Aesthetic and Reconstructive Eyelid Surgery

What makes up the anterior, middle, and posterior lamellae of the eyelid?

The three lamellae or “layers” of the eyelid are anatomical divisions that help with the understanding of lid function and lid surgery.

The anterior lamella is defined as the skin and underlying orbicularis muscle.

The middle lamella is the orbital septum and accompanying fatty pads.

The posterior lamella is the conjunctiva and levator apparatus and corresponding lower lid retractors.

Describe the surface anatomy findings of the aged eyelid and the underlying structures responsible.

Four key features are apparent on the surface examination of the aged eyelid: contour irregularities, the lid crease, lid position, and rhytids.

Contour irregularities that are often apparent are because of protruding periorbital fat pads; principally the medial upper fat pad and the lower lid fat pads.

An elevated lid crease represents stretch or dehiscence of the levator apparatus from the tarsal plate and is often a tell-tale sign of lid ptosis.

Lower lid position that is descended away from the corneoscleral limbus is indicative of lower lid laxity and poor canthal support. Often a negative canthal tilt (downward slope of a line drawn from the medial canthus to the lateral canthus) and scleral show (a viewable strip of white sclera between the lower corneoscleral limbus and lid border) are present as well. Upper lid position that encroaches on the upper corneoscleral limbus raises suspicion that ptosis is present.

Brow strain and horizontal forehead rhytids often accompany lid ptosis and dermatochalasis.

What are the analogous structures in the upper and lower eyelid?

The levator aponeurosis is specific to the upper eyelid and is analogous to the capsulopalpebral fascia of the lower lid.

Describe the anatomy of the orbicularis oculi muscle.

The orbicularis oculi muscle is a complex array of concentrically oriented muscles with origins medial to the medial canthus and insertions lateral to the lateral canthus. Further differentiation is made based on the location relative to the underlying lid structures; oriented in a concentric manner from outside to in they are the orbital orbicularis, preseptal orbicularis, and pretarsal orbicularis. Further divisions (based on function and innervation) can be made, principally the inner canthal orbicularis and the extracanthal orbicularis.

Describe the functional role of the orbicularis muscle.

The orbicularis muscle is responsible for eyelid closure (both passive blink and active squint), corneal protection, and lubrication, and as a pump of the lacrimal sac. The inner canthal orbicularis (that orbicularis which resides within 1 cm of the medial canthus) is responsible for passive involuntary blink; the extracanthal orbicularis (that orbicularis which resides outside the inner canthal portion) is responsible for voluntary protective forceful blinking.

Describe the location and function of the lacrimal sac.

The lacrimal sac resides lateral and posterior to the base of the nasal sidewall within the lacrimal crest. The upper portion of the sac is wrapped on its anterior and posterior aspects by the anterior and posterior medial heads of the orbicularis muscle, hence the muscle’s pump action on it. The lacrimal system is a conduit for the passage of tears from the eye (exiting via the upper and lower canalicular systems) into the nasal sinus. Obstruction within this low-pressure system can result in epiphora (excess tearing) or mucocele.

What is Whitnall’s tubercle?

Whitnall’s tubercle is minor bony spur on the inner aspect of the lateral orbital rim that represents the bony insertion point of the lateral canthal tendon.

What nearby anatomic structure helps locate Whitnall’s tubercle?

Eisler’s fat pad is a minor fat pad located superficial to and immediately above Whitnall’s tubercle immediately under the orbital septum. Identifying Eisler’s fat pad is one method of locating the insertion of the lateral canthal tendon.

What is Bell’s phenomenon?

This is the reflex upward rotation of the globe during lid closure. This acts as a further protective mechanism of the cornea. It is present in most patients but not in all.

How many fatty compartments are there in the upper eyelid? Describe them. How can they be told apart?

There are two separate fatty pads in the upper eyelid, the nasal or medial pad and the central pad. Both reside directly under the orbital septum and superficial to the levator apparatus. The medial fatty pad is located above the medial canthus and can be identified by its whitish-yellow color. The central fatty pad is more centrally located approximating the level of the medial corneoscleral limbus and is deeper yellow in color.

How many fatty compartments are there in the lower eyelid? How can they be told apart?

In contrast to the upper eyelid, the lower eyelid has three fatty compartments; the nasal (or medial), central, and lateral fatty pads. Similarly, the medial fatty pad is more whitish-yellow in color and the other two are deeper yellow.

What structure divides the medial from the central fatty pad in the lower eyelid?

The inferior oblique muscle divides the medial from the central fatty pad in the lower eyelid. It is because of this location that it is at high risk for injury during lower lid procedures. Extreme caution should be exercised when manipulating the central or medial fatty pads to avoid injury to this extraocular muscle.

What is the most commonly injured muscle in upper lid blepharoplasty?

The superior oblique. It resides deep and medial to the medial fat pad.

Describe the innervation of the orbicularis muscle.

The differing function of the orbicularis is based on its anatomic location and is reflected in its differing nerve input.

The extracanthal orbicularis muscle is primarily responsible for purposeful, voluntary, and forceful lid closure. This portion of the muscle is innervated by branches of the frontal and zygomatic branches of the facial nerve.

The inner canthal orbicularis (that portion of the muscle in proximity to the medial canthus) is responsible for involuntary lid closure and blinking. This muscle is primarily driven by buccal branch innervation. Injury to the buccal branch or inner canthal orbicularis can severely affect proper lid function and corneal lubrication and protection. The extracanthal orbicularis is more expendable.

What is the difference between blepharochalasis and dermatochalasis?

Blepharochalasis is characterized by intermittent inflammation of the eyelid with exacerbations and remissions of eyelid edema. This process results in a stretching and subsequent atrophy of the eyelid tissue and over time recurrent episodes and aged appearance. There is typically no associated pain or erythema and it primarily affects young women. Dermatochalasis is defined as an excess of skin of the eyelids that is congenital or age related.

What are three common presenting findings in upper lid ptosis?

Depressed lid position, brow strain, and a high-riding or absent lid crease.

What are the degrees of levator function?

Levator function is expressed as the distance between excursion of upper lid margin from full down gaze to full up gaze without brow movement. Excellent (>10 mm), good (8–10 mm), fair (5–7 mm), or poor (1–4 mm). The proper procedure for ptosis repair is often based on levator function.

What are the common methods of ptosis repair?

Fasanella–Servat procedure is an example of a transconjunctival approach to ptosis repair. Levator advancement is an example of open transcutaneous ptosis repair. Lid suspension to the brow with either fascia or a silicone sling is an example of a procedure used for severe ptosis with minimal levator function.

What are the differences between the Asian eyelid and the Occidental eyelid?

Asian eyelids are marked by the presence of epicanthal folds and lack of pretarsal show. The lid crease is significantly lower relative to the ciliary margin than that of Caucasian eyelids (4–6 mm compared with 8–10 mm). The insertion of the orbital septum relative to the tarsus is lower in Asian eyelids, thus periorbital fat is typically seen lower in the eyelid and closer to the lid crease compared with Caucasians. The Asian lid crease may or may not obscure the medial canthus.

What are the goals of Asian eyelid surgery?

The “double eyelid surgery” focuses on establishing a modicum of visible pretarsal lid and developing a lid fold that is seen separately from the lid margin, preserving the epicanthal fold. Incisions are made within the lid at the desired level of fold creation, excess fat is removed, and fixation sutures are placed to control the height of the lid crease. It is critical to maintain a low lid crease and the epicanthal fold, lest a Caucasian eyelid result occurs.

What are the surgical options for minimal upper lid ptosis repair with good levator function?