Advances in ophthalmic plastic and reconstructive surgery最新文献

Based on the pathology of the eye socket and periorbital deficiencies, three distinct classes of patients can be recognized: I. Those who solely have eye socket deficiency with normal orbital and periorbital tissue. The suggested surgical treatment for this class of patient would be a skin or mucosa graft. II. Patients who have inadequate lining, as well as orbital volume deficiency. The preferred reconstructive approach includes cartilage (rib or ear) with or without fat graft, and skin or mucosa grafts for eye socket expansion. III. For failed reconstructions of classes I and II or for patients with severe orbital and periorbital deficiencies, the choice is one of three flaps: If the superficial temporal vessels and the postauricular skin is intact, the ideal flap is postauricular fasciocutaneous. If the postauricular skin has previously been used yet the superficial vasculature is intact, a secondary flap is the better choice. In cases where both postauricular skin and superficial temporal vessels have been sacrificed the recommended flap is a free flap with microvascular anastomosis.

The replacement of any anatomic structure by artificial means remains a challenge. This is particularly true in the facial area. The replacement must be one which blends with the adjacent tissues as well as replaces the missing structures. Careful planning and meticulous attention to detail in fabrication of a prosthesis can enable the maxillofacial prosthodontist to make a major contribution in the rehabilitation of the patient with an orbital defect.

An expansion prosthesis has been developed for the anophthalmic or microphthalmic socket. Orthodontic wire covered with silicone tubing is fused onto a conventional methyl-methacrylate ocular prosthesis. The use of this device is illustrated in a case report.

Primary to the development of an acceptable and functional facial prosthesis is the impression procedure. The fabrication of a facial prosthesis combines the art and science of anatomy, cosmesis, and function, to develop a nonliving substitute to replace altered, missing, or defective regions of the head and neck area. Success depends on patient's cooperation, motivation, and commitment to treatment as well as the technical and artistic scope of the facial prosthetic service.

Three dimensional images reconstructed from two dimensional CT scans allow improved analysis of complex orbitocranial bony deformities. This evaluation may be useful in patients with defects resulting from trauma, tumor, congenital abnormalities, or developmental disorders. Diagnosis, surgical management, and long-term follow-up evaluation may be aided by improved understanding of bony contour and volume analysis. Computer designed prostheses can be fabricated to precisely match bony defects and may be used as an alloplastic implant or as a model to aid intraoperative contouring of an autogenous bone graft. The limitations of three dimensional imaging include artifacts in the reconstructed images, increased radiation exposure, and increased cost. The technology is still evolving and the indications and benefits remain undefined at the present time.

In patients with congenital anophthalmos and severe microphthalmos, a tiny orbit and socket exist with little eyelids, frequently preventing retention of a standard conformer or prosthesis. Socket expansion is sometimes impossible with microorbitism; the retention of a prosthesis is also difficult when malformations of the eyelids exist. The treatment of these difficult cases includes three stages. The first stage is orbital expansion that depends on the cephalometric studies of the patient: transverse osteotomy on the maxilla and the zygomatic bone with lateral bar by extracranial route, vertical osteotomy on the roof of the orbit by intracranial route. In some cases, the osteotomy includes expansion in the transverse and vertical diameter with bone grafts in the defects and on the lateral and superior rims. Simultaneously, socket expansion is performed by incision of the conjunctival sac circumferentially, with mucosal or split skin grafts on a conformer. The second stage includes eyelid reconstruction by different flaps. A third stage is frequently needed for correction of eyelid malposition on the prosthesis: ptosis, entropion surgery. Two cases of congenital anophthalmos are reported. Methods and indications of treatment are discussed.

Facial asymmetry and cosmetic deformity can occur following enucleation. The effect of enucleation on the growth of the orbit can be demonstrated in the rabbit and cat by early enucleation, X-ray study and dry skull measurements. In 42 human patients the anophthalmic orbital changes are determined by roentgenograms. The influencing factors of age and the use of implants are discussed as to changes in the rim, orbital walls and volume, and optic foramina measurements. Growth retardation due to roentgen ray therapy and other clinical aspects are considered which would influence the appropriate clinical management.

Early socket stimulation is crucial for management of congenital anophthalmos and microphthalmos among infants. Progressive sized hard conformers and lid expansion devices can expand the small socket in these patients. The ocularists' management of these two conditions is discussed and techniques are introduced.