Akira Obana

Dr. Akira Obana

Department of Ophthalmology, Seirei Hamamatsu General Hospital, HAMAMATSU BioPhotonics Innovation Chair, Institute for Medical Photonics Research, Preeminent Medical Photonics Education & Research Center, Hamamatsu University School of Medicine, Shizuoka, Japan
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Research Focus & Metrics

Academic Career Length

32Years (1995-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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1 May 2018 in Archives of Biochemistry and Biophysics
Verified
Journal Article
Closed access
IEIgor V. Ermakov
Igor V. Ermakov
MEMaia Ermakova
Maia Ermakova
MSMohsen Sharifzadeh
Mohsen Sharifzadeh
AGAruna Gorusupudi
Aruna Gorusupudi
KFKelliann Farnsworth
Kelliann Farnsworth
WGWerner Gellermann
Werner Gellermann

1 October 2017 in Investigative Ophthalmology & Visual Science
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Journal Article
Open access
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Akira ObanaAkira Obana
Akira Obana
HSHiroyuki Sasano
Hiroyuki Sasano
SOShigetoshi Okazaki
Shigetoshi Okazaki
YOYoshiro Otsuki
Yoshiro Otsuki
TSTakahiko Seto
Takahiko Seto
YGYuko Gohto
Yuko Gohto
Purpose: To determine the constituents and origin of the yellow pigment in surgically removed lamellar hole-associated epiretinal proliferation (LHEP) in patients with lamellar macular hole (LMH). Methods: This prospective case series comprised nine eyes with LMH in patients aged 41 to 83 years. The presence of LHEP was confirmed by preoperative optical coherence tomography; the distribution of macular pigment was observed by two-wavelength fundus autofluorescence technique before and after surgery. The subjects underwent a 25-gauge vitrectomy, and the surgically removed epiretinal membranous tissue was fixed with formalin. The specimens were examined using resonance Raman microscopy, and paraffin sections were stained with antiglial fibrillary acidic protein. Results: Seven cases presented with LHEP, and the presence of yellow pigment was confirmed using an operating microscope. Carotenoid-specific Raman signals with three major Raman peaks could be identified in the specimens with LHEP. These specimens were positive for glial fibrillary acidic protein staining. Using the fundus autofluorescence technique, a central defect in the distribution of the macular pigment was noted in the exact area of the lamellar hole. This type of defect was no longer visible after surgical repair of the lamellar hole. Conclusions: The constituents of the yellow pigment in the removed LHEP were carotenoids that typically originate from the macular xanthophyll pigments at the fovea. Since LHEP is reported to be composed of Müller cells, we hypothesize that xanthophyll carotenoids at the fovea are contained in the Müller cells.

24 June 2020 in Scientific Reports
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Journal Article
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Akira ObanaAkira Obana
Akira Obana
YGYuko Gohto
Yuko Gohto
RNRisa Nakazawa
Risa Nakazawa
TMTakanobu Moriyama
Takanobu Moriyama
WGWerner Gellermann
Werner Gellermann
PBPaul S. Bernstein
Paul S. Bernstein
The effect of a high dose lutein/zeaxanthin supplement on macular pigment optical density (MPOD) and skin carotenoid (SC) levels in healthy subjects was investigated. This is a prospective, single-arm, open-label study. Subjects were 16 Japanese, age 26–57 years. Subjects took a supplement containing 20 mg/day of lutein, 4 mg/day of zeaxanthin, and other antioxidants (vitamin C, vitamin E, zinc, copper) for 16 weeks. MPOD levels were measured by a two-wavelength autofluorescence imaging technique. SC levels were measured by reflection spectroscopy. Total volume of MPOD within 9° eccentricity significantly increased by week 8 and continued to increase until week 16 (p < 0.0001, two-way factorial ANOVA). The increase rate of MPOD was significantly higher in subjects with body mass index (BMI) less than 25 kg/m2 (n = 13) compared to those of 25 kg/m2 and higher (n = 3). SC levels increased significantly by week 4 and continued to increase until week 16 (p < 0.0001, two-way factorial ANOVA). All subjects completed the study without any serious adverse events. These results demonstrated the effectiveness of a high dose lutein/zeaxanthin supplement for MPOD volume and SC levels without serious adverse events.

15 June 2012 in Japanese Journal of Ophthalmology
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Journal Article
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MTMasaki Tanito
Masaki Tanito
Akira ObanaAkira Obana
Akira Obana
YGYuko Gohto
Yuko Gohto
SOShigetoshi Okazaki
Shigetoshi Okazaki
WGWerner Gellermann
Werner Gellermann
AOAkihiro Ohira
Akihiro Ohira

27 June 2019 in Scientific Reports
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Journal Article
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Akira ObanaAkira Obana
Akira Obana
YGYuko Gohto
Yuko Gohto
WGWerner Gellermann
Werner Gellermann
IEIgor V. Ermakov
Igor V. Ermakov
HSHiroyuki Sasano
Hiroyuki Sasano
PBPaul Bernstein
Paul Bernstein
Carotenoids are anti-oxidative agents. Human skin and eyes contain specific carotenoid species known to prevent various pathologies caused by oxidative stress. We quantified skin and eye carotenoid levels and investigated their potential correlation in a population including 985 Japanese patients and staff members of an ophthalmology clinic (577 men, 408 women, mean age of 69.7 ± 13.6 [SD]). Skin carotenoid (SC) and macular pigment (MP) levels were measured with reflection spectroscopy and autofluorescence imaging methods, respectively. The mean SC index was 343.1 ± 142.1 (SD). SC indices for women were higher than for men (382 vs 315, p < 0.001). Smokers and overweight subjects (BMI ≥ 25) had lower SC indices. Subjects taking lutein supplements had higher SC indices than non-supplementing subjects (415 vs 325, p < 0.001). SC and MP indices were significantly correlated. The obtained data set can be used for reference purposes by Japanese subjects and researchers interested in tissue responses to diets high in carotenoids and lutein supplementation.

9 October 2015 in PLOS ONE
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Journal Article
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Akira ObanaAkira Obana
Akira Obana
MTMasaki Tanito
Masaki Tanito
YGYuko Gohto
Yuko Gohto
SOShigetoshi Okazaki
Shigetoshi Okazaki
WGWerner Gellermann
Werner Gellermann
PBPaul S. Bernstein
Paul S. Bernstein
To investigate macular pigment optical density (MPOD) and serum concentration changes of lutein in Japanese subjects participating in a clinical trial in which two formulations of lutein and zeaxanthin supplements with different physiochemical properties are used. Thirty-six healthy volunteers were recruited into this prospective, randomized, parallel-group, double-masked comparative study at a single institute. Two products were used, FloraGLO® (Kemin Japan) and XanMax® (Katra Phytochem). The lutein particle size and zeaxanthin concentrations differed between the formulations. The subjects consumed one of the two supplements for a duration of up to 6 months. MPOD levels were measured by resonance Raman spectrometry at baseline and once a month until the end of the study. Serum lutein concentration was measured at baseline, month 3, and month 6. The subjects were also tested for contrast sensitivity, glare sensitivity, visual acuity, and in addition had a focal electroretinogram measured. The mean serum lutein concentrations increased significantly after the first three months, but the mean MPOD levels in either supplement group did not show any statistically significant increase. A detailed analysis, however, revealed three response patterns in both groups for the increase of MPOD levels and serum lutein concentration, i.e. “retinal responders”, who had an increase of both MPOD levels and serum lutein concentrations (n = 13), “retinal non-responders”, who had only increased serum concentrations and no change in MPOD levels (n = 20), and “retinal and serum non-responders”, who had neither MPOD level nor plasma concentration increases (n = 3). The subjects with low MPOD levels at baseline appeared to show increased MPOD levels at the 6 month time point upon lutein supplementation (r = -0.4090, p = 0.0133). Glare sensitivity improved in retinal responders in both supplement groups, while there were no remarkable changes in contrast sensitivity. No statistically significant differences could be detected for MPOD levels and serum lutein concentrations between the two investigated lutein supplement formulations. Responses to lutein supplementation regarding MPOD levels and serum lutein concentrations varied between subjects. Subjects with lower MPOD levels at baseline responded well to lutein supplementation. However, since the number of subjects was low, a further study with more subjects is needed to prove that subjects with low MPOD levels will benefit from lutein supplementation. UMIN-CTR UMIN000004593