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Biomedical subjects

R L Dallow

Publications and source records attributed to R L Dallow.

At least 19 recordsLinked to original sources
PubMed1986

Computed tomography of lymphoproliferative disease of the orbit. Report of 50 patients.

Orbital lymphoproliferative disease is one of the most common causes of exophthalmos and palpable masses in the anterior part of the orbit. Axial and coronal computed tomography (CT) is the method of choice for localizing the lesion and determining the extent of involvement. The CT features are non-specific but are highly suggestive in the proper clinical setting. The most important CT findings consist of: round, oval or elongated lobular masses, commonly in the extraconal space, with intraconal extension in large tumors. In some lesions, linear infiltrates radiate from the bulk of the mass into the adjacent fascial compartments. Tumors in proximity to the globe, wrap around the scleral-uveal coat causing no indentation but displacement of the globe from the mass effect. Similar molding occurs along the orbital walls, especially laterally from extraconal lesions. Bone destruction or remodeling of bone is rarely seen in orbital lymphoma. No diagnostic enhancement patterns were observed following contrast infusion. The majority of lymphoid tumors were situated anteriorly and superiorly.

Adult↗
PubMed1984

Lymphocyte surface markers in orbital lymphoid neoplasms.

Since the malignant nature of many orbital lymphoid infiltrates is difficult to assess from pathologic examination alone, over the past four years lymphocyte surface marker studies have been added to the evaluation of 23 such cases. Only 10 of the 23 could be confidently classified as malignant lymphoma by histology alone. However, monoclonal surface immunoglobulin was found in 15, supporting the pathologic diagnosis of malignancy in eight and adding seven that could not have been diagnosed otherwise. Clinical evaluation, including a median follow-up of 18 months, revealed manifestations of systemic lymphoma in six of those 15; two had been diagnosed only by surface markers. In contrast, only one of eight cases lacking monoclonal surface immunoglobulin exhibited clinical evidence of malignancy (that case was also indeterminate by histologic criteria). The addition of surface marker analysis permits more accurate diagnosis of orbital lymphoma than is possible from pathologic study alone. This technique can suggest the subtype of lymphoma.

Adult↗
PubMed1981

Conjunctival cysts of the orbit following enucleation.

Four patients developed orbital conjunctival cysts following enucleation. The cysts were demonstrated by ultrasonography and computerized tomography and confirmed by histopathology. They were lined by a non-keratinizing stratified squamous epithelium without goblet cells and contained fluid with mucinous strands. They were excised at eight, seven, and seven, and 25 years post-enucleation, respectively, the latter being the longest interval yet recorded. A simple classification of conjunctival cysts of the orbit is proposed and the mechanisms of the development of cysts in anophthalmic sockets are discussed. The effects of secretory rate and cyst growth are reviewed and surgical management in prevention and treatment of these lesions is outlined.

Adult↗
PubMed1980

CT and ultrasound in the diagnosis of cavernous hemangioma and lymphangioma of the orbit.

Eighteen cases of cavernous hemangioma and seven cases of lymphangioma of the orbit were evaluated with regard to contrast enhancement, hemogeneity, type of margin, anatomic location, and associated changes in he bone. Hemangiomas usually demonstrated homogeneous contrast enhancement, a relatively smooth margin, intraconal location, with occasional extension to the orbital apex, and focal bone expansion. Lymphangiomas showed either minimal heterogeneous or absence of contrast enhancement, irregular margins, and anterior and posterior locations. Ultrasonography of hemangiomas showed high amplitude and closely packed echoes from vessel walls adjacent to blood-filled spaces. Lymphangiomas had a similar ultrasound pattern, but with very wide separation of echoes due to larger fluid lakes.

Adolescent↗
PubMed1979

Immersion ultrasonography: simultaneous A-scan and B-scan.

In eyes with opaque media, ophthalmic ultrasound provides a unique source of information that can dramatically affect the course of patient management. In addition, when an ocular abnormality can be visualized, ultrasonography provides information that supplements and complements other diagnostic testing. It provides documentation and differentiation of abnormal states, such as vitreous hemorrhage and intraocular tumor, as well as differentiation of orbital tumors from inflammatory causes of exophthalmos. Additional capabilities of ultrasound are biometric determinations for calculation of intraocular lens implant powers and drug-effectiveness studies. Maximal information is derived from ultrasonography when A-scan and B-scan techniques are employed simultaneously. Flexibility of electronics, variable-frequency transducers, and the use of several different manual scanning patterns aid in detection and interpretation of results. The immersion system of ultrasonography provides these features optimally.

Carcinoma↗
PubMed1979

Computed tomography of masses in the lacrimal gland region.

Twenty patients with mass lesions in the lacrimal gland region were evaluated with computed tomography (CT). The extent of the mass and its relationship to the globe, optic nerve, and extraocular muscles were clearly seen. The CT appearance on plain scan and the presence or absence of contrast enhancement, bone involvement, and cystic components often suggested the specific pathological diagnosis. Although orbital ultrasonography and CT were frequently complementary, ultrasonography was more definitive in inflammatory diseases, while CT demonstrated better extraorbital extension.

Adenocarcinoma↗
PubMed1978

Reliability of orbital diagnostic tests: ultrasonography, computerized tomography, and radiography.

A series of 342 patients with unilateral exophthalmos underwent orbital diagnostic studies including ultrasonography, computerized tomography, radiographic studies, and vascular contrast studies. Each test was found to have diagnostic capabilities that complemented other studies depending upon the specific disease process involved. No one test was entirely adequate without supplementary information from the other tests. Radiographic studies demonstrated bony abnormality in 50% of the tumor cases, but in only 28% of the entire series of exophthalmos cases. Computerized tomography demonstrated diagnostic soft tissue abnormality in 86% of tumors, 43% of inflammatory diseases, and an overall yield of 62% positive results. Ultrasonography proved the most versatile test for evaluation of orbital soft tissues, with 80% positive results for tumors, 87% for inflammatory disorders, and 78% overall accurate orbital diagnosis. Erroneous tumor diagnosis of 7% with computerized tomography and 3% with ultrasonography were corrected by combining these two studies, because they tend to err in opposite directions. Combination of ultrasound and CT scan resulted in a 98% correct diagnosis of all types of orbital diseases.

Bone Diseases↗
PubMed1978

Bilateral dural arteriovenous malformations simulating dysthyroid ophthalmopathy.

The clinical recognition of dural arteriovenous malformations (AVM) is a challenge to the ophthalmologist. Unilateral dural AVMs produce monocular signs which may simulate orbit disease. A patient with bilateral dural AVMs presenting with bilateral congestive exophthalmos resembling dysthyroid ophthalmopathy is reported. Spontaneous resolution of the ocular manifestations occurred.

Aged↗
PubMed1976

Unilateral endocrine exophthalmos. Diagnostic problems in association with computed tomography.

Swollen orbital extraocular muscles may mimic an orbital apex tumor on computed tomography. In five of our patients, in spite of highly suggestive findings on CT scanning, indicating the presence of an orbital apex lesion, the correct diagnosis proved to be endocrine exophthalmos. The value of complementary CT projections and of orbital ultrasonography to assist in the differential diagnosis is discussed, and the additional contribution of orbital phlebography for the confirmation of lesions in the orbital apex is emphasized.

Adult↗
PubMed1975

Evaluation of unilateral exophthalmos with ultrasonography: analysis of 258 consecutive cases.

Ultrasound examination has emerged as a valuable technique for defining soft tissue abnormalities of the eye and orbit. As high frequency sound waves (5 to 20 megahertz) are projected through soft tissues, echoes are produced at tissue interfaces. These echoes are displayed on oscilloscopes as either one-dimensional amplitude spikes (A-mode ultrasonography), or as dots integrated into a two-dimensional image representing a thin section through the entire orbit (B-scan ultrasonography). A-mode indicates tissue substance, while B-scan illustrates tissue morphology. With this technique, orbital tumors are clearly distinguished in terms of their location, size, and configuration, as well as the basic tissue type (cystic, solid, angiomatous or infiltrative). Other orbital processes are defined by ultrasonography also, including inflammatory conditions such as diffuse pseudotumor or cellulitis, congestive conditions such as dysthyroid exophthalmos, and orbital hemorrhage. Intracranial and vascular etiologies of exophthalmos have no specific ultrasound signs. In a series of 258 consecutive patients with unilateral exophthalmos examined with ultrasonography, diagnosis of tumor was made in 26 percent (66 cases). Overall accuracy of orbital tumor diagnosis by ultrasonography was 94 percent in this series. Tumor localization, configuration, and extent indicated by the test aided in selecting surgical approaches. Other patients in the series were diagnosed ultrasonically as a variety of other entities, mostly inflammatory and dysthyroid exophthalmos. Normal ultrasound studies were found in 19 percent. None of these patients had subsequent diagnosis of tumor. Diagnostic ultrasonography is capable of detecting orbital tumors and distinguishing them from inflammatory, congestive, and other causes of exophthalmos with a high degree of reliability. The test is painless, well tolerated, non-invasive, and non-toxic. It now has a prominent role in evaluation of any patient with exophthalmos.

Abscess↗