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Th1- and Th2-type cytokines in chronic ocular allergy
No full textBACKGROUND:
Previous reports have suggested that Th2-type cytokines are important in the pathogenesis of ocular allergic diseases. The purpose of this study is to measure levels and mRNA expression of Th1- and Th2-type cytokines in patients with active vernal keratoconjunctivitis (VKC) and atopic keratoconjunctivitis (AKC).
METHODS:
Tear samples and tear-isolated cells were obtained from 9 healthy participants (CT--controls), 28 VKC, and 6 AKC patients. IL-4, IL-13, and interferon gamma (IFNgamma) tear levels were determined by ELISA, and IL-4 and IFNgamma tear cell mRNA expression by RT-PCR. Effects of these cytokines on IL-6 and IL-8 secretion, and on ICAM-1 expression by conjunctival fibroblasts, were evaluated by ELISA and flow cytometry respectively.
RESULTS:
Interleukin-4 tear levels were increased in VKC and AKC compared with CT, but only IFNgamma significantly correlated with corneal involvement. An IL-4/13-dominant profile was found in 50% of VKC and in 17% of AKC patients, while a IFNgamma-dominant profile was found in 18% of VKC and in 17% of AKC patients. IL-4 and IFNgamma transcripts were detected in tear cells from 11 out of 12 VKC patients. IFNgamma upregulated expression of ICAM-1 on conjunctival fibroblasts and the secretion of IL-6 and IL-8.
CONCLUSIONS:
Although both IL-4 and IFNgamma are detected in tears, only IFNgamma levels correlated with disease severity and upregulated ICAM-1 on conjunctival fibroblasts, suggesting the role of IFNgamma in the inflammatory phase of chronic allergic eye diseases
The effect on the macular function of laser photocoagulation for diabetic macular edema.
No full textThe benefit of focal and grid-laser photocoagulation in reducing the risk of visual loss from diabetic macular edema has been established. In order to investigate the effect of this treatment on macular function, 30 diabetics with macular edema and 1.0 visual acuity were tested before and after laser treatment at intervals of 1 week, and 1 and 3 months, respectively. The test was carried out by means of nyctometry, contrast sensitivity, hue discrimination and critical flicker frequency of blue cones. All patients had abnormal results in macular tests before treatment. During the follow-up, visual acuity remained stable and the macular tests did not statistically modify, except for nyctometry, which deteriorated at the 1-week follow-up (P = 0.02) and then increased to the basal values, and contrast sensitivity [improved at the last control (P = 0.006)]. Clinical regression of macular edema was observed, but macular function tests never normalized. Patients with diabetic macular edema and good visual acuity should be monitored with many functional methods, and laser treatment should be performed before macular function deteriorates irreversibly
Tear histamine and histaminase during the early (EPR) and late (LPR) phases of the allergic reaction and the effects of Lodoxamide.
No full textCorneal confocal microscopy in patients with vernal keratoconjunctivitis
Full text linkPurpose: To compare corneal morphologic features using in vivo confocal microscopy in vernal keratoconjunctivitis (VKC) patients compared with normal subjects. Design: Prospective, comparative study. Participants: Thirty-two VKC patients (26 males, 6 females; mean age, 17.1 years) and 40 normal subjects (20 males, 20 females; mean age, 19.3 years) were included. Methods: All subjects underwent a full ophthalmologic examination. Confoscan CS4 (Nidek, Gamagori, Japan) images of the central cornea were obtained with a ×40 noncontact lens and Z-ring device. Main Outcome Measures: The superficial and basal epithelium, subbasal nerve plexus, anterior stroma, stromal nerves, and endothelium of the central cornea were studied. Results: The VKC patients had increased diameter, reflectivity, and presence of nuclear activation of superficial epithelial cells; reduced density of the basal membrane; lower density of keratocytes, increased presence of activated keratocytes, and inflammatory cells in the anterior stroma; and lower density and number of fibers, lower number of beadings, and higher grade of tortuosity of fibers in the subbasal nerve plexus. Increased alterations in thickness, deflections, and tortuosity were observed in stromal corneal nerves. An increased number of inflammatory cells in close proximity to the subbasal and stromal nerve fibers also was observed in VKC subjects. Conclusions: Corneal involvement in VKC is associated with alterations of the epithelium and subbasal and stromal corneal nerves. These changes may relate to the tear dysfunction and nonspecific hyperreactivity typical of these patients. Corneal confocal microscopy is a useful tool for studying in vivo pathologic corneal changes in VKC. Financial Disclosure(s): The author(s) have no proprietary or commercial interest in any materials discussed in this article. © 2012 American Academy of Ophthalmology
PERIPAPILLARY FUNDUS PERIMETRY IN EYES WITH GLAUCOMA
Full text linkAbstract: Aims: To evaluate, with fundus perimetry, the peripapillary differential light threshold (DLT) in eyes with glaucoma and ocular hypertension (OHT), and compare it with peripapillary retinal nerve fibre layer (RNFL) thickness.
Methods: 35 glaucomatous, 29 OHT and 24 control eyes were included. Peripapillary DLT at 1 degrees from the optic nerve head was quantified with fundus perimetry; peripapillary RNFL thickness was measured over the same area by optical coherence tomography.
Results: Mean (SD) peripapillary DLT was 19.2 (1.7), 17.6 (4.2) and 10.1 (6.9) dB in control, OHT and glaucomatous eyes, respectively (p < 0.001). Mean (SD) RNFL thickness was 98.4 (35.3), 83.9 (35.1) and 55.8 (28.2) mu m, respectively (p < 0.001). Mean peripapillary DLT showed higher sensitivity and specificity in differentiating the three groups compared with RNFL thickness.
Conclusion: Progressive, significant reduction of peripapillary DLT was documented in OHT and glaucomatous eyes compared with controls (p < 0.001). DLT reduction parallels RNFL reduction
Cytostatic and Cytotoxic Effects of 5-Fluorouracil on Human Corneal Epithelial Cells and Keratocytes.
Full text linkPURPOSE:: To investigate the effects of various 5-fluorouracil (5-FU) concentrations, exposure times, and application techniques on in vitro-cultured human corneal cells. METHODS:: Human corneal epithelial cell (HCEC) and human corneal keratocyte (HCK) cultures were exposed to different 5-FU concentrations (0.025%-1%) and incubation durations (5 minutes to 2 hours). The cytostatic effect was evaluated as the percentage of inhibition of migration relative to the control. The evaluation of cytotoxic effect included both phase contrast microscopic observations and viability measures performed using an MTT [3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide)] colorimetric assay. The results are expressed as ratio of optical density (OD) reduction 24 hours after exposure. RESULTS:: The cytostatic effect was time and dose dependent. The 50% inhibiting dose was 0.55% after 1 hour of incubation for HCECs and was 0.5% after 2 hours of incubation for HCKs. A 100% inhibitory effect was never observed at any concentration or incubation duration. No cytotoxic changes were observed using an 5-FU concentration of <1%; 1% 5-FU showed time-dependent cytotoxic changes in HCEC cultures only. MTT analysis showed no OD reduction at 5-FU concentrations of <1%, whereas 1% 5-FU showed OD reduction <50% at any tested exposure time. HCECs showed higher reduction in OD than HCKs. CONCLUSIONS:: 5-FU formulations topically used in clinical practice showed limited toxicity in normal cultured corneal epithelial cells and keratocytes
In vitro effects of fluorochinolone and aminoglycoside antibiotics on human keratocytes
No full textAbstract
PURPOSE:
The purpose of this study was to assess the cytotoxic effects of the fluoquinolone ofloxacin and the aminoglycoside netilmicin on stromal human keratocytes in vitro.
METHODS:
Cultured human keratocytes were exposed to various concentrations of ofloxacin or netilmicin (0.16-5.0 mg/mL). Both cell proliferation (MTT assay) and cell morphology (phase-contrast microscopy) were evaluated after 1, 4, 12, and 24 hours of incubation. Measurement of annexin V binding performed in association with the dye exclusion test using propidium iodide (PI) was also performed by FACS analysis after 4 hours of exposure.
RESULTS:
Both antimicrobials induced dose- and time-dependent morphologic changes in keratocytes, yet the effects of netilmicin were minimal. After 24 hours of exposure, both drugs induced a dose-dependent inhibition of cell proliferation; however, ofloxacin demonstrated significantly more toxic effects than netilmicin (t test for ED50 values, P < 0.0001). Statistical differences between 2 antibiotics start at concentrations above 1.25 mg/mL (ANOVA with post-hoc test, P < 0.01). Expression of the apoptotic marker annexin V was unaffected by antibiotic exposure, whereas the uptake of the necrotic marker PI was increased by ofloxacin (5 mg/mL) but not by netilmicin (ofloxacin versus netilmicin, ANOVA, P < 0.05).
CONCLUSIONS:
Relative effects of aminoglycosides and fluoroquinolones on stromal keratocytes appear to be different: netilmicin was shown to be significantly less toxic than ofloxacin. This finding is particularly relevant in deciding the optimal antibiotic to be applied in clinical situations in which the epithelium is absent or compromised, as after photorefractive keratectomy, alkali burns, or ulcerative keratiti
Effects of Th2 cytochines on expression of collagen, MMP-1 and TIMP-1 in conjunctival fibroblasts
No full textPURPOSE. To determine whether cytokines involved in chronic allergic conjunctival disorders may affect formation of giant papillae and tissue remodeling. METHODS. Conjunctival fibroblast cultures were challenged with different concentrations of human recombinant interleukin (IL)-4, IL-13, interferon (IFN)-γ and tumor necrosis factor (TNF)-α. Procollagens I (PIP) and III (PIIIP), matrix metalloproteinase (MMP)-1 and -9, and tissue inhibitor of metalloproteinase (TIMP)-1 were measured in supernatants, and their respective mRNAs were evaluated by RT-PCR. RESULTS. IL-4 and -13 (10 ng/mL) significantly increased production and expression of PIP compared with nonstimulated cells, whereas IFN-T elicited the opposite effect, at both the protein and mRNA levels. Both IL-4 and -13 significantly decreased production of MMP-1 and increased that of TIMP-1, whereas TNF-α increased production of MMP-1 and -9. Expression of MMP-1 was reduced by IL-4 and increased by the other tested cytokines, whereas expression of TIMP-1 was increased by all tested cytokines. CONCLUSIONS. IL-4 and -13 increased production of collagen and modified the equilibrium between MMP-1 and its inhibitor, TIMP-1. These effects were partially opposed by IFN-γ and TNF-α
Vernal keratoconjunctivitis-like disease in adults
Full text linkPURPOSE: To identify clinical, demographic, immunologic, and health-related quality-of-life data from a cohort of vernal keratoconjunctivitis (VKC) patients with the onset of the disease after puberty (VKC-like disease).
DESIGN: Retrospective, observational case series.
METHODS: Forty-nine patients with late-onset VKC-like disease from among 600 consecutive VKC patients. History of disease, test results for allergen sensitivity, signs and symptoms, impact of disease on work productivity, health-related quality of life, and treatment satisfaction were assessed. In addition, multiplex bead analysis for Th1/Th2 cytokines were carried out in tear samples from 20 VKC patients (10 adults and 10 children) and from 10 normal subjects.
RESULTS: A family history of allergy was positive in only 28% and positive prick test results were present in 55% of the 49 VKC-like adult patients. Based on typical signs and symptoms, 48% were affected by the limbal form, 33% were affected by the tarsal form, and 19% were affected by the mixed form. Corneal ulcer complicated the disease in only 2 adult patients. Although the disease was not considered a limiting factor for work, productivity was reduced by 26% and social activities were reduced by 31% during active flare-ups. No significant differences were found in tear cytokine pattern production between VKC in children and VKC in adults.
CONCLUSIONS: A late onset VKC-like disease can appear in young adults with signs and symptoms similar to those in pediatric disease, but with less corneal involvement
Effects of cyclosporin A on human conjunctival fibroblasts
No full textobjective: To evaluate the effects of cyclosporin A (CsA) on cytokine and/or collagen production, cell growth, and apoptosis in conjunctival fibroblast cultures.
Methods: Fibroblast cultures derived from normal subjects and patients with vernal keratoconjunctivitis and pemphigoid were exposed to different concentrations of CsA for either 24 hours or 30 days. The effects were evaluated by the colorimetric MTT (3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyl tetrazolium bromide) test to assess cell proliferation, and by the measurement of procollagen I (PIP) and procollagen III (PIIIP) cytokines and total protein in culture medium. CsA-induced apoptosis was assessed by fluorescence-activated cell sorter analysis.
Results: After 24 hours of exposure to doses of CsA of more than 10 mug/mL, cell proliferation and migration were significantly reduced. Cyclosporin A reduced PIP and interleukin 1 (IL-1) production in a dose-dependent manner. Interleukin 6 and IL-8 were increased by 10 mug/mL of CsA, whereas transforming growth factor P, PIIIP, and total protein were unaffected. Cyclosporin A exposure induced apoptosis in a time- and dose-dependent manner. Long-term exposure to CsA reduced IL-6 but did not modify PIIIP production.
Conclusion: Exposure to CsA directly modified fibroblast behavior.
Clinical Relevance: Cyclosporin A ability to accelerate apoptosis in clinically fibrotic tissues may prove to be therapeutic and useful in hyperproliferative conjunctival disorders
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