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12 results on '"Shuichi Yamamoto"'

1. Changes in subfoveal choroidal thickness and reduction of serum levels of vascular endothelial growth factor in patients with POEMS syndrome

Author

Masayasu Kitahashi, Shuichi Yamamoto, Satoshi Kuwabara, Toshiyuki Oshitari, Sonoko Misawa, Hirotaka Yokouchi, and Takayuki Baba

Subjects
Adult, Male, Vascular Endothelial Growth Factor A, Fovea Centralis, medicine.medical_specialty, Pathology, Fundus Oculi, Enzyme-Linked Immunosorbent Assay, Organomegaly, 03 medical and health sciences, Cellular and Molecular Neuroscience, chemistry.chemical_compound, 0302 clinical medicine, Ophthalmology, Humans, Medicine, Fluorescein Angiography, Aged, Retrospective Studies, POEMS syndrome, medicine.diagnostic_test, Choroid, business.industry, Choroid Diseases, Middle Aged, Fluorescein angiography, medicine.disease, Sensory Systems, Vascular endothelial growth factor, Thalidomide, Vascular endothelial growth factor A, medicine.anatomical_structure, chemistry, POEMS Syndrome, Disease Progression, 030221 ophthalmology & optometry, Female, sense organs, medicine.symptom, business, Polyneuropathy, Biomarkers, Tomography, Optical Coherence, 030217 neurology & neurosurgery, Follow-Up Studies, medicine.drug
Abstract

Aims To determine the changes in the subfoveal choroidal thickness (CT), the foveal thickness (FT) and the serum level of vascular endothelial growth factor (VEGF) after thalidomide treatment in patients with polyneuropathy, organomegaly, endocrinopathy, monoclonal gammopathy and skin changes (POEMS) syndrome. Methods We studied 13 left eyes of 13 treatment-naive patients with POEMS syndrome. The subfoveal CT and FT were determined by enhanced depth imaging optical coherence tomography, and the serum level of VEGF was determined by ELISA at the baseline and at 6 months after thalidomide treatment. The correlations in the serum level of VEGF and the subfoveal CT or the FT at the baseline and at 6 months after treatment were determined. Results Together with the reduction in the serum level of VEGF, the subfoveal CT was also reduced significantly from 439.1±66.5 µm at the baseline to 307.2±75.4 µm at 6 months (p=0.001). The mean FT at the baseline was 236.4±30.7 µm which did not change significantly at 6 months at 228.1±33.1 µm (p>0.05). The change in the subfoveal CT was significantly and linearly correlated with the change in the serum level of VEGF at 6 months after treatment (r=0.67, p=0.011). Conclusions The significant correlation between the CT and the serum level of VEGF may offer clues on the pathogenesis of ocular diseases of POEMS syndrome and on the role of serum VEGF on the choroid.

Published
2016

2. Visual outcomes after surgery for primary rhegmatogenous retinal detachment in era of microincision vitrectomy: Japan-Retinal Detachment Registry Report IV.

Author

Takayuki Baba, Ryo Kawasaki, Keita Yamakiri, Takashi Koto, Koichi Nishitsuka, Shuichi Yamamoto, and Taiji Sakamoto

Abstract

Background/Aim: To determine the preoperative ocular factors and surgical methods that led to best-corrected visual acuity (BCVA) after pars plana vitrectomy (PPV) or scleral buckling (SB) for rhegmatogenous retinal detachment (RRD). Methods: This was a prospective, nationwide, multicentre, observational study. Data from the Japanese Retina and Vitreous Society registry from 2016 to 2017 were used to determine the association between preoperative clinical factors, surgical procedures and postoperative BCVA at 6 months. Japanese individuals >40 years of age were included. Eyes with proliferative vitreoretinopathy were included. The primary outcome was the percentage of eyes that achieved 20/25 vision. Results: Of the 3219 registered cases, 2192 met the inclusion criteria (344 SB, 1738 PPV, 110 PPV+SB). Cases with preoperative BCVA (≤0 logarithm of the minimum angle of resolution (logMAR) units) had good postoperative BCVA (OR=3.97, CI 2.87 to 5.51). Older age (>70 years), low intraocular pressure (<10 mm Hg), high myopia (<-5 dioptres), multiple retinal breaks (>4), giant retinal tear (>90°), wide retinal detachment (>3 quadrants) and macula-off detachment were associated with less probability of postoperative 20/25 vision (OR=0.39, 0.64, 0.62, 0.60, 0.12, 0.51 and 0.36, respectively). Postoperative BCVA was 0.03±0.23 and 0.10±0.32 logMAR units after SB and PPV, respectively. The percentage of cases that achieved 20/25 vision was not significantly different after PPV or SB if cases that had concurrent cataract surgery were excluded (p=0.251). Conclusions: Better BCVA in patients with RRD who had undergone PPV was observed. However, if concurrent cataract surgery is not performed, BCVA will be comparable with either PPV or SB. [ABSTRACT FROM AUTHOR]

Published
2021
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3. Relationship between retinal microstructures and visual acuity after cataract surgery in patients with retinitis pigmentosa

Author

Ken Kumagai, Shuichi Yamamoto, Takeshi Sugawara, Gen Miura, Akira Hagiwara, Yosuke Nakamura, Mariko Egawa, and Yoshinori Mitamura

Subjects
Male, medicine.medical_specialty, Visual acuity, genetic structures, medicine.medical_treatment, Visual Acuity, After cataract, Cellular and Molecular Neuroscience, chemistry.chemical_compound, Lens Implantation, Intraocular, Ophthalmology, Retinitis pigmentosa, Electroretinography, medicine, Humans, Retinal Photoreceptor Cell Inner Segment, In patient, Postoperative Period, Fluorescein Angiography, Retrospective Studies, Retina, Phacoemulsification, business.industry, Retinal, Middle Aged, Cataract surgery, Retinal Photoreceptor Cell Outer Segment, medicine.disease, eye diseases, Sensory Systems, Surgery, medicine.anatomical_structure, chemistry, Female, sense organs, Inner segment, medicine.symptom, business, Retinitis Pigmentosa
Abstract

To study the relationship between the retinal microstructures and the best-corrected visual acuity (BCVA) after cataract surgery in patients with retinitis pigmentosa (RP).58 eyes of 43 consecutive RP patients who underwent cataract surgery were studied. The BCVA was measured before and 3 months after the surgery. The appearance of the inner segment/outer segment (IS/OS) line of the photoreceptors in the optical coherence tomographic (OCT) images at the fovea was graded; Grade 1, IS/OS line not visible; Grade 2, IS/OS line abnormal or discontinuous; and Grade 3, IS/OS line normal. The central foveal thickness (CFT) and the length of the IS/OS line were measured in the spectral-domain OCT images.The postoperative BCVAs in logMAR units (Grade 1, 1.04±0.36; Grade 2, 0.33±0.16; Grade 3, 0.08±0.14) and the improvements in the BCVA in logMAR units (Grade 1, 0.22±0.28; Grade 2, 0.53±0.48; Grade 3, 0.54±0.35) were significantly different among Grade 1, 2 and 3 groups (p0.0001, p=0.0378; respectively). A postoperative BCVA of0.2 logMAR units was achieved in 0% in Grade 1, 20% in Grade 2 and 74% in Grade 3 (p0.0001). There was a significant correlation between the postoperative BCVA and the length of the IS/OS line (r=-0.601 p0.0001) or the CFT (r=-0.510, p0.0001).The presence of normal IS/OS line in the OCT images is associated with good visual recovery after cataract surgery in RP patients. The integrity of the IS/OS line may be important for predicting good postoperative BCVA.

Published
2014

4. Correlation of changes in serum level of VEGF and peripapillary retinal thickness in patients with POEMS syndrome.

Author

Hirotaka Yokouchi, Takayuki Baba, Sonoko Misawa, Toshiyuki Oshitari, Satoshi Kuwabara, and Shuichi Yamamoto

Abstract

Aim To determine whether changes in the serum levels of vascular endothelial growth factor (VEGF) after thalidomide therapy will affect the peripapillary retinal thickness (pRT) associated with optic disc oedema (ODE) in patients with polyneuropathy, organomegaly, endocrinopathy, monoclonal gammopathy and skin changes (POEMS) syndrome. Methods This was a retrospective, observational case series of 23 right eyes of 23 treatment-naïve patients with POEMS syndrome and ODE whose intracranial pressure was within the normal range. The pRT was determined by spectral- domain optical coherence tomography, and the serum level of VEGF was determined by ELISA at baseline and 6 months after the thalidomide therapy. We determined whether a change in the pRT from baseline was significantly correlated with the serum level of VEGF from that at 6 months after the thalidomide treatment. Results Six months after treatment, the mean serum level of VEGF was significantly reduced from 7153±4214 pg/mL to 1067±769 pg/mL (p<0.001), and the pRT was significantly decreased from 471.2±203 µm to 318.1±53.9 µm (p<0.001). The change in the pRT from baseline was significantly and linearly correlated with the change in the serum level of VEGF from that at 6 months after treatment (r=0.67, p=0.00039). Conclusions The close relationship between the pRT and the serum level of VEGF may offer clues on the pathogenesis of POEMS syndrome and potentially add a new candidate cause for the pathogenesis of ODE. [ABSTRACT FROM AUTHOR]

Published
2020
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5. Correlation of visual recovery with presence of photoreceptor inner/outer segment junction in optical coherence images after epiretinal membrane surgery

Author

Yoshinori Mitamura, Takayuki Baba, Kaori Hirano, and Shuichi Yamamoto

Subjects
Male, Fovea Centralis, medicine.medical_specialty, Visual acuity, genetic structures, medicine.medical_treatment, Visual Acuity, Vitrectomy, Foveal thickness, Cellular and Molecular Neuroscience, Optical coherence tomography, medicine, Humans, Retinal Photoreceptor Cell Inner Segment, Postoperative Period, Aged, Aged, 80 and over, Retina, medicine.diagnostic_test, business.industry, Epiretinal Membrane, Middle Aged, Retinal Photoreceptor Cell Outer Segment, medicine.disease, Functional recovery, eye diseases, Sensory Systems, Surgery, Ophthalmology, medicine.anatomical_structure, Time course, Female, Epiretinal membrane, medicine.symptom, business, Tomography, Optical Coherence
Abstract

Aims:To investigate the relationship between the presence of the photoreceptor inner and outer segment (IS/OS) junction and visual acuity after epiretinal membrane (ERM) surgery.Methods:Seventy eyes of 70 consecutive patients who had undergone vitrectomy for idiopathic ERM were examined by optical coherence tomography before and 3 and 6 months after surgery. The IS/OS junction was graded into three grades. The time course of recovery of the IS/OS junction, central foveal thickness (CFT) and best corrected visual acuity (BCVA) during the postoperative period was studied.Results:A normal IS/OS junction was detected in 47.1% of the eyes before surgery and in 65.7% at 3 months and 75.7% at 6 months after. There was a significant correlation between the IS/OS grade and BCVA before and at 3 and 6 months after the operation (p = 0.0001, pConclusions:The presence of a normal IS/OS junction was associated with good visual acuity after ERM surgery. A normal IS/OS junction probably indicates morphological and functional recovery of the photoreceptors.

Published
2008

6. Mitochondria- and caspase-dependent cell death pathway involved in neuronal degeneration in diabetic retinopathy

Author

Sayon Roy, Shuichi Yamamoto, Nobuhiko Hata, and Toshiyuki Oshitari

Subjects
Retinal Ganglion Cells, Programmed cell death, medicine.medical_specialty, Pathogenesis, Cellular and Molecular Neuroscience, Diabetes mellitus, Internal medicine, medicine, Humans, Ganglion cell layer, Caspase, Aged, bcl-2-Associated X Protein, Retina, Diabetic Retinopathy, Cell Death, biology, Caspase 3, business.industry, Diabetic retinopathy, Middle Aged, medicine.disease, Caspase 9, Sensory Systems, Mitochondria, Ophthalmology, Endocrinology, medicine.anatomical_structure, Caspases, biology.protein, sense organs, business, Signal Transduction, Retinopathy
Abstract

Background: Neuronal abnormalities are associated with the pathogenesis of diabetic retinopathy. However, the mechanisms for neuronal cell death in diabetic retinopathy remain unclear. Aim: To determine whether altered expression of Bax, caspase-9 and -3 is associated with degenerative neurons in diabetic retinopathy. Methods: Immunohistochemistry was performed on cryosections obtained from five pairs of normal and five pairs of age-matched diabetic human retinas. Diabetic eyes had no proliferative diabetic retinopathy and no histories of photocoagulation or ocular surgery. In this study, Fluoro-Jade B (FJB) was used as a marker for identification of degenerative neurons. Results: In diabetic retinas, Bax overexpression coexisted with FJB positive signals in the ganglion cell layer (GCL) compared with very low FJB levels in the normal retina. Increased level of the active forms of caspase-9 and -3 expressions coexisted with FJB positive cells in the GCL of diabetic retinas compared with those in normal retinas. Conclusions: Upregulation of Bax, caspase-9 and -3 expression was associated with neuronal degeneration in diabetic retinopathy. The mitochondria- and caspase-dependent cell-death pathway may be, in part, associated with neuronal degeneration in diabetic retinas.

Published
2008

7. Normal S cone electroretinogram b-wave in Oguchi's disease

Author

Kazuo Kawasaki, Shuichi Yamamoto, Masanori Hayashi, Yutaka Shirao, Shinobu Takeuchi, and Katsutoshi Kita

Subjects
Congenital stationary night blindness, medicine.medical_specialty, genetic structures, Blindness, medicine.diagnostic_test, Oguchi's disease, business.industry, Significant difference, Short wavelength sensitive, Cone (category theory), Original articles - Clinical science, medicine.disease, eye diseases, Sensory Systems, Cellular and Molecular Neuroscience, Ophthalmology, medicine, sense organs, business, Erg, Electroretinography
Abstract

AIM The short wavelength sensitive (S) cone electroretinograms (ERGs) were examined in two patients with Oguchi’s disease to study S cone function. METHODS Ganzfeld colour flashes under bright white background illumination were used to elicit S cone, and mixed long (L) and middle (M) wavelength sensitive cone ERGs. RESULTS The S cone ERG b-wave was normal with short wavelength stimuli with normal L and M cone responses in both patients. CONCLUSIONS These ERG results indicate that the S cone system as well as the L and M cone system is not defective in Oguchi’s disease, while the S cone responses are not detectable in the complete type of congenital stationary night blindness as reported previously. The results imply that there is a significant difference in the way the S cone system is affected in different forms of stationary night blindness, and that the S cone and rod do not share the same arrestin system.

Published
1997

8. Changes in subfoveal choroidal thickness and reduction of serum levels of vascular endothelial growth factor in patients with POEMS syndrome.

Author

Hirotaka Yokouchi, Baba, Takayuki, Sonoko Misawa, Masayasu Kitahashi, Toshiyuki Oshitari, Satoshi Kuwabara, and Shuichi Yamamoto

Abstract

Aims: To determine the changes in the subfoveal choroidal thickness (CT), the foveal thickness (FT) and the serum level of vascular endothelial growth factor (VEGF) after thalidomide treatment in patients with polyneuropathy, organomegaly, endocrinopathy, monoclonal gammopathy and skin changes (POEMS) syndrome. Methods: We studied 13 left eyes of 13 treatmentnaïve patients with POEMS syndrome. The subfoveal CT and FT were determined by enhanced depth imaging optical coherence tomography, and the serum level of VEGF was determined by ELISA at the baseline and at 6 months after thalidomide treatment. The correlations in the serum level of VEGF and the subfoveal CT or the FT at the baseline and at 6 months after treatment were determined. Results: Together with the reduction in the serum level of VEGF, the subfoveal CT was also reduced significantly from 439.1±66.5 mm at the baseline to 307.2 ±75.4 mm at 6 months (p=0.001). The mean FT at the baseline was 236.4±30.7 mm which did not change significantly at 6 months at 228.1±33.1 mm (p>0.05). The change in the subfoveal CT was significantly and linearly correlated with the change in the serum level of VEGF at 6 months after treatment (r=0.67, p=0.011). Conclusions The significant correlation between the CT and the serum level of VEGF may offer clues on the pathogenesis of ocular diseases of POEMS syndrome and on the role of serum VEGF on the choroid. [ABSTRACT FROM AUTHOR]

Published
2017
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9. Photoreceptor impairment on optical coherence tomographic images in patients with retinitis pigmentosa

Author

Ken Kumagai, Shuichi Yamamoto, Yoshinori Mitamura, Takayuki Baba, and Akira Hagiwara

Subjects
medicine.medical_specialty, Visual acuity, genetic structures, medicine.diagnostic_test, business.industry, Disease progression, Retinal, Coherence (statistics), medicine.disease, Sensory Systems, Surgery, Cellular and Molecular Neuroscience, Ophthalmology, chemistry.chemical_compound, medicine.anatomical_structure, chemistry, Optical coherence tomography, Retinitis pigmentosa, medicine, In patient, sense organs, medicine.symptom, business, External limiting membrane
Abstract

Morphological assessments of the photoreceptors can be useful in estimating the disease progression in retinitis pigmentosa (RP).1–3 Using spectral-domain optical coherence tomography, the external limiting membrane (ELM) and cone outer segment tips (COST) can be clearly detected in addition to photoreceptor inner/outer segment junction (IS/OS). To date, the IS/OS as well as the ELM and COST have been analysed after macular surgery.4 ,5 In RP patients, however, changes of the COST line and correlations among the IS/OS, ELM and COST lines remain unclear. We have already reported that the IS/OS length was significantly correlated with visual acuity or retinal sensitivity and that the progressive IS/OS shortening is associated with worsening of visual function during RP progression.1 ,2 The purposes of this study were to examine the changes of the COST line in RP patients and to investigate the correlations among the IS/OS, ELM and COST lines. After obtaining approval from the Institutional Review Board and informed consent, this study was done on 263 eyes of 133 consecutive patients with RP. RP patients were …

Published
2012

10. Correlation between retinal sensitivity and photoreceptor inner/outer segment junction in patients with retinitis pigmentosa

Author

Akira Hagiwara, S. Aizawa, Takayuki Baba, Shuichi Yamamoto, and Yoshinori Mitamura

Subjects
Male, medicine.medical_specialty, genetic structures, Retina, Cellular and Molecular Neuroscience, chemistry.chemical_compound, Optical coherence tomography, Ophthalmology, Retinitis pigmentosa, Humans, Medicine, Photoreceptor Cells, In patient, Retinal pigment epithelium, medicine.diagnostic_test, business.industry, Disease progression, Retinal, Anatomy, medicine.disease, eye diseases, Sensory Systems, Normal functioning, medicine.anatomical_structure, chemistry, Disease Progression, Female, sense organs, business, Retinitis Pigmentosa, Tomography, Optical Coherence
Abstract

The earliest histopathological change in retinitis pigmentosa (RP) is a shortening of the photoreceptor outer segments.1 Therefore, morphological assessments of the photoreceptors can be useful in estimating the disease progression in RP patients. In the optical coherence tomography (OCT) images, the photoreceptor inner/outer segment junction (IS/OS) is observed as a distinct, highly reflective line just vitread of the retinal pigment epithelium. A continuous IS/OS line has been shown to indicate a normal alignment of the membranous discs in the photoreceptor outer segments.2 Because the alignment of the discs is necessary for the normal functioning of the photoreceptors, the continuous IS/OS line would strongly suggest that the photoreceptors would function normally. Several OCT studies have been conducted on RP patients to determine whether a significant correlation exists between the IS/OS line and the visual acuity.3–5 Sandberg et al 3 graded the IS/OS into three groups; …

Published
2008

11. Retinal detachment with macular hole following intravitreal bevacizumab in patient with severe proliferative diabetic retinopathy

Author

Noriko Asaumi, Yoshinori Mitamura, K. Ogata, Toshiyuki Oshitari, and Shuichi Yamamoto

Subjects
Adult, Male, medicine.medical_specialty, genetic structures, Fundus Oculi, medicine.medical_treatment, Retinal perforation, Angiogenesis Inhibitors, Vitrectomy, Antibodies, Monoclonal, Humanized, Cellular and Molecular Neuroscience, Diabetes mellitus, Ophthalmology, medicine, Humans, In patient, Intravitreal bevacizumab, Macular hole, Diabetic Retinopathy, business.industry, Retinal Detachment, Antibodies, Monoclonal, Retinal detachment, Diabetic retinopathy, Retinal Perforations, medicine.disease, eye diseases, Sensory Systems, Bevacizumab, sense organs, business
Abstract

We read with interest the article by Arevalo et al 1 about the development of a tractional retinal detachment (TRD) following the use of intravitreal bevacizumab (Avastin; Genetech Inc., San Francisco, California, USA) as an adjuvant to vitrectomy for the management of severe proliferative diabetic retinopathy (PDR). They warned that TRD might occur or progress shortly after intravitreal bevacizumab. We present a case of a retinal detachment with macular hole (MH–RD) that developed after intravitreal bevacizumab that was used for neovascular glaucoma as a result of severe PDR. A 40-year-old man with diabetes of 19 years presented with PDR and neovascular glaucoma in the right eye that was refractory to panretinal photocoagulation (PRP). He was being treated with insulin but had …

Published
2008

12. Correlation between peripapillary retinal thickness and serum level of vascular endothelial growth factor in patients with POEMS syndrome.

Author

Hirotaka Yokouchi, Takayuki Baba, Sonoko Misawa, Setsu Sawai, Masayasu Kitahashi, Toshiyuki Oshitari, Satoshi Kuwabara, and Shuichi Yamamoto

Subjects
RETINA analysis, RETINAL diseases, VASCULAR endothelial growth factors, OPTICAL coherence tomography, EDEMA
Abstract

Aims To determine whether there is a significant correlation between the peripapillary retinal thickness (pRT) and the serum level of vascular endothelial growth factor (VEGF) in patients with polyneuropathy, organomegaly, endocrinopathy, monoclonal gammopathy and skin changes (POEMS) syndrome. Methods This was a cross-sectional, observational case series. We studied 34 eyes of 17 treatment-naïve patients with POEMS syndrome whose intracranial pressure was within the normal range. The spectral-domain optical coherence tomographic (SD-OCT) examinations consisted of circle scans of 3.45 mm diameter around the optic disc. The pRT was automatically measured in the SD-OCT images and was used for the statistical analysis. The serum level of VEGF was measured by ELISAs, and the correlation between the pRT and the serum level of VEGF was determined. Multivariable logistic regression analyses were used to identify independent factors that were correlated with the pRT. Results There was a significant positive correlation between the serum levels of VEGF and the average pRT of the two eyes of each patient (r=0.81, p<0.0001). There was a significant correlation between the pRT of the right and left eyes with an intraclass correlation coefficient of 0.839. Multiple regression analysis showed that the serum levels of VEGF were independent contributors to the pRT (standard regression coefficient=0.59, p=0.012). Conclusions The significant correlation between the pRT and the serum level of VEGF suggests that the higher serum level of VEGF might be associated with the development of the optic disc oedema in patients with POEMS syndrome. [ABSTRACT FROM AUTHOR]

Published
2016
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