Network


Latest external collaboration on country level. Dive into details by clicking on the dots.

Hotspot


Dive into the research topics where Anat Loewenstein is active.

Publication


Featured researches published by Anat Loewenstein.


Ophthalmology | 2010

Randomized, Sham-Controlled Trial of Dexamethasone Intravitreal Implant in Patients with Macular Edema Due to Retinal Vein Occlusion

Julia A. Haller; Francesco Bandello; Rubens Belfort; Mark S. Blumenkranz; Mark C. Gillies; Jeffrey S. Heier; Anat Loewenstein; Y. Yoon; Marie-Louise Jacques; Jenny Jiao; Xiao-Yan Li; Scott M. Whitcup

OBJECTIVE To evaluate the safety and efficacy of dexamethasone intravitreal implant (DEX implant; OZURDEX, Allergan, Inc., Irvine, CA) compared with sham in eyes with vision loss due to macular edema (ME) associated with branch retinal vein occlusion (BRVO) or central retinal vein occlusion (CRVO). DESIGN Two identical, multicenter, masked, randomized, 6-month, sham-controlled clinical trials (each of which included patients with BRVO and patients with CRVO). PARTICIPANTS A total of 1267 patients with vision loss due to ME associated with BRVO or CRVO. INTERVENTION A single treatment with DEX implant 0.7 mg (n = 427), DEX implant 0.35 mg (n = 414), or sham (n = 426). MAIN OUTCOME MEASURES The primary outcome measure for the pooled data from the 2 studies was time to achieve a > or =15-letter improvement in best-corrected visual acuity (BCVA). Secondary end points included BCVA, central retinal thickness, and safety. RESULTS After a single administration, the time to achieve a > or =15-letter improvement in BCVA was significantly less in both DEX implant groups compared with sham (P<0.001). The percentage of eyes with a > or =15-letter improvement in BCVA was significantly higher in both DEX implant groups compared with sham at days 30 to 90 (P<0.001). The percentage of eyes with a > or =15-letter loss in BCVA was significantly lower in the DEX implant 0.7-mg group compared with sham at all follow-up visits (P< or =0.036). Improvement in mean BCVA was greater in both DEX implant groups compared with sham at all follow-up visits (P< or =0.006). Improvements in BCVA with DEX implant were seen in patients with BRVO and patients with CRVO, although the patterns of response differed. The percentage of DEX implant-treated eyes with intraocular pressure (IOP) of > or =25 mmHg peaked at 16% at day 60 (both doses) and was not different from sham by day 180. There was no significant between-group difference in the occurrence of cataract or cataract surgery. CONCLUSIONS Dexamethasone intravitreal implant can both reduce the risk of vision loss and improve the speed and incidence of visual improvement in eyes with ME secondary to BRVO or CRVO and may be a useful therapeutic option for eyes with these conditions.


Ophthalmology | 2011

Dexamethasone intravitreal implant in patients with macular edema related to branch or central retinal vein occlusion twelve-month study results

Julia A. Haller; Francesco Bandello; Rubens Belfort; Mark S. Blumenkranz; Mark C. Gillies; Jeffrey S. Heier; Anat Loewenstein; Young Hee Yoon; Jenny Jiao; Xiao-Yan Li; Scott M. Whitcup

OBJECTIVE To evaluate the safety and efficacy of 1 or 2 treatments with dexamethasone intravitreal implant (DEX implant) over 12 months in eyes with macular edema owing to branch or central retinal vein occlusion (BRVO or CRVO). DESIGN Two identical, multicenter, prospective studies included a randomized, 6-month, double-masked, sham-controlled phase followed by a 6-month open-label extension. PARTICIPANTS We included 1256 patients with vision loss owing to macular edema associated with BRVO or CRVO. METHODS At baseline, patients received DEX implant 0.7 mg (n = 421), DEX implant 0.35 mg (n = 412), or sham (n = 423) in the study eye. At day 180, patients could receive DEX implant 0.7 mg if best-corrected visual acuity (BCVA) was <84 letters or retinal thickness was >250 μm. MAIN OUTCOME MEASURES The primary outcome for the open-label extension was safety; BCVA was also evaluated. RESULTS At day 180, 997 patients received open-label DEX implant. Except for cataract, the incidence of ocular adverse events was similar in patients who received their first or second DEX implant. Over 12 months, cataract progression occurred in 90 of 302 phakic eyes (29.8%) that received 2 DEX implant 0.7 mg injections versus 5 of 88 sham-treated phakic eyes (5.7%); cataract surgery was performed in 4 of 302 (1.3%) and 1 of 88 (1.1%) eyes, respectively. In the group receiving two 0.7-mg DEX implants (n = 341), a ≥ 10-mmHg intraocular pressure (IOP) increase from baseline was observed in (12.6% after the first treatment, and 15.4% after the second). The IOP increases were usually transient and controlled with medication or observation; an additional 10.3% of patients initiated IOP-lowering medications after the second treatment. A ≥ 15-letter improvement in BCVA from baseline was achieved by 30% and 32% of patients 60 days after the first and second DEX implant, respectively. CONCLUSIONS Among patients with macular edema owing to BRVO or CRVO, single and repeated treatment with DEX implant had a favorable safety profile over 12 months. In patients who qualified for and received 2 DEX implant injections, the efficacy and safety of the 2 implants were similar with the exception of cataract progression. FINANCIAL DISCLOSURE(S) Proprietary or commercial disclosure may be found after the references.


Retina-the Journal of Retinal and Vitreous Diseases | 2006

Electrophysiologic and retinal penetration studies following intravitreal injection of bevacizumab (Avastin).

Jonathan Shahar; Robert L. Avery; Gad Heilweil; Adiel Barak; Esther Zemel; Geoffrey P. Lewis; P.T. Johnson; Steven K. Fisher; Ido Perlman; Anat Loewenstein

Purpose: Intravitreal bevacizumab (Avastin; Genentech Inc., San Francisco, CA) is a new treatment for age-related macular degeneration. The aim of this study was to evaluate retinal penetration and toxicity of bevacizumab. Methods: Ten albino rabbits were injected intravitreally with 0.1 mL (2.5 mg) of Avastin into one eye and 0.1 mL saline into the fellow eye. The electroretinogram (ERG) was recorded after 3 hours, 3 days, and 1, 2, and 4 weeks. The visual evoked potential (VEP) was recorded after 4 weeks. Confocal immunohistochemistry was used to assess retinal penetration. Results: The ERG responses of the control and experimental eyes were similar in amplitude and pattern throughout the follow-up period. The flash VEP responses of the experimental eyes were of normal pattern and amplitude and did not differ from those recorded by stimulation of the control eye alone. Full thickness retinal penetration was present at 24 hours and was essentially absent at 4 weeks. Conclusions: Bevacizumab was found to be nontoxic to the retina of rabbits based on electrophysiologic studies. Full thickness retinal penetration may explain observed clinical effects of intravitreal bevacizumab. Although it is difficult to directly extrapolate to humans, our study supports the safe use of intravitreal bevacizumab injection.


Nature Genetics | 2003

Heterozygous mutations of the kinesin KIF21A in congenital fibrosis of the extraocular muscles type 1 (CFEOM1).

Koki Yamada; Caroline Andrews; Wai Man Chan; Craig A. McKeown; Adriano Magli; Teresa de Berardinis; Anat Loewenstein; Moshe Lazar; Michael O'Keefe; Robert D. Letson; Arnold London; Mark S. Ruttum; Naomichi Matsumoto; Nakamichi Saito; Lisa Morris; Monte A. Del Monte; Roger H. Johnson; Eiichiro Uyama; Willem A. Houtman; Berendina De Vries; Thomas J. Carlow; Blaine L. Hart; Nicolas Krawiecki; John M. Shoffner; Marlene C. Vogel; James A. Katowitz; Scott M. Goldstein; Alex V. Levin; Emin Cumhur Sener; Banu T. Öztürk

Congenital fibrosis of the extraocular muscles type 1 (CFEOM1; OMIM #135700) is an autosomal dominant strabismus disorder associated with defects of the oculomotor nerve. We show that individuals with CFEOM1 harbor heterozygous missense mutations in a kinesin motor protein encoded by KIF21A. We identified six different mutations in 44 of 45 probands. The primary mutational hotspots are in the stalk domain, highlighting an important new role for KIF21A and its stalk in the formation of the oculomotor axis.


British Journal of Ophthalmology | 2014

Guidelines for the management of neovascular age-related macular degeneration by the European Society of Retina Specialists (EURETINA)

Ursula Schmidt-Erfurth; Victor Chong; Anat Loewenstein; Michael Larsen; Eric H. Souied; Reinier O. Schlingemann; Bora Eldem; Jordi Monés; G. Richard; Francesco Bandello

Age-related macular degeneration (AMD) is still referred to as the leading cause of severe and irreversible visual loss world-wide. The disease has a profound effect on quality of life of affected individuals and represents a major socioeconomic challenge for societies due to the exponential increase in life expectancy and environmental risks. Advances in medical research have identified vascular endothelial growth factor (VEGF) as an important pathophysiological player in neovascular AMD and intraocular inhibition of VEGF as one of the most efficient therapies in medicine. The wide introduction of anti-VEGF therapy has led to an overwhelming improvement in the prognosis of patients affected by neovascular AMD, allowing recovery and maintenance of visual function in the vast majority of patients. However, the therapeutic benefit is accompanied by significant economic investments, unresolved medicolegal debates about the use of off-label substances and overwhelming problems in large population management. The burden of disease has turned into a burden of care with a dissociation of scientific advances and real-world clinical performance. Simultaneously, ground-breaking innovations in diagnostic technologies, such as optical coherence tomography, allows unprecedented high-resolution visualisation of disease morphology and provides a promising horizon for early disease detection and efficient therapeutic follow-up. However, definite conclusions from morphologic parameters are still lacking, and valid biomarkers have yet to be identified to provide a practical base for disease management. The European Society of Retina Specialists offers expert guidance for diagnostic and therapeutic management of neovascular AMD supporting healthcare givers and doctors in providing the best state-of-the-art care to their patients. Trial registration number NCT01318941.


Ophthalmology | 2000

Hyperhomocystinemia in patients with nonarteritic anterior ischemic optic neuropathy, central retinal artery occlusion, and central retinal vein occlusion

Pazit Pianka; Yehoshua Almog; Oran Man; Michaela Goldstein; Ben-Ami Sela; Anat Loewenstein

OBJECTIVE This study aimed to determine the prevalence of hyperhomocystinemia among patients with nonarteritic anterior ischemic optic neuropathy (NAION), central retinal artery occlusion (CRAO), or central retinal vein occlusion (CRVO). DESIGN Retrospective, case-control study. PARTICIPANTS The study cohort consisted of 74 consecutive patients with NAION, CRAO, or CRVO who were examined at the Retina or Neuro-ophthalmological Unit of the Tel-Aviv Sourasky Medical Center from 1998 through 1999. The control group consisted of 81 consecutive patients of similar gender and age with no history of these pathologic conditions. MAIN OUTCOME MEASURES Plasma homocystine levels of all study participants were obtained. RESULTS Eighteen of 40 patients (45%) with NAION and eight of 13 patients (61.5%) with CRAO had hyperhomocystinemia compared with three of 21 (14.3%) in the CRVO group (P < 0.001) and eight (9.8%) in the control group (P < 0.0001). Hypertension and ischemic heart disease were significantly more prevalent in the NAION patients with elevated plasma homocystine. CONCLUSIONS Our findings suggest that hyperhomocystinemia is a risk factor for NAION and CRAO.


Neuron | 2003

Area-Specific Amblyopic Effects in Human Occipitotemporal Object Representations

Yulia Lerner; P Pianka; B Azmon; H. Leiba; C. Stolovitch; Anat Loewenstein; Michal Harel; Talma Hendler; Rafael Malach

The role of early visual experience in the establishment of human high-order visual areas is poorly understood. Here we investigated this issue using human amblyopia--a developmental visual disorder, which manifests a central vision (acuity) deficit. Previous fMRI studies of amblyopes have described abnormal functional activations in early retinotopic areas. Here we report the surprising finding of a selective object-related abnormality in high-order occipitotemporal cortex. Specifically, we found that face-related cortical areas show a severe disconnection from the amblyopic eye, while building-related regions remain essentially normal. The selectivity of the deficit highlights the differential computations performed in the different object-related areas and is compatible with the suggested association of face regions with analysis of fine detail.


Journal of Glaucoma | 2003

HYPERHOMOCYSTINEMIA IN PSEUDOEXFOLIATION GLAUCOMA

Igal Leibovitch; Shimon Kurtz; Gabi Shemesh; Michaella Goldstein; Ben-Ami Sela; Moshe Lazar; Anat Loewenstein

PurposeTo determine the prevalence of hyperhomocystinemia in patients with pseudoexfoliation glaucoma. Patients and MethodsThis prospective study included 30 patients with glaucoma and 30 age-matched controls with no history of ocular disease who were undergoing routine physical checkups. Plasma homocysteine levels of all the study participants were determined using high-performance liquid chromatography, and values exceeding 15 &mgr;mol/L were considered elevated. ResultsThe mean plasma homocysteine level was 16.80 ± 3.20 and 12.39 ± 1.97 &mgr;mol/L in glaucoma patients and controls, respectively (P <0.0001). Fifteen glaucoma patients (50%) had hyperhomocystinemia compared with 3 controls (10%) (P = 0.0015). ConclusionHyperhomocystinemia may be associated with pseudoexfoliation glaucoma, which may partially explain the increased risk of vascular diseases among patients with pseudoexfoliation syndrome.


Ophthalmology | 1997

Late Onset Corneal Haze after Photorefractive Keratectomy for Moderate and High Myopia

Isaac Lipshitz; Anat Loewenstein; David Varssano; Moshe Lazar

BACKGROUND Corneal haze after photorefractive keratectomy (PRK) usually appears within 4 weeks after the procedure. A new type of corneal haze, starting relatively late after PRK, is reported. METHODS The authors reviewed the files of their first 1000 consecutive patients who completed a follow-up of 12 months or more and identified all those who had clear corneas for at least 4 months, after which corneal haze appeared. The clinical course in these patients was evaluated. RESULTS Late onset corneal haze (LOCH) had occurred in 18 eyes of 17 patients (incidence, 1.8%), appearing 4 to 12 months after PRK and resulting in decreased visual acuity and regression. Treatment with topical steroids or reoperation resulted in partial reversibility of haze and regression. CONCLUSIONS A new entity of LOCH is described. The appearance of LOCH suggests that corneal healing and remodeling continue for at least 1 year after PRK.


Ophthalmologica | 2011

Management of Retinal Vein Occlusion – Consensus Document

Gabriel Coscas; Anat Loewenstein; Albert J. Augustin; Francesco Bandello; Maurizio Battaglia Parodi; M. Paolo Lanzetta; Jordi Monés; Marc D. de Smet; G. Soubrane; Giovanni Staurenghi

Retinal vein occlusion (RVO) can have severe consequences for the people affected by the disease, including visual loss with costly social repercussions. Currently, there is no European consensus with regard to the management of RVO. Following a careful review of the medical literature as well as the data from several clinical trials, a collaborative group of retina specialists put forth practical recommendations based on the best available scientific evidence for the clinical approach to RVO. Taking into consideration the recent advances in diagnostic tools and management options, the present document aims to provide the European ophthalmologists with guidelines for clinical practice to the benefit of their patients.

Collaboration


Dive into the Anat Loewenstein's collaboration.

Top Co-Authors

Avatar
Top Co-Authors

Avatar
Top Co-Authors

Avatar
Top Co-Authors

Avatar

Ido Perlman

Rappaport Faculty of Medicine

View shared research outputs
Top Co-Authors

Avatar

Elad Moisseiev

University of California

View shared research outputs
Top Co-Authors

Avatar
Top Co-Authors

Avatar
Top Co-Authors

Avatar

Esther Zemel

Rappaport Faculty of Medicine

View shared research outputs
Top Co-Authors

Avatar
Top Co-Authors

Avatar

Michaela Goldstein

Tel Aviv Sourasky Medical Center

View shared research outputs
Researchain Logo
Decentralizing Knowledge