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PubMed1978

Catecholamine-containing and acetylcholinesterase-positive nerve fibres in the rabbit conjunctiva.

The innervation of the rabbit conjunctiva was investigated histochemically. Nerves containing acetylcholinesterase (AChE) were demonstrated using a copper thiocholine technique. Sympathetic nerve fibres were demonstrated using either the formaldehyde-induced fluorescence (FIF) or glyoxylic acid induced fluorescence (GIF) method. In addition, GIF and AChE-reactions were performed consecutively for the demonstration of fluorescent and AChE-positive nerves in the same specimen. The number of AChE-positive nerve fibres exceeded that of fluorescent fibres. Both fibre types were more numerous in the stroma of the limbal and tarsal conjunctiva than in the fornix. In the epithelium, only a few AChE-positive nerves were observed. These are assumed to be sensory. Most nerves seemed to contain both catecholamine-containing and AChE-positive fibres. However, nerves fibres containing only AChE-activity were also found. The blood vessels of the conjunctiva were innervated by both fluorescent and AChE-positive nerves, the distribution and number of which differed slightly.

Acetylcholinesterase↗

PubMed1981

Peroperative protection of cornea and conjunctiva.

In 221 consecutive cataract extractions the peroperative epithelial damage was assessed by vital staining with 1% lissamine green, using logarithmic grading (grade 5 more than 10 000 stained dots) on cornea and on the superior, medial, lateral, and inferior conjunctiva. Evenly spread dots were seen on the cornea in 63 per cent of the eyes not subjected to protective treatment. In 35 per cent we observed staining caused by taut suturing of cornea and/or conjunctiva, in 10 per cent horizontal lines due to corneal bending during the extraction. The cornea was protected most effectively by healon (1% instilled once). Saline (4 or 5 instillations during the operation sufficed) protected equally well as gelatin sponge, methylcellulose, polyvinyl alcohol, and a soft contact lens. The inferior conjunctiva was protected only by healon, the superior also by saline, gelatin sponge, and polyvinyl alcohol.

Adult↗

PubMed1994

Effect of addition of hyaluronic acid to highly concentrated insulin on absorption from the conjunctiva in conscious diabetic dogs.

Insulin absorption from the conjunctiva was investigated in five pancreatectomized diabetic mongrel dogs, with the nasolacrimal ducts occluded by micro plugs to prevent insulin absorption from nasolacrimal membrane. In the anaesthetized state, highly concentrated porcine insulin (1000 units mL-1, pH 7.4) was absorbed rapidly and significantly from the conjunctiva. Plasma immunoreactive insulin concentrations increased significantly up to 3 h after insulin administration to conjunctival membranes. Plasma glucose concentration decreased significantly compared with saline control experiments after insulin administration (10 units kg-1) at 3 h (8.3 +/- 0.1 vs 15.6 +/- 0.6 mmol, P < 0.01). However, in the conscious state, there was no significant increase in the plasma insulin levels after topical insulin administration. To improve insulin absorption in the conscious state, we examined the effect of increasing viscosity of insulin preparation with hyaluronic acid. In anaesthetized experiments, there were no significant changes in the bioavailability of insulin after addition of hyaluronate (0.84 +/- 0.11 vs 0.87 +/- 0.05%). In the conscious state, with addition of hyaluronic acid, the area under the curve of plasma insulin concentration was significantly increased (1842 +/- 383 vs 75 +/- 24 m units min L-1, P < 0.01). The bioavailability of insulin absorption was significantly increased after addition of hyaluronate (0.68 +/- 0.14 vs 0.03 +/- 0.01%, P < 0.01). From this study we could demonstrate that the conjunctiva is a potential route for insulin administration, and increased viscosity by the addition of hyaluronate was found effective in increasing the bioavailability of insulin absorption from conjunctival membrane in the conscious state.

Absorption↗

PubMed1977

Epidemic caprine keratoconjunctivitis: experimentally induced disease with a pure culture of Mycoplasma conjunctivae.

The induction of caprine keratoconjunctivitis by the subconjunctival inoculation of a cloned culture of Mycoplasma conjunctivae is described. The clinical course of the experimental disease was similar to that noted in naturally occurring outbreaks of "pink-eye" among goats, and biopsies of inflamed conjunctivae showed similar histological response. M. conjunctivae was consistently recovered from the inflamed conjunctival tissues of inoculated animals that developed ocular disease, thus fulfilling Koch's postulates and establishing this organism as an etiological agent of caprine keratoconjunctivitis. Immunological studies suggested that cellular immune mechanisms may play a role in protecting animals from disease produced by this mycoplasma.

Animals↗

PubMed1979

Isolation of Chlamydia trachomatis from different areas of conjunctiva in relation to intensity of hyperendemic trachoma in school children in Southern Tunisia.

The simplified one-passage technique of culture in irradiated McCoy cells, in conjunction with certain other developments in technique, was used to isolate Chlamydia trachomatis from specimens collected from 78 children with trachoma in Douz, Southern Tunisia. The results show that C. trachomatis is not confined to the upper tarsal area of the conjunctiva in hyperendemic trachoma. The higher isolation rate and corresponding increase in the number of inclusions obtained from swabbings of the upper fornix and lower lid in addition to the conventional collection from the upper tarsus show the superiority of collecting specimens for culture from the whole conjunctiva. Specimens could be collected from the whole conjunctiva by using 1 swab for each eye and pooled for subsequent inoculation, so that the laboratory incurred no additional work. A close correlation was observed between isolation rate, together with the number of inclusions, obtained in cell culture, and intensity of inflammatory disease in hyperendemic trachoma. The sensitivity and practicability of this cultural test should provide a valuable laboratory index for use in epidemiological and therapeutic studies of trachoma.

Child↗

PubMed1983

Unusual features in the conjunctiva and cornea of the normal guinea-pig: clinical and histological studies.

Clinical and histological studies of the outer eyes of newborn and adult female guinea-pigs were carried out together with histological studies of fetal eyes. Fine superficial corneal vessels, extending from the limbus, were seen in most newborn and adult eyes and were also present in histological preparations of fetal eyes. These vessels were therefore considered to be features of the normal guinea-pig eye. Masses of tissue composed of lymphoid cells, which were often organised into germinal centres, were found in the fornices of newborn and adult eyes. Smaller accumulations of lymphoid cells were found in fetal eyes, and this lymphoid tissue was therefore also considered to be a normal feature of the guinea-pig eye. In adult eyes mild but short-lived oedema or hyperaemia of the palpebral conjunctiva was quite common. There were no differences in the amounts of conjunctival cellular infiltration in these eyes c found in fetal eyes, and this lymphoid tissue was therefore also considered to be a normal feature of the guinea-pig eye. In adult eyes mild but short-lived oedema or hyperaemia of the palpebral conjunctiva was quite common. There were no differences in the amounts of conjunctival cellular infiltration in these eyes c found in fetal eyes, and this lymphoid tissue was therefore also considered to be a normal feature of the guinea-pig eye. In adult eyes mild but short-lived oedema or hyperaemia of the palpebral conjunctiva was quite common. There were no differences in the amounts of conjunctival cellular infiltration in these eyes compared with normal eyes, and these inflammatory changes were therefore not considered to be significant.

Animals↗

PubMed1998

Gefarnate increases PAS positive cell density in rabbit conjunctiva.

AIMS: The effects of three drugs for the treatment of gastritis and gastric ulcer--gefarnate, ecabet sodium, and troxipide--on periodic acid Schiff (PAS) positive cell density in rabbit conjunctiva in vivo were investigated. METHODS: Eye drops containing gefarnate (0.1%, 1%), ecabet sodium (0.1%, 1%), or troxipide (0.1%, 1%) were instilled in both eyes of rabbits, six times a day for 7 days. On the eighth day, filter paper was gently pressed on the bulbar and palpebral conjunctiva, and impression cytology was performed with PAS staining. Three points in each specimen were selected randomly, and PAS stained cells were counted. RESULTS: The instillation of gefarnate increased PAS positive cell density significantly at the concentration of 1% (p < 0.05). In contrast, instillation of ecabet sodium or troxipide failed to change PAS positive cell density. CONCLUSIONS: These results demonstrated that gefarnate stimulates PAS positive cell density in rabbit conjunctiva.

Abietanes↗

PubMedDate not supplied

Results of autografting of marginal conjunctiva in pterygium excision.

PURPOSE: To investigate and compare the efficiency of autografting of marginal conjunctiva (autograft of marginal conjunctiva technique, AMCT) and the bare sclera technique (BST) in pterygium excision. MATERIALS AND METHODS: In this study, 51 eyes of 51 patients who underwent pterygium surgery using the AMCT (group 1) were compared to 45 eyes of 45 patients who underwent pterygium excision using the BST (group 2), with regard to epithelialisation, recurrence and complication of the procedures. Patients were followed up for 15.37 +/- 12.01 months in group 1 and for 18.57 +/- 10.42 months in group 2. RESULTS: Postoperative epithelialisation was completed in 4.34 +/- 1.27 days in group 1 and in 5.61 +/- 1.71 days in group 2. Epithelialisation was completed earlier in group 1 than group 2 (p < 0.05). Recurrences were detected in 7 eyes (13.73%) of group 1 and in 17 eyes (37.78%) of group 2. The difference between the groups was statistically significant (p < 0.01). No postoperative complications were seen in either of the groups. CONCLUSIONS: The AMCT was found to be a more efficient procedure than the BST. Autografting of marginal conjunctiva may be a useful alternative treatment in pterygium surgery due to higher success and lower recurrence rates.

Adult↗

PubMed1992

The inferior conjunctiva of the monkey.

Light- and electron-microscopical techniques were used to study the structure of the inferior conjunctiva of monkeys including the third eyelid (nictitating membrane). The cell layers of the conjunctival epithelium were 8-10 at the margin, 6-8 near the limbus and 2-4 in other areas except in the third eyelid where there were 1-4 layers. The epithelium was 90-100 microns thick at the margin and 35-40 microns at the other areas except at the third eyelid where it was 10-45 microns thick; near the limbus it was 55-60 microns thick. The morphological differences between the epithelia of the various areas of the inferior conjunctiva are highlighted. The similarities and differences between the human and monkey inferior conjunctivas are discussed.

Animals↗

PubMed1991

Polymorphonuclear leukocytes and bacterial growth of the normal and mildly inflamed conjunctiva.

We examined 304 conjunctiva in 152 subjects by clinical, cytologic, and bacteriologic methods. Bacteriologic samples were evaluated after a 48-hour incubation. Bacterial growth was found in 8 (20.5%) of 39 patients with clinically normal conjunctiva and no polymorphonuclear leukocytes (PMNs), and in 8 (61.5%) of 13 subjects with clinically normal conjunctiva and evidence of PMNs. Bacterial growth also was observed in 4 (40.0%) of 10 patients with clinically mild conjunctivitis and no PMNs, in 10 (24.4%) of 41 patients with clinically mild conjunctivitis and a mixture of inflammatory cells or predominantly lymphocytes, and in 37 (75.5%) of 49 patients with clinically mild conjunctivitis and evidence of PMNs. The presence of PMNs was well correlated with the existence of rapid-growing bacteria.

Adolescent↗

PubMed1991

Nosocomial infections of ocular conjunctiva in newborns delivered by cesarian section.

Colonization of the ocular conjunctiva in newborns delivered by cesarian section occurs usually within the first day of life. We have studied the flora of the ocular conjunctiva at birth, from 19 newborns delivered by cesarian section, coming from two different maternity hospitals. Ocular conjunctiva cultures yielded the main predominant flora in both maternity hospitals considered. The most common genus of this flora are: Staphylococcus, Corynebacterium and Propionibacterium acnes. Peptostreptococcus productus, Neisseria, Eubacterium and Clostridium perfringens are isolated occasionally. In newborns delivered by cesarian section, this flora principally acquired may be the consequence of the presence of bacteria in the ambient air, as well as differences in care provided by the nosocomial personnel.

Bacteria, Aerobic↗

PubMed1994

Detection of varicella-zoster virus DNA in conjunctivas of patients with herpes zoster.

Detection of varicella-zoster virus (VZV) DNA was carried out in the conjunctivas of 18 patients with herpes zoster by polymerase chain reaction. The rate of VZV DNA detection in conjunctivas was 3/4 in herpes zoster ophthalmicus associated with eruption on the dorsum nasi, 2/5 in herpes zoster ophthalmicus without eruption on the dorsum nasi, 1/2 in herpes zoster with eruption on the cheek and lower jaw, 1/2 in generalized herpes zoster and 0/5 in herpes zoster associated with eruption on the trunk or extremities, respectively. The reason for the detection of VZV DNA in conjunctivas is discussed.

Adult↗

PubMed2003

Nociceptive sensation and sensitivity evoked from human cornea and conjunctiva stimulated by CO2.

PURPOSE: To compare sensation and sensitivity evoked from human cornea and conjunctiva stimulated by CO2. METHODS: Twenty healthy participants were recruited for the study. Central corneal and temporal conjunctival chemical sensation and sensitivity of only one eye of each subject were evaluated. Air mixed with different concentrations of CO(2) was delivered by a modified Belmonte pneumatic esthesiometer. The ascending method of limits was used to determine the sensitivity and subjects were required to characterize the sensation at threshold. RESULTS: The sensations evoked by CO(2) in the cornea and conjunctiva were stinging or burning. The sensation evoked by mechanical stimulation was that of irritation. The corneal and conjunctival chemical thresholds were 31% +/- 2% and 54% +/- 5% CO(2) (mean +/- SE), respectively. The corneal and conjunctival mechanical thresholds were 80 +/- 6 and 140 +/- 10 mL/min (mean +/- SE), respectively. The corneal sensitivity was significantly higher for both mechanical and chemical stimuli (P < 0.05). CONCLUSIONS: The results suggest that CO(2) stimulates similar corneal and conjunctival nociceptors in that the interpretations were the same (i.e., nociceptive). The central cornea had a higher sensitivity to CO(2) than the temporal conjunctiva, which may reflect a different peripheral innervation, such as different nerve density or different receptor characteristics. Sensations evoked by mechanical and chemical stimulation were different, which suggests that at the peripheral level, the two modalities stimulate two different kinds of molecular receptors or channels and that this information is somehow retained within the nociceptive system.

Adult↗

PubMed2005

M cells in the follicle-associated epithelium of the rabbit conjunctiva preferentially bind and translocate latex beads.

PURPOSE: This study investigates the presence of M cells in the rabbit conjunctiva. Resolving whether the conjunctiva contains M cells is important, because at other mucosal sites, these antigen sampling cells are known to initiate the mucosal immune response and to act as a site of entry for opportunistic pathogens. METHODS: Fluorescent 0.2-microm polystyrene latex beads were either instilled into the conjunctival sac for 20 to 120 minutes in vivo or applied to flat mounts in vitro. Specimens were assessed by epi-fluorescence stereomicroscopy, widefield fluorescence microscopy, confocal scanning laser microscopy, and transmission and scanning electron microscopy. RESULTS: Latex beads preferentially bound to a subpopulation of cells in the epithelium overlying mucosal lymphoid follicles in the fornix region. At 4 degrees C, the beads were associated with the apical surface of cells that had longer, more irregular microvilli than the surrounding epithelial cells. Within 20 minutes of an in vivo exposure, latex beads were internalized by the follicle-associated epithelial cells and with time moved into the underlying follicle region. After 120 minutes of in vivo exposure, latex beads could be found in cervical lymph nodes. CONCLUSIONS: This study demonstrates that the follicle-associated epithelium of the rabbit conjunctiva contains a cell with morphologic characteristics and the ability to bind and translocate latex beads, which make it indistinguishable from antigen sampling M cells in the rabbit cecum and tonsils. Consistent with its hypothesized antigen sampling role, beads that have been translocated by this cell are rapidly transferred to cervical lymph nodes.

Animals↗

PubMed2005

In vitro comparison of cytoprotective and antioxidative effects of latanoprost, travoprost, and bimatoprost on conjunctiva-derived epithelial cells.

PURPOSE: In a previous study, it was demonstrated that in vitro in a human conjunctiva-derived cell line, latanoprost in its commercial presentation appeared to be less toxic than the benzalkonium chloride (BAC) it contains as a preservative. Through a microplate cytometry technique, the investigation was furthered by study of whether the three commercially available antiglaucoma prostaglandin analogs could protect the same cell line in vitro against BAC toxicity and whether an antioxidative mechanism could be involved in such prostaglandin effects. METHODS: Human conjunctiva-derived epithelial cells from the Chang cell line were exposed to three prostaglandins in their commercial presentation (latanoprost, travoprost, and bimatoprost) and to three concentrations of BAC (0.02%, 0.015%, and 0.005%), corresponding to the concentrations contained in the three prostaglandin eyedrops. Each solution was diluted to 1/10 and was applied for 30 minutes Cellular membrane integrity, cytosolic H2O2, cytosolic O2*- and apoptosis were evaluated using neutral red, H2DCF-DA, hydroethidine, and Yopro-1 probes, respectively. RESULTS: Cellular viability decreased as BAC concentration increased, but it was accompanied by concentration-dependent toxicity. Toxicity of latanoprost and travoprost commercial solutions was statistically significantly lower than their respective BAC concentrations (P < 0.01), whereas bimatoprost induced no significant effects. There was a statistically significant decrease in H2O2 detection with cells exposed to latanoprost (P < 0.01) and travoprost (P < 0.01) and a lower detection of O2*- with cells exposed to latanoprost (P < 0.01) compared with the corresponding BAC concentration alone. The Yopro-1 test showed a BAC-induced apoptotic effect that increased with its concentration. Latanoprost and travoprost produced proapoptotic effects compared with control (P < 0.01), but these were lower than their respective preservative concentrations (statistically significant difference; P < 0.01). CONCLUSIONS: Latanoprost and travoprost were responsible for significant protective effects against BAC toxicity on conjunctiva-derived epithelial cells in vitro, probably related to their antioxidative properties. The low toxicity of the bimatoprost solution did not reveal a possible antioxidative effect. Reduced reactive oxygen species production could be the main mechanism by which prostaglandin analogs protect epithelial cells from the proapoptotic effects of BAC. Further studies will be useful to confirm this hypothesis.

Amides↗

PubMed2006

Immunogenicity and antigenicity of allogeneic amniotic epithelial transplants grafted to the cornea, conjunctiva, and anterior chamber.

PURPOSE: To determine the immunogenic characterization of amniotic epithelium (AE), by examining the fate of allogeneic AE grafts heterotopically transplanted in the eye. METHODS: Intact AE from enhanced green fluorescence protein (EGFP) transgenic mice (C57BL/6 background) and wild-type C57BL/6 mice were transplanted onto cornea or conjunctiva, or inserted into the anterior chamber (AC) of normal BALB/c mice, C57BL/6 mice, or BALB/c mice presensitized to donor antigens. For repeated AE transplantation experiments, AE was grafted in the other eye 7 days after the first grafting. Graft fate was assessed clinically and histologically at selected intervals after grafting. Infiltrating inflammatory cells were examined immunohistochemically. Sensitization to alloantigens by AE was assessed by the delayed hypersensitivity (DH) response. RESULTS: In normal recipients, GFP+ cells were absent in EGFP donor-derived AE grafts by day 21 on cornea and by day 7 on conjunctiva. AE grafts implanted in the AC survived for >8 weeks. In presensitized recipients and recipients that underwent repeated AE implantation, graft survival was markedly shorter than in normal recipients. DH was induced at 2 weeks, but failed to be induced at 4 weeks after grafting on cornea or at 8 weeks after grafting on conjunctiva and in the AC of normal recipients. CONCLUSIONS: Fresh allogeneic AE expressed immunogenicity when placed on the ocular surface, although no memory of allospecific DH was acquired. Allogeneic AE is clearly vulnerable to immune rejection in specifically sensitized recipients.

Amnion↗

PubMed2003

Impression cytology on conjunctiva and cornea in dry eye patients establishes a correlation between squamous metaplasia and dry eye clinical severity.

PURPOSE: To obtain deeper knowledge of the cellular transition in squamous metaplasia, and to look for a correlation between the clinical grade of severity of dry eye and the grade of squamous metaplasia of the corneal and conjunctival epithelium, studied by impression cytology. METHODS: A total of 143 patients with dry eye disorders of different grades of clinical severity and 33 control subjects of matched age and sex were studied. Symptoms, clinical tests (including Schirmer test, slit-lamp examination, break-up time, rose Bengal staining, vanishing lacunar sulci, and neovascularization), and tear osmolarity were used to establish the diagnosis of dry eye. The subjects were classified into six clinical grades, grade 0 indicating normal and grades 1 to 5 progressively more severe dry eye. Impression cytology specimens were taken from the central cornea and different areas of the conjunctiva of one eye from all patients. A morphologic and morphometric study of the photographs obtained by light microscopy showed cell size, nuclear size, nuclear-cytoplasmic ratio (N:C) in nonsecretory epithelial cells, and density of goblet cells. RESULTS: Morphometric and morphologic studies of the ocular surface cells indicated significant differences, mainly in cell sizes, nuclear alterations, and the N:C ratio, in nonsecretory epithelial cells of the conjunctiva and cornea, and in goblet cell densities from the conjunctiva, between the clinically normal eyes and those with the five grades of clinical severity of dry eye, with different degrees of squamous metaplasia. CONCLUSIONS: A morphologic and morphometric analysis of the ocular surface from patients with dry eye obtained by impression cytology led us to draft a new grading system containing one normal level and five levels of squamous metaplasia. This new grading system is based on a significant decrease in the number of goblet cells with less periodic acid-Schiff-hematoxylin-positive staining, an increase in nonsecretory cell size, more marked cell separation, a lower N:C ratio, and an increase in nuclear alterations. The clinical severity of the dry eye correlates with these alterations.

Adult↗

PubMed2003

Biopsy of the conjunctiva in dry eye patients establishes a correlation between squamous metaplasia and dry eye clinical severity.

PURPOSE: The aim of this work was to evaluate the different grades of squamous metaplasia of the conjunctiva during the clinical course of dry eye syndrome, detecting the most characteristic morphological and morphometric changes by biopsy in order to provide a diagnostic classification. METHODS: The conjunctiva was studied under light microscopy by conventional histological methods and by morphometric analysis in 165 patients and in 33 controls. Patients were classified according to the Schirmer 1 test, break-up time, rose Bengal staining, osmolarity and impression cytology. The epithelium and connective tissue, with their different cells and other structures, were studied. RESULTS: The conjunctiva in dry eye patients showed progressive stratification, hyperplasia, hypertrophy and cellular flattening, with loss of goblet cell density and mucous layer. We found five pathological grades of squamous metaplasia and one normal grade. Clear nuclear alterations (indentation and binucleation) were found in the early grades of dry eye syndrome, but pyknotic nuclei and anucleated cells were only seen in the most severe grades. The smallest epithelial cells were found in the control group and their size increased with the severity of the dry eye syndrome. From the earliest stages to the most severe cases, increases in cellular separation were observed. There was also an increase in the number of inflammatory cells. Blood and lymphatic vessels showed alterations only in the most severe cases. CONCLUSIONS: This is the first grading system proposed for biopsy evaluation of the ocular surface in dry eye patients. These morphological and morphometric studies alone were able, even in the earliest phases of dry eye, 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 increases in the stratification, epithelial cellular size and a general loss of goblet cells.

Biopsy↗