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PubMed1990

Force necessary to fracture the orbital floor.

Current thought on the pathophysiology of orbital wall fractures postulates either a "hydraulic" or a "buckling" mechanism. Evidence from cadaver, dried skull, and theoretical model studies supports both theories. No in vivo data, human or nonhuman primate, are available that quantitate the force necessary to fracture the orbital floor by either of the two mechanisms. We developed an apparatus that delivers quantifiable force only to the globe, without occluding the orbital opening or striking the orbital rim. We used it on 11 anesthetized Macaca fascicularis monkeys. Following a single bilateral application, the orbits were exenterated, and the orbital walls and orbital contents were examined to determine the extent of injuries. Fractures were described, diagrammed, and photographed. Fracture of the orbital floor was consistently produced at and above a force of 2.08 J. Posterior ruptures of five eyes occurred over the same range. We provide the first accurate measurements of the force required to produce orbital blow-out fractures in a live primate model. We show that orbital floor fractures can occur at low energies with direct ocular trauma only ("pure" hydraulic mechanism). Orbital wall fractures failed to protect the globe from rupture in 23% of cases.

Animals↗

PubMed2002

Clinical presentation and treatment of secondary orbital lymphoma.

PURPOSE: To describe the clinical features and histologic classification of orbital lymphoma secondary to systemic non-Hodgkin lymphoma, to evaluate the efficacy of various treatment modalities for controlling the orbital component of disease, and to analyze vision-related outcomes. METHODS: In this retrospective case series, the clinical records of patients diagnosed with orbital lymphoma who were treated between January 1999 and May 2001 at the University of Texas M.D. Anderson Cancer Center were reviewed. Demographic data, histologic classification of lymphoma, immunophenotype, stage of disease, treatment outcomes, vision-related outcomes, and duration of follow-up after the diagnosis of orbital lymphoma were recorded in each case. RESULTS: At the time of diagnosis, all 15 patients identified either had a previous history of non-Hodgkin lymphoma or had simultaneous involvement of lymph node or other sites. Ten patients (67%) had intermediate-grade or high-grade lymphoma. All 15 patients had a B-cell phenotype. Systemic chemotherapy or immunotherapy was the initial treatment modality in 13 patients; the other 2 patients were treated with radiation as the initial mode of therapy. Eleven patients (73%) achieved complete regression of the orbital tumor; one patient had partial regression of the orbital lymphoma. Loss of vision secondary to compressive optic neuropathy was seen in 5 patients (33%); in 3 of these patients, the orbital lymphoma was diagnosed early and treatment was successful in reversing the loss of vision. One patient had irreversible vision loss secondary to compressive optic neuropathy; in this case, therapy had not been initiated until several months after onset of symptoms. Another patient died of lymphoma before the orbital disease could have responded to therapy. CONCLUSIONS: Because of often widespread systemic involvement and a usually more aggressive histologic classification than primary orbital lymphomas, secondary orbital lymphomas warrant treatment with systemic chemotherapy or systemic immunotherapy. In some cases, combining such systemic therapy with local radiation treatment is beneficial. Loss of vision as the result of compressive optic neuropathy in this setting can be reversed if systemic therapy is initiated soon after the onset of progressive signs and symptoms of orbital disease.

Adult↗

PubMed1999

Squamous cell carcinoma of the sinonasal tract invading the orbit.

OBJECTIVE/HYPOTHESIS: The treatment of squamous cell carcinoma (SCC) of the sinonasal tract has evolved from routine exenteration of the orbital contents to sparing of the orbit when the SCC does not transgress the periorbita. Nonetheless, the influence of this change in treatment over the rate of local recurrence or survival has not been clearly elucidated. The objective was to ascertain whether orbital sparing surgery for the treatment of SCC of the paranasal sinuses influences the rate of local recurrence or survival. STUDY DESIGN: This is a retrospective study of patients presenting with SCC arising in the sinonasal tract, treated primarily at the University of Pittsburgh Medical Center from 1977 to 1990, including meta-analysis of the English literature regarding SCC of the sinonasal tract. METHODS: Review of medical records regarding demographics, histology, extension of tumor, pathologic results, type of surgery, adjunctive therapy, and outcome. Articles for meta-analysis were identified by Medline search and cross-referencing. RESULTS: Fifty-eight patients with orbital invasion, including bone and/or soft tissue invasion, were included in the study. Patients presenting with invasion of the bony orbit without soft tissue invasion were treated with maxillectomy and/or ethmoidectomy, sparing the orbital contents. Patients presenting with invasion of the orbital bones and soft tissues were treated with ethmoidectomy or maxillectomy, including orbital exenteration. At 3 years' follow-up, 52% of the patients whose orbit was exenterated were alive and without evidence of disease, compared with 59% of the patients whose orbit was spared. This difference was not statistically significant. Similarly, the rate of local recurrence was not statistically significant (P > .05). A meta-analysis of the literature revealed similar results. CONCLUSIONS: Our data suggest that sparing of the soft tissues of the orbit when the periorbita has not been transgressed by SCC does not downgrade the rate of cure or local control.

Carcinoma, Squamous Cell↗

PubMed1999

Course of proptosis in patients with Graves' disease after endoscopic orbital decompression.

AIM: To evaluate the results of follow-up and postoperative course of proptosis in patients with Graves' disease who underwent combined transconjunctival and transnasal endoscopic orbital decompression. METHODS: Charts of patients with Graves' disease who underwent orbital decompression using combined transconjunctival and transnasal endoscopic technique were reviewed. The surgical technique involved preservation of the strut of bone between the lamina papyracea of the ethmoid and floor of the orbit of the maxilla. Data pertaining to patient demographics, previous treatments for orbital manifestations of Graves' disease, and preoperative and postoperative otolaryngologic and ophthalmologic examination findings were obtained. Postoperative course of reduction in proptosis was evaluated based on Hertel exophthalmometry measurements obtained in four intervals: 1) 0 to 1 month, 2) 1 month to 3 months, 3) 3 to 6 months, 4) 6 to 12 months. RESULTS: Twenty-eight orbital decompressions were performed on 15 patients. All patients were unresponsive to corticosteroids and orbital irradiation. Ten orbits exhibited preoperative and postoperative visual acuity of 20/20. Vision improved in nine orbits and did not change in six orbits. Proptosis was reduced in 25 orbits. Postoperative course of reduction in proptosis varied within year 1, with the smallest proptosis measurements documented between 6 and 12 months. CONCLUSIONS: Combined transconjunctival and transnasal endoscopic orbital decompression with preservation of the strut resulted in regression of proptosis, marked reduction in postoperative diplopia development, and improvement of visual acuity in patients with Graves' disease. Course of reduction in proptosis varied within postoperative 1 year, with the biggest reduction occurring between 6 and 12 months.

Adolescent↗

PubMed1989

Blow-in fractures of the orbit.

A blow-in fracture is an inwardly displaced fracture of the orbital rim or wall resulting in decreased orbital volume. The purpose of this study is to classify orbital blow-in fractures, describe the distinguishing clinical and radiologic features, and review the result of treatment. The series consists of 41 patients with blow-in fractures (34 males and 7 females). The mean age of the patients was 36 years. All were treated between 1979 and December of 1986 at Sunnybrook Medical Centre in Toronto. Clinical features of blow-in fractures were primarily related to the decrease in volume of the orbital cavity. Proptosis was a consistent finding, and in 27 percent of patients, the globe was further displaced in a coronal plane. Restricted ocular motility and diplopia were documented in 24 and 32 percent of patients, respectively. Fracture fragments displaced into the orbit resulted in globe rupture in 12 percent of patients, superior orbital fissure syndrome in 10 percent, and optic nerve injury in 1 patient. Blow-in orbital injuries were classified as pure fractures, consisting of an isolated blow-in of a segment of the roof, floor, or walls, or impure fractures, where the orbital rim itself was disrupted. In all cases, early decompression of the orbit and open reduction of fractures was necessary. Late sequelae of blow-in fractures were primarily related to injuries of intraorbital contents. Twelve percent of patients underwent enucleation and 8 percent reported persistent diplopia. Despite the presence of superior orbital fissure syndrome and complete ophthalmoplegia in 10 percent of patients, early orbital decompression resulted in resolution of nerve palsies in all but one patient.

Adolescent↗

PubMed2003

Plaque radiotherapy for selected orbital malignancies: preliminary observations: the 2002 Montgomery Lecture, part 2.

PURPOSE: To describe the principles and preliminary results of plaque brachytherapy for selected orbital malignancies. METHODS: A custom-designed Iodine-125 plaque, designed to deliver a target dose of 50 Gray, was placed surgically in the region from which an orbital malignancy was partially resected. The mean dose to the target area was 50 Gray. The initial and follow-up patient data were reviewed. RESULTS: Of the 8 patients, the diagnosis was adenoid cystic carcinoma of the lacrimal gland (4 cases), orbital invasion by basal cell carcinoma (2), orbital extension of conjunctival melanoma (1), and metastatic carcinoma (1). Of the 4 with adenoid cystic carcinoma, there was microscopic residual tumor after excision and orbital exenteration was considered. Three have tumor control with follow-up of 1, 3, and 6 years. One patient required exenteration for recurrence separate from the field of brachytherapy and is free of tumor after 10 years. All 4 patients are alive and well with tumor control. Of the 2 patients with orbital extension of basal cell carcinoma, tumor control without recurrence has been achieved in both after 2 years. The patient with orbital metastasis responded to plaque radiotherapy, with no orbital recurrence, but died of systemic metastasis. The patient with orbital melanoma had local orbital recurrence separate from the area of irradiation and is currently being treated for systemic metastasis. CONCLUSIONS: Based on preliminary observations, plaque radiotherapy appears to be a reasonable alternative to exenteration and external irradiation for selected orbital malignancies.

Adult↗

PubMed1990

Correlation of orbital computed tomography and antibodies in patients with hyperthyroid Graves' disease.

The purpose of this study was to elucidate the incidence of orbital changes in computed tomography, and the relationships of orbital changes with eye-muscle antibody (EMAb), thyrotrophin-binding inhibitor immunoglobulin (TBII), antithyroglobulin antibody (TgAb) and anti-thyroid microsomal antibody (MsAb), in 55 consecutive patients with hyperthyroid Graves' disease. EMAb was demonstrated by an immunoperoxidase technique. The results showed that the prevalence of orbital fat increase, extraocular muscle enlargement, lacrimal gland enlargement and optic nerve swelling were 54.5, 41.8, 21.8 and 16.5% respectively. There were 32.7% of patients without any orbital changes. The patients with extraocular muscle enlargement, lacrimal gland enlargement and optic nerve swelling had higher titres of EMAb than the patients without these orbital changes. The patients with lacrimal gland enlargement had a lower TBII index than those without. There was no difference in TgAb or MsAb between the patients with extraocular muscle enlargement, lacrimal gland enlargement, optic nerve swelling or orbital fat increase and those patients without these orbital changes. The patients with extraocular muscle enlargement, optic nerve swelling and orbital fat increase had a higher degree of exophthalmos than the patients without these orbital changes. EMAb was negatively correlated with TBII. However, there was no correlation between EMAb and TgAb or MsAb. The degree of exophthalmos was positively correlated with EMAb and negatively correlated with age. There was no correlation between exophthalmos and TBII, TgAb or MsAb. In conclusion, although the pathogenesis of orbital changes and hyperthyroidism is different, a close link between these two entities is suggested by the high incidence of orbital changes in hyperthyroid Graves' disease.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗

PubMed1997

Orbital granulocytic sarcoma.

AIM: Orbital granulocytic sarcoma is a localised tumour composed of cells of myeloid origin. Histological diagnosis can be difficult in patients with poorly differentiated orbital tumours and no evidence of systemic leukaemia. The naphthol AS-D chloracetate esterase (Leder stain) and immunohistochemical stains for lysozyme and MAC387 were used to determine the staining characteristics of these tumours. A case series of seven patients with orbital granulocytic sarcoma is presented. METHODS: Seven patients with orbital granulocytic sarcoma were studied. Haematoxylin and eosin, Leder, and lysozyme stained sections were available in seven cases. Unstained formalin fixed paraffin embedded sections of seven cases were available for immunohistochemical evaluation using the avidin-biotin-complex technique for MAC387. RESULTS: The mean age of presentation of the orbital tumour was 8.8 years. Four patients presented with an orbital tumour before any systemic manifestations of leukaemia. In two cases the diagnosis of the orbital tumour and systemic leukaemia was made simultaneously. There was one case of established systemic myeloid leukaemia in remission with the subsequent development of orbital granulocytic sarcoma. Six of seven cases (86%) were positive for the Leder stain. Five of seven cases (71%) showed positive immunoreactivity with lysozyme. The immunohistochemical stain for MAC387 was positive in all seven cases (100%) including one case that was negative for both lysozyme and Leder stains. CONCLUSIONS: Orbital granulocytic sarcoma is a tumour that affects children and can present with rapidly progressive proptosis. This tumour may develop before, during, or after the occurrence of systemic leukaemia. The combination of Leder and lysozyme stains is useful in the diagnosis of orbital granulocytic sarcoma. MAC387 may be a more reliable marker for orbital granulocytic sarcoma.

Acute Disease↗

PubMed2003

Transmaxillary approach to the orbit: an anatomic study.

OBJECTIVE: Various approaches to expose the orbit have been used, such as cranial, lateral, and medial approaches. In an effort to gain exposure to the orbit without necessitating a craniotomy, we have developed a transmaxillary approach to the orbit. METHODS: An approach was developed that uses data obtained by performing 24 orbit dissections in 12 cadaveric heads. After sublabial incision to expose the maxilla, maxillotomy is performed and the course of the infraorbital nerve is identified. The orbital floor is opened, and the orbit is accessed. RESULTS: This technique offers access to the inferomedial and inferolateral orbit and to the inferior aspect of the optic nerve. CONCLUSION: The transmaxillary approach provides an entirely extradural approach to the orbit. This technique combines the benefits of a cosmetically acceptable approach with orbitotomy and avoids the use of craniotomy and brain retraction to access the deep medial, lateral, and inferior orbit. We advocate the transmaxillary approach to the orbit in cases of inferomedial posterior intraconal and inferolateral lesions as an alternative and adjunct to the standard techniques of orbital surgery.

Cadaver↗

PubMed1986

Clinical implications of orbital cellulitis.

Periorbital and orbital cellulitis are clearly two distinct disorders with different etiologies. Periorbital cellulitis is well-documented as a more common infectious process limited to the eyelids in the preseptal region. In contrast, orbital cellulitis represents a more severe, but less common, infection of the orbit posterior to the septum with or without subperiosteal abscess, orbital abscess, or cavernous sinus thrombosis. A retrospective review of the clinical and laboratory data of 137 cases of orbital and periorbital cellulitis was performed. Periorbital cellulitis was documented in 98 cases (71%), in contrast to orbital cellulitis which was noted in 39 (28%) patients. All patients with orbital cellulitis received intravenous antibiotics, however, surgical therapy was necessary for progression of orbital cellulitis in 49% of patients. The majority of patients underwent incision and drainage of an abscess in the orbit. Complications as a result of orbital cellulitis occurred in nine (23%) of the patients. A distinction is made between the clinical entity of periorbital cellulitis and orbital cellulitis. Separating these clinical entities on the basis of physical examination and radiographic studies is important because the medical and surgical management of these two disease processes is different.

Abscess↗

PubMedDate not supplied

Computed tomographic patterns of orbital cellulitis due to sinusitis.

PURPOSE: To describe the CT findings of orbital cellulitis due to sinusitis. METHODS: The records and CT scans of 45 consecutive patients with orbital cellulitis due to sinusitis treated at the Hospital of the Medical School of Ribeirão Preto were analyzed by a radiologist and two orbital surgeons. RESULTS: Three major types of CT changes were observed: diffuse fat infiltration, subperiosteal abscess and orbital abscess. Diffuse fat infiltration (characterized by an increased density of the extra- or intraconal fat) was seen in 11 patients (24.44%). A subperiosteal abscess was diagnosed in 28 patients (62.23%). A surgically proved orbital abscess was detected in 6 patients (13.33%). CONCLUSIONS: In all cases of orbital cellulitis due to sinusitis intraorbital changes can be detected by CT scans either as a diffuse infiltration of the orbital fat or as a detachment of the periorbita (subperiosteal abscess) or a true orbital abscess. Category I of Chandler orbital cellulitis classification (inflammatory edema) must be understood as a stage of a process that is already happening within the orbit and, as the term "preseptal cellulitis" means a palpebral infection, this designation should not be used to stage orbital cellulitis.

Adolescent↗

PubMed2001

[Clinical and MRI diagnosis of nasopharyngeal carcinoma with orbital spread].

OBJECTIVE: To study the routes, clinical manifestations and MRI characteristics of nasopharyngeal carcinoma (NPC) with orbital spread. METHODS: Twenty (23 eyes) such cases were selected, including 6 (7 eyes) preradiotherapy cases and 14 (16 eyes) postradiotherapy cases. The magnetic resonance imaging (MRI) axial, coronal, sagittal routine procedures and gadolinium-diethylene triamine pentaacetic acid (GD-DTPA) contrast-enhanced scan were performed. Fatty-restraint scan was performed after enhancement only on 3 cases. The diagnosis in all the patients was proved by the biopsy from the nasopharynx. RESULTS: (1) Single orbit involvement was seen in 17 patients, 12 in the left and 5 in the right orbit. Bilateral orbit involvement was only found in 3 patients. (2) Major clinical manifestations of orbital involvement by NPC included: 13 cases (15 eyes) suffered from decrease of visual acuity, 9 cases (10 eyes) with exophthalmos, 11 patients (12 eyes) with ocular movement disorder, 7 cases (9 eyes) with diplopia and 5 cases (7 eyes) with blepharoptosis. (3) MRI appearances: There were 13 cases (15 eyes) with optic nerve involvement, 9 patients (11 eyes) with abnormalities in extraocular muscle, 8 cases (9 eyes) with retrobulbar tumor and 15 cases (17eyes) with orbital apex and orbital lamina bony involvement. (4) The three main routes for orbital involvement in NPC patients were as follows: (a) through cavernous sinus (the skull base) to superior orbital fissure. (b) through paranasal sinus (particularly the ethmoid sinus). (c) through pterygopalatine fossa to inferior orbital fissure. CONCLUSION: MR imaging is very useful to demonstrate the presence, location and extent of orbital involvement in NPC patients.

Adult↗

PubMed2004

[Orbital complications of acute sinusitis].

OBJECTIVES: We investigated orbital complications of acute sinusitis. PATIENTS AND METHODS: We retrospectively evaluated 25 patients (13 males, 12 females; mean age 21 years; range 2-56 years) treated for orbital complications of acute sinusitis. The symptoms, physical findings, and prognosis of the patients were investigated. Cases were evaluated according to age, sex, etiologic factors, localization, treatment, morbidity, and mortality. RESULTS: There were periorbital cellulitis in 20 patients (80%), orbital cellulitis in 2 patients (8%), and subperiosteal abscess in 3 patients (12%). In 5 of 9 cases who were above 16 years of age, a history of surgery and trauma were present. All the patients received high-dose intravenous antibiotic therapy. Three cases with subperiosteal abscess and 2 cases with orbital cellulitis underwent endoscopic surgery. Orbital complications recurred in two patients. There was no mortality or blindness after the treatment of orbital complications of acute sinusitis. Diplopia persisted only in two cases. CONCLUSION: Orbital complications in adult patients are often related with trauma. The patients with orbital complications should be treated with aggressive parenteral antibiotics. Surgical treatment is indicated when subperiosteal orbital abscess, orbital cellulitis, and orbital abscess are seen.

Abscess↗

PubMed1994

Trigeminal sensory loss in orbital disease.

A study was undertaken to estimate the incidence of periorbital trigeminal sensory loss with different types of orbital disease and to determine whether the area of loss is related to the location or nature of the underlying condition. A retrospective review was carried out of the clinical case notes of patients identified from the orbital diagnostic database held at Moorfields Eye Hospital. A total of 103 patients (51 male, 52 female), aged between 11 and 84 years (median 51 years), had signs of periorbital trigeminal sensory loss at the time of investigation for orbital disease and in 14/103 (13%) this sensory loss was symptomatic. Sensory loss was due to trauma in eight cases (8%), benign orbital disease in 54 (52%), and malignant disease in 41 cases (40%). The relative frequency of recorded sensory changes is about 9% for malignant tumours, 5% for benign tumours, 4% after orbital trauma, 3% for orbital inflammatory disease, and less than 1% for orbital structural anomalies. Relative corneal hypoaesthesia occurred in 40/103 (39%) cases. Periorbital sensory loss was recorded in about 3% of patients with orbital disease and, in contrast with commonly held views, malignancy was not the most common cause of sensory loss. The affected dermatome is a useful guide to the location of orbital disease, but a poor indication of underlying pathology. Relative corneal hypoaesthesia appears unrelated to the type of disease or to its location within the orbit.

Adolescent↗

PubMed2002

Postenucleation orbits in retinoblastoma: treatment with 125I brachytherapy.

PURPOSE: Children with retinoblastoma that extends into or through the choroid, sclera, or optic nerve are at risk of developing orbital disease, as well as metastases. Previously, these enucleated orbits were treated with external beam radiotherapy in addition to chemotherapy. 125I brachytherapy for tumors in and around the eye was pioneered by Sealy in Cape Town, South Africa, in 1974. In 1983, he developed a technique to irradiate the contents of the orbit while limiting the dose to the bony orbit and eyelids. METHODS AND MATERIALS: Six nylon tubes containing 125I seeds were implanted through the eyelids around the periphery of the orbit. Each contained a metal gutter that screens the outer part of the seeds from the bony orbit. A seventh unscreened tube was placed in the center, and a metal disc with 125I seeds on its posterior surface was secured beneath the eyelids. Between 1983 and 2000, 57 orbits were treated in 56 children with retinoblastoma. Thirty-six were treated prophylactically and 21, with tumor at the resection line of the nerve, extrascleral tumor, or metastases, were treated therapeutically. They received a median dose of 34 Gy in 70 h; 30 also received chemotherapy. Children with tumor at the resection line of the nerve also received treatment to the craniospinal axis. RESULTS: The median follow-up of the 35 patients treated prophylactically was 35 months (range 0-187). Seven patients died, 6 of metastases, at a median of 10 months (range 4-29) after the implant. Eight of the 13 patients with microscopic extraocular tumor survived a median of 29 months (range 5-156). None of the 8 patients presenting with orbital tumor or metastases survived. No orbital recurrences developed in any of the patients. Cosmesis was considerably improved compared with previous forms of irradiation. CONCLUSION: Orbital brachytherapy is an effective method of irradiating the orbit to prevent recurrent tumor, the treatment time is short, and the cosmesis is much more acceptable than with other forms of irradiation. No facial atrophy or second nonocular tumors have occurred.

Antineoplastic Agents↗

PubMed2002

Orbital symmetry as a tool for understanding the bonding in Krossing's cation.

The geometric and electronic structure of Krossing's cation, Ag(eta(2)-P(4))(2)(+), which shows an unexpected planar coordination environment at the metal center and D(2)(h) symmetry both in solution and in the solid state, have been investigated using density functional theory and orbital-symmetry-based energy decomposition. The analysis reveals that the contribution from electrostatic interactions to the bond energy is greater than that of orbital interactions. Partitioning of the latter term into the irreducible representations shows that, in addition to the 5s orbital, 5p orbitals of silver act as acceptor orbitals for electron donation from sigma(P-P) orbitals (a(1)(g), b(1)(u)) and n(P) orbitals (b(3)(u)). Back-donation from the 4d(10) closed shell of Ag into sigma orbitals of the pnictogen cages (b(2)(g)) is also important. However, this contribution is shown not to determine the D(2)(h) structure, contradicting conclusions from the pioneering study of the title cation (J. Am. Chem.Soc. 2001, 123, 4603). The contributions from the irreducible representations to the stabilizing orbital interactions in the D(2)(h) structure and in its D(2)(d)-symmetric conformer are analogous, indicating that the planar coordination environment at the metal center in Ag(eta(2)-P(4))(2)(+) is induced by intermolecular rather than by intramolecular interactions. Because ethylene coordination to a metal ion is an elementary reaction step in industrial processes, the bonding in Ag(C(2)H(4))(2)(+) has been analyzed as well and compared to that in Krossing's cation. Surprisingly, similar contributions to the bond energies and an involvement of metal 4d and 5p orbitals have been found, whereas a recent atoms in molecules analysis suggested that the metal-ligand interactions in silver(I) olefin complexes fundamentally differ from those in tetrahedro P(4) complexes. The only qualitative difference between the bonding patterns in Ag(eta(2)-P(4))(2)(+) and Ag(C(2)H(4))(2)(+) is the negligible energy contribution from the b(3)(u) irreducible representation in the ethylene complex because a respective symmetry-adapted linear combination of ligand orbitals is not available.

Journal Article↗

PubMed2000

Orbital fractures due to domestic violence: an epidemiologic study.

Domestic violence is an important cause of orbital fractures in women. Physicians who treat patients with orbital fractures may not suspect this mechanism of injury. The purpose of this study was to assess the association between domestic violence and orbital fractures. A medical center-based case-control study with matching on age and site of admission was done. Medical center databases were searched using ICD-9 codes to identify all cases of orbital fractures encountered during a three-year period. Medical records of female patients age 13 and older were reviewed along with those of age, gender and site of admission matched controls. A stratified exact test was employed to test the association between domestic violence and orbital fracture. Among 41 adult female cases with orbital fractures treated at our medical center, three (7.3%) reported domestic violence compared to zero among the matched controls (p = 0.037). We believe that domestic violence may be under-reported in both orbital fracture cases and controls. This may result in an underestimate of the orbital fracture versus domestic violence association. Domestic violence is a serious women's health and societal problem. Domestic violence may have a variety of presentations, including illnesses and injuries. Orbital fracture is an identifiable manifestation of domestic violence. Domestic violence is more likely to be detected in adult female hospital patients with orbital fracture than in matched controls with any other diagnosis. Physicians who treat patients with orbital fractures should be familiar with this mechanism of injury.

Journal Article↗

PubMed2005

Effect of tomographic orbit and type of rotation on apparent myocardial activity.

OBJECTIVES: In myocardial perfusion imaging, the type of orbit that provides the best image quality is still the subject of debate. This study correlates the effects of angular rotation (180 degrees vs. 360 degrees), type of orbit (circular vs. body contouring) and location of the heart within the orbit, with changes in spatial resolution and consequential changes in the uniformity of short axis slices of a normal myocardial phantom. METHODS: All studies were performed on a dual-head gamma camera equipped with low energy all-purpose collimators. A myocardium was suspended in air with no scattering or attenuating material present. SPECT acquisitions were performed using circular and body-contouring orbits of various radii and with the myocardium at the maximum off-axis position. RESULTS: The average uniformity of myocardial short axis slices was approximately 4% for 360 degrees circular orbits and for 180 degrees circular orbits where the myocardium was close to the centre of rotation. With body-contouring orbits, the average uniformity increased to 8% and 18% when the myocardium was located on the long and short axes of rotation, respectively. Changes in system resolution with a rotation of >3 mm increased non-uniformities in the myocardial images. CONCLUSIONS: Changes in resolution associated with the angular rotation, type of orbit and myocardial location affect the apparent distribution of activity in short axis slices of the heart. The most uniform images were obtained with a 360 degrees circular orbit. Results with a 180 degrees circular orbit and both 360 degrees and 180 degrees body-contouring orbits were highly dependent on the location of the myocardium.

Heart↗