摘要:

A wide variety of complications of the anophthalmic socket develop in patients after enucleation. including enophthalmos, superior sulcus deformities, eyelid malpositions, implant migration and extrusion, poor prosthetic motility, and socket contraction. Changes in the orbital blood flow and metabolic activity of the socket tissues and atrophy of the orbital fat occurring after enucleation have been suggested as two theoretical mechanisms that result in the development of these clinical conditions. Lack of scientific evidence and a limited understanding of the pathophysiologic basis of the features of anophthalmos led us to evaluate the validity of these proposed mechanisms in an animal model. Selected parameters of the normal orbits were compared with the contralateral anophthalmic orbits at different time intervals after surgery. Orbital blood flow was studied with selective ophthalmic artery angiography and radioactive microsphere techniques. Ophthalmic arteriography demonstrated symmetric caliber and filling characteristics of the major orbital vessels of the control and experimental orbits, although their topographic course was slightly more tortuous in the anophthalmic socket. Results of radioactive microsphere analysis of capillary blood flow per weight of the different orbital tissue compartments of the animals in the long-term group showed no significant difference between the normal and anophthalmic sockets. These findings provide evidence that the circulation dynamics and blood flow to orbital tissues do not change after enucleation surgery.

ISSN:0740-9303    

出版商:OVID    

年代:1990

数据来源: OVID

摘要:

The pathophysiologic mechanisms responsible for the clinical features of the anophthalmic socket are poorly understood. Atrophy of orbital fat has been thought to be a major contributing cause of enophthalmos and the superior sulcus deformities that develop after enucle-ation, but it has never been demonstrated histopathologically or confirmed by scientific analysis. This study was undertaken to investigate the changes that occur in the orbital fat compartment of the anophthalmic socket in an animal model by measuring orbital soft tissue mass and evaluating adipocyte cell size.Instead of reduction in the tissue mass, a statistically significant greater weight of the fat and connective tissue compartment was found in the anophthalmic orbit by nearly 13% compared to the control orbit in the animals in the long-term group. No significant change in the mean maximal diameter of adipocytes developed 7 months after enucleation. These analyses do not support the concept that orbital fat atrophy or a reduction of metabolic activity occurs in the anophthalmic socket in this animal model. From these results and our previous findings that the circulation dynamics and blood flow to orbital tissues do not change after enucleation, we propose that the pathophysiologic basis of the problems associated with anophthalmos is a disturbance in the spatial architecture and interrelationships of the multiple tissue components of the orbit, not a change in the orbital blood flow or development of fat atrophy.

ISSN:0740-9303    

出版商:OVID    

年代:1990

数据来源: OVID

摘要:

Five patients with orbital pseudotumor refractive to initial therapy are discussed. Three had a destructive gran-ulomatous process associated with a sclerosing component. Two exhibited a predominantly lymphocytic infiltration. Chemotherapy with Prednisone (100 mg/day) and either Cytoxan (100 mg/day) or Chlorambucil (10 mg/day) in 5-day pulses is described. All patients responded clinically to this treatment without unfavorable side effects.

ISSN:0740-9303    

出版商:OVID    

年代:1990

数据来源: OVID

摘要:

A case history is presented of a patient who sustained visual loss and a third-nerve palsy after the application of monopolar electrocautery to the orbital apex. Because the third-nerve palsy resolved and most of the vision was regained, it is theorized that the neurological deficits were secondary to myelin damage caused by the monopolar electrocoagulator. The purpose of this article is to compare the effects of monopolar electrocoagulation, bipolar electrocoagulation, and hot-wire cautery on decompressed optic nerves of cats. Although all three forms of coagulation are capable of causing demyelination within the optic nerve when used on the nerve sheath, mono-polar electrocoagulation resulted in the greatest degree of demyelination and bipolar electrocoagulation resulted in the least demyelination.

ISSN:0740-9303    

出版商:OVID    

年代:1990

数据来源: OVID

摘要:

Wooden foreign bodies in the orbit are not detectable by standard roentgenography. Reports in the literature on the ability of computed tomography (CT) to detect orbital wooden foreign bodies have varied. To evaluate whether magnetic resonance imaging (MRI) would offer any advantage over CT in detecting wood in the orbit, MRI and CT were performed on an in vitro model of wooden foreign bodies in the orbit. Woods of different types and sizes were studied in vegetable fat backgrounds chosen to simulate orbital fat. On CT, most types of wood were hypodense to fat. Appropriate window settings were critical in the detection of wood by CT: in this model, a window width of 1000 Hounsfield units was optimal. On MRI. all types of wood were hypointense to fat. Small pieces of wood were surrounded by an MRI truncation artifact consisting of hyperintense spots. TI-weighted images demonstrated wood better than T2-weighted images and required less scanning time than either proton density or T2-weighted images. MRI was superior to CT in detecting the smallest pieces of wood. The role of MRI in the detection of orbital wooden foreign bodies in clinical practice remains to be determined.

ISSN:0740-9303    

出版商:OVID    

年代:1990

数据来源: OVID

摘要:

To compare the results of primary and secondary intraorbital implants after enucleation, we retrospectively studied the surgical outcomes of 114 patients. In 44 patients the implant was inserted immediately after enucleation and in the remaining 70 patients the implant was inserted at a later date. To achieve a satisfactory cosmetic result, additional procedures were needed in 11% of the patients with a primary implant and in 49% of those with a secondary implant. The insertion of an implant at the time of enucleation has distinct advantages over the insertion of the implant at a later date.

ISSN:0740-9303    

出版商:OVID    

年代:1990

数据来源: OVID

摘要:

We present a new approach to the bipedicle myocutaneous upper eyelid to lower eyelid flap in the repair of cicatricial ectropion in lower eyelid reconstruction, and in the release of tension caused by a previous cheek rotational flap. By incorporating the pedicles into the flap design, we prevent the persistent lymphedema and the raw tissue placed against exposed epidermis encountered in previous bipedicle myocutaneous flaps. Although there may be disadvantages associated with this procedure, we have not encountered any to date. Advantages of this procedure include the double source of blood supply and the superior cosmetic result as well as the avoidance of a second operative procedure. We recommend the use of the bipedicle myocutaneous flap in selected cases.

ISSN:0740-9303    

出版商:OVID    

年代:1990

数据来源: OVID

摘要:

Isolated extraocular muscle metastasis is rare and is unreported for thyroid carcinoma. The authors describe a 72-year old man who presented with pain, redness, and proptosis of the right eye. Orbital computed tomography showed a large fusiform soft tissue mass along the medial aspect of the right orbit, involving the medial rectus. Orbital exploration disclosed a mass within the medial rectus muscle sheath involving the muscle belly. Histopathologic examination including electron microscopy, revealed metastatic thyroid carcinoma. Systemic treatment with radioactive iodine was recommended and refused by the patient. One year later, he died of complications from his metastatic disease.

ISSN:0740-9303    

出版商:OVID    

年代:1990

数据来源: OVID

摘要:

A new concept for elevating a switch flap from the lower eyelid and then closing the defect is advocated. This flap is composed of two different-sized lamellae, the horizontally extended anterior lamella and the conventional wedge-shaped posterior lamella and lid margin. The donor's defect is to be closed with each lamella; the posterior lamella is horizontally advanced and directly closed with the aid of lateral canthotomy and cantholysis, and the anterior lamella is closed directly by extending the incision laterally to the temporal region and advancing the skin superolaterally. The switch flap can be applied to previously unindicated, nontypical upper eyelid defects by means of the split lamella concept and procedure. An illustrative case is presented.

ISSN:0740-9303    

出版商:OVID    

年代:1990

数据来源: OVID

摘要:

A case of nodular fasciitis occurring in the eyelid is presented. The clinical and pathologic features of this rare cause of an eyelid mass are discussed. Nodular fasciitis should be considered in the pathologic differential diagnosis of connective tissue tumors of the periorbital region. It is important not to confuse nodular fasciitis with fibrosarcoma. as simple excision is curative for this condition.

ISSN:0740-9303    

出版商:OVID    

年代:1990

数据来源: OVID