The Experts below are selected from a list of 69 Experts worldwide ranked by ideXlab platform

Okihiro Nishi - One of the best experts on this subject based on the ideXlab platform.

  • correlation between metamorphopsia and epiretinal membrane optical coherence tomography findings
    Ophthalmology, 2009
    Co-Authors: Akinari Watanabe, Sachiko Arimoto, Okihiro Nishi
    Abstract:

    Purpose To examine the retinal morphologic features of metamorphopsia caused by epiretinal membrane (ERM) and to determine whether spectral-domain optical coherence tomography (SD-OCT) correlated with metamorphopsia. Design Retrospective case series. Participants This study included 19 eyes of 19 patients with ERM diagnosed by clinical ophthalmic findings and SD-OCT. Methods The 19 eyes were classified into 3 groups based on Amsler Chart results: no metamorphopsia (n = 4), local metamorphopsia (n = 8), and broad metamorphopsia (n = 7). The thickness of the 3 inner retinal layers: inner nuclear layer (INL), outer plexiform layer (OPL), and outer nuclear layer (ONL), on 5 horizontal SD-OCT cross-sections (1 line through the fovea, 2 regularly spaced lines superior to the fovea, and 2 regularly spaced lines inferior to the fovea) were measured using the electronic calipers of the SD-OCT system. Main Outcome Measures Correlation between INL, OPL, and ONL thickness with metamorphopsia and visual acuity. Results Metamorphopsia was detected in the same position as edematous areas of the INL with a thickness >50 μm. The maximum INL thickness was relatively significantly different between the subjects with no metamorphopsia and those with local or broad metamorphopsia (vs local, P = 0.06; vs broad, P = 0.04). Visual acuity significantly correlated with both maximum INL thickness (A = −0.681; P = 0.001) and maximum ONL thickness (A = −0.708; P Conclusions Metamorphopsia induced by ERM may be related to the edematous areas of the INL detected with SD-OCT. The classification of ERM based on INL thickness is a potentially useful indication for surgery. Financial Disclosure(s) The authors have no proprietary or commercial interest in any of the materials discussed in this article.

Lars Frisén - One of the best experts on this subject based on the ideXlab platform.

  • The Amsler grid in modern clothes.
    The British journal of ophthalmology, 2009
    Co-Authors: Lars Frisén
    Abstract:

    Background: The Amsler Chart, a printed grid with a central fixation mark, is widely used to test for central/paracentral scotomata and metamorphopsias. Abnormal results are easily recognised but are not directly accessible to quantitative analysis. Negative results may be misleading, because it is never known how good an observer the subject is. Methods: A new version was created in computer graphics. The grid was made to sweep the tested area in an optic flow manner. The sweeps provided seamless coverage, counteracted the Troxler fade-from-view effect, and encouraged stable fixation. Simulations of scotomata and metamorphopsias allowed quantitative evaluations of subject performance. Results: Normal observers consistently detected absolute paracentral scotomata subtending ⩾2°. Grid deformation was consistently detected at 4′ near fixation, whereas up to 20′ was needed at the grid border. A patient with real metamorphopsia reproducibly nulled the apparent deformation of the grid in a manner closely matching his own renditions. Conclusions: The classical Amsler grid can be made to meet modern demands of quality control and quantitative measurements. The new “MacuFlow” test is freely accessible on the internet. Test results can easily be transmitted electronically for evaluation at distance.

Ishida Susumu - One of the best experts on this subject based on the ideXlab platform.

  • Increased macular choroidal blood flow velocity during systemic corticosteroid therapy in a patient with acute macular neuroretinopathy
    'Dove Medical Press Ltd.', 2012
    Co-Authors: Hashimoto Yuki, Saito Wataru, Mori Shohei, Saito Michiyuki, Ishida Susumu
    Abstract:

    Purpose: The precise mechanism causing outer retinal damage in acute macular neuroretinopathy (AMN) remains unclear. In this study, choroidal blood flow velocity was quantitatively evaluated using laser speckle flowgraphy (LSFG) in a patient with AMN who received systemic corticosteroid therapy. Methods: Corticosteroids were systemically administrated across 4 months for an AMN patient. LSFG measurements were taken ten consecutive times before treatment and at 1 week and 1, 3, and 10 months after the onset of therapy. The square blur rate, a quantitative index of relative blood flow velocity, was calculated using LSFG in three regions: Square 1, the macular lesion with findings of severe multifocal electroretinography amplitude reduction, and Squares 2 and 3, funduscopically normal-appearing retinal areas with findings of moderate and mild multifocal electroretinography amplitude reduction, respectively. Results: The AMN lesion gradually decreased after treatment and improved results were detected on the Amsler Chart, as well as on optical coherence tomography and scanning laser ophthalmoscopy. When the changing rates of the macular flow were compared with the mean square blur rate level before treatment (100%), 14.6%, 24.5%, 12.9%, and 16.3% increases were detected in Square 1 (macular lesion) at 1 week and 1, 3, and 10 months after treatment, respectively. Similarly, in Square 2 (normal-appearing area next to the lesion), 12.6%, 18.6%, 6.7%, and 8.3% increases were also noted at 1 week and 1, 3, and 10 months after treatment, respectively. In Square 3 (normal-appearing area apart from the lesion), 16.0%, 15.1%, 19.1%, and 3.8% increases were measured at 1 week and 1, 3, and 10 months after treatment, respectively. Conclusion: In a patient with AMN, choroidal blood flow velocity at the lesion site, which was examined with LSFG, sequentially increased during systemic corticosteroid therapy, together with improvement of visual function. The present findings suggest that choroidal circulation impairment relates to the pathogenesis of AMN, extending over a wider area in the posterior pole than the site of an AMN lesion per se

Ishida S - One of the best experts on this subject based on the ideXlab platform.

  • Increased macular choroidal blood flow velocity during systemic corticosteroid therapy in a patient with acute macular neuroretinopathy
    Dove Medical Press, 2012
    Co-Authors: Hashimoto Y, Saito W, Mori S, Saito M, Ishida S
    Abstract:

    Yuki Hashimoto,1 Wataru Saito,1,2 Shohei Mori,1 Michiyuki Saito,1 Susumu Ishida1,21Department of Ophthalmology, 2Department of Ocular Circulation and Metabolism, Hokkaido University Graduate School of Medicine, Sapporo, JapanPurpose: The precise mechanism causing outer retinal damage in acute macular neuroretinopathy (AMN) remains unclear. In this study, choroidal blood flow velocity was quantitatively evaluated using laser speckle flowgraphy (LSFG) in a patient with AMN who received systemic corticosteroid therapy.Methods: Corticosteroids were systemically administrated across 4 months for an AMN patient. LSFG measurements were taken ten consecutive times before treatment and at 1 week and 1, 3, and 10 months after the onset of therapy. The square blur rate, a quantitative index of relative blood flow velocity, was calculated using LSFG in three regions: Square 1, the macular lesion with findings of severe multifocal electroretinography amplitude reduction, and Squares 2 and 3, funduscopically normal-appearing retinal areas with findings of moderate and mild multifocal electroretinography amplitude reduction, respectively.Results: The AMN lesion gradually decreased after treatment and improved results were detected on the Amsler Chart, as well as on optical coherence tomography and scanning laser ophthalmoscopy. When the changing rates of the macular flow were compared with the mean square blur rate level before treatment (100%), 14.6%, 24.5%, 12.9%, and 16.3% increases were detected in Square 1 (macular lesion) at 1 week and 1, 3, and 10 months after treatment, respectively. Similarly, in Square 2 (normal-appearing area next to the lesion), 12.6%, 18.6%, 6.7%, and 8.3% increases were also noted at 1 week and 1, 3, and 10 months after treatment, respectively. In Square 3 (normal-appearing area apart from the lesion), 16.0%, 15.1%, 19.1%, and 3.8% increases were measured at 1 week and 1, 3, and 10 months after treatment, respectively.Conclusion: In a patient with AMN, choroidal blood flow velocity at the lesion site, which was examined with LSFG, sequentially increased during systemic corticosteroid therapy, together with improvement of visual function. The present findings suggest that choroidal circulation impairment relates to the pathogenesis of AMN, extending over a wider area in the posterior pole than the site of an AMN lesion per se.Keywords: laser speckle flowgraphy, choroidal circulation, multifocal electroretinography, square blur rat

D. Stevens - One of the best experts on this subject based on the ideXlab platform.

  • THU0345 Screening for Reversible Hydroxychloroquine-Related Ocular Toxicity Using an Amsler Grid
    Annals of the Rheumatic Diseases, 2015
    Co-Authors: S. Banerjee, James Ritchie, Lyn Williamson, D. Stevens
    Abstract:

    Background Hydroxychloroquine is a disease modifying anti-rheumatic drug (DMARD) that has been used to treat a number of rheumatological conditions including rheumatoid arthritis, connective tissue diseases and increasingly, osteoarthritis. The main clinical concern with long term use is the rare complication of retinopathy. Significant retinopathy has only been reported in the literature in around 50 cases 1 , with over one million patients taking the drug. Nonetheless, it remains a concern. The signs of retinal toxicity are not specific to quinolone toxicity. Moreover, by the time even the earliest changes appear, there is some degree of irreversible damage 2 . Consideration was given to methods of detecting toxicity at the reversible stage. Static perimetry is time consuming and rarely available outside the hospital setting. However, the Amsler Grid is a simple and inexpensive visual test that can be self-administered by the patient. Objectives To assess patient awareness of the ocular side effects of Hydroxychloroquine and compliance with the local recommendation for annual eye testing. To assess patients9 ability to understand and use the Amsler Grid as a screening tool. Methods We produced our own Hydroxychloroquine information booklet, based on the Arthritis UK leaflet, with the inclusion of an Amsler Grid and instructions on how to use it. This was posted to 728 patients identified from our database as taking Hydroxychloroquine, with an accompanying questionnaire. Patients were asked the following questions: How long have you been taking Hydroxychloroquine? Are you aware that is recommended that you have an annual eye check-up whilst taking Hydroxychloroquine? If so, have you been having a yearly eye check-up? If not, please state a reason. Did you find the new Hydroxychloroquine booklet: a) Easy to understand b) Contained: too much information/too little information/just right Were you able to understand and use the Amsler Chart? Results 334 of 728 patients returned a completed questionnaire. 35% of patients had been taking Hydroxychloroquine for over 5 years. 72% were aware that a yearly eye test was recommended and 75% were having one. Reasons cited for not having annual testing included financial difficulty, mobility problems and lack of motivation. 93% reported that the booklet was easy to understand and 95% felt it contained just the right amount of information. 92% of patients reported being able to understand and use the Amlser grid. Conclusions The vast majority of patients found the new information booklet informative and user friendly. Our new booklet may help to increase awareness of ocular side effects, and to provide accessible screening for those who struggle to see an optician. Further work is needed to validate use of the Amsler Grid in rheumatology patients, but these results suggest its inclusion in a patient leaflet may be a useful adjunct to annual eye testing. If validated as a sensitive test for detecting ocular side effects of Hydroxycholoroquine during the reversible stage, the Amsler Grid could represent a superior, simpler and more cost-effective screen than yearly eye review. References Yam JCS, Kwok AKH. Ocular toxicity of hydroxychloroquine. Hong Kong Med J. 2006; 12:294-304. The Royal College of Ophthalmologists - Hydroxychloroquine and Ocular Toxicity. Recommendations on Screening – October 2009 Disclosure of Interest None declared