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Results for “Ciliary Body”

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At least 127 records · Page 7Linked to original sources

PubMed1994

Dipivefrin reduces blood flow in the ciliary body in humans.

PURPOSE: Adrenergic substances are used widely for lowering intraocular pressure in the treatment of glaucoma. The hypothetic mechanisms for lowering the intraocular pressure by adrenergic drugs are decreased blood flow in the ciliary body and direct receptor-related reduction of aqueous humor production. The aim of this study is to measure noninvasively the blood flow in the anterior uvea in humans after topically administered dipivefrin. METHOD: The blood flow of iris and ciliary body was measured by laser Doppler flowmetry. Laser Doppler flowmetry blood flow and results of the electrocardiogram were simultaneously measured and stored over a period of 3 minutes. In the authors' setup, laser light was projected by a fiber optic transcorneally onto the iris or 2 mm transscerally from the limbus into the ciliary body. For improvement of the signal-to-noise ratio, a statistical averaging procedure was performed by averaging 100 sweeps of 2 seconds of the digitalized laser Doppler flowmetry signals triggered by the R-onset of the electrocardiogram (averaging laser Doppler flowmetry). Using this method, reproducible pulse curves of blood flow of iris and ciliary body were established with systolic maxima and diastolic minima. In a double-blind study design involving 33 young, healthy persons (mean age, 25 +/- 7 years), the effect of topically administered dipivefrin, naphazoline, and NaCl solution (0.9%) on the blood flow of iris and ciliary body was examined. RESULTS: Dipivefrin reduces significantly (average, 49%) the mean blood flow in the ciliary body. Naphazoline and NaCl solution do not change the blood flow in the ciliary body. Dipivefrin, naphazoline, and 0.9% NaCl show no significant effect on the iridal blood flow. CONCLUSION: The observed data suggest that dipivefrin decreases ciliary body blood flow.

Administration, Topical↗

PubMed2001

Ocular pANCA antigens are expressed in nonpigmented ciliary body epithelium and are conserved in multiple mammalian species.

PURPOSE: pANCA marker autoantibody is expressed by a subset of patients with anterior uveitis. A recombinantly isolated pANCA monoclonal antibody, Fab 5-3, identifies ocular expression of corresponding pANCA antigens in human ciliary body and retina. In this study, Fab 5-3 was used to explore pANCA antigen expression in ocular tissues of multiple mammalian species and identify the ciliary body cell type expressing the pANCA antigen. METHODS: Ocular tissues were obtained from several mammalian species and evaluated for expression of the pANCA (Fab 5-3) antigen(s) using immunohistochemistry and Western analysis of tissue extracts. Additionally, primary cultures of nonpigmented and pigmented rabbit ciliary body epithelium were analyzed for pANCA expression using immunofluorescence and Western analysis. RESULTS: Ocular pANCA (Fab 5-3) antigen expression was observed by immunohistochemistry only in the cytoplasm of retinal ganglion cells and ciliary body epithelium. Retinal antigen expression was conserved in all species examined. Ciliary body expression was observed in human, rabbit, rat, and mouse, but not in pig or cow. Antigen expression in the rabbit ciliary body was restricted to the nonpigmented layer as defined in primary cultures of nonpigmented and pigmented ciliary body epithelium. Immunoreactive proteins in both the human and rabbit included a 32-33 kDa doublet (histone H1), and novel 80 and 100 kDa proteins. CONCLUSIONS: This study identifies ocular pANCA antigen expression in multiple mammalian species localized to the retinal ganglion cell layer and the non-pigmented ciliary body epithelium. The present study also establishes novel 80 and 100 kDa proteins which may correspond to the cytoplasmic antigens detected in situ and can be further characterized biochemically and immunologically using small animal model systems.

Animals↗

PubMed1993

Ascorbic acid regeneration by bovine iris-ciliary body.

Ocular tissues appear to require high levels of ascorbic acid and the elucidation of the mechanisms by which those tissues maintain the vitamin in its reduced state remains an important objective. The regeneration of ascorbate from its oxidative by-product, dehydroascorbic acid (DHAA), was studied in bovine iris-ciliary body. Iris-ciliary body was removed by scalpel, weighed, minced, and homogenized in 20 mM MOPS, 62 mM sucrose, and 0.1 mM EDTA at pH 7.0. The homogenate was centrifuged and precipitated with ammonium sulfate such that maximal DHAA reducing activity was enhanced in a 50-75% ammonium sulfate fraction. This fraction was employed for subsequent characterization of DHAA reduction by iris-ciliary body. Results indicate that the iris-ciliary body enzymatically reduces DHAA to ascorbate at a rate significantly greater than can be accounted for by a nonenzymatic glutathione-dependent mechanism. In addition, saturation kinetics are observed, and the enzymatic activity is dependent on protein concentration, DHAA concentration, and reduced glutathione (GSH) concentration. The activity is sensitive to pH, to high temperature, and to digestion by trypsin and is greatest in the presence of both GSH and NADPH. The reducing activity is therefore attributed to one or more proteins that are distinct from the known ascorbate regenerating enzyme, GSH-dependent DHAA reductase (EC 1.8.5.1).

Animals↗

PubMed1989

[Mesectodermal leiomyoma of the ciliary body--clinical aspects, surgery and immunohistochemistry].

The clinical, surgical and light microscopical features of a mesectodermal leiomyoma of the ciliary body are presented. Slit-lamp examination of a 63-year old woman strongly suggested a malignant lesion of the ciliary body and the peripheral choroid. Following cryoretinopexy and argonlaser-photocoagulation, the tumor and the adjacent portion of the cornea, angle structures, iris, ciliary body, choroid and sclera were removed en bloc. The defect was covered by a corneosclerotransplant 14 mm in diameter. Histological examination revealed a well circumscribed tumor of the ciliary body, consisting of sheets of fusiform cells. Intracytoplasmatic filaments gave a positive reaction to an actin antibody (Actin HHF 35 MA 931), demonstrating the smooth muscle origin of the ciliary body tumor by immunocytochemical means.

Biomarkers, Tumor↗

PubMedDate not supplied

Ciliary body adenoma after application of mitomycin.

PURPOSE: To describe a ciliary body tumor that was detected in a rabbit eye. METHODS: For a specific experiment, the rabbit underwent trabeculectomy with mitomycin. The eye was evaluated by electron microscopy 5 weeks following surgery. RESULTS: A ciliary body tumor was discovered in close relation to pigmented epithelial cells. The tumor cells were large with a small amount of pigment and contained prominent vesicles. CONCLUSIONS: The development of a ciliary body adenoma may be caused by the application of mitomycin. Whether the demonstrated tumor was benign or malignant could not be determined. While it could not be proven that the tumor developed related to the use of mitomycin, this possibility may be important for surgeons using this substance.

Adenoma↗

PubMed1981

Ciliary body reattachment in ocular hypotony.

Ocular hypotony associated with detachment of the ciliary body without evident cyclodialysis has been corrected by reattachment of the ciliary body to the sclera. This was achieved by suturing the ciliary body to sclera under microscopic control. It would seem that prolonged hypotony of this type can be cured by this method.

Adult↗

PubMed1999

[Observation of physiological change in the human ciliary body using an ultrasound biomicroscope during accommodation].

PURPOSE: To evaluate changes in the ciliary body during accommodation using an ultrasound biomicroscope (UBM). SUBJECTS AND METHODS: Eleven healthy persons, aged from 24 to 33 years, served as subjects. They were asked to lie in the supine position and to fixate a target placed on the ceiling 2 m above with the left eye. A concave lens with the power of -6 to -8 diopters was then placed before the fixating left eye. The thickness of the ciliary body in the right eye was measured by UBM in the nonaccommodative and accommodative states. FINDINGS: The anterior chamber in the right eye became significantly shallow during accommodation. The thickness of the ciliary body significantly increased during accommodation at 0.5 mm and 1.0 mm posterior to the scleral spur. It significantly decreased at 2.0 mm, 2.5 mm and 3.0 mm posterior to the scleral spur. CONCLUSION: During induced accommodation in the left eye, the anterior portion of the ciliary body in the right eye increased and the posterior portion decreased in thickness. The findings imply that the circular ciliary muscles are mainly involved in accommodation and not the longitudinal muscles.

Accommodation, Ocular↗

PubMed2004

[Ciliary body melanomas. Survival and prognostic aspects after brachytherapy or proton therapy].

INTRODUCTION: Our main goals were to study the survival of patients with uveal melanomas involving the ciliary body 5 and 10 years after treatment and to review prognosis. MATERIAL AND METHODS: This study investigated 106 tumors (27 ciliary body melanomas and 79 choroidal-ciliary melanomas) of patients treated between June 1983 and April 1998. Seventy-two patients were treated with 106-ruthenium applicators and 34 were treated with proton therapy. Some large tumors or recurrences required a second treatment. The mean follow-up period was 91 months. RESULTS: The mean tumor sizes before treatment were 6,6mm for melanoma thickness and 10.3mm for mean largest basal melanoma diameters (LTD). Of the patients studied, 71% were still alive at 5 years, 35% had metastasis and 27.7% developed recurrences. Multivariate analysis showed that the risk factors for melanoma-related death were LTD greater than 13mm, presence of exudative retinal detachment, macroscopic iris root involvement at the time of diagnosis, and choroidal-ciliary location. DISCUSSION AND CONCLUSION: With 71% of patients still alive at 5 years, this review shows that melanomas involving the ciliary body do not seem less severe than more posterior uveal tumors. Because of size differences between ciliary body melanomas and choroidal-ciliary melanomas, we cannot come to the conclusion that choroidal-ciliary melanomas have a poorer prognosis than ciliary body melanomas. Largest tumor diameter over 13mm, presence of exudative retinal detachment, and macroscopic iris root involvement at the time of diagnosis are important risk factors for melanoma-related death, as shown by the multivariate analysis.

Adolescent↗

PubMed1996

Hemangioma of the ciliary body: a case report and review of the literature.

This paper documents a case of ciliary body hemangioma discovered in the eye of a 72-year-old white man during routine ocular examination. The correct differential diagnosis was not made clinically despite the use of A and B scan ultrasonography and also a fluorescein-angiographic study. This rare tumor was removed by a sector cyclectomy after apparent growth, onset of anterior uveitis and demonstration of fluorescein dye leakage. Histopathologic examination revealed that the tumor consisted of capillaries and large vascular loculi containing numerous erythrocytes. The histopathologic diagnosis was a mixed capillary-cavernous hemangioma of the ciliary body. The results suggest that when a ciliary body tumor is suspected to be malignant, an attempt can be made to excise it. This report encourages the conservative surgical treatment of the ciliary body tumor avoiding the sacrifice of the entire ocular globe.

Aged↗

PubMed1992

[Effects of atropine on acetylcholine levels in the rat iris-ciliary body].

In an attempt to estimate the in vivo acetylcholine level in rat iris-ciliary body, animals were sacrificed by microwave irradiation which rapidly inactivates metabolic enzymes. Acetylcholine levels in the iris-ciliary body were determined by high-performance liquid chromatography with electrochemical detection. The acetylcholine level in rat iris-ciliary body per gram tissue protein was 58.8 +/- 5.0 nmol/g (mean +/- SEM, n = 9). A single instillation of 5 microliters of an 0.05% atropine to one eye of a rat decreased acetylcholine level in the iris-ciliary body by 17% half an hour after administration (p less than 0.02).

Acetylcholine↗

PubMed1992

[Effects of alpha 2-agonist apraclonidine on norepinephrine levels in the rat iris-ciliary body].

In an attempt to estimate the in vivo catecholamine level in rat iris-ciliary body, animals were sacrificed by microwave irradiation which rapidly inactivates metabolic enzymes. Catecholamine levels in the iris-ciliary body were determined by high-performance liquid chromatography with electrochemical detection. The norepinephrine level in rat iris-ciliary body per gram tissue protein was 3.56 +/- 0.22 micrograms/g (21.1 +/- 1.3 nmol/g)(mean +/- SEM, n = 7). Neither dopamine nor epinephrine were detected. A single instillation of 5 microliters of an 0.05% apraclonidine (alpha 2-agonist) to one eye of a rat increased the norepinephrine level in the iris-ciliary body by 7.7% one hour after administration (p less than 0.05).

Adrenergic alpha-Agonists↗

PubMed1991

Medulloepithelioma of the ciliary body.

Neuroepithelial tumors of the ciliary body occur more seldom than retinoblastoma. The congenital form is called medulloepithelioma, the adult-acquired adenoma or adenocarcinoma. Medulloepitheliomas consist of organoid epithelial structures developing anteriorly along surfaces such as the iris. The authors report on a congenital type unusually growing not only anteriorly along the lens, but also posteriorly along the retina's surface causing retinal detachment.

Child↗

PubMed2000

Melanocytoma (magnocellular nevus) of the ciliary body: report of 10 cases and review of the literature.

PURPOSE: To describe the characteristics of melanocytoma (magnocellular nevus) of the ciliary body, an unusual melanocytic tumor. DESIGN: Retrospective, clinicopathologic case series. METHODS: Ten melanocytomas of the ciliary body were examined histopathologically. Five tumors were also examined by transmission electron microscopy. The clinical histories were abstracted from the patients' medical records. We compared the clinical, histopathologic, and ultrastructural findings of our 10 cases with those previously reported in the literature. MAIN OUTCOME MEASURES: To define clinical and histopathologic parameters of this rare tumor. RESULTS: A total of 40 cases were summarized, including our 10 and 30 previously reported cases. The mean age of the 40 cases was 47 years. Twenty-six patients were female (65%), fourteen were male (35%). No laterality was observed. Eighty percent of the patients were white and 10% were black. The most common clinical presentation was an asymptomatic dark spot involving the iris and ciliary body or the sclera. Involvement of chamber angle structures, with or without intrascleral extension, was observed in 85% (34 of 40 patients); but only 12% (2 of the 17 patients for whom information about intraocular pressure and local extension was available) had elevated preoperative intraocular pressure. By electron microscopy, two distinct cell types were observed. CONCLUSIONS: Melanocytomas can usually be distinguished from other pigmented lesions of the ciliary body by histopathologic criteria, but may be difficult to differentiate before surgery from other pigmented ciliary body tumors, including malignant melanomas, adenomas, and adenocarcinomas of the pigmented ciliary epithelium. Most tumors can be managed conservatively by iridocyclectomy.

Adult↗

PubMed1996

Ultrasound biomicroscopic study of ciliary body thickness after topical application of pharmacologic agents.

PURPOSE: To examine the changes in ciliary body thickness after topical application of pilocarpine, cyclopentolate hydrochloride, and PhXA41, a prostaglandin F2alpha analog. METHOD: We used high-frequency Humphrey UBM840 ultrasound biomicroscope to examine 36 healthy young Japanese subjects. RESULTS: The mean ciliary body thickness increased from 0.67 +/- 0.07 mm to 0.073 +/- 0.08 mm (P < .01) after application of 2% pilocarpine; 1% cyclopentolate hydrochloride and 0.005% PhXA41 decreased the mean ciliary body thickness from 0.75 +/- 0.07 mm to 0.69 +/- 0.05 mm (P < .05) and from 0.78 +/- 0.06 mm to 0.75 +/- 0.06 mm (P < .01), respectively. CONCLUSIONS: Our ultrasound study clearly indicates that pilocarpine increased comparative thickness of the ciliary body by 8.3%, whereas PhXA41 decreased comparative thickness by 3.3% in a manner similar to cyclopentolate hydrochloride.

Administration, Topical↗

PubMed2000

Ciliary body PDT in pigmented rabbit eyes: effect of single and repeated treatment.

PURPOSE: To investigate the morphologic and hypotensive effect of contact transscleral ciliary body PDT in pigmented rabbit eyes. METHODS: The right eyes of 33 pigmented rabbits were irradiated using chloraluminum sulfonated phthalocyanine as photosensitizer and a diode laser (670 nm) as the light source. Twenty-five animals received a single treatment. Eight animals received a second treatment 13 days after the first one. Photosensitizer was administered by means of continuous intravenous infusion. Ciliary body was irradiated transsclerally by means of an optic fiber applied on the corneoscleral limbus. In all cases 14-16 laser applications were performed to cover 360 degrees of the ciliary body. Animals were followed for a maximum of 30 days by means of tonometry and biomicroscopy. Retreatments were performed using the same irradiation protocol. At the end of the follow up time animals were sacrificed and their were eyes prepared for light and electron microscopy. RESULTS: Transscleral ciliary body PDT resulted in significant but temporary reduction of IOP in all cases. The effect lasted about two weeks. Retreatment led to a new significant drop of the IOP, which lasted about two weeks again. In histological examination the initial effect was vascular thrombosis, followed by edema and disintegration of the ciliary epithelial layers. In all cases the appearance of the ciliary body had returned to normal 15 days after irradiation. CONCLUSION: Contact transscleral PDT with the treatment parameters used in this study results in significant but temporary functional and morphological alteration in pigmented rabbits ciliary body.

Aluminum↗

PubMed1991

Bicarbonate transport mechanisms in rabbit ciliary body epithelium.

Sections of whole ciliary body dissected from Dutch belted rabbits were incubated with the cell entrappable pH probe BCECEF-AM. This led to a highly specific localization of epifluorescence emission at the exposed, non-pigmented cell layer (npe) of the dual layered epithelium that covers this organ. The BCECF-loaded tissue sections were superfused in a flow-through chamber and the intracellular pH (pHi) of small groups (10-20) of cells was derived from the ratio of the emission intensities derived from excitations at 490 and 440 nm. In CO2/HCO3- Ringer's, npe pHi = 7.09 +/- 0.11. Replacement of CO2/HCO3- by Hepes increased pHi by 0.22 +/- 0.02, indicating alkali secretory activity under the bicarbonate-rich conditions. Replacement of Cl- by gluconate elicited a rapid, 0.6-U increase in pHi. This effect exhibited little dependence on Na+ and was inhibited by 0.5 mM dihydro-4,4'-diisothiocyanatostilbene -2,2'-disulfonate (H2DIDS). These results indicate the presence of an electroneutral Cl-/base exchange activity. Elevation of [K-] (by partial replacement of Na+) also elicited increases in pHi. In Cl(-)-free media pHi reached 7.8-8.0, a condition under which intracellular [HCO3-] is at least twice as high as its extracellular value. This effect did not occur in the absence of Na+. The Na(+)-dependent high [K+]-induced pHi increase was inhibited by H2DIDS. The effects of Ba2+ on pHi, alone and in combination with high [K+], as well as that of full K+ removal, suggested that the link between high [K+] and pHi increase was mainly due to the effect of cell depolarization on an electronegative Na+ dependent HCO3- transporter. Under normal physiological conditions, the two acid/base transport systems are the main determinants of npe pHi.

Animals↗

PubMed2002

Medulloepithelioma of the ciliary body.

A rare case of medulloepithelioma of the ciliary body is described. The tumour necessitated enucleation of the eye; histopathological diagnosis was benign nonteratoid medulloepithelioma of the ciliary body.

Child↗

PubMed1998

[Cytotoxic effect of mitomycin C on the nonpigmented epithelium of ciliary body in rabbit eyes].

OBJECTIVE: To observe pathomorphological changes of nonpigmented epithelial cells (NECs) of ciliary body after local single application of mitomycin C (MMC) during sclerectomy in rabbit eyes, and to explore cytotoxic effect of MMC on ciliary body. METHODS: A single five minutes intraoperative exposure to the agent MMC (0.2 mg/ml, 0.1 ml) was used during sclerectomy in rabbit eyes. The treated area was rinsed with 20 ml normal saline. The NECs of ciliary body at the operated area were observed under light microscope and transmission electron microscope on the 7th and 28th day postoperatively. RESULTS: On the 7th day postoperatively, the NECs were swollen, and the intracellular abundant mitochondria were swollen and vacuolized. String pearls-like membrane-encapsulated vacuoles were present in the intervals of beta-cell membrane of the NECs. On the 28th day postoperatively, these damages were gradually recovered. CONCLUSIONS: These findings suggest a toxic effect of MMC on the NECs of ciliary body, possibly that can decrease the aqueous production and intraocular pressure, even causing persistent hypotony.

Animals↗