Yutaka Yamada

Dr. Yutaka Yamada


Research Focus & Metrics

Academic Career Length

5Years (2022-Present)

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

Representative Publications

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14 July 2022 in Medicina
Verified
Journal Article
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YYYutaka Yamada
Yutaka Yamada
YTYoshihiro Takamura
Yoshihiro Takamura
TMTakehiro Matsumura
Takehiro Matsumura
MGMakoto Gozawa
Makoto Gozawa
MMMasakazu Morioka
Masakazu Morioka
MIMasaru Inatani
Masaru Inatani
Background and Objectives: The presence of refractory cases resistant to anti-vascular endothelial growth factor (VEGF) therapy for diabetic macular edema (DME) is a problem in clinical practice. This study aimed to explore the less responsive area of optical coherence tomography (OCT) 3D map the characteristics of naïve DME cases after their first anti-VEGF. Materials and Methods: In 46 patients with DME who received an intravitreal injection of anti-VEGF agents, retinal thickness in 100 sections of the macular area was measured by 3D-mapping mode using OCT before and 1 month after injection. The density of the microaneurysm (MA) was calculated using merged images of the OCT map and fluorescein angiography. Results: One month after injection, the central retinal thickness significantly decreased (p < 0.0001). In severe edema (retinal thickness more than 500 µm), the area percentages with a reduction rate of the retinal thickness greater than 30% and less than 5% were 6.4 ± 6.6% and 10.1 ± 4.6%, respectively. The reduction rate of the retinal thickness varied from section to section. The mutual distance between the areas of maximum thickness before and after the injection averaged 1.22 ± 0.62 mm apart. The reduction rate of retinal thickness in the thickest region before injection was significantly higher (p = 0.02), and that in the thickest region after injection was lower (p = 0.001) than in the other regions. MA density in the residual edema was significantly higher than in the edema-absorbed area (p = 0.03). Conclusion: DME has areas that show low response to the reduction in retinal thickness with anti-VEGF therapy. A high density of MA may be associated with this pathogenesis.

9 August 2022 in Journal of Clinical Medicine
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Journal Article
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HOHideyuki Oshima
Hideyuki Oshima
YTYoshihiro Takamura
Yoshihiro Takamura
THTakao Hirano
Takao Hirano
MSMasahiko Shimura
Masahiko Shimura
MSMasahiko Sugimoto
Masahiko Sugimoto
MIMasaru Inatani
Masaru Inatani
Diabetic macular edema (DME) induces visual disturbance, and intravitreal injections of anti-vascular endothelial growth factor (VEGF) drugs are the accepted first-line treatment. We investigate its impact on glycemic control after starting VEGF treatment for DME on the basis of a questionnaire and changes in hemoglobin A1c (HbA1c). We conducted a retrospective multicenter study analyzing 112 patients with DME who underwent anti-VEGF therapy and their changes in HbA1c over two years. Central retinal thickness and visual acuity significantly improved at three months and throughout the period after initiating therapy (p < 0.0001); a significant change in HbA1c was not found. A total of 59.8% of patients became more active in glycemic control through exercise and diet therapy after initiating therapy, resulting in a significantly lower HbA1c at 6 (p = 0.0047), 12 (p = 0.0003), and 18 (p = 0.0117) months compared to patients who did not. HbA1c was significantly lower after 18 months in patients who stated that anti-VEGF drugs were expensive (p = 0.0354). The initiation of anti-VEGF therapy for DME affects HbA1c levels in relation to more aggressive glycemic control.

Verified
Journal Article
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YOYusuke Orii
Yusuke Orii
EKEriko Kunikane
Eriko Kunikane
YYYutaka Yamada
Yutaka Yamada
MMMasakazu Morioka
Masakazu Morioka
KIKentaro Iwasaki
Kentaro Iwasaki
MIMasaru Inatani
Masaru Inatani
Purpose: To evaluate the concentrations of brimonidine and brinzolamide in the vitreous and aqueous humor after instillation of a 0.1% brimonidine tartrate and 1% brinzolamide fixed-combination ophthalmic suspension. Methods: The present investigation involved patients with macular holes or idiopathic epiretinal membranes who were planning to undergo vitrectomy. One week prior to surgery, the patients received twice-daily topical treatment with 0.1% brimonidine tartrate and 1% brinzolamide fixed-combination ophthalmic suspension. Before vitrectomy, vitreous and aqueous humor samples were collected, and the mean concentrations of brimonidine and brinzolamide were determined through liquid chromatography-tandem spectrometry. Results: Ten eyes (nine phakic and one pseudophakic eyes; 10 patients) were examined. The concentration of brimonidine in vitreous and aqueous humor samples was 5.02 ± 2.24 and 559 ± 670 nM, respectively. The concentration of brimonidine in the vitreous humor, which is needed to activate α2 receptors, was >2 nM in all patients. The concentration of brinzolamide was 8.96 ± 4.65 and 1100 ± 813 nM, respectively. However, there was no significant correlation between the concentrations of brimonidine in the vitreous and aqueous humor samples. Conclusions: Sufficient concentrations of brimonidine were detected in all vitreous samples. The dissociated correlation of the drug concentrations between aqueous and vitreous humors implies the possibility of another pathway to vitreous humor, different from the pathway to aqueous humor.

22 December 2024 in Journal of Clinical Medicine
Verified
Journal Article
Open access
PDF file
YYYutaka Yamada
Yutaka Yamada
YTYoshihiro Takamura
Yoshihiro Takamura
MMMasakazu Morioka
Masakazu Morioka
HOHideyuki Oshima
Hideyuki Oshima
MGMakoto Gozawa
Makoto Gozawa
MIMasaru Inatani
Masaru Inatani
Background/Objectives: Microaneurysms (MAs) are important in the pathology of diabetic macular edema (DME) and its response to anti-vascular endothelial growth factor (VEGF) therapy. This study aimed to clarify the morphological characteristics of MAs in residual edema following consecutive faricimab injections, a bispecific antibody against angiopoietin-2 and VEGF. Methods: We selected patients with DME who exhibited residual edema after three monthly injections of faricimab. In both the residual and absorbed areas of edema, we counted the turnover of MAs, including those that were lost and those that were newly formed. The total number of MAs was determined based on the merged images from an optical coherence tomography (OCT) map and fluorescein angiography. Results: A total of 8 of the 42 patients who received three monthly injections of faricimab showed residual edema one month after the injections. In the residual edema, the density of MAs and the number of maintained MAs were significantly higher (p = 0.04), while the number of disappeared MAs (p = 0.04) and MA turnover (p = 0.01) were lower compared to the absorbed areas. Among the MAs that persisted after the initial injection, the proportion of large-sized MAs (p = 0.01) and their density were significantly greater than those in the absorbed area. In conclusion, the residual areas following three doses of faricimab displayed a higher MA density, less MA loss, and a high density of large-sized MAs compared to the absorbed areas. Our data suggest that large-size MAs located in the residual edema are characteristic of DME cases refractory to faricimab treatment.