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Stefano Barabino

Publications and source records attributed to Stefano Barabino.

16 recordsLinked to original sources
PubMed2006

Keratocyte apoptosis and failure of corneal allografts.

BACKGROUND: Murine models of high-risk and low-risk corneal transplantation were used to determine the role of keratocyte apoptosis in the failure of orthotopic allogeneic corneal transplants. MATERIALS AND METHODS: Normal (low-risk, low-rejecting) and inflamed/vascularized (high-risk, high-rejecting) BALB/c recipient beds received fully mismatched C57BL/6 corneal allografts. Apoptosis was detected in the corneal stroma at various time points using an in situ terminal deoxynucleotide tranferase-mediated dUTP nick-end labeling assay, and ex vivo via Western analysis for active caspase-3. Apoptosis was also measured in a (donor-type) C57BL/6 keratocyte cell line after stimulation of Fas or via use of various pro-inflammatory cytokines. RESULTS: Significantly more apoptotic cells were present in the stroma of rapidly rejecting high-risk corneal allografts compared with low-risk grafts. Apoptotic cells were shown to be nearly uniformly CD45 and hence of a non-hematopoetic lineage. Apoptosis, however, was not present in highly inflamed but ungrafted corneas. Apoptosis was induced in keratocytes in vitro by dual stimulation with agonistic Fas mAb and either interleukin-1beta or tumor necrosis factor-alpha. CONCLUSION: Apoptosis of resident non-bone marrow-derived fibroblastic cells of the corneal stroma is strongly correlated with the failure of corneal allografts, particularly in the highly inflamed microenvironment of the high-risk allograft.

Animals↗
PubMed2005

Effects of a 0.9% sodium chloride ophthalmic solution on the ocular surface of symptomatic contact lens wearers.

BACKGROUND: Ocular surface-related discomfort is the main reason for stopping contact lens wear. We carried out a study to evaluate the efficacy of preservative-free artificial tears containing 0.9% sodium chloride on ocular surface signs and symptoms in contact lens wearers experiencing discomfort and its possible influence on the duration of contact lens wear. METHODS: We studied 49 contact lens wearers experiencing discomfort who had normal results of slit-lamp biomicroscopy, a fluorescein tear film break-up time (BUT) of 10 seconds or more, and wetting greater than 5 mm in 5 minutes on the Schirmer 1 test with and without anesthesia. Twenty-nine subjects (16 men and 13 women with a mean age of 32.5 years [standard deviation (SD) 8.7 years]) received one instillation of the 0.9% sodium chloride solution four times daily in the lower conjunctival fornix for 21 days. Twenty subjects (12 men and 8 women with a mean age of 35.1 [SD 6.2] years) received no drops and served as a control group. The overall comfort and duration of contact lens wear, results of tear film analysis and adverse events were recorded on days 7 and 21. Patients rated their symptoms (while not receiving any medications or hydrating solutions) on a 100-mm visual analogue scale with "Excellent (lenses not felt)" at the left and "Very uncomfortable (lenses cause irritation or discomfort)" at the right. Measurement of corrected visual acuity, slit-lamp examination, determination of the tear film BUT, the Schirmer 1 test with and without anesthesia, and assessment of the colour and surface of the lens were performed at baseline and at day 21. We analysed the data for the more uncomfortable eye or, if the eyes were equally uncomfortable, the right eye. RESULTS: Significant lessening of ocular discomfort was observed in the treatment group during the study: the mean rating on the visual analogue scale at baseline was 60.2 mm (SD 12.7 mm), compared with 35.8 mm (SD 18.0 mm) at day 21 (p < 0.001, Student's t test). The duration of contact lens wear was significantly longer at day 21 than at baseline (7.0 [SD 2.6] hours vs. 6.4 [SD 2.6] hours, p < 0.05, Student's t test), and the proportion of subjects with conjunctival hyperemia was significantly lower at day 21 (48.3% vs. 82.8%, p < 0.05, chi2 test). No statistically significant changes were observed in tear film BUT, results of the Schirmer 1 test, corneal punctate staining by fluorescein or results of tear film analysis. The treatment was well tolerated by all patients. No significant differences in any of the variables studied were observed in the control group. INTERPRETATION: Treatment with a preservative-free 0.9% sodium chloride ophthalmic solution reduced ocular surface discomfort and extended the duration of contact lens wear without interfering with the tear film or contact lens materials. Long-term studies are needed to confirm the role of this solution in reducing discomfort experienced by contact lens wearers.

Adult↗
PubMed2005

Radiotherapy-induced ocular surface disease.

Today radiation is routinely used as a therapeutic modality for select tumors of the orbit, adnexa, paranasal sinus, and nasopharynx. Despite significant improvements in mechanisms of delivery and protective shielding, acute and chronic complications of radiation can affect different segments of the eye. In this report, we provide an overview of ocular damage secondary to radiotherapy. We identify the characteristic clinical changes and underlying pathophysiologic mechanisms involving the ocular surface and provide a rational approach to their prevention and treatment.

Eye↗
PubMed2005

Distribution of conjunctival HLA-DR expression and the pathogenesis of damage in early dry eyes.

PURPOSE: To examine the expression of HLA-DR, a marker of inflammation, in the early stages of dry eye disease and to locate the appearance of this marker on specific areas of the bulbar conjunctiva. METHODS: Dry eye patients were identified and their condition classified as mild (n = 16) or moderate (n = 16) based on Schirmer testing, vital staining, tear break-up time, and symptom questionnaire scores. Brush cytology was used to collect epithelial cells from the nasal, temporal, and superior conjunctivae of patients and age-matched controls. HLA-DR positive cells were detected by immunohistochemical staining and quantified. RESULTS: Patients with moderate dry eye had the highest rate of conjunctival HLA-DR-positive cells, with significantly higher rates than controls regardless of which region of the conjunctiva was sampled (P < 0.01). The mild dry eye group had similar rates of HLA-DR-positive cells in the superior conjunctival region compared with controls. However, in the nasal and temporal regions, they displayed a significantly higher rate of HLA-DR-positive cells than controls (P < 0.01) and the nasal region showed a significant difference (P < 0.01) when compared with the temporal one. Some of these mild dry eyes had no vital staining. CONCLUSIONS: The HLA-DR expression pattern in mild and moderate dry eyes appears to reflect disease progression. Overexpression of HLA-DR in mild dry eyes showing no vital staining suggests that inflammation may be a primary cause of ocular surface damage. These data support the use of immunomodulatory drugs in the treatment of dry eye disease.

Adult↗
PubMed2005

The controlled-environment chamber: a new mouse model of dry eye.

PURPOSE: To develop a controlled-environment chamber (CEC) for mice and verify the effects of a low-humidity setting on ocular surface signs in normal mice. METHODS: Eight- to 12-week-old BALB/c mice were used in a controlled-environment chamber (CEC) where relative humidity (RH), temperature (T), and airflow (AF) are regulated and monitored. Mice were placed into the CEC and exposed to specific environmentally controlled conditions (RH = 18.5% +/- 5.1%, AF = 15 L/min, T = 21-23 degrees C) for 3, 7, 14, and 28 days. Control mice were kept in a normal environment (RH = 50%-80%, no AF, T = 21-23 degrees C) for the same duration. Aqueous tear production by means of the cotton thread test, corneal fluorescein staining (score, 0-15), and goblet cell density in the superior and inferior conjunctiva were measured by a masked observer. RESULTS: No statistically significant differences between the groups were found at baseline. Decreased tear secretion and increased corneal fluorescein staining were significantly present on day 3, 7, 14, and 28 in animals kept in the CEC. Goblet cell density was significantly decreased in the superior conjunctiva on day 7, and on day 3, 7, and 14 in the inferior conjunctiva in the CEC-kept mice compared with control animals. CONCLUSIONS: This study indicates that exposure of normal mice to a low-humidity environment in a CEC can lead to significant alterations in tear secretion, goblet cell density, and acquisition of dry eye-related ocular surface signs.

Air↗
PubMed2005

Novel expression and characterization of lymphatic vessel endothelial hyaluronate receptor 1 (LYVE-1) by conjunctival cells.

PURPOSE: Lymphatic vessel endothelial hyaluronic acid receptor (LYVE-1) is a newly discovered lymphatic-specific marker. To date, there is no report of its expression on conjunctival cells. The purpose of this study was to investigate the expression of LYVE-1 in normal conjunctiva, to phenotype LYVE-1+ cells, and to study changes in their expression levels during corneal inflammation. METHODS: Flat-mounted conjunctivae or cross sections of eyeballs were harvested from BALB/c mice (6-8 weeks of age) for immunofluorescent confocal microscopic studies. RESULTS: The data demonstrate, for the first time, that in addition to its expression on lymphatic vessels, LYVE-1 was expressed on CD45+, CD11b+, and CD31- conjunctival cells, indicating a bone-marrow-derived monocytic lineage. Surprisingly, the number of cells that expressed LYVE-1 decreased during corneal inflammation, in conjunction with ingrowth of lymphatics into the cornea. CONCLUSIONS: A new population of monocytic cells has been found to express LYVE-1 in normal conjunctiva. These cells that normally express LYVE-1 may act as a reservoir for lymphangiogenesis and cell recruitment when the immune system is challenged.

Animals↗
PubMed2004

Amniotic membrane transplantation in a case of ligneous conjunctivitis.

PURPOSE: To report a case of ligneous conjunctivitis treated with amniotic membrane transplantation. DESIGN: Interventional case report. METHODS: A 44-year-old woman presented with woodlike lesions in the upper and lower tarsal conjunctiva, blepharoptosis, and reduced visual acuity in the left eye. After confirmation of the diagnosis of ligneous conjunctivitis, she underwent amniotic membrane transplantation. RESULTS: At the 2-month, 4-month, and 6-month examinations, the tarsal conjunctiva appeared free from membranes. At 8 months, the patient underwent amniotic membrane transplantation for small recurrences. At the 36-month examination, no membranes were evident, and visual acuity was 20/20. CONCLUSIONS: In this first report of amniotic membrane transplantation in a case of ligneous conjunctivitis, we found that conjunctival reconstruction shows promising results in this difficult-to-manage disease.

Adult↗
PubMed2004

Tear film and ocular surface tests in animal models of dry eye: uses and limitations.

Many ocular surface tests have been developed for the clinical diagnosis of keratoconjunctivitis sicca, and several have been used to 'validate' animal models of Sjogren's and non-Sjogren's dry eye. However, many of these tests themselves have not been systematically studied or standardized, and yet their use in animal models of dry eye is common. This review provides a rational approach and systematic review of the tear film and ocular surface tests described in the literature that may be applicable to the current animal models of dry eye, with particular emphasis on their limitations, along with some suggestions regarding their standardization and applications in eye research.

Animals↗
PubMed2003

Role of amniotic membrane transplantation for conjunctival reconstruction in ocular-cicatricial pemphigoid.

PURPOSE: To evaluate the role and the effectiveness over time of amniotic membrane transplantation (AMT) as a first-step procedure to treat conjunctival reconstruction in late-stage ocular-cicatricial pemphigoid (OCP). DESIGN: Prospective interventional noncomparative case series. PARTICIPANTS: Nine eyes (9 patients) with advanced OCP. METHODS: Preoperatively, the ocular surface conditions were evaluated by immunohistochemistry of conjunctival biopsy and impression cytology specimens. The amniotic membrane was obtained during cesarean section from women who were 39 weeks pregnant and seronegative for human immunodeficiency virus, hepatitis B and C, and syphilis; it was processed, histologically tested, and stored at -80 degrees C. After scar tissue was removed, the preserved amniotic membrane was placed over the cornea, the bulbar, and tarsal conjunctiva, and was secured with 8-0 Vicryl sutures to the conjunctival edges and the deep fornices with double-armed 6-0 silk sutures. In 2 cases a double layer of amniotic membrane was transplanted. All patients received immunosuppressive systemic therapy and preservative-free tear substitutes and steroids topically for at least 6 months. During follow-up (average, 48 weeks; range, 28-96 weeks), a new standardized method was used to evaluate the fornix depth, and impression cytology testing was performed and conjunctival inflammation recorded and used as parameters for monitoring disease activity. MAIN OUTCOME MEASURES: Symblepharon, increased inferior fornix depth, presence of conjunctival goblet cells, and the degree of conjunctival inflammation. RESULTS: The conjunctival surface was free from symblepharon in all subjects for the first 16 weeks. At the week 28 examination, a small area of symblepharon was present in four eyes (44.4%). The depth of the fornix was significantly (P < 0.0001, analysis of variance) improved at weeks 4, 16, and 28. The normal conjunctival epithelium with goblet cells was restored in 6 of 9 eyes (66.7%) at the week 4 examination and in 4 eyes (44.4%) at the week 28 examination. Conjunctival inflammation was clinically but not statistically reduced. The visual acuity improved in 5 subjects. CONCLUSIONS: AMT can be a first-step procedure for ocular surface reconstruction in OCP, but its effectiveness deteriorates slightly over time.

Aged↗
PubMed2003

Amniotic membrane transplantation elicits goblet cell repopulation after conjunctival reconstruction in a case of severe ocular cicatricial pemphigoid.

PURPOSE: The surgical procedures used until now to rebuild the conjunctiva in patients affected by ocular cicatricial pemphigoid (OCP) have not demonstrated appreciable anatomical and functional success. This study reports the postoperative clinical and cytological outcomes of a human amniotic membrane transplantation (AMT) to rebuild the conjunctiva in a case of late stage OCP. METHODS: We present a 75-year-old woman with a severe form of pemphigoid with entropion, trichiasis, symblepharon and blunting of the fornices, who underwent excision of the scarred and inflamed tissue covering the ocular surface and AMT. RESULTS: Our data show an improvement of the ocular surface condition, with reacquired fornix depth, reduced inflammation and presence of goblet cells at each follow-up. CONCLUSION: Amniotic membrane transplantation was successful as a first step procedure to reduce inflammation and to rebuild a physiological conjunctival epithelium in late stage OCP.

Aged↗
PubMed2003

Systemic linoleic and gamma-linolenic acid therapy in dry eye syndrome with an inflammatory component.

PURPOSE: To evaluate the efficacy and anti-inflammatory activity of systemic linoleic (LA) and gamma-linolenic acid (GLA), which decrease chronic inflammation in rheumatoid arthritis, on the ocular surface of patients with keratoconjunctivitis sicca. METHODS: In a randomized clinical trial, 26 patients with aqueous-deficient keratoconjunctivitis sicca were consecutively selected from patients presenting to Department of Neurosciences, Ophthalmology and Genetics, University of Genoa. The diagnosis was based on dry eye symptom survey score, Schirmer-1 test values, positive vital staining with lissamine green, and fluorescein break-up time (FBUT). All patients had ocular surface inflammation based on HLA-DR expression, a major histocompatibility class II antigen, on epithelial bulbar conjunctiva samples. The subjects were randomly divided into two groups of 13 patients each. The study group received tablets containing LA (28.5 mg) and GLA (15 mg) twice daily for 45 days and used tears; the control group received a tear substitute and a placebo tablet for 45 days. RESULTS: Statistically significant changes in symptoms (p < 0.005), lissamine green staining (p < 0.005), and ocular surface inflammation (p < 0.05) occurred in the study group compared with controls. HLA-DR expression varied from 58.5 +/- 14.1% positive conjunctival cells to 41.3 +/- 18.9% in the treated group and from 61.4 +/- 21.9% to 58.0 +/- 13.3% in the controls. No statistically significant difference between groups was found for FBUT and the Schirmer-1 test. CONCLUSIONS: Therapy with LA and GLA and tear substitutes reduces ocular surface inflammation and improves dry eye symptoms. Long-term studies are needed to confirm the role of this new therapy for keratoconjunctivitis sicca.

Conjunctiva↗
PubMed2002

HLA-DR expression in conjunctival cells after latanoprost.

The purpose of this randomized, controlled, masked study was to evaluate the effects of latanoprost 0.005% (Xalatan, Pharmacia and Upjohn, Milan, Italy) on the ocular surface in patients with ocular hypertension or primary open-angle glaucoma. The study group included 14 patients who underwent latanoprost 0.005% eye drops once a day in both eyes for 4 months. The control group underwent unpreserved substitute tears eye drops (Aquasalina, Bruschettini, Genoa, Italy) with the same posology and the same concentration of benzalkonium chloride (0.02%). Patients were controlled at 1, 3 and 4 months for symptoms, intraocular pressure, corneal sensitivity (Cochet-Bonnet test) and fluorescein staining. At the same control times, they underwent impression cytology and conjunctival brush cytology. Immunohistochemical techniques were used to detect HLA-DR expression in conjunctival cells. At each control, no significant statistical differences were found between the study and the control group, except for a higher expression of HLA-DR in the latanoprost group (p < 0.001). Since HLA-DR is a marker of ocular surface inflammation, this study suggests that a subclinical inflammatory reaction is present in the ocular surface of patients under latanoprost therapy. The pathway by which the inflammation is stimulated is yet unknown.

Aged↗
PubMedDate not supplied

Automated lamellar keratoplasty for recurrent granular corneal dystrophy after phototherapeutic keratectomy.

PURPOSE: To evaluate the safety and efficacy of automated lamellar keratoplasty for the treatment of recurrent granular corneal dystrophy after phototherapeutic keratectomy (PTK). METHODS: We performed a prospective interventional noncomparative case study of nine eyes (seven patients) with severe recurrent granular corneal dystrophy after PTK. An automated microkeratome was used to cut partial-thickness sections through the anterior surface of the donor and host corneas. The donor disc was placed on the recipient bed with four or eight interrupted sutures. The sutures were removed between 4 and 6 weeks postoperatively. Visual acuity, corneal clarity, corneal thickness, and corneal topography were assessed before and at different time points after surgery. RESULTS: During a mean follow-up period of 18.9 +/- 4.1 months, all grafts were transparent without visible opacity at the interface, and no serious complications occurred. In all cases, the visual acuity improved: seven eyes had best spectacle-corrected visual acuity of > or = 20/40; two eyes reached 20/25. At last follow-up > 12 months postoperatively, the mean corneal refractive power had significantly increased by 2.34 +/- 0.93 diopters (D) (P<.001), and the corneal astigmatism significantly decreased by 0.91 +/- 0.98 D (P<.05). The mean corneal thickness was 477.4 +/- 26.9 microm preoperatively and 507.8 +/- 23.4 microm at last follow-up (P<.001). CONCLUSIONS: Our findings suggest that automated lamellar keratoplasty for the treatment of recurrent granular corneal dystrophy is a safe and effective method of improving visual acuity, but recurrence remains a risk.

Adult↗