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Biomedical subjects

R C Eagle

Publications and source records attributed to R C Eagle.

At least 217 records · Page 12Linked to original sources
PubMed1987

Acute band keratopathy following intracameral Viscoat.

Band keratopathy developed rapidly in two patients following uneventful phacoemulsification and intraocular lens implantation using BSS Plus (balanced salt solution enriched with glutathione, bicarbonate, and glucose) infusion and Viscoat (chondroitin sulfate-sodium hyaluronate), which was left in the anterior chamber at the conclusion of the procedure. Histopathologic evaluation of corneal tissue obtained from one patient at the time of edetic acid chelation revealed histochemical findings consistent with anterior stromal calcification. To investigate a possible relationship between Viscoat and the rapid onset of band keratopathy, Viscoat formulated with varying concentrations of phosphate buffer was injected intracamerally into 42 rabbit eyes. Within 48 hours, clinically obvious corneal opacification developed in nine (47%) of 19 eyes injected with the commercial preparation of Viscoat. Also, similar opacification developed in ten (77%) of 13 eyes that received Viscoat formulated with twice the phosphate concentration of the commercial preparation. Band keratopathy did not develop any of ten eyes that received Viscoat with one fourth the commercial phosphate concentration. In selected opacified corneas, the presence of phosphorus in the subepithelial and posterior corneal stroma was confirmed by histochemical stains and energy-dispersive x-ray analysis.

Aged↗
PubMed1987

Orbital metastasis from a carcinoid tumor. Computed tomography, magnetic resonance imaging, and electron microscopic findings.

An otherwise asymptomatic 63-year-old woman with a history of a carcinoid tumor of the ileum and a cutaneous melanoma of the shoulder developed unilateral proptosis. Orbital ultrasonography, computed tomography, and magnetic resonance imaging revealed a large, well-circumscribed orbital mass involving the superior rectus muscle. The surgically excised tumor was studied by light microscopy, histochemistry, and transmission electron microscopy. These studies confirmed the diagnosis of carcinoid tumor. The clinical and pathologic features of this rare type of orbital metastasis are discussed.

Carcinoid Tumor↗
PubMed1987

The effect of pre-enucleation radiotherapy on mitotic activity of choroidal and ciliary body melanomas.

The authors studied the mitotic activity of 21 choroidal and ciliary body melanomas treated by external beam radiotherapy (2000 rad in 5 fractions over 5-7 days) before enucleation and 21 case-by-case matched nonirradiated uveal melanomas. The Wilcoxon signed ranks test and McNemar's fourfold table test were used to compare the mitotic activity of the irradiated and nonirradiated tumors. The results of these analyses suggest that pre-enucleation external beam radiotherapy substantially reduces the mitotic activity of posterior uveal melanomas (P less than 0.005). This information supports current efforts to mount a successful randomized clinical trial of pre-enucleation radiotherapy in high-risk patients with choroidal and ciliary body melanomas.

Choroid Neoplasms↗
PubMed1987

Iridocorneal endothelial syndrome with contralateral guttate endothelial dystrophy. A light and electron microscopic study.

Both eyes from a 75-year-old woman who had unilateral closed-angle glaucoma, characteristic endothelial specular microscopic findings, and slowly progressive tractional iris abnormalities consistent with essential iris atrophy were obtained postmortem and studied by light, scanning, and transmission electron microscopy. Clinically, the nonglaucomatous right eye had an open-angle, normal iris, and severe endothelial dystrophy with three-plus corneal guttae. In this eye, results of histopathologic examination disclosed marked endothelial degeneration and typical guttate excrescences on Descemet's membrane. In contrast, the endothelium in the fellow eye with the essential iris atrophy variant of the iridocorneal endothelial (ICE) syndrome was strikingly different. The endothelial cells were relatively well preserved and exhibited marked pleomorphism, anisocytosis, and flat, occasionally paired oval nuclei. Binucleate cells also were observed. The endothelial monolayer had secreted a new layer of fibrillar extracellular matrix material on the posterior surface of Descemet's membrane. Extracellular matrix material was found interposed between the iris and cornea in zones of synechial closure, and an endothelial membrane was present on the anterior surface of the iris. These observations support the hypothesis that the iris abnormalities in essential iris atrophy are secondary to endothelial proliferation. The endothelial cells displayed neither tonofilaments nor abundant apical microvilli. The latter observation suggests that increased numbers of endothelial microvilli are not responsible for the characteristic specular microscopic picture seen in the ICE syndrome.

Aged↗
PubMed1986

Cataracts in patients heterozygous for galactokinase deficiency.

The role of heterozygous galactokinase deficiency in the development of presenile cataracts is presently undetermined. Erythrocyte galactokinase activity was measured from 95 normal Caucasian subjects and from 39 Caucasian patients who had developed idiopathic bilateral cataracts between ages 20 and 55. The diagnosis of heterozygous galactokinase deficiency was based on the following criteria: galactokinase activity more than 2.0 SD below the control population mean; when available, familial evidence for heterozygous galactokinase activity was used as additional evidence. Three of 39 patients (1/13) with cataracts were found to be carriers of the galactokinase deficiency allele (P less than 0.001). Two heterozygotes had high dietary galactose intake suggesting a possible relationship between a high galactose diet and cataract formation. Dietary information was unavailable for the third heterozygote. We conclude that there is a high prevalence of heterozygous galactokinase deficiency existing in patients less than 55 yr of age with cataracts, and recommend that adults at risk restrict their consumption of dairy products.

Adolescent↗
PubMed1984

Pathology of human cystoid macular edema.

The light and electron microscopic findings are reviewed in two patients who had eyes enucleated for peripheral choroidal malignant melanomas. Preoperatively, cystoid macular edema was documented by fluorescein angiography in the melanoma-containing eye in both patients. Intracytoplasmic swelling (edema) of the Müller (glial) cells is the anatomical basis for the macular edema. Intercellular (extracellular) collections of fluid probably are late, endstage results of the process that result form prolonged, excessive, intracellular edema, cell death and disruption. The process probably rests on an ischemic basis, as evidenced by severe changes in the microvasculature. In the one patient in whom the optic nerve was available for study, marked intracellular swelling (edema) of glial cells in the lamina choroidalis of the optic nerve head was present, associated with compression of the adjacent axons. The nearby temporal, parapapillary retina also showed edema of Müller cells, and compression of the nerve fibers (ganglion cell axons), suggesting a more widespread process than was clinically evident. Again, severe changes were present in the microvasculature, both in the optic nerve and parapapillary retina. The underlying cause of the microvasculature changes that lead to ischemia, perhaps an intrinsic pharmacologic agent, is yet to be found.

Choroid Neoplasms↗
PubMed1984

Immunohistochemical and ultrastructural studies on the exenterated orbital tissues of a patient with Graves' disease.

The exenterated orbital contents obtained post mortem from a 47-year-old man who had an eight-month history of treated hyperthyroidism and a two-month history of visual complaints were examined histopathologically, immunohistochemically, and by electron microscopy. All of the extraocular muscles were massively enlarged, due to early diffuse endomysial fibrosis, mucopolysaccharide deposition, and a predominantly perivascular lymphocytic and plasmacytic infiltration. Histochemical stains revealed that the intramuscular mucopolysaccharides were weakly sulfated and polycarboxylated, establishing that they were products of fibroblastic activation rather than derived from mast cells. Subsarcolemmal deposits in the myofibers were shown by electron microscopy to be collections of glycogen rosettes with intermixed lipid deposits. These inclusions were interpreted as secondary phenomena due to abnormal muscle energetics from restrictions in contractility, and not as evidence of a primary degeneration of the extraocular muscle fibers themselves. The sarcomeric organization of the striated muscle cells was undisturbed, and therefore the pathologic changes occurred int he interstitial space of the endomysium. A monoclonal antibody specific for neurofilaments (antibody 4.3 F9) revealed, in comparison with normal controls, a preferential loss of large-type axons of the proximal segment of the orbital portion of the optic nerve as well as in the intracanalicular portion. The axonal loss was associated with a mildly increased number of astrocytes as demonstrated by an antibody against glial fibrillary acidic protein. The meninges of the optic nerve, the orbital fat, and the tendons of the extraocular muscles were uninflamed. The foregoing findings are compatible with a compressive optic neuropathy mediated by the massively swollen extraocular muscles impinging upon the optic nerve at the orbital apex.

Aminosalicylic Acid↗
PubMed1984

Electron microscopic study of corneal epithelial-endothelial interactions in organ culture.

The interactions between rabbit corneal epithelium and endothelium were investigated in an organ culture model using scanning electron microscopy and correlative light microscopy. Following mechanical removal of corneal endothelium, corneal epithelium was observed to migrate across the cut surface of the corneal stroma and onto the denuded Descemet's membrane after 48 hours in organ culture. By 72 hours, a distinct line of contact between the migrated epithelium and endothelium was established. Following epithelial-endothelial contact, no cellular migration occurred. Corneal endothelial inhibition of epithelial migration may be a major factor in the prevention of surface epithelial invasion and proliferation following surgery and trauma.

Animals↗
PubMed1984

Mechanisms of maculopathy.

This article will review the cellular constituents of the macula and speculate on their contribution to the pathogenesis of macular disease. The retinal pigment epithelium (RPE) has been implicated in senile macular degeneration (SMD). Over time, RPE dysfunction and death may result from the cumulative effect of light and free radical damage. Inherited metabolic abnormalities or the degree of uveal pigmentation could increase the RPE's susceptibility to environmental stress. In exudative SMD, the excessive production of extracellular matrix material by the RPE may contribute to sub-RPE neovascularization and disciform scar formation. Macular edema reflects a breakdown in the blood-retinal barrier. Inflammatory mediators produced in the anterior segment may cause aphakic cystoid macular edema (CME). Recent observations suggest that Müller cell dysfunction is important in CME. Vascular incompetence, as well as capillary occlusion characterize diabetic retinopathy. Angiogenic factors elaborated by ischemic retina are thought to be the stimulus for neovascularization. Diabetic tractional macular detachment results from neovascular proliferation on the partially detached vitreous. Posterior vitreous detachment predisposes to epiretinal gliosis. Endogenous infections and metastatic neoplasms have a predilection for the macula, reflecting the region's high blood flow.

Atrophy↗
PubMed1984

Conjunctival synthetic fiber granuloma. A lesion that resembles conjunctivitis nodosa.

Histopathologic examination of forniceal conjunctival lesions excised from five young patients revealed granulomatous inflammation surrounding filamentous foreign material. Polarization microscopy, special histochemical stains, scanning electron microscopy and energy dispersive x-ray elemental analysis identified the inciting material as predominantly synthetic fabric fiber. Three of these cases initially were diagnosed as conjunctivitis nodosa, an inflammatory reaction to caterpillar setae. Many synthetic fibers contained numerous granules of titanium, barium, or zinc delustering agent, which served to differentiate them from natural fibers or caterpillar hairs. Synthetic fabric fiber is a previously unrecognized cause of conjunctival inflammatory mass lesions.

Adolescent↗