of the levator aponeurosis and tightening. Further evolution has led to techniques that use adjustable suture plication either alone or in conjunction with aesthetic blepharoplasty.
Problem
Upper eyelid ptosis is a lowering of the upper eyelid margin in relation to superior limbus. Normally, the eyelid covers 1-2 mm of the upper limbus of the cornea. When the ptotic lid covers enough of the upper limbus or pupil it can result in both functional and aesthetic deformities. The severity of ptosis is classified by determining how much of the upper limbus is covered by the lid margin: mild is 2 mm, moderate is 3 mm, and severe is 4+ mm. Levator function is classified based on the distance of lid margin excursion: excellent is 12-15 mm, good is 8-12 mm, fair is 5-7 mm, and poor is 2-4 mm.
Epidemiology
Frequency
The frequency of upper eyelid ptosis is difficult to determine. However, it is increasingly recognized in the elderly population. This is particularly true in patients who have undergone cataract extraction or lens replacement, perhaps due to stretching or disruption of the levator muscle when the eye is propped open using retractors.
Etiology
The etiology of blepharoptosis can be classified based on whether it is true ptosis or pseudoptosis, congenital or acquired, and unilateral or bilateral. True ptosis can be congenital or acquired. Congenital ptosis is associated with neurogenic or myogenic origins. In a study of patients with unilateral congenital upper eyelid ptosis, Bagheri et al reported a direct correlation between levator muscle function, lid fissure height, and margin reflex distance, which, according to the investigators, demonstrates the association of levator muscle dysfunction with the development and severity of congenital ptosis. [11]
Acquired causes include mechanical, traumatic, and senile lid ptosis. In a study of 96 sets of identical twins, Satariano et al identified hard or soft contact lens use as a risk factor for acquired upper eyelid ptosis, unrelated to genetic disposition. No association was found between acquired upper eyelid ptosis and body mass index, work stress, sleep, smoking, sun exposure, or alcohol use. [12]
Pseudoptosis, the appearance of ptosis without true lid margin ptosis or levator dysfunction, can be due to severe blepharochalasia, asymmetry, or changes in ocular volume. Rarely, ptosis occurs as a complication following orbitozygomatic complex injuries; the levator becomes detached from the superior tarsal plate. [13]
Pathophysiology
Congenital ptosis typically involves isolated myogenic dystrophy resulting in an underdeveloped levator muscle with poor functions. [14, 15] Congenital presentation also can include neurogenic origins such as cranial nerve (CN) III palsy and Marcus-Gunn pupil. Acquired ptosis also can be of neurogenic pathology and include acquired CN III palsy and Horner cervical sympathetic nerve palsy. In older patients, myogenic ptosis is caused by a thinning, lengthening, or, less often, disinsertion of the levator aponeurosis from the tarsal plate.
In addition, acquired muscular dystrophy, progressive external ophthalmoplegia, and myasthenia gravis all can be causes of late-onset ptosis. With the exception of the neurogenic and myasthenic types of ptosis, levator function is usually good in acquired ptosis. Traumatic ptosis varies according to the location of the injury to the levator muscle or lid mechanism. Mechanical ptosis is due to a tumor, cyst, or enlarged lacrimal gland pushing down the eyelid. Pseudoptosis refers to the drooping lid skin of blepharochalasis and to the apparent ptosis seen in the postenucleation eyelid.
Presentation
Ptosis of the eyelids can have a subtle presentation and even go unnoticed by the patient. Presenting signs include a high tarsal fold, persistent wrinkles in the forehead due to contraction of the frontalis muscle, and asymmetric elevation of the eyebrows, greater on the affected side. In severe cases, patients complain of restricted visual fields. Patients presenting for cosmetic surgical procedures on the face also may demonstrate some degree of upper eyelid ptosis. In apparently unilateral cases, the "normal" appearing eye is checked by closing the affected one to see if a milder degree of ptosis is noted.
Indications
Many techniques have been used to correct upper eyelid ptosis. Consider the degree of ptosis and levator function when weighing surgical options. Patients with poor levator function (< 10 mm of excursion) and moderate ptosis (< 3 mm) will likely require suspension of the lid from the frontalis muscle. Patients with poor levator function but severe ptosis (4 mm or greater) are managed with resection of a segment of the levator muscle. Patients who have good levator function (>10 mm excursion) can obtain long-term correction of the ptosis using plication of the distal levator muscle aponeurosis. Patients with minor ptosis (< 2 mm) and good levator function (>10 mm excursion) are candidates for the Fasanella-Servat mullerectomy.
In addition, when these patients also are undergoing cosmetic facial surgery, they can be treated successfully with transpalpebral blepharoplasty plication of the levator aponeurosis. In most of these patients with senile ptosis, simple plication of the levator may suffice.
Current expert recommendations indicate that in the case of mild-to-moderate blepharoptosis alone, performing Müller muscle–conjunctival resection repair is recommended because it can accommodate the use of general anesthesia without sacrificing efficacy. With moderate-to-severe blepharoptosis, performing levator advancement under local anesthesia and using intraoperative patient cooperation allows for lower revision rates. [16, 17]
Relevant Anatomy
The upper eyelid is divided anatomically into the anterior lamella, comprising skin and orbicularis muscle and the posterior lamella, which consists of the tarsus and conjunctiva. The upper eyelid is further divided by the supratarsal fold into tarsal and orbital segments of the orbicularis muscle. The supratarsal fold is formed by the insertion of the levator aponeurosis and the orbital septum on the deep surface of the orbicularis oculi. These layers, which make up the pretarsal fascia, insert into the anterior aspect of the tarsus and fix the structures of the anterior and posterior lamellas.
The levator muscle, which is approximately 45 mm in length, is a skeletal muscle under voluntary control of CN III. It originates within the apex of the orbital cone and inserts on the levator aponeurosis. The levator aponeurosis extends for 12 mm superior to the supratarsal fold between the levator muscle and Müller muscle. Müller muscle is a smooth muscle under control of autonomic system, which lies beneath the aponeurosis adjacent to the conjunctiva.
Failure to recognize the complex anatomy of the thin, mobile upper eyelid can lead to injury of the levator aponeurosis during cosmetic blepharoplasty while trying to locate the supraorbital fat pads.
Contraindications
Because ptosis correction can be performed under local anesthesia, with proper operative selection there are no specific surgical contraindications to surgery. Purely cosmetic procedures should be avoided in patients with dry eye syndrome. Patients who are undergoing concomitant procedures may require general anesthetic; in these patients, careful preoperative evaluation with regard to the degree of ptosis and planned correction is required.
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Blepharoplasty, upper lid ptosis surgery. Intraoperative photo of levator muscle.
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Blepharoplasty, upper lid ptosis surgery. Intraoperative photo of levator plication.
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Upper lid ptosis surgery. Correction of ptosis using blepharoplasty plication of the levator. In addition, the patient had facial rejuvenation and endoscopic brow lift.
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Blepharoplasty, upper lid ptosis surgery. Correction of ptosis, with incomplete correction of asymmetry.