Advances in ophthalmic plastic and reconstructive surgery最新文献

The etiology of traumatic optic neuropathy is uncertain, except when intraocular pressure is elevated and CRAO can be observed. Various mechanisms have been implicated, and the etiology probably varies with individual cases. Prognosis is best when vision is initially intact and subsequently deteriorates, suggesting compression that may be reversible. Some authorities recommend high doses of systemic steroids as initial therapy. Anatomically, the orbit is a relatively closed compartment, and significant pressure may develop following intraorbital hemorrhage, edema, or emphysema. When clinical signs of severe orbital hemorrhage and pressure (proptosis) are associated with an optic neuropathy, the clinician is faced with a difficult decision. Mechanical decompression of the orbit is technically within our ability, and considerable positive experience has been derived from the treatment of compressive optic neuropathy in Grave's disease. Although the efficacy of decompression in trauma is uncertain, the literature provides anecdotal reports of restored vision. With full informed consent regarding these issues, orbital decompression seems appropriate for the rare case in which clinical signs of orbital pressure are impressive.

Trauma to the orbit is evaluated with a careful history, a thorough physical examination, and specific radiographic studies. Orbital trauma involves a wide range of conditions, including soft tissue adnexal injury, orbital contusion, optic nerve damage, ocular injury, intraorbital foreign bodies, and orbital fractures. This article emphasizes the importance of an accurate history and a comprehensive examination. It highlights relevant questions to ask, discusses the meaning of pertinent complaints, describes steps in the examination, discusses the diagnostic importance of the physical findings, and recommends specific radiographic studies for accurate identification and localization of orbital fractures and intraorbital foreign bodies.

This article considers the complications of orbital trauma surgery. In addition, ocular as well as nonocular complications of orbital trauma are outlined. Knowledge of the workup of specific types of orbital fractures will help prevent common sequelae of unrecognized orbital fractures: (a) orbital contour abnormalities, and (b) late enophthalmos. Complications of orbital fracture repair that relate directly to the alloplastic implant include (a) orbital cellulitis due to an infected implant, (b) anterior extrusion of the implant, (c) compression of the optic nerve by the implant, (d) dacryocystitis due to obstruction of the lacrimal sac by the implant, and (e) late proptosis due to hemorrhage into the fibrous capsule that surrounds the implant. Surgical techniques that minimize such complications are emphasized.

A successfully rehabilitated anophthalmic socket must hold and support a prosthetic device that mimics the contralateral globe. The goal is symmetry. Static symmetry of the palpebral apertures, canthal angles, and superior sulci are basic objectives. Full versions of the socket implant and prosthesis and full upper lid excursion are definitely desirable but difficult to attain. Adequate lid levels and contours and sufficiently deep conjunctival fornices are necessary to keep the prosthesis in place. Buccal mucous membrane and composite dermis-fat grafts as well as vascular pedical flaps can be used to expand contracted sockets. Canthal tendon shortening and fixation can be effectively used to reestablish lid and canthal contours and to support the prosthesis.

Computed tomography (CT) can be used to aid surgical decision making when the clinical picture is unclear. Patients with blowout fractures and a large amount of orbital expansion and soft tissue herniation have a high risk for developing enophthalmos. Patients with entrapped inferior rectus muscles on CT may continue to have significant diplopia unless they are treated surgically.

Seemingly trivial adnexal injuries may be associated with extensive injuries to the globe, orbit, and brain. A meticulous ophthalmologic examination and orbital and brain computed tomography (CT) scans (axial and coronal views) are essential for complete evaluation of these patients. The ophthalmologist must remain an active participant in the management of these patients to preserve the integrity of the globe.