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PubMed1979

Mucolipidosis IV. Histopathology of conjunctiva, cornea, and skin.

The condition of a 4-year-old white girl of Ashkenazi Jewish parents was diagnosed as mucolipidosis IV on the basis of marked corneal clouding and severe psychomotor retardation, in the absence of facial-skeletal dysplasia or abnormal mucopolysacchariduria. The results of histochemical and ultrastructural studies of conjunctiva, skin, and corneal epithelium confirmed the combined storage of acid mucopolysaccharide and complex lipid substances. An unusual histopathologic feature of mucolipidosis IV is the predisposition of extreme storage involvement of corneal epithelial cells with relative sparing of the keratocytes, which is a finding of potential therapeutic implication. In addition, application of electron microscopic study of cultured amniotic cells and conjunctival biopsy specimens to assess for the parents the mother's subsequent pregnancy additional emphasizes the value of ultrastructural studies in the diagnosis of lysosomal storage disease.

Amniotic Fluid↗
PubMed1980

Combined surgery and cryotherapy for diffuse malignant melanoma of the conjunctiva.

Two patients who had refused exenteration for widespread conjunctival melanoma were treated by a combination of cryotherapy and surgical excisions. Cryotherapy was delivered only to the extensive areas of flat intraepithelial melanocytic proliferation (precancerous melanosis), while the surgical excisions were performed on the focal nodules, representing localized invasive melanoma. In our two patients, the invasive nodules measured, respectively, 1.2 and 1.5 mm in greatest thickness, placing them in a low to borderline risk group for metastasis. Repeated cryoapplicatons were required to control the widespread flat intraepithelial disease. The conjunctiva tolerated these procedures well because the substantia propria is not sacrificed as it must be in surgical conjunctivectomy, allowing comparatively normal reepithelialization to occur from adjacent zones, after the treated epithelium containing the melanocytes sloughs. No evidence of invasive melanoma (cancerous melanosis) has developed in any of the cryotreated areas of intraepithelial disease (precancerous melanosis); sequential biopsies have established that the atypical melanocytes have disappeared from the epithelium.

Adult↗
PubMed1984

Chemical preparation of the eye in ophthalmic surgery. III. Effect of povidone-iodine on the conjunctiva.

A half-strength povidone-iodine (Betadine) solution was used topically as part of the preoperative chemical preparation of the eye. Aerobic and anaerobic bacterial cultures of the conjunctiva were taken before and after the chemical preparation in 30 consecutive patients; the second eye served as a control. In the control eyes, no significant change in the number of colonies or species of bacteria was found. In the povidone-iodine-treated eyes, the numbers of colonies decreased 91% and the number of species decreased 50% (statistically significant). We therefore recommend that a half-strength povidone-iodine solution be used as part of the chemical preparation of the eye for surgery.

Administration, Topical↗
PubMed1976

Pigmented squamous cell carcinoma of cornea and conjunctiva: A light microscopic, histochemical, and ultrastructural study.

A light microscopic, histochemical, and ultrastructural study was performed on tissue obtained from a pigmented squamous cell carcinoma of the cornea and conjunctiva. To the best of our knowledge this is the first time that one of these rare pigmented squamous cell carcinomas of the ocular mucous membrane has been described in detail. The occurrence of this neoplasm, which needs to be differentiated from other pigmented lesions, and particularly epibulbar melanomas, underscores the fact that all pigmented tumors are not melanomas. The study revealed that melanin granules, which accounted for the pigmentation of the neoplasm, were present in variable numbers in neoplastic squamous cells, Langerhans cells, macrophages, and stellate cells identified as melanocytes with mature melanosomes. Premelanosomes were not observed in any of these cells types. Current concepts concerning the common association of Langerhans cells with their characteristic intracytoplasmic "Birbeck granules" and melanocytes are discussed.

Carcinoma, Squamous Cell↗
PubMed2006

Localization of candidate stem and progenitor cell markers within the human cornea, limbus, and bulbar conjunctiva in vivo and in cell culture.

Corneal diseases are some of the most prevalent causes of blindness worldwide. While the most common treatment for corneal blindness is the transplantation of cadaver corneas, expanded limbal stem cells are finding recent application. Unknown, however, is the identity of the actual repopulating stem cell fraction utilized in both treatments and the critical factors governing successful engraftment and repopulation. In order to localize potential stem cell populations in vivo, we have immunohistochemically mapped a battery of candidate stem and progenitor cell markers including c-Kit and other growth factor receptors, nuclear markers including DeltaNp63, as well as adhesion factors across the cornea and distal sclera. Cell populations that differentially and specifically stained for some of these markers include the basal and superficial limbal/conjunctival epithelium and scattered cells within the substantia propria of the bulbar conjunctiva. We have also determined that the culture of differentiated cornea epithelial cells as dissociated and explant cultures induces the expression of several markers previously characterized as candidate limbal stem cell markers. This study provides a foundation to explore candidate corneal stem cell populations. As well, we show that expression of traditional stem cell markers may not be reliable indicator of stem cell content during limbal stem cell expansion in vitro and could contribute to the variable success rates of corneal stem cell transplantation.

Adult↗
PubMed2000

Changes in histamine content following pharmacologically-induced mast cell degranulation in the rat conjunctiva.

Compound 48/80 was applied into one eye of male Wistar rats and a drop of vehicle into the contralateral eye. Another group of rats received sodium cromoglycate in both eyes every 6 h for a period of 48 h. One eye was challenged with compound 48/80 30 min after the end of treatment with sodium cromoglycate. The eyes were monitored clinically and the histamine content of the conjunctiva was determined fluorometrically. The basal histamine levels in rat conjunctival homogenates were quantified. Pharmacologically-induced mast cell degranulation by a single application of 0.1 g ml(-1)of compound 48/80 resulted in significant decreases of conjunctival histamine levels 1, 12 and 24 h after challenge. Sodium cromoglycate prevented the effect of compound 48/80 when administered into the eye prior to the challenge with the non-immunogenic histamine releaser. Upon termination of the application, the membrane stabilizer was unable to reverse the reduced histamine levels in the conjunctival homogenates.

Animals↗
PubMed1992

Krause's end-bulb microtumor of the conjunctiva: optic and ultrastructural description of a case.

Ultrastructural examination of a conjunctival biopsy of a 90-year-old woman with a history of chronic lymphatic leukemia showed numerous densely packed structures located below the epithelial conjunctival layer. They were composed of concentrical flattened lamellae arranged around one or several clear cores containing a large number of mitochondria. The plasma membranes of the lamellae displayed large numbers of pinocytotic vesicles and resembled perineurial cell processes. The central areas were thought to be axons. Because of their conjunctional location and morphological features. The structures were categorized as nerve endings of the Krause's end-bulb type. The aberrant and profuse growth of these structures led to the diagnosis of Krause's end-bulb microtumor of the conjunctiva. We compare our findings with mucosal neuromas, paraneoplastic lesions and age-related alterations are discussed, although they differ morphologically from Krause's end-bulb microtumor.

Aged↗
PubMed1982

Release of fibrinolytic activators from the cornea and conjunctiva.

The authors studied the release of fibrinolytic activators from in vitro cultures of human and animal cornea with the following main findings: (1) the epithelium is the main activator source; (2) the addition of tripeptide, salicylate, chloroquine and phorbolester to the culture medium increases the fibrinolytic activity of the cultures; (3) corticosteroids depress the fibrinolytic activity; (4) explants of human conjunctiva also release fibrinolytic activators. The pathophysiological role of this activator is unknown. Hypothetically, besides preventing fibrin deposition on the surface of the eye, this activator may also stimulate leucocyte migration, activate procollagenase, protect the endothelial pump, and regulate vascular permeability and angiogenesis in the cornea.

Animals↗
PubMed1981

[Pigmented deposits into conjunctiva after local application of epinephrine (author's transl)].

Prolonged local application of epinephrine produces deposits of pigment in the conjunctiva, which is found in conjunctival cysts or crypts. The fine granular structure sometimes shows concentric layers. Granular particles seen by electron microscope are often found adsorbed to the surface of microvilli. It is not known whether the electron-sense particles in the cysts or crypts have developed from active secretion or by influx from the conjunctival surface. The metabolic product of locally applied epinephrine is probably not a typical melanin (negative Masson-Hamperl staining), but appears to be a related pigment.

Aged↗
PubMed1993

cAMP-specific phosphodiesterase inhibitor, rolipram, reduces eosinophil infiltration evoked by leukotrienes or by histamine in guinea pig conjunctiva.

The effect of rolipram, an isozyme IV-selective inhibitor of cAMP-specific phosphodiesterase, was evaluated in a guinea pig eye model of tissue eosinophilia. (R)-rolipram was administered by gavage to guinea pigs 1 h prior to topical ocular challenge with a mixture of leukotrienes (LTs) (10 ng LTB4 + 1000 ng LTD4/eye) or with histamine dihydrochloride (1 mg/eye). Conjunctivae were evaluated histologically 6 h after challenge. Eosinophil counts per millimeter of conjunctival epithelium in LT-challenged animals that received (R)-rolipram at dosages of 0.1, 0.3, 1, 3, or 10 mg/kg were reduced by 63, 63, 84, 81 and 90% respectively, compared to LT-challenged controls. Reduction was statistically significant (P < 0.05) at all dosages. Eosinophil counts per millimeter of epithelium in histamine-challenged animals that received 10 mg/kg (R)-rolipram were reduced by 79% compared to histamine-challenged controls (P < 0.01). The results indicate that (R)-rolipram inhibits the response to two distinct classes of mediator in this model of eosinophil infiltration, adding support to the contention that isozyme IV-selective cAMP phosphodiesterase inhibitors offer therapeutic potential for human asthma.

3',5'-Cyclic-AMP Phosphodiesterases↗
PubMed1993

Adhesion molecules in normal human conjunctiva. An immunohistological study using monoclonal antibodies.

In this immunohistochemical light microscopic study we applied a panel of monoclonal antibodies to study the expression pattern of adhesion molecules in normal human conjunctiva from 15 patients. The molecules we analyzed included the VLA-family VLA-1-6, the leukocyte integrins LFA-1, Mac-1 and p150,95, the immunoglobulins LFA-3, CD2, ICAM-1 and VCAM-1 and the selectin ELAM-1. Our results show that only VLA-2, VLA-3, LFA-3, and the VLA-alpha 6 subunit are expressed on the epithelium. A strongly basal accentuation of the VLA-alpha 6 subunit indicates its possible relevance in anchoring the epithelium at the substantia propria. Intraepithelial T cells were VLA-1, VLA-5, LFA-1, and CD2 positive. Endothelial cells expressed VLA-1, VLA-2, VLA-3, VLA-5, VLA-alpha 6, ICAM-1, and LFA-3. ELAM-1 was seen only in specimens from five patients. Interestingly, mast cells were positive for VLA-3 and VLA-5, both of which are receptors for fibronectin, indicating that these integrins play an important role in mast cell function. Our study builds the basis for further investigations in adhesion molecules in conjunctival diseases.

Adolescent↗
PubMed1995

Evaluation of the range of areas of the fluorescein staining patterns of the tarsal conjunctiva in man.

Fluorescein dye is commonly used to highlight the tarsal conjunctiva in man to facilitate diagnosis of papillary conjunctivitis. A quantitative analysis of the fluorescein-highlighted features could be useful in both assignment of severity grades as well as for objective comparisons but no data is available on the distributions of sizes (areas) of these features. An exploratory, range-finding study was undertaken to provide data on feature areas that might be encountered. After application of fluorescein, 35 mm photographs were taken at a fixed distance with zone 1/zone 2 (Allansmith) of the tarsal plate aligned perpendicular to the camera. The photographs were projected, an overlay of 150 to 180 contiguous features outlined by fluorescein made and planimetry used to assess the areas and area distributions of the features on tarsal plates clinically graded with stages 1 to 4 papillary hypertrophy. For zone 1 of the tarsal plate in asymptomatic subjects, a fluorescein solution highlights the limits of features that enclose an area averaging 30,000 microns2 (range 8000 to 120,000; median area of close to 35,000 microns2). The areas of these features were generally normally distributed and there was little variation in feature areas across the zone. At different stages of clinical papillary conjunctivitis, the areas of the negative staining patterns are larger. Averages of 60,000 to 90,000 microns2, median values of close to 70,000 microns2 and individual feature areas up to 350,000 microns2 were seen in mildly symptomatic patients. These distributions were generally heterogeneous and showed a skewed distribution. Areas averaging up to 0.755 mm2 (range 0.6 to 3.2 mm2) were measured in moderate to severe papillary hypertrophy.

Cell Count↗
PubMed1982

Adult cystinosis: electron microscopy of the conjunctiva.

An ultrastructural study was made on the conjunctiva of a 38-year-old man with adult cystinosis. Intracellular cystine crystals were found not only in fibroblasts but also in numerous macrophages. Both fibroblasts and macrophages showed increased pinocytosis. Occasionally there were macrophage degenerations with extracellular cystine crystals present. Whether this increased macrophage reaction indicates a specific difference to childhood cystinosis remains a matter of speculation.

Adult↗
PubMed2004

[Association of malignant tumors of the conjunctiva and HIV infection in Kinshasa (D. R. Congo). First results].

BACKGROUND: Conjunctival carcinomas are tumors especially of the 6th/7th decades. They occur in Germany with a frequency of 1/20,000. For years it has been well known that in Africa the number of malignant tumors of the conjunctiva has been increasing. The reasons for that are not well known. HIV is a possible pathogenetic cofactor. METHOD: A histological examination of 34 specimens was performed in Rostock on conjunctival tumors removed at the Ophthalmologic Department of the University of Kinshasa in 2001. The study included 23 female and 11 male patients aged 20-75 years (mean 42). All patients underwent serological investigation for HIV infection. RESULTS: Of 34 patients 18 were HIV positive. Of the HIV-positive patients, six had a squamous cell carcinoma, seven a CIN (conjunctival intraepithelial neoplasia) I-III, and five a pinguecula. Of the HIV-negative patients, five showed a squamous cell carcinoma, eight a CIN I-III, one a pinguecula, one a sebaceous gland carcinoma, and one a papilloma. The average age of the HIV-positive patients with a squamous cell carcinoma was 41 years compared to the HIV-negative patients with 58 years. CONCLUSIONS: There was no difference in frequency of conjunctival intraepithelial neoplasia between HIV-positive or HIV-negative patients. HIV-positive patients with a squamous cell carcinoma were on average 17 years younger. UV radiation is the main risk factor and HIV infection is a possible carcinogenic cofactor. Investigations on additional viral infections as possible pathogenetic factors and on changed tumor suppressor genes are needed.

AIDS Serodiagnosis↗
PubMed1998

[Bacterial colonization of conjunctiva with Propionibacterium acnes before and after polyvidon iodine administration before intraocular interventions].

BACKGROUND: Propionibacterium acnes has been described as a causative agent of postoperative endophthalmitis. This gram-positive, immotile, non-spore-forming bacterium is highly pleomorphic and grows under conditions of low to no oxygen concentration. It is commonly found on the skin at the openings of sebaceous glands and on hairs. A near-symptomless postoperative endophthalmitis occurs particularly when Propionibacteria are enclosed in the capsular bag. We investigated to what extent the number of P. acnes in the conjunctival sac can be reduced by preoperative disinfection with polyvidone iodine (1%). PATIENTS AND METHODS: A total of 261 patients with intrabulbar surgery had two conjuctival swabs taken: the first immediately prior to preoperative preparation in the operating theatre, following in-patient application of antibiotic eye drops (Polymyxin-B-sulfat, Neomycinsulfat and Gramicidin in combination); the second swab was taken after disinfection with polyvidone iodine before opening the conjunctiva. RESULTS: Of the 261 swabs, 60 (23%) taken prior to polyvidone iodine application were positive for Propinibacterium acnes. Following polyvidone iodine treatment, a further 5 (1.9%) remained culture-positive. After disinfection, 55 (92%) of the 60 positive swabs for Propionibacterium acnes remained culture-negative. CONCLUSIONS: We concluded that a significant reduction of P. acnes can be achieved by preoperative application of polyvidone iodine (1%) (P < 0.001).

Anti-Infective Agents, Local↗
PubMed2001

[TFF peptides. New mucus-associated secretory products of the conjunctiva].

The molecular architecture of the human ocular mucus is not yet completely understood. Recently, TFF peptides (formerly known as trefoil factors or P-domain peptides) could be identified as new constituents of this delicate mucus. Members of the TFF-peptide family are typical secretory products of mucous epithelia and three are known in humans and designated as TFF1, TFF2 and TFF3. They enhance cell migratory processes (motogenic effect), they show anti-apoptotic effects and are inflammatory modulators Both TFF1 and TFF3 expression could be monitored by the reverse transcription-polymerase chain reaction (RT-PCR) in the human conjunctiva; in contrast, TFF2 transcripts were not detectable. Using immunohistochemistry, TFF1 and TFF3 peptides were found in varying concentrations solely in secretory vesicles of conjunctival goblet cells. This localisation matches precisely that of the secretory mucin MUC5AC. Thus, conjunctival TFF1 and TFF3 have to be considered as typical mucin-associated peptides probably modulating the rheological properties of the ocular mucus and the tear fluid. Future investigations are in progress to elucidate the role of TFF-peptides during pathological conditions of the eye as well as their diagnostic and therapeutic potential.

Conjunctiva↗
PubMed2002

Morphological evidence of M cells in healthy canine conjunctiva-associated lymphoid tissue.

PURPOSE: To characterize the follicle-associated epithelium (FAE) and organized lymphoid nodules from dog nictitating membranes to determine if canine conjunctiva-associated lymphoid tissue (CALT) contains M cells analogous to those described in other regions of mucosa-associated lymphoid tissue (MALT). METHODS: Nictitan lymphoid follicles from 15 healthy dogs (30 eyes) were harvested immediately post-mortem. Twelve follicles from each nictitating membrane were isolated. Four follicles from each eye of 10 dogs were examined by light microscopy, transmission electron microscopy and scanning electron microscopy. Five of the 10 dogs were treated with a heat-killed staphylococcal topical suspension immediately prior to euthanasia. Nictitan follicles from five other dogs were processed for immunohistochemistry to characterize follicle lymphocyte populations. RESULTS: The FAE overlying CALT demonstrated morphology characteristic of M cells, including attenuated apical cell surface with blunted microvilli and microfolds, invaginated basolateral membrane forming a cytoplasmic pocket containing lymphocytes and macrophages, and diminished distance between the apical and pocket membrane. Heat-killed bacteria were bound to the surface and transcytosed to the cytoplasmic pocket of CALT M cells. Immunohistochemistry of organized lymphoid tissue subtending the FAE demonstrated B-cell germinal centers with T-cell predominant apical caps. CONCLUSIONS: In canine CALT, the FAE overlying lymphoid follicles, as well as the distribution of T and B lymphocytes subtending this region, contain morphologic and functional features analogous to MALT described in other regions. Documentation of canine conjunctival M cells is of clinical relevance in the study of primary ocular diseases, as well as a potential means of vaccination or drug delivery.

Animals↗