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Dive into the research topics where Irene Barbazetto is active.

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Featured researches published by Irene Barbazetto.


Archives of Ophthalmology | 1999

Photodynamic Therapy With Verteporfin for Choroidal Neovascularization Caused by Age-related Macular Degeneration: Results of a Single Treatment in a Phase 1 and 2 Study

Ursula Schmidt-Erfurth; Joan W. Miller; M. Sickenberg; Horst Laqua; Irene Barbazetto; Evangelos S. Gragoudas; Leonidas Zografos; Bertrand Piguet; Constantin J. Pournaras; Guy Donati; Anne Marie Lane; Reginald Birngruber; Hubert van den Berg; H. Andrew Strong; Ulrike Manjuris; Todd Gray; Mario Fsadni; Neil M. Bressler

OBJECTIVE To evaluate the safety and short-term visual and fluorescein angiographic effects of a single photodynamic therapy treatment with verteporfin with the use of different dosage regimens in patients with choroidal neovascularization (CNV) from age-related macular degeneration. DESIGN Nonrandomized, multicenter, open-label, clinical trial using 5 dosage regimens. SETTING Four ophthalmic centers in North America and Europe providing retinal care. PARTICIPANTS Patients with subfoveal CNV caused by age-related macular degeneration. METHODS Standardized protocol refraction, visual acuity testing, ophthalmic examination, color photographs, and fluorescein angiograms were used to evaluate the effects of a single treatment of photodynamic therapy with verteporfin. Follow-up was planned through 3 months in 97 patients and for less than 3 months in 31 other patients. RESULTS The mean visual acuity change (and range of change) from baseline at the follow-up examination at week 12 after a single treatment with regimens 1 through 5 was -0.2 (-3 to +2), -0.9 (-9 to +5), -1.6 (-9 to +2), +0.4 (-8 to +7), and +0.1 (-8 to +9) lines, respectively. Only the highest light dose (150 J/cm2) in regimens 2 and 3, which produced angiographic nonperfusion of neurosensory retinal vessels, caused marked vision loss. Some cessation of fluorescein leakage from CNV was achieved without loss of vision when the light dose used was less than 150 J/cm2. Systemic adverse events were rare. Cessation of fluorescein leakage from CNV was noted in all regimens by 1 week after photodynamic therapy. Fluorescein leakage from at least a portion of the CNV reappeared by 4 to 12 weeks after treatment in almost all cases. Progression of classic CNV beyond the area of CNV identified before treatment was noted in 42 (51%) of the 83 eyes with classic CNV followed up for 3 months after a single treatment. Eyes in which the area of any CNV leakage at 12 weeks was less than at baseline had a significantly better visual acuity outcome (+0.8 line) than eyes in which CNV leakage progressed (-0.8 line). CONCLUSIONS Photodynamic therapy with verteporfin achieved short-term cessation of fluorescein leakage from CNV without loss of vision or growth of classic CNV in some patients with age-related macular degeneration. Except for nonperfusion of neurosensory retinal vessels at a light dose of 150 J/cm2, no other adverse events were of concern. Randomized clinical trials to investigate whether this new modality can preserve vision in patients with CNV secondary to age-related macular degeneration are justified.


Retina-the Journal of Retinal and Vitreous Diseases | 2008

Type 3 Neovascularization: The Expanded Spectrum of Retinal Angiomatous Proliferation

K. Bailey Freund; I Van Ho; Irene Barbazetto; Hideki Koizumi; Ketan Laud; Daniela Ferrara; Yoko Matsumoto; John A. Sorenson; Lawrence A. Yannuzzi

Background: Retinal angiomatous proliferation (RAP) is a distinct form of neovascularization in patients with age-related macular degeneration. Lacking definitive sequential histopathologic evidence of its intraretinal versus choroidal origin, the clinical observations of early stages of RAP lesions may provide clues to help further expand our understanding of this entity. Methods: Five eyes of four patients with early Stage 1 RAP were examined. Fundus photography, fluorescein and indocyanine green angiography as well as time-domain and spectral-domain optical coherence tomography were performed. Images were assessed to determine the characteristics of neovascularization in early stage RAP lesions and the response of the lesions to treatment or observation. Results: The analysis of the selected cases suggests a choroidal origin of the neovascular complex with the early formation of a retinal choroidal anastomosis without evidence of underlying occult Type 1 neovascularization. Three eyes responded to a single treatment with intravitreal ranibizumab (0.5 mg) and 2 eyes (1 patient) resolved spontaneously without treatment. Conclusion: The neovascularization in RAP may originate not only from deep retinal capillaries but also from the choroid. We therefore propose the more descriptive term “Type 3 neovascularization” for this entity to emphasize the intraretinal location of the vascular complex and distinguish this type from the two types of neovascularization previously described by J. Donald Gass in his classic text.


American Journal of Ophthalmology | 2009

Refractory Neovascular Age-related Macular Degeneration Secondary to Polypoidal Choroidal Vasculopathy

Minhee Cho; Irene Barbazetto; K. Bailey Freund

PURPOSE To describe a neovascular pattern associated with treatment-refractory neovascular age-related macular degeneration (AMD). DESIGN A retrospective observational case series. METHODS SETTING Clinical practice. PATIENT POPULATION Twelve eyes of 12 patients with neovascular AMD in which a poor anatomic response to anti-vascular endothelial growth factor (VEGF) therapy was related to polypoidal choroidal vasculopathy (PCV). OBSERVATION PROCEDURE Slit-lamp biomicroscopy, optical coherence tomography, fluorescein and indocyanine green angiography. MAIN OUTCOME MEASURES Snellen visual acuity (VA), anatomic response to therapy including presence or absence of retinal edema, hemorrhage, and lipid exudates. RESULTS New or persistent PCV was identified in a cohort of patients demonstrating increasing macular exudation despite regular intravitreal ranibizumab (Lucentis; Genentech Inc, South San Francisco, California, USA) or bevacizumab (Avastin; Genentech Inc) injections for a minimum of 6 months. Treatment with verteporfin photodynamic therapy (PDT), PDT/anti-VEGF combination therapy, or continued anti-VEGF monotherapy resulted in complete resolution of exudation in 9 of 12 patients and partial resolution of exudation in the remaining 3 patients. CONCLUSION Treatment-refractory neovascular AMD may harbor vascular abnormalities such as PCV. Modifications in therapeutic protocols may be indicated in order to improve visual and anatomic outcomes in this population.


Ophthalmology | 2002

Benefits and complications of photodynamic therapy of papillary capillary hemangiomas

Ursula Schmidt-Erfurth; Christine Kusserow; Irene Barbazetto; Horst Laqua

OBJECTIVE To evaluate the potential benefit and risks of photodynamic therapy (PDT) in the treatment of papillary capillary hemangioma. DESIGN Prospective, noncomparative, interventional case series. PARTICIPANTS Five patients with solitary capillary hemangioma on the temporal portion of the optic nerve presenting with exudative decompensation and decrease in visual acuity (VA). METHODS All eyes received a standardized PDT treatment with 6 mg/kg body surface area verteporfin and application of 100 J/cm(2) light at 692 nm. One to three PDT courses were performed until resolution of exudation was achieved. A continuous follow-up was provided with documentation 1 week before and at 4 to 6 weeks, 3 months, and 12 months after the last treatment application. MAIN OUTCOME MEASURES Functional parameters included best-refracted VA (Early Treatment Diabetic Retinopathy Study), and central scanning laser ophthalmoscope (SLO) scotometry and peripheral (automated perimetry) visual fields; anatomic parameters were presence of retinal edema or serous detachment (ophthalmoscopy) and tumor size (ultrasonography). RESULTS Pretreatment VA levels ranged from 20/40 to 20/800; posttreatment levels ranged from 20/64 to 20/2000. Tumor regression with resolution of macular exudate and serous retinal detachment was obtained in all eyes. A decline in VA of 1, 3, and 10 lines, respectively, was documented in three patients. Complications included transient decompensation of vascular permeability, occlusion of retinal vessels, and ischemia of the optic nerve. CONCLUSIONS PDT is successful in reducing tumor size and exudative activity. Vaso-occlusive effects at the level of the retina and optic nerve compromise the functional benefit. Parameters proven safe in choroidal neovascularization may be inappropriate in retinal capillary lesions of the optic nerve.


American Journal of Ophthalmology | 2009

Vitreomacular Adhesion in Active and End-Stage Age-related Macular Degeneration

C. D. Robison; Ilse Krebs; Susanne Binder; Irene Barbazetto; Athanasios I. Kotsolis; Lawrence A. Yannuzzi; Alfredo A. Sadun; J. Sebag

PURPOSE To evaluate vitreomacular relations in different stages of age-related macular degeneration (AMD) without the influence of genetics and environmental factors. DESIGN Retrospective, observational case series. METHODS This was a multicenter study consisting of 29 previously untreated subjects with active exudative (wet) AMD in one eye and active nonexudative (dry) AMD in the fellow eye who were compared with 10 previously untreated subjects with end-stage geographic atrophy in one eye and an end-stage fibrotic (disciform) scar in the fellow eye. All subjects were studied with ultrasonography to identify the presence of posterior vitreous detachment (PVD) and by optical coherence tomography to detect vitreomacular adhesion (VMA). RESULTS The incidence of PVD in eyes with nonexudative AMD was 20 (69%) of 29, compared with 6 (21%) of 29 with active exudative AMD (P = .002). VMA was present in 11 (38%) of 29 of eyes with exudative AMD and in only 3 (10%) of 29 eyes with nonexudative AMD (P = .008). The incidence of PVD in geographic atrophy was 7 (70%) of 10, compared with 4 (40%) of 10 with disciform scar (P = .44). VMA was present in 2 (20%) of 10 eyes with disciform scars and in 0 (0%) of 10 eyes with geographic atrophy (P = .48). CONCLUSIONS PVD may protect against exudative AMD, whereas VMA may promote exudative AMD. This phenomenon is not evident in end-stage disease because of an increased incidence of PVD and a decreased incidence of VMA in eyes with disciform scars. Genetic and environmental factors do not seem to influence these observations.


Evidence-based Eye Care | 2000

Photodynamic Therapy With Verteporfin for Choroidal Neovascularization Caused by Age-related Macular Degeneration

Joan W. Miller; Ursula Schmidt-Erfurth; M. Sickenberg; Constantin J. Pournaras; Horst Laqua; Irene Barbazetto; Leonidas Zografos; Bertrand Piguet; Guy Donati; Anne Marie Lane; Reginald Birngruber; Hubert van den Berg; H. Andrew Strong; Ulrike Manjuris; Todd Gray; Mario Fsadni; Neil M. Bressler; Evangelos S. Gragoudas

OBJECTIVES To evaluate safety and short-term visual acuity and fluorescein angiographic effects of photodynamic therapy (PDT) after retreatments with verteporfin for choroidal neovascularization (CNV) in age-related macular degeneration (AMD) that demonstrated fluorescein leakage after at least 1 course of PDT. DESIGN Nonrandomized, multicenter, open-label phase 1 and 2 clinical trial using 2 different retreatment dosage regimens. SETTING Four ophthalmic centers in Europe and North America providing retinal care. METHODS Standardized protocol refraction, visual acuity testing, ophthalmic examinations, color photographs, and fluorescein angiograms were used to evaluate the results of multiple PDT treatments. Two regimens (regimens 2 and 4) for treatment and retreatment were chosen from 5 used in a single-treatment study. Both regimens used a verteporfin dose of 6 mg/m2 infused for 10 minutes. However, regimen 2 used a light dose of 100 J/cm2 applied 20 minutes after the start of the verteporfin infusion, whereas regimen 4 used a light dose of 50, 75, or 100 J/cm2 applied 15 minutes after infusion commenced. Posttreatment evaluations were planned in 31 participants up to 3 months after up to 2 retreatments given at 2- or 4-week intervals after initial PDT treatment. Similar posttreatment evaluations were planned after retreatments in 5 additional participants who were reenrolled some time more than 12 weeks after an initial PDT treatment. RESULTS The average visual acuity change for the 31 participants who had retreatment within 2 to 4 weeks after the initial treatment and a follow-up examination 16 to 20 weeks after the initial treatment was 0.2 lines (range, -4 to 4 lines) in regimen 2 and -1.0 line (range, -5 to 3 lines) in regimen 4. Similar outcomes were noted in the 5 reenrolled participants. Cessation of fluorescein leakage from classic CNV for at least 1 to 4 weeks could be achieved without loss of visual acuity after at least 2 treatments in 2 (6.5%) of 31 patients. Similar to single-treatment effects, the disappearance of leakage was documented regularly at 1 week after each retreatment. Fluorescein leakage reappeared by 4 to 12 weeks after a retreatment in almost all cases. However, compared with baseline, leakage activity appeared to be reduced after multiple PDT courses. For the 31 patients who had follow-up for 3 months after the last retreatment and had received retreatment 2 to 4 weeks after the initial treatment, progression of CNV beyond the area identified before the retreatment was noted in 10 (48%) of the 21 eyes with classic CNV in regimen 2 and 9 (90%) of 10 eyes in regimen 4. The rate and severity of ocular or systemic adverse events were not increased by multiple applications. CONCLUSIONS Multiple applications of PDT with verteporfin achieve repetitive, short-term cessation of fluorescein leakage from CNV secondary to AMD, without loss of visual acuity. This strategy can be used in randomized clinical trials investigating the efficacy of verteporfin in PDT for recurrent fluorescein dye leakage from persistent or recurrent CNV, following an initial or subsequent PDT treatment, with maintenance of visual acuity. Retreatments may achieve progressive cessation of leakage and prevent further growth of CNV and subsequent visual loss.


American Journal of Ophthalmology | 2010

Incidence of New Choroidal Neovascularization in Fellow Eyes of Patients Treated in the MARINA and ANCHOR Trials

Irene Barbazetto; Namrata Saroj; Howard Shapiro; Pamela Wong; Allen C. Ho; K. Bailey Freund

PURPOSE To explore whether monthly intravitreal ranibizumab injections are associated with a lower rate of new choroidal neovascularization (CNV) in fellow eyes of patients with unilateral neovascular age-related macular degeneration. DESIGN Retrospective data analysis of randomized, controlled clinical trials. METHODS Incidence of new CNV in fellow eyes was calculated at 12 and 24 months from 2 clinical trials (the Minimally Classic/Occult Trial of the Anti-VEGF Antibody Ranibizumab in the Treatment of Neovascular Age-Related Macular Degeneration [MARINA] study and the Anti-VEGF Antibody for the Treatment of Predominantly Classic Choroidal Neovascularization in Age-Related Macular Degeneration [ANCHOR] study), based on fluorescein angiographic reading center criteria and investigator evaluation. Patients treated with monthly ranibizumab (0.3 and 0.5 mg) were compared with those receiving a sham injection (MARINA) or photodynamic therapy (ANCHOR). RESULTS In MARINA, new CNV developed in fellow eyes in 20.3% of the 0.3-mg ranibizumab group by 12 months and in 30.4% by 24 months. The conversion rate in the 0.5-mg ranibizumab group was 21.1% and 38.0% by 12 and 24 months, respectively. In the sham group, 26.4% converted by 12 months and 36.3% converted by 24 months. In ANCHOR, fellow eyes in 15.9% of the 0.3-mg ranibizumab group converted by 12 months and fellow eyes in 23.8% converted by 24 months. The conversion rate in the 0.5-mg ranibizumab group was 24.3% and 35.1% by 12 and 24 months, respectively. In the photodynamic therapy group, 25.4% converted by 12 months and 38.8% converted by 24 months. Differences in conversion rates at 12 and 24 months between the 0.3-mg or 0.5-mg ranibizumab groups and respective controls (sham or photodynamic therapy) were not statistically significant. CONCLUSIONS Results of this study do not support the hypothesis that monthly ranibizumab injections reduce the rate of CNV development in untreated fellow eyes.


Biomedical Engineering Online | 2003

A Method of Drusen Measurement Based on the Geometry of Fundus Reflectance

R. Theodore Smith; Takayuki Nagasaki; Janet R. Sparrow; Irene Barbazetto; Caroline C. W. Klaver; J. Chan

BackgroundThe hallmarks of age-related macular degeneration, the leading cause of blindness in the developed world, are the subretinal deposits known as drusen. Drusen identification and measurement play a key role in clinical studies of this disease. Current manual methods of drusen measurement are laborious and subjective. Our purpose was to expedite clinical research with an accurate, reliable digital method.MethodsAn interactive semi-automated procedure was developed to level the macular background reflectance for the purpose of morphometric analysis of drusen. 12 color fundus photographs of patients with age-related macular degeneration and drusen were analyzed. After digitizing the photographs, the underlying background pattern in the green channel was leveled by an algorithm based on the elliptically concentric geometry of the reflectance in the normal macula: the gray scale values of all structures within defined elliptical boundaries were raised sequentially until a uniform background was obtained. Segmentation of drusen and area measurements in the central and middle subfields (1000 μm and 3000 μm diameters) were performed by uniform thresholds. Two observers using this interactive semi-automated software measured each image digitally. The mean digital measurements were compared to independent stereo fundus gradings by two expert graders (stereo Grader 1 estimated the drusen percentage in each of the 24 regions as falling into one of four standard broad ranges; stereo Grader 2 estimated drusen percentages in 1% to 5% intervals).ResultsThe mean digital area measurements had a median standard deviation of 1.9%. The mean digital area measurements agreed with stereo Grader 1 in 22/24 cases. The 95% limits of agreement between the mean digital area measurements and the more precise stereo gradings of Grader 2 were -6.4 % to +6.8 % in the central subfield and -6.0 % to +4.5 % in the middle subfield. The mean absolute differences between the digital and stereo gradings 2 were 2.8 +/- 3.4% in the central subfield and 2.2 +/- 2.7% in the middle subfield.ConclusionsSemi-automated, supervised drusen measurements may be done reproducibly and accurately with adaptations of commercial software. This technique for macular image analysis has potential for use in clinical research.


Ophthalmologica | 2007

Ocular Photodynamic Therapy – Standard Applications and New Indications (Part 2)

Stefan Mennel; Irene Barbazetto; Carsten H. Meyer; Silvia Peter; Michael Stur

Photodynamic therapy (PDT) has become a well-established treatment for vascular forms of age-related macular degeneration (AMD). The implementation of evidence-based medicine principles into the treatment regimen of AMD seems to be immensly important, since AMD continues to be the most frequent cause of blindness among patients older than 65 years in industrialized countries. Numerous randomized prospective studies demonstrated high levels of evidence for the efficacy of various treatment approaches such as laser photocoagulation, PDT, subretinal surgery or novel anti-angiogenic drugs [Arch Ophthalmol 2006;124:597–599]. The high evidence shown by these studies supported the rationale to use PDT also in additional, less frequent, vasoproliferative diseases. Although these ‘case series’ and ‘individual case control studies’ have a low level of evidence, they give us important information for treatment decisions in these rare conditions. The goal of this survey is to review the current literature regarding PDT in vasoproliferative and exudative ocular diseases outside AMD. Many studies modified the treatment parameters of PDT to address the specific pathology of the underlying disease. Table 1 summarizes the diseases and treatment parameters that are described in this part 2, the entire table of this review is included in part 1 (www.karger.com/doi/10.1159/ 000101922).


Investigative Ophthalmology & Visual Science | 2008

Comprehensive analysis of the candidate genes CCL2, CCR2, and TLR4 in age-related macular degeneration.

Dominiek D. G. Despriet; Arthur A. B. Bergen; Joanna E. Merriam; Jana Zernant; Gaetano R. Barile; R. Theodore Smith; Irene Barbazetto; Simone van Soest; Arne Bakker; Paulus T. V. M. de Jong; Rando Allikmets; Caroline C. W. Klaver

PURPOSE To determine whether variants in the candidate genes TLR4, CCL2, and CCR2 are associated with age-related macular degeneration (AMD). METHODS This study was performed in two independent Caucasian populations that included 357 cases and 173 controls from the Netherlands and 368 cases and 368 controls from the United States. Exon 4 of the TLR4 gene and the promoter, all exons, and flanking intronic regions of the CCL2 and CCR2 genes were analyzed in the Dutch study and common variants were validated in the U.S. study. Quantitative (q)PCR reactions were performed to evaluate expression of these genes in laser-dissected retinal pigment epithelium from 13 donor AMD and 13 control eyes. RESULTS Analysis of single nucleotide polymorphisms (SNPs) in the TLR4 gene did not show a significant association between D299G or T399I and AMD, nor did haplotypes containing these variants. Univariate analyses of the SNPs in CCL2 and CCR2 did not demonstrate an association with AMD. For CCR2, haplotype frequencies were not significantly different between cases and controls. For CCL2, one haplotype containing the minor allele of C35C was significantly associated with AMD (P = 0.03), but this did not sustain after adjustment for multiple testing (q = 0.30). Expression analysis did not demonstrate altered RNA expression of CCL2 and CCR2 in the retinal pigment epithelium from AMD eyes (for CCL2 P = 0.62; for CCR2 P = 0.97). CONCLUSIONS No evidence was found of an association between TLR4, CCR2, and CCL2 and AMD, which implies that the common genetic variation in these genes does not play a significant role in the etiology of AMD.

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