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The opposite conditions of ectropion and entropion are caused by a similar pathogenesis and can be treated with similar principles. Therefore, they are presented in this chapter as two variations of the same entity. The traditional concept of inverting surgery for ectropion or everting surgery for entropion does not take into account that the most adequate procedure should simply aim to repair involutional pathology and try to restore normal anatomy.

The successful treatment of periocular tumors depends on the accomplishment of three primary goals: • Cure of the tumor • Preservation of function • Cosmetic reconstruction Balancing efforts to achieve these three goals can challenge the reconstructive surgeon. Whereas generous surgical margins enhance cure rates, they can lead to extensive cosmetic and functional morbidity. By contrast, modest surgical margins may simplify reconstruction, improve cosmetic outcomes, and preserve function of critical periorbital anatomy only to increase the risk of tumor recurrence. Strong evidence supports the use of Mohs micrographic surgery to treat periorbital malignancies, due to its reliably high cure rates and maximal preservation of healthy tissue [22].

The treatment of upper eyelid retraction represents one of the most challenging aspects of ophthalmic plastic surgery. This entity produces an unnatural physical appearance, often referred to as the “stare,” which can give the illusion of exophthalmos (Fig. 3.1). In addition, retraction can lead to lagophthalmos and exposure keratopathy with sequelae that are potentially sight-threatening. Numerous surgical procedures have been described regarding the correction of upper lid retraction, with varying results, further complicating the treatment of this condition. For the purposes of this review the authors will focus on the surgical correction of thyroid-related retraction.

The eyelids are a critical structure, paramount in maintaining the health of the eye and ocular surface. Malpositioning of the eyelid leads to a variety of problems that leaves the patient uncomfortable and often seeking intervention. When addressing lid malpositioning, there are two primary goals: first, to maintain or restore function, and second, to achieve this in an aesthetically pleasing manner. The two are intertwined as surgery is approached for functional or for cosmetic purposes.

A perfect knowledge of orbital anatomy is indispensable for accurately diagnosing orbital diseases and for performing safe orbital surgery. During the 19th and 20th centuries, many studies and many dissections were done in an effort to produce the actual conception of orbital anatomy. One characteristic of the human orbit is the great variability of the anatomical structures found, especially the arteries, which gives to each orbit its particularities. Before the routine use of CT scanning or MRI, it was very difficult for an ophthalmologist or an orbital surgeon to appreciate the arrangement of structures within the orbit. However, it is possible to give a general view of the organization of orbital anatomy, describing the main, well-known variations. In his book Clinical and surgical orbital anatomy Dutton said: “few areas in ophthalmology have proven to be as elusive or difficult to teach as orbital anatomy” [21].

Capillary hemangioma is the commonest childhood orbital vascular anomaly, usually presents as a painless swelling or vascular marking of the eyelids, and typically enlarges in infancy before undergoing spontaneous regression during childhood [8, 24]. Most periorbital hemangiomas pose no threat to visual development, but larger lesions may result in amblyopia due to mechanical ptosis, induced astigmatism, or displacement of the globe (Figs. 6.1, 6.2).

Vascular anomalies of the orbit include venouslymphatic malformations (VLM). These lesions, often referred to as lymphangioma, are considered congenital and most commonly present in childhood. Approximately one-third are identified in the first weeks of life [17]. VLM represented 4% of 1,264 orbital tumors in Shields’ series [35] and 3% of 600 in Iliff and Green’s series [20]. The most common presenting sign is painful unilateral proptosis resulting from spontaneous hemorrhage (Fig. 7.1a). Less commonly, VLM may enlarge slowly (Fig. 7.2a, b).

Graves’ disease (GD) is a systemic autoimmune disease that targets the thyroid, orbit, and skin. Thyroid-associated orbitopathy (TAO) describes the orbital and periorbital manifestations of the disease [33, 34, 159]. Several important concepts have emerged in the pathogenesis of TAO that potentially explain the manifestations of the disease. Immune recognition of “foreign” and “self ” is predicated upon molecular recognition of target structures. The mechanisms of immune recognition and discrimination of self and nonself is beyond the scope of this chapter, but several important epitopes or molecular targets have emerged that may prove relevant to the pathogenesis of TAO and GD. It is increasingly clear that a single target may not fully explain the diverse systemic- and anatomic-specific disease manifestations.

The autoimmune process at the root of thyroid orbitopathy (TRO) leads to accumulation of complex carbohydrates called glycosaminoglycans and collagen within the extraocular muscles and orbital fat. The consequent edema and fi- brosis lead to marked swelling of the soft tissues confined within the boundary of the bony orbit with an increase in intraorbital pressure. Rarely, the increased intraorbital pressure is a cause of potentially sight-threatening conditions such as optic neuropathy or exposure keratopathy, but more frequently it leads to different degrees of venous congestion, strabismus, eyelid swelling, retraction, and exophthalmos. The latter four are principally responsible for the major aesthetic changes affecting patients with TRO.

Children suffering from congenital clinical anophthalmos or microphthalmos require prolonged and complicated socket management, and this is more difficult when the globe is not clinically apparent [19]. Therapeutic options include the use of rigid conformers [6, 7], low hydrophilic [8] or, more recently, highly hydrophilic self-expanding hydrogel expanders [23, 28].