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At least 217 records · Page 12Linked to original sources
PubMedDate not supplied

Ultrastructural study of the conjunctiva in patients with keratoconjunctivitis sicca not associated with systemic disorders.

PURPOSE: The aim of this work was to evaluate ultrastructural alterations of the conjunctiva during the clinical course of keratoconjunctivitis sicca (KCS), and to detect its earliest and most characteristic morphological changes. METHODS: The conjunctiva was studied in biopsies from 75 patients and 10 controls. Patients were classified according to the results of the Schirmer I test, break-up time, rose Bengal staining, osmolarity and impression cytology. RESULTS: The conjunctiva in these KCS patients showed progressive hyperplasia, hypertrophy and cellular flattening, with diminution of goblet cell density and microvilli. In the severe cases, the epithelial cells lost their organelles, and fibrous material increased. From the early phases of KCS, clear nuclear alterations (indentation, binucleation) were found, but pyknotic nuclei or anucleated cells were only observed in the most severe cases. From the earliest stages to the most severe cases of KCS, decreases in cell membrane interdigitations were observed parallel to increases in the number and size of desmosomes. There were also increases in the number of inflammatory cells. Alterations in blood vessels were only observed in the most severe cases. CONCLUSIONS: Morphological studies alone were able even in the earliest phases of KCS, to detect the squamous metaplasia that progresses from the surface of the epithelium to the connective tissue. This degenerative or adaptative cellular process was characterized mainly by marked proliferation of the cytoskeleton and a general loss of organelles, mitochondria being the least affected.

Biopsy↗
PubMed2005

Fibrous connective tissue between Müller's muscle and the palpebral conjunctiva as a reinforcement structure and a natural barrier for the upper eyelid.

This study was performed to illustrate and discuss the significance of fibrous connective tissue between the Müller's muscle and the palpebral conjunctiva. Nine upper eyelids of 6 Oriental cadavers were microscopically examined; ages at death ranged from 72 to 91 years. Tissue of the posterior lamella of the upper eyelid was removed without the orbital septum and orbital fat. Removed eyelids were incised perpendicularly at the center of the eyelid. After pretreatment, sliced sections were stained with Hematoxylin and Eosin and examined microscopically. A thick fibrous connective tissue was found to exist between the Müller's muscle and the palpebral conjunctiva. The connective tissue continued proximally to the intermuscular transverse ligament and was distally attached to the posterior site of the upper aspect of the tarsus. All cases showed infiltration of lymphocytes from the conjunctiva; however, these were completely blocked by the fibrous connective tissue and never reached Müller's muscle. This connective tissue supports eyelid traction and is a natural barrier for the Muller's muscle against conjunctivitis.

Aged↗
PubMed1987

Cyclo-oxygenase and lipoxygenase pathways in cynomolgus and rhesus monkey conjunctiva, anterior uvea and eyelids.

The capacity of cynomolgus and rhesus monkey conjunctiva, anterior uvea and eyelids to synthesize cyclo-oxygenase and lipoxygenase products from arachidonic acid was assessed. Both conjunctiva and eyelid tissues of cynomolgus and rhesus monkeys synthesized detectable amounts of cyclo-oxygenase and lipoxygenase products, indicating the presence of cyclo-oxygenase and 5- and 12-lipoxygenase activities in these tissues. In comparison, cynomolgus anterior uvea synthesized a considerably lesser amount of cyclo-oxygenase products. The cyclo-oxygenase activity was considerably greater than the lipoxygenase activity in cynomolgus and rhesus conjunctiva and eyelids.

Animals↗
PubMed1994

Mucosa specific lymphocytes in the human conjunctiva, corneoscleral limbus and lacrimal gland.

Conjunctiva associated lymphoid tissue shows several similarities to mucosa associated lymphoid tissue of the gut and respiratory tract. These similarities have been described in relation to lymphocyte subpopulations and epithelial cell morphology. However, unlike the lymphoid tissue of the gut and respiratory tract, mucosa specific lymphocytes have not been described in the ocular mucosa. In this study we demonstrated the presence of mucosa specific lymphocytes bearing the Human Mucosal Lymphocyte-1 antigen (beta 7 integrin), in the human conjunctiva, limbus and lacrimal gland. The distribution of this subset of lymphocytes corresponded to the distribution of CD8+ T-cells and was found maximally in the epithelium of the epibulbar conjunctiva and in the lacrimal gland. The Human mucosal lymphocyte antigen may function to determine mucosal homing of this particular subset of CD8+ T-cells, which in turn, may have special function in immunological defense and tolerance mechanisms occurring at mucosal surfaces.

Adolescent↗
PubMedDate not supplied

Tied and tidy: closing the conjunctiva over adjustable sutures.

BACKGROUND: Adjustable sutures have revolutionized strabismus surgery. Numerous techniques have been described that aim to facilitate postoperative adjustment. Nevertheless, some sort of procedure is always necessary following adjustable suture surgery and has to be arranged within 24 hours. Where no adjustment is required, the muscle needs to be secured at the existing position and the conjunctiva, sometimes left on a loop, has to be tidied up and sutured. METHODS: As fewer than half of the operated on eyes need a final adjustment, we describe a technique whereupon the muscle is left on a loop and the conjunctiva is closed over it with two interrupted polyglactin 910 sutures. If an adjustment is deemed necessary, one of the sutures has to be cut and replaced at the end of the procedure. When the result of squint surgery is satisfactory and no muscle movement is needed, no further manipulation of the conjunctiva is required. CONCLUSIONS: In a series of 17 patients, we have found this technique to be excellent for patient comfort and time efficiency. We have not encountered any muscle slippage. We think that the ease of postoperative management may tend to bias the surgeon against adjustment.

Adolescent↗
PubMed2000

In vivo behavior of peptide-specific T cells during mucosal tolerance induction: antigen introduced through the mucosa of the conjunctiva elicits prolonged antigen-specific T cell priming followed by anergy.

The mucosa of the conjunctiva is an important site of entry for environmental Ags as well as Ags emanating from the eye itself. However, very little is known about T cell recognition of Ag introduced through this important mucosal site. We have characterized the in vivo process of CD4 T cell recognition of Ag delivered via the conjunctival mucosa. Application of soluble OVA to the conjunctiva of BALB/c mice induced potent T cell tolerance. APC-presenting OVA peptide in vivo was only found in the submandibular lymph node and not in other lymph nodes, spleen, or nasal-associated lymphoid tissue. Similarly, in TCR transgenic DO11. 10 adoptive transfer mice, OVA-specific CD4+ T cell clonal expansion was only observed in the submandibular lymph node following conjunctival application of peptide. These experiments thus define a highly specific lymphatic drainage pathway from the conjunctiva. OVA-specific T cell clonal expansion peaked at day 3 following initiation of daily OVA administration and gradually declined during the 10-day treatment period, but remained elevated compared with nontreated adoptive transfer mice. During this period, the T cells expressed activation markers, and proliferated and secreted IL-2 in vitro in response to OVA stimulation. In contrast, these cells were unable to clonally expand in vivo, or proliferate in vitro following a subsequent OVA/CFA immunization. These results suggest that Ag applied to a mucosal site can be efficiently presented in a local draining lymph node, resulting in initial T cell priming and clonal expansion, followed by T cell anergy.

Administration, Topical↗
PubMed1999

[Goblet cells density of bulbar conjunctiva after long-term topical antiglaucoma agents].

AIM: The purpose of this study was to determine the effect of long-term topical antiglaucoma therapy on goblet cells density of the bulbar conjunctiva. MATERIAL AND METHODS: Conjunctiva impression cytology specimens from 59 glaucoma patients and 30 healthy people were assessed quantitatively by light microscopy. Patients with glaucoma were on a stable regimen of one (beta-blocker alone) or two (beta-blocker with miotic) topically administered medications for a minimum 1-year. RESULTS: The results show statistically significant decrease in goblet cells associated with number of antiglaucoma drugs and duration of treatment. CONCLUSIONS: Long-term topical antiglaucoma treatment decrease goblet cells population of bulbar conjunctiva.

Adrenergic beta-Antagonists↗
PubMed1999

[Effect of vitamin A palmitate on the synthesis of mucins in cultured conjunctiva].

PURPOSE: To evaluate the effect of vitamin A palmitate on the synthesis of mucins from goblet cells in cultured rabbit conjunctiva. METHODS: Palpebral conjunctiva was obtained from 12 white rabbits and was cultured in serum-free RCGM 2 which was developed for culture of rabbit corneal epithelial cells. This method eliminated retinol in the serum. High-performance liquid chromatography was used in quantitating N-acetylneuraminic acid contained in the sugar chain as an indicator of mucin content. RESULTS: Addition of vitamin A palmitate to the cultured medium resulted in significant increase in the amount of N-acetylneuraminic acid in the medium. CONCLUSIONS: The increase in N-acetylneuraminic acid in the cultured medium suggests that the increase of goblet cells in cultured conjunctiva is related to the synthesis of mucins due to vitamin A. RCGM 2 as a culture medium promises to be useful in evaluating the pharmacological activity of vitamin A. High-performance liquid chromatography facilitated quantitation of mucins in the culture medium.

Animals↗
PubMed1999

Nucleotide stimulation of Cl(-) secretion in the pigmented rabbit conjunctiva.

We evaluated the role of extracellular UTP and other nucleotides in the regulation of active ion transport across the pigmented rabbit conjunctiva. When added to the mucosal side of the conjunctiva, UTP (0.01-1000 microM), increased the short-circuit current by up to 14. 6 +/- 2.1 microA/cm(2). The half-maximal concentration was 11.4 +/- 2.3 microM. The serosal absence of Cl(-), serosal presence of 10 microM bumetanide, and mucosal presence of 0.3 mM N-phenylanthranilic acid significantly reduced the change in the short-circuit current (DeltaIsc) induced by 10 microM UTP by 78, 77, and 42%, respectively. Mucosal 10 microM UTP significantly increased (36)Cl flux in the serosal-to-mucosal direction by 0.17 microEq/cm(2)/h, while not affecting mucosal-to-serosal (36)Cl flux. By contrast, (22)Na transport in either direction was unaffected. The rank order of DeltaIsc elicited by adenosine and nucleotides was consistent with the predominant involvement of P2Y purinergic receptors in the UTP effect on conjunctival ion transport. Moreover, the DeltaIsc elicited by UTP was inhibited by 0.05 and 1 mM suramin (a P2-purinergic receptor antagonist), resulting in a rightward shift of the half-maximal concentration to 106.7 +/- 1.3 microM. In conclusion, the primary effect of UTP on ion transport in the pigmented rabbit conjunctiva is stimulation of Cl(-) secretion, possibly at the P2Y(2) and/or the P2Y(4) receptor on the mucosal side of the tissue. Because of the coupling of fluid flow with Cl(-) secretion, UTP or its analogs may be considered for stimulating transconjunctival fluid flow in the dry-eye state.

Adenosine↗
PubMed2000

Membrane-associated mucins in normal human conjunctiva.

PURPOSE: To examine the presence of specific membrane-associated mucins in normal human conjunctiva. METHODS: Glycoconjugates were extracted from membranes with two detergents: octylglucoside and Triton X114. Mucins were separated by cesium chloride density gradient centrifugation. Size was assessed by gel filtration on Sepharose CL2B and charge by ion-exchange chromatography on MonoQ. Cross reaction with antibodies against mucin gene products was assessed in blots of electrophoresis gels. RESULTS: Extraction of total tissue membranes yielded material with a buoyant density typical of mucins. Gel filtration showed material reacting with antimucin antibodies in a range of molecular sizes. Agarose electrophoresis confirmed the presence of MUC1 and MUC4 and the absence of MUC2 or MUC5AC. Isolation of membrane mucins by sequential, exhaustive extraction with octylglucoside followed by Triton X114 suggested the existence of mucins in different membrane environments. Reagents to carbohydrate epitopes revealed high mobility material, comigrating with MUC1 and MUC4. Low mobility membrane-bound mucins did not cross-react with any antibodies to mucin genes known to be expressed in human conjunctiva. CONCLUSIONS: Membrane-associated mucins are distinct from secreted mucins in normal human conjunctiva. MUC1 and MUC4 mature products decorate the membranes of conjunctival epithelial cells. Their segregation between octyl glucoside and the detergent and aqueous phases of Triton X114 suggests a variety of membrane anchoring modes.

Cell Membrane↗
PubMed1999

[The evaluation of morphological status of bulbar conjunctiva after long-term antiglaucoma drug therapy].

UNLABELLED: The aim of this study was to examine the histopathologic picture of bulbar conjunctiva in glaucoma patients receiving topical antiglaucoma treatment. MATERIAL AND METHODS: Generally healthy patients with primary open angle glaucoma (POAG) and primary angle closure glaucoma (PACG) were included in our study. Conjunctiva specimens were obtained from the area of further fistula of 51 patients undergoing trabeculectomies and assessed by routine histopathological staining. RESULTS: Non-specific inflammatory infiltration, thickening of the epithelium, decreased numbers of Goblet cells, proliferation of fibroblasts, collagen deposition and fibrosis were observed in the obtained material. Changes in cellular profile and in the extracellular composition of bulbar conjunctivas in patients receiving long-term topical antiglaucoma treatment were detected.

Adult↗
PubMed2000

Microvascular blood is distributed more to venules than to arterioles in patients with Buerger's disease. Observation of bulbar conjunctiva by intravital microscope system.

BACKGROUND: It has been a matter of controversy whether abnormalities of organs other than extremities may be a clinical manifestation of Buerger's disease (thromboangiitis obliterans; TAO). In the present investigation, our aim was to quantitatively characterise the configuration of microvascular networks in bulbar conjunctiva, which is not affected apparently, in patients with thromboangiitis obliterans. METHODS: Nine men with thromboangiitis obliterans attended our hospital and nine male volunteers as normal controls were enrolled in this study. We observed and analysed the configuration of the network of a bulbar conjunctiva by use of intravital microscope system with computer assisted image processing functions. Microvessel density was defined as a summation of vessel length in a ROI area and tortuosity was evaluated by a ratio of vessel length to direct distance of both terminals. RESULTS: In the microcirculation of bulbar conjunctiva in thromboangiitis obliterans, arteriole diameter was significantly decreased and density of venules was significantly increased. Increased venular density was mainly explained by increased tortuosity of venules. CONCLUSIONS: Consequently, microvascular blood was distributed more to venules than to arterioles in patients with thromboangiitis obliterans. Venule/arteriole ratios of diameter, tortuosity and microvessel density may be useful parameters to characterize the configuration of microvascular networks in thromboangiitis obliterans.

Adult↗
PubMed2001

Elevated expression of transglutaminase 1 and keratinization-related proteins in conjunctiva in severe ocular surface disease.

PURPOSE: In severe ocular surface diseases, pathologic keratinization of the ordinarily nonkeratinized corneal and conjunctival mucosal epithelia results in severe visual loss. The expression in conjunctivalized corneas of various proteins known to play important roles in the physiological keratinization process in human epidermis was examined to better understand the mechanism of keratinization. METHODS: Conjunctiva covering the cornea was examined in 12 eyes with ocular surface disease in the chronic cicatricial phase. These comprised four Stevens-Johnson syndrome, four ocular cicatricial pemphigoid, and four chemical injuries. Normal conjunctivas from four age-matched individuals served as controls. Semiquantitative reverse transcription-polymerase chain reaction (RT-PCR) was used to investigate transglutaminase 1 gene expression and immunohistochemistry to study the expression of transglutaminase 1 protein along with other keratinization-related proteins (involucrin, loricrin, filaggrin, and cytokeratins 1 and 10) and cytokeratin pairs 4/13 and 3/12. RESULTS: Semiquantitative RT-PCR showed that transglutaminase 1 mRNA expression was upregulated in keratinized conjunctiva compared with normal. Also, in this tissue, immunohistochemistry demonstrated elevated levels of transglutaminase 1, involucrin, filaggrin, and the cytokeratin pair 1/10. Levels of loricrin and cytokeratin pairs 4/13 and 3/12, however, remained the same. CONCLUSIONS: Various keratinization-related proteins, transglutaminase 1 included, are most likely involved in the pathogenesis of cicatrizing ocular surface diseases.

Adult↗
PubMedDate not supplied

[Morphopathogenesis of the amniotic membrane after its transplantation in the course of experimental conjunctiva plasty].

The paper contains the results of an experimental study of the clinical healing of the standard wound defect in the bulbar conjunctiva of rabbit after conjunctiva-plasty involving the use of the human amnion transplant; there is also a description of a histological study of reparative processes in the adjacent tissues and a description of morphological changes occurring in the transplant during the healing process. The study was made on 14 rabbits (28 eyes). It was established that the wound-surface healing occurs, beneath the amnion transplant, without a pronounced inflammation, scarring or immunologic-rejection reaction; its sequence is typical of inflammation and compensatory processes with the formation, in the outcome, of the conjunctiva coating of the eyeball, whose color and composition are ordinary.

Amnion↗
PubMed2004

[Structural and immunohistochemical changes of conjunctiva induced by topical glaucoma medication].

PURPOSE: The topical medication represents the first line therapy for the primary open angle glaucoma. The study is aimed at assessing the structural and immunohistochemical changes of conjunctiva induced by topical glaucoma medication. METHODS: For this purpose, we carried out a 40 weeks, prospective, experimental, epidemiological-operational and randomized study enrolling 18 patients (36 eyes) with recently primary open angle glaucoma. The eyes were divided into treatment (non-selective beta blockers or selective, prostaglandin analogues, topical carbonic anhydrase inhibitors) in four groups. The assessment was performed by comparison with control group (4 patients) who was instilled with natural tears (with different preservative). Both the cytology and the conjunctival biopsy specimens were investigated by histological exams and immunohistochemistry using different monoclonal antibodies. The study was performed by collaboration with The National Institute of Research and Development in Pathology and Biomedical Sciences-"V. Babes"-Bucharest. RESULTS: The morphometric analysis of histological sections of conjunctiva showed the following changes: squamous metaplasia (significant increases in the thickness and number of epithelial cell layers), inflammation (increase the number of lymphocytes, macrophages and fibroblasts) and subconjunctival fibrosis. According to the type of medication, we observed the significant increase of subepithelial collagen density and degenerative changes of fibrocytes, the reduction of extracellular matrix and also the up-regulation of antibodies against matrix metalloproteinase and allergic changes. According to structural changes, the immunohistochemistry confirmed the tendency of chronic inflammation. CONCLUSIONS: This study revealed important structural and immunohistochemical changes of conjunctiva after topical glaucoma medication. The category and the intensity of these changes are dependent on the sort of therapy and the topical treatment period. The findings showed that benzalkonium chloride (the most common preservative of antiglaucoma drugs) is a major factor for conjunctival metaplasia.

Administration, Topical↗
PubMedDate not supplied

Squamous cell carcinoma of the eyelid arising from palpebral conjunctiva.

We reported a 58-year-old Japanese man with squamous cell carcinoma (SCC) of the left upper eyelid arising from the palpebral conjunctiva. The tumor had been incised by a former doctor under the diagnosis of chalazion. Histopathological examination of the relapsed tumor revealed atypical squamous cells invading towards the eyelid skin from the epithelium of palpebral conjunctiva. We performed a total resection of the tumor and reconstructed the upper eyelid by the technique of Mustarde's switch flap. During 10 months of follow-up, neither local recurrence nor metastasis has been detected and the reconstructed eyelids showed good course in function and in appearance. SCC of the palpebral conjunctiva is quite rare, however, it often resembles chronic conjunctivitis or chalazion. It is important to consider the possibility of SCC in addition to sebaceous carcinoma when we see a patient with an eyelid lesion, even one which looks like a benign condition such as chronic conjunctivitis or chalazion.

Carcinoma, Squamous Cell↗
PubMed1977

[Morphogenesis and features of the pathogenesis of adenovirus and chlamydial infections of the conjunctiva].

Morphogenesis of adenovirus (epidemic keratoconjunctivitis) and chlamydia (paratrachoma) infections was studied on the material consisting of scrapings of the conjunctiva and biopsy specimens taken from 410 patients, by histological, cytological, histo- and cytochemical electron-microscopic and immunohistochemical methods. The investigations conducted showed that the morphogenesis of adenovirus and chlamydia infection of the conjunctiva was underlaid by a complex of pathological disorders including changes in the epithelium, where the cytopathogenic effect of the pathogene was realized, and changes in the conjunctiva tissue proper, the latter being transformed in these infections into the organ of immunogenesis.

Adenoviridae Infections↗
PubMed1990

Thromboxane A2-mimetics are potent microvascular permeability factors in the conjunctiva.

These studies demonstrate that the thromboxane (Tx) A2 mimetics U-46619, U-44069 and carbocyclic-TxA2 elicit a microvascular permeability response in the conjunctiva. U-46619 and U-44069 are among the most potent microvascular permeability factors described to date for the conjunctiva; their potency is exceeded only by that reported for leukotrienes D4 and E4. The conjunctival microvascular permeability response to U-46619 was inhibited by the TxA2-antagonists daltroban (BM 13505) and SQ 29548. Prostaglandin (PG) D2 also increased conjunctival microvascular permeability, but was less potent than U-46619 and far less susceptible to pretreatment with daltroban or SQ 29548. PGE2, PGF2 alpha and the prostacyclin analog carbocyclin did not increase conjunctival microvascular permeability. It appears that the conjunctiva exhibits a unique microvascular permeability response to TxA2-mimetics: this view is experimentally supported by the absence of a cutaneous microvascular permeability response to U-46619, U-44069 and carbocyclic-TxA2.

15-Hydroxy-11 alpha,9 alpha-(epoxymethano)prosta-5↗