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Yokohama-shi, Japan

Nakasato H.,Yokohama City University | Uemoto R.,Yokohama City University | Kawagoe T.,Yokohama City University | Okada E.,Okada Eye Clinic | Mizuki N.,Yokohama City University
British Journal of Ophthalmology | Year: 2012

Aim: To describe a new method of removing dislocated nuclear fragments smaller than one-fourth the size of the lens nucleus through the sclerocorneal incision made for cataract surgery. Methods: Dislocated lens nuclear fragments on the surface of the retina were removed from six eyes of six consecutive patients. An anterior vitreous cutter with a 27-gauge chandelier endoilluminator (Twinlight illumination) tied to its sleeve was inserted into the eye through the incision made for cataract surgery and used for core vitrectomy. A fragmatome with another 27-gauge chandelier endoilluminator (Twinlight illumination) fibre was used to grasp and move the larger dislocated nuclear fragments into the anterior chamber where they were divided and removed. Results: All dislocated nuclear fragments were removed through the incision for cataract surgery, and a posterior chamber lens was implanted in each patient without major complications. Conclusions: The procedure can be used to remove dislocated lens nuclear fragments from the surface of the retina through the incision for cataract surgery. Neither a second surgery, which would require three ports, nor the body of instruments for vitreal surgery are needed with this procedure. Source


Yoshida M.,Kyorin University | Meguro A.,Yokohama City University | Yoshino A.,Yokohama City University | Nomura N.,Yokohama City University | And 2 more authors.
Clinical Ophthalmology | Year: 2013

Purpose: Polymorphisms in the insulin-like growth factor 1 (IGF1) gene were previously associated with high or extreme myopia in Caucasian and Chinese populations. In the present study, we investigated whether IGF1 polymorphisms are associated with high myopia in a Japanese population. Methods: A total of 446 Japanese patients with high myopia (#-9.00 diopters) and 481 Japanese healthy controls (+1.50 diopters to -1.50 diopters) were recruited. We genotyped seven tagging single-nucleotide polymorphisms (SNPs) in IGF1 and assessed allelic and haplotypic diversity in cases and controls. Results: There were no statistically signifcant differences in the allele frequencies of IGF1 SNPs and genotypes between cases and controls (P.0.05). However, the A allele of rs5742629 and the G allele of rs12423791 were associated with a moderately increased risk of high myopia (odds ratio [OR] =1.20 and OR =1.21, respectively) with borderline statistical signifcance (P=0.0502, corrected P (Pc) =0.21 and P=0.064, Pc=0.29, respectively). The haplotype consisting of the A allele of rs5742629 and the G allele of rs12423791 was marginally associated with the risk of high myopia (P=0.041; OR =1.21); this association was not signifcant after correction (Pc=0.19). Conclusion: We found that the IGF1 SNPs are not signifcantly associated with high myopia in our Japanese population. Our results are in contrast to a previous study in which extreme myopia cases had signifcantly higher frequencies of the G allele of rs5742629 and the C allele of rs12423791 than controls. Therefore, the IGF1 SNPs may not be important factors for susceptibility to high myopia in all populations. Further genetic studies are needed to elucidate the possible contributions of the IGF1 region to the development of high myopia. © 2013 Yoshida et al. Source


Saadat K.A.S.M.,University of Tokyo | Murakami Y.,Kyushu University | Tan X.,University of Tokyo | Nomura Y.,University of Tokyo | And 4 more authors.
FEBS Open Bio | Year: 2014

In this study, we show augmented autophagy in the retinal pigment epithelial cell line ARPE-19 when cultured in the presence of the lipofuscin pigment A2E. A2E alone does not induce RPE cell death, but cell death was induced in the presence of A2E with the autophagy inhibitor 3-methyladenine (3MA), with a concomitant increase in the generation of mitochondrial reactive oxygen species. On the other hand, the ATP production capacity of mitochondria was decreased in the presence of A2E, and pharmacological inhibition of autophagy had no additional effects. The altered mRNA expression level of mitochondrial function markers was confirmed by real-time polymerase chain reaction, which showed that the antioxidant enzymes SOD1 and SOD2 were not reduced in the presence of A2E alone, but significantly suppressed with the addition of 3MA. Furthermore, transmission electron micrography revealed autophagic vacuole formation in the presence of A2E, and inhibition of autophagy resulted in the accumulation of abnormal mitochondria with loss of cristae. Spheroid culture of human RPE cells demonstrated debris accumulation in the presence of A2E, and this accumulation was accelerated in the presence of 3MA. These results indicate that autophagy in RPE cells is a vital cytoprotective process that prevents the accumulation of damaged cellular molecules. © 2014 The Authors. Source


Kanemaki N.,Azabu University | Meguro A.,Yokohama City University | Yamane T.,Yokohama City University | Takeuchi M.,Yokohama City University | And 4 more authors.
Clinical Ophthalmology | Year: 2015

Purpose: Many studies have investigated the relationship of paired box 6 (PAX6) gene polymorphisms with the risk of high myopia, but the results across studies remain inconsistent and ambiguous. In the present work, we investigated whether PAX6 polymorphisms are associated with high myopia in a Japanese population. Methods: A total of 1,585 Japanese patients with high myopia (spherical equivalent [SE] <-9.00 diopters [D]) and 1,011 Japanese healthy controls (SE≥-1.00 D) were recruited. To compare genotype frequencies between cases and controls, we genotyped five single nucleotide polymorphisms in the PAX6 gene that are reportedly associated with high/extreme myopia: rs662702, rs3026393, rs644242, rs3026390, and rs667773. Results: For rs662702, rs644242, and rs667773, odds ratios (ORs) for their risk alleles tended to increase with the progression of SE and axial length in the additive and recessive models. Of these, rs644242 had the highest OR (2.56) in patients with SE <-15 D in both eyes in the recessive model. On the other hand, for rs3026393 and rs3026390, the ORs for their risk alleles tended to increase according to the progression of SE and axial length in the dominant model. Of the two, rs3026393 had the highest OR (2.32) in patients with SE<-15 D in both eyes in the dominant model. However, no significant associations were identified in this study. Conclusion: We found that these PAX6 single nucleotide polymorphisms were associated with an increased risk of extreme myopia. Although the results, which are in agreement with some previous studies, did not reach statistical significance, PAX6 single nucleotide polymorphisms may be important risk factors for the development of extreme myopia. Further genetic studies with larger sample sizes and taking into account the degree of myopia are needed to clarify the contribution of PAX6 variants in myopia development. © 2015 Kanemaki et al. Source


Yoshida M.,Kyorin University | Meguro A.,Yokohama City University | Okada E.,Okada Eye Clinic | Nomura N.,Yokohama City University | Mizuki N.,Yokohama City University
Molecular Vision | Year: 2013

Purpose: The fibroblast growth factor 10 (FGF10) gene polymorphism rs339501 was previously reported to be associated with high myopia in a Chinese population. In the present study, we investigated whether FGF10 polymorphisms are associated with extreme myopia in a Japanese population as well. Methods: A total of 433 Japanese patients with extreme myopia (≤ -10.00 diopters) and 542 Japanese healthy controls (+1.50 to -1.50 diopters) were recruited. We genotyped seven tagging single-nucleotide polymorphisms (SNPs), including rs339501, in FGF10. We also performed an imputation analysis to evaluate the potential association of ungenotyped FGF10 SNPs, and 34 SNPs were imputed. Results: It was found that rs339501 and rs12517396 exhibited the strongest association with extreme myopia (p=3.9 × 10-4, corrected p [Pc]=0.0030). A significant association was also observed for rs10462070 (p=6.5 × 10-4, Pc=0.0059). These three SNPs were in strong linkage disequilibrium (D' ≥0.99, r2 ≥0.96). However, the frequency of the A allele of rs339501 was increased in cases compared to controls, which differs from the increased frequency of the G allele in cases in the previous Chinese population. Conclusions: Three FGF10 SNPs in complete linkage disequilibrium-rs339501, rs12517396, and rs10462070-were associated with extreme myopia in the Japanese population, and the risk allele of rs339501 differed from the previous Chinese population. Therefore, these three SNPs may not be an important risk factor for susceptibility to extreme myopia. Further studies are needed to elucidate the possible contribution of the FGF10 region in the development of extreme myopia. © 2013 Molecular Vision. Source

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