Biomedical subjects

R B O'Grady

Publications and source records attributed to R B O'Grady.

At least 19 recordsLinked to original sources

PubMed2001

Mucolipidosis IV in an African American patient with new findings on electron microscopy.

PURPOSE: We report an unusual case of mucolipidosis IV in a patient of African ancestry, with intracytoplasmic inclusions of the corneal endothelium found on electron microscopy. METHOD: Clinical description with light and electron microscopy. RESULTS: We describe a case of mucolipidosis IV diagnosed in a patient of African ancestry after penetrating keratoplasty. Electron microscopic evaluation revealed intracytoplasmic inclusions in both the corneal epithelium and endothelium. CONCLUSION: The diagnosis of mucolipidosis in a patient of African ancestry is unusual, as this genetic disorder is found predominantly in individuals of Jewish descent. Corneal endothelial involvement in mucolipidosis IV has not previously been reported.

Adolescent↗

PubMed2000

Dimension-based visual attention modulates dual-judgment accuracy in Duncan's (1984) one- versus two-object report paradigm.

Four experiments, adapting the object-judgment paradigm developed by J. Duncan (1984), examined the relationship between object-based and domain-based mechanisms of visual attention. The experiments demonstrated a cross-domain cost, in terms of accuracy, when observers made dual color-form judgments to one or two overlapping objects presented briefly, relative to within-domain, dual-color and dual-form judgments. This domain-based selection effect was additive to an object-based effect, a cost of making dual judgments to separate objects, as reported by J. Duncan (1984). The pattern of object- and domain-based effects points to a capacity limitation in how multidimensional features are bound into a coherent object representation, consistent with the dimension-weighting account of H. J. Miller, D. Heller, and J. Ziegler (1995), which postulates that there is a limit to the total selection weight available to be allocated to an object's dimensions.

Adolescent↗

PubMed2000

Object-based selection operates on a grouped array of locations.

In two experiments, space- and object-based selection effects were investigated, using variants of the ring-cuing paradigm of Egly and Homa (1984). The results revealed significant cuing modulation for nonring configurations of target locations spanning a range of retinal eccentricities, with the cuing effects independent of eccentricity and confined to the configuration of locations (rather than extending to locations within the space enclosed by the cued configuration). These results are consistent with object-based selection operating on a grouped spatial array (Vecera & Farah, 1994). Object selection may be based on a supradimensional saliency map representation of the field, modulated by feature-specific segmentation mechanisms (e.g., an object may be made salient on the basis of its color). Complex objects may be represented by grouped saliency signals. In this way, a two-dimensional spatial (saliency) representation may provide the common format for object-based selection, prior to full object definition.

Adult↗

PubMed1998

Intrastromal clefts in keratoconus patients with hydrops.

PURPOSE: To report the clinical appearance and course of intrastromal clefts occurring with acute hydrops in keratoconus. METHODS: In eight patients with bilateral keratoconus, nine eyes developed acute corneal hydrops complicated by intrastromal cleft formation. One patient developed this complication in both eyes. The patients, three female and five male, had a mean age of 20 years (range, 11 to 36 years) and were followed after onset of acute hydrops for a median of 8 months (range, 2.5 to 21 months). The patients in this retrospective study were identified and had been treated at one of two institutional cornea referral practices. RESULTS: In eight of nine eyes with intrastromal clefts, complete cleft closure occurred between 6 weeks and 6 months. In one eye, cleft closure was nearly complete in a patient followed up for only 4.5 months after onset of hydrops. Corneal stromal neovascularization developed in six of the nine of eyes. At the last follow-up visit, four of the six untreated eyes had a best-corrected visual acuity of 20/200 or worse. The patient with intrastromal clefts in both eyes did not develop stromal neovascularization and achieved a contact lens corrected visual acuity of 20/40 or better in each eye without surgical intervention. CONCLUSIONS: Intrastromal cleft formation is a manifestation of corneal hydrops in keratoconus. Single or multiple clefts can occur, and bilateral involvement is possible. Clefts generally close over a period of months, but stromal neovascularization is common and may compromise future graft survival.

Acute Disease↗

PubMed1995

Cat model for intraocular pressure reduction after transscleral Nd:YAG cyclophotocoagulation.

Transscleral neodymium:yttrium-aluminum-garnet (Nd:YAG) laser cyclophotocoagulation (TSNYC) is used to lower intraocular pressure (IOP) in glaucoma patients refractory to conventional medical and surgical therapy. Our study investigates the ability of TSNYC to lower IOP in normal cats. One eye of 13 cats was treated with non-contact TSNYC. Mean pretreatment IOP was 25 mm Hg (vs. 25.3 mm Hg in contralateral control eyes). Eyes received 80 laser applications over 360 degrees delivered at least 3 mm posterior to the limbus with maximum power (8 to 9 joules) and maximum retrofocus (3.6 mm). Eyes were retreated if IOP was not reduced below baseline after 2 weeks. By 4 weeks, IOP was decreased in all treated eyes by a mean of 29.2% and was maintained as long as 20 weeks (mean decrease 14.8%). IOP in 10 eyes was lowered after a single treatment session. Of these, 2 eyes had IOP spikes > 10 mm Hg prior to IOP reduction. Three cats required retreatment to maintain IOP reduction. All eyes developed transient (< 4 weeks) postoperative uveitis and 3 eyes developed rubeosis iridis which resolved with topical corticosteroids. Histologic examination (6 weeks post-treatment) showed focal disruption of the pigment epithelium and to a lesser degree the nonpigmented epithelium at the base of the ciliary body and in the valleys of the pars ciliaris. The epithelium at the apices of the ciliary processes appeared intact. Vascular engorgement was variably present. This study demonstrates that TSNYC lowers IOP in cats. This animal model will be useful for investigating mechanism(s) responsible for TSNYC-induced IOP reduction.

Animals↗

PubMed1993

Subepithelial mucinous corneal dystrophy. Clinical and pathological correlations.

We describe a family with an unusual autosomal dominant anterior corneal dystrophy. The onset was characterized by frequent, recurrent corneal erosions in the first decade. This subsided during adolescence and was followed by progressive decreased vision. Slit-lamp examination revealed bilateral subepithelial opacities and haze, involving the entire cornea, but most dense centrally. Histopathological study revealed a subepithelial band of eosinophilic, periodic acid-Schiff-positive, alcian blue-positive, hyaluronidase-sensitive material anterior to Bowman's layer. Electron microscopy demonstrated subepithelial deposition of fine fibrillar material consistent with glycosaminoglycan. Immunohistochemical analysis indicated that the accumulated material contained a combination of chondroitin 4-sulfate and dermatan sulfate. This unique condition clinically resembled Grayson-Wilbrandt dystrophy, but differed histochemically. To our knowledge, this anterior corneal dystrophy has not previously been reported, and it is best described by the name "subepithelial mucinous corneal dystrophy."

Aged↗

PubMed1992

Atypical magnetic resonance findings in an orbitofrontal cholesterol granuloma.

Cholesterol granuloma of the orbit is an uncommon entity, although it frequently occurs in the middle ear and petrous apex. It is isodense with brain on computed tomographic scanning and cannot always be differentiated from more serious conditions. Magnetic resonance imaging (MRI) has facilitated the preoperative diagnosis of cholesterol granuloma outside of the orbit because of high signal characteristics on T1- and T2-weighted images. These findings have been considered nearly pathognomonic, but they have previously been described in only one patient with orbitofrontal involvement. We present a case of orbitofrontal cholesterol granuloma with uncharacteristic signal intensities on magnetic resonance imaging.

Adult↗

PubMed1991

Scleritis and Wegener's granulomatosis in children.

We treated two children with scleritis (one unilateral, one bilateral), in whom Wegener's granulomatosis was diagnosed on the basis of pathologic changes in respiratory tract mucosa. Both patients were girls, 13 and 14 years of age, respectively. One patient had otitis media and a nodular scleritis. Laboratory test results demonstrated an increased erythrocyte sedimentation rate and microscopic hematuria. A biopsy of the sinus confirmed the diagnosis of Wegener's granulomatosis. The second patient had fever, arthralgias, a nonproductive cough, and bilateral scleritis. Laboratory test results demonstrated an increased erythrocyte sedimentation rate, positive test results for rheumatoid factor, and bilateral pulmonary nodules on chest x-ray. Open-lung biopsy confirmed the diagnosis of Wegener's granulomatosis. Both patients responded well to treatment with a combination of prednisone and cyclophosphamide.

Adolescent↗

PubMed1991

Lattice corneal dystrophy type IIIA. Clinical and histopathologic correlations.

All three types of lattice corneal dystrophy are inherited and localized, and they largely involve linear corneal amyloid deposits. We encountered two white families with lattice corneal dystrophy which closely resembled type III. Four generations of one family and three of another family exhibited lattice corneal dystrophy. Because both families are from Caccamo, Sicily, Italy, we believe it is likely that both are from a single mutation. Thick, ropy lattice lines were seen to traverse the corneas almost from limbus to limbus and were easily detected with direct illumination. Histopathologic examination revealed accumulations of varying sized amyloid deposits in the stroma and ribbons of amyloid between the stroma and Bowman's layer typical of lattice corneal dystrophy type III. We have named the disease in this family lattice corneal dystrophy type IIIA, because of three differences from lattice corneal dystrophy type III: the presence of corneal erosions, the occurrence in whites, and the autosomal dominant inheritance pattern.

Aged↗

PubMed1991

Hemangiopericytoma of the lacrimal sac.

Hemangiopericytomas of the orbit are rare tumors with low malignancy potential. To the authors' knowledge, only three previous cases of these tumors occurring in the lacrimal sac have been reported. The authors report a fourth case. Follow-up was obtained on the first reported case, and the patient in that case had a recurrence after 15 years. These tumors should be totally excised and followed for long periods of time.

Adult↗

PubMed1989

Reis-Bücklers' corneal dystrophy. Immunofluorescent and electron microscopic studies.

The anterior stroma, epithelium, and Bowman's layer have been proposed as the site of primary pathology in Reis-Bücklers' corneal dystrophy (RBCD). Immunofluorescent localization of laminin and bullous pemphigoid antigen (BPA) was compared with the ultrastructure of RBCD. As previously reported, patchy deposition of characteristic "peculiar curly" filaments was found in the supra-Bowman's, subepithelial fibrous tissue. We also recognized areas of early involvement with deposition of this "peculiar curly" material between a distorted epithelial basal lamina and a normal undisturbed Bowman's layer. In normal cornea, laminin and BPA localized to the epithelial basal lamina. In RBCD, laminin and BPA were in a piebald mosaic distribution throughout the aberrant subepithelial fibrous tissue between the basal lamina and the buried Bowman's layer. This indicates that RBCD is an epithelial disease, with the "peculiar curly" material paralleling the distribution of the attachment proteins.

Aged↗

PubMed1985

Lipid keratopathy in rabbits. An animal model system.

Rabbits rendered hypercholesterolemic on a high cholesterol diet while subjected to corneal suture placement to induce neovascularization made useful models for qualitatively and quantitatively studying lipid keratopathy. Forty rabbit eyes were subjected to placement of four sutures located between 1 and 4 mm from the limbus. The neovasculature grew at a constant rate of 0.24 mm/day, unaffected by serum cholesterol levels. Rabbits fed cholesterol prior to surgery were the earliest to display lipid keratopathy, followed by those who began cholesterol feedings on the day of surgery, and last by rabbits who began receiving high cholesterol food seven days following suture placement. A description of the corneal neovascularization process and histopathological and biochemical analyses of the induced lipid keratopathy are presented.

Animals↗

PubMed1984

Ophthalmologic findings in acquired immune deficiency syndrome (AIDS).

Forty-one homosexually active men had ophthalmologic and immunologic evaluations. Four of eight with acquired immune deficiency syndrome (AIDS) had abnormal ocular findings that included cotton-wool spots, retinal hemorrhages, cytomegalovirus, retinitis and conjunctivitis due to cytomegalovirus, and keratoconjunctivitis sicca. The other four patients with AIDS and 33 homosexual male controls had normal ocular examinations. Patients with AIDS and abnormal eye findings had a notably lower total leukocyte count, absolute lymphocyte count, percentage T-helper lymphocytes, helper-suppressor lymphocyte ratio, hematocrit level, and platelet count than patients with AIDS and normal results on eye examination or controls. All patients with AIDS and abnormal eye examination results died; the four other patients with AIDS and normal eye findings remain alive. These observations suggest that ophthalmologic abnormalities are common in patients with AIDS, are associated with severe immunoregulatory abnormalities, and carry a poor prognosis.

Acquired Immunodeficiency Syndrome↗

PubMed1984

Mucinous adenocarcinoma of the eyelid. A case report.

A 52-year-old man had a rapidly growing cystic-appearing lesion on his lower eyelid. Excisional biopsy disclosed a mucinous sweat gland adenocarcinoma and the mucinous material (presumably sialomucin) accounted for the transillumination property of the tumor. These carcinomas should be considered in the differential diagnosis of cystic eyelid lesions.

Adenocarcinoma, Mucinous↗

PubMed1981

Conjunctival inflammation and amyloidosis in allergic granulomatosis and angiitis (Churg-Strauss syndrome).

A 37-year-old woman developed nodular, waxy conjunctival lesions associated with the exacerbation of Churg-Strauss syndrome. Conjunctival and skin biopsy specimens demonstrated a diffuse inflammatory process composed of eosinophils, plasma cells, lymphocytes, and focal collections of histiocytes. There were amyloid deposits in the conjunctiva and skin. To our knowledge, this is the first report of conjunctival changes and amyloidosis associated with the Churg-Strauss syndrome.

Adult↗

PubMed1981

Pilomatrixoma (benign calcifying epithelioma of Malherbe).

A 24-year-old white man had a large subcutaneous discolored tumefaction of the right lower lid, successfully treated by two separate incision and drainage procedures. Microscopic appearance initially suggested basal cell epithelioma, but further studies provided a correct diagnosis of pilomatrixoma (calcifying epithelioma of Malherbe). This lesion probably represents aberrant primitive germ cells differentiating towards a hair matrix cell. Basaloid and squamoid (shadow) cells with or without focal calcifications in shadow cell areas are typical, and the clinical presentation is also highly suggestive of pilomatrixoma.

Adult↗

PubMed1979

Bone formation in association with a limbal dermoid.

A healthy female infant was born with a unilateral limbal dermoid. When the lesion was surgically excised, a plaque of bone was found under the scleral portion of the lesion. The occurrence of bone in ocular dermoinds is extremely uncommon and, to our knowledge, has been reported only twice in dermoids that occur in epibulbar locations away from the limbus.

Dermoid Cyst↗

PubMed1977

Intravitreal amphotericin B treatment of Candida endophthamitis.

A 43-year-old heroin addict with Candida albicans endophthalmitis was treated with a single 5-mug intravitreal injection of amphotericin B. The diagnosis was confirmed by smears and cultures of a vitrous aspiration. The patient's accidental death seven weeks after treatment enabled us to obtain histopathologic evidence that the infection had been cured and that the amphotericin B had had no toxic effect on the retina. Intravitral amphotericin B should be considered an important mode of treatment of Candida endophthalmitis.

Adult↗