The correction of the deformities associated with aging eyes is based on the principles of the facial subunits. There are many different techniques reported in the plastic surgery literature. In this chapter, the basic principles of aesthetic surgery of the eyes will be presented, and it is hoped that this will be a platform from which the many different proposed techniques and points of contention of blepharoplasty can be evaluated and understood.
A fundamental concept in viewing the eyelid is that it is composed of three distinct anatomic layers: the external coverage or skin, a middle support layer, and an internal lining (Figure 9–1). Together, they form a tri-lamellar structure supported and anchored across the orbital rim by the medial and lateral canthal tendons. The outermost layer of this trilamellar structure consists of the outer coverage of skin, which is especially thin over the tarsus and preseptal areas with minimal to no subcutaneous fat. The middle, or supportive layer, includes the orbicularis muscles, with the pretarsal portion lying in front of the tarsal plate. Finally, the deepest layer is the pre-orbital portion of this tri-lamellar structure, which lies anterior to the orbital septum.
The anatomy of the periorbital region. The upper and lower eyelids are suspended in space, tethered medially and laterally by the canthal tendons and, in turn, are lined to Whitnall and Lockwood ligaments. The orbital and palpebral lobes of the lacrimal gland are divided by Whitnall ligament. The orbital septum inserts at the orbital rim, except inferolaterally where it inserts beyond the rim forming Eisler recess. (Reproduced, with permission, from Spinelli H. Atlas of Aesthetic Eyelid and Periocular Surgery. Copyright Elsevier 2004.)
The tarsal plate is a rigid cartilaginous-like structure that measures 4 to 6 mm in the lower lid and 8–10 mm in the upper lid (see Figure 9–1). This structure is pierced by glands that drain or open posterior to the eyelashes. The tarsal plates are the end point for retractor insertion and provide lid stability and orientation. It is an especially important structure for vertical support and eyelid rigidity.
The orbicularis oculi muscle is in the same contiguous layer as the frontalis, the occipitalis, and the superficial musculo-aponeurotic system of the midface. It has a medial and lateral raphé and is divided into three divisions: preorbital, preseptal, and pretarsal. It functions as a sphincter. The orbicularis muscle is innervated by the facial nerve (cranial nerve VII) and, hence, with facial nerve paralysis, the cornea and globe are typically exposed owing to an atonic eyelid.
The orbital septum is confluent with the periosteum of the skull and the orbit. Analogously, the inferior orbital septum is intimately linked to the periosteum and the capsulopalpebral fascia.