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Publications (6)11.69 Total impact

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    ABSTRACT: Hemicentral retinal vein occlusion (hCRVO) is a disease related to CRVO but not to branch retinal vein occlusion (BRVO). We reported a significant correlation between aqueous vascular endothelial growth factor (VEGF) levels and the implicit time of 30-Hz flicker electroretinogram (ERG) in CRVO eyes. The purpose of this study was to compare aqueous VEGF levels and ERG components between hCRVO and BRVO eyes. The medical records of patients with macular edema secondary to hCRVO (12 eyes) or BRVO (16 eyes) and received an intravitreal injection of bevacizumab (IVB) at the Nagoya University Hospital from July 2009 to May 2013 were reviewed. Full-field ERGs were recorded before the IVB. Aqueous humor was collected just before the IVB to measure VEGF concentration. Differences in aqueous VEGF level and ERG components between hCRVO and BRVO eyes were determined. Mean aqueous VEGF concentration in hCRVO eyes was significantly higher than that in BRVO eyes (504 vs. 148 pg/ml, P < 0.05). The implicit time of 30-Hz flicker ERG was significantly longer in hCRVO than in BRVO eyes (33.5 vs. 29.8 ms, P < 0.01). The significant difference in VEGF levels in aqueous and implicit times of 30-Hz flicker ERG suggest that retinal ischemia is more manifest in hCRVO than in BRVO eyes.
    Japanese Journal of Ophthalmology 03/2014; · 1.27 Impact Factor
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    ABSTRACT: To determine how different intraoperative surgical procedures affect the mid-vitreous temperature. The vitreous temperatures were monitored continuously with an intravitreal thermocouple in 87 eyes of 81 cases undergoing vitrectomy. Thirty-three eyes had diabetic retinopathy (DR), 35 eyes had an epiretinal membrane, and 19 eyes had an idiopathic macular hole. In eyes with DR, the correlation between the number of photocoagulations (PCs) and the change in temperature was analyzed. The temperature was also recorded before and after combined phacoemulsification and aspiration (PEA) and vitrectomy in 10 eyes. The average mid-vitreal temperature before the vitrectomy was 33.0±1.3º C, after core vitrectomy was 30.7±1.7º C, after membrane peeling was 32.9±1.3º C, and after peripheral vitrectomy was 29.2±1.4º C. The temperature before PC was 29.8±1.3º C, and it increased to 31.5±1.9º C post-PC. The differences in the temperatures between consecutive procedures were significant (P<0.01, respectively, Wilcoxon signed-rank test). The difference in the temperatures of the same procedures among the different diseases was not significant except after membrane peeling. The maximum increase in the average temperature during PC was 3.3º C. A significant correlation was detected between the number of PCs and the duration of the PCs, and between the duration of PCs and the change in vitreous temperature after PC (r = 0.719, P = 0.0010, and r = 0.800, P = 0.0002, respectively, Spearman's rank correlation coefficient test). The temperature after PEA decreased significantly by 2.3º C. Our results showed that the vitreous temperatures vary during different vitrectomy procedures.
    Investigative ophthalmology & visual science 02/2014; · 3.43 Impact Factor
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    ABSTRACT: To assess the relationship between intraocular soluble heparan sulfate (HS) concentration and age in subjects with and without diabetic retinopathy. Vitreous from subjects with idiopathic maculopathies (n=17), i.e., macula hole or epiretinal membrane, or nonproliferative diabetic retinopathy (non-PDR; n=5) and aqueous humor from subjects with PDR (n=16), non-PDR (n=7), or cataracts (n=15) was collected. The levels of HS and vascular endothelial growth factor (VEGF) were measured using enzyme-linked immunosorbent assay. Concentrations of sulfated glycosaminoglycan were determined through dimethylmethylene blue-based assay. The effect of the vitreal HS level on the binding of exogenous VEGF to surface-bound heparin was determined in vitro. The level of HS in vitreous samples from subjects with idiopathic maculopathies increased concomitantly with age (p=0.020, R (2)=0.327). Meanwhile, HS levels in aqueous humor were lower in PDR subjects than in non-PDR (p=0.003) and cataract subjects (p=0.007). However, the PDR subjects were significantly younger than the non-PDR subjects (p<0.001) or cataract subjects (p<0.001). When the three groups were controlled for age, the levels of HS glycosaminoglycans were no longer different between the three (p=0.247). The increasing level of HS or sulfated glycosaminoglycan in the vitreous was associated with its increased inhibitory effect on interaction between VEGF and surface heparin in vitro (p=0.014, R (2)=0.377). The HS level of the intraocular fluid increased with age. The possible link between low HS in intraocular fluid and increased localization of VEGF at the retinal surface may provide one explanation for the higher susceptibility of younger subjects with diabetes mellitus to developing PDR.
    Molecular vision 01/2013; 19:1125-31. · 1.99 Impact Factor
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    ABSTRACT: Purpose: Although bevacizumab, a humanized monoclonal antibody against vascular endothelial growth factor (VEGF), is effective in treating ocular neovascularization, there are some concerns about whether blocking VEGF might be harmful to retinal neurons. The purpose of this study was to evaluate the effects of preoperative intravitreal bevacizumab (IVB) on the visual function of eyes with proliferative diabetic retinopathy (PDR). Methods: Thirty eyes of 23 patients (13 men and 10 women) with PDR who were treated at the Nagoya University Hospital from November 2006 to October 2009 were studied. All of the eyes were treated with 1.25 mg/0.05 ml of IVB 2-8 days before the vitrectomy. The protocol was approved by the Institutional Review Board of Nagoya University, and a written informed consent was obtained from each patient. All of the eyes had an active proliferative membrane with vitreous hemorrhage, but the fundus was visible. The mean age of the patients was 41.6 ± 10 years (range, 27-59), and the mean follow-up period was 9.7 ± 8.9 months (range, 1-24) after the vitrectomy. The visual acuity (VA) was measured, the visual fields were determined by Goldmann perimetery, and full-field electroretinograms (ERGs) were recorded before IVB, and before and after the vitrectomy. Fluorescein angiography was also performed before and after IVB. The area of the visual field was measured using a computer software (Scion Image). Results: All eyes showed a regression of the new vessels and a reduction of fluorescent leakage from the new vessels after IVB. In addition, there was less bleeding during the removal of the proliferative membrane. The average VA was improved postoperatively from 20/250 to 20/70. However, there was no significant change in the amplitudes of the a- (from 261.4 to 259.2 µV) and b-waves (from 256.9 to 253.3 µV) of the ERGs, and there was no significant change in the visual field area after the surgery (from 8,322.5 to 7,496.3 degrees(2)). No significant ocular or systemic adverse events were observed. Conclusion: IVB-assisted vitrectomy led to an improvement of the VA in eyes with PDR without significant adverse events. There was no change in the visual fields and ERGs. Although only a small number of patients were studied, we conclude that IVB is most likely not harmful to retinal neurons if bevacizumab is washed out in less than 1 week. In addition, preoperative IVB made the surgery much easier by decreasing the activity of new vessels.
    Ophthalmic Research 09/2012; 49(1):30-36. · 1.56 Impact Factor
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    ABSTRACT: Central retinal vein occlusion (CRVO) leads to retinal ischemia, which then induces an upregulation of vascular endothelial growth factor (VEGF). The aim of this study was to determine whether a significant correlation exists between the ocular VEGF levels and the amplitudes and implicit times of different components of the electroretinogram (ERG) in eyes with a CRVO. The medical records of the 20 consecutive patients who had macular edema secondary to CRVO and were examined at the Nagoya University Hospital from November 2008 to February 2010 were reviewed. Because all the patients were scheduled to receive an intravitreal injection of bevacizumab (IVB), it was possible to collect samples of the aqueous humor before the IVB. The correlation between the different components of the ERGs and the VEGF concentration in the aqueous was determined. The mean VEGF concentration of the aqueous humor was 416 pg/mL with a range of 100-1260 pg/mL. The b/a ratio of the single flash ERGs (P = 0.049; ρ = -0.45), implicit times of the cone a-wave (P = 0.028; ρ = 0.50), cone b-wave (P = 0.0059; ρ = 0.63), and 30 Hz flicker ERGs (P = 0.0058; ρ = 0.63) were significantly correlated with the VEGF concentration in the aqueous. The significant correlations between the different components of the ERGs and the aqueous VEGF concentration indicate that full-field ERGs can be used to detect the CRVO patients at a high risk of developing neovascularization of the iris.
    Investigative ophthalmology & visual science 06/2011; 52(8):5737-42. · 3.43 Impact Factor
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    ABSTRACT: A patient with macular edema secondary to a branch retinal vein occlusion (BRVO) was treated with intravenous injections of infliximab, an antitumor necrosis factor (TNF)-alpha antibody, for her rheumatoid arthritis (RA). Before the injection, the thickness of the right fovea, determined by optical coherent tomography, was 629 mum and the best-corrected visual acuity (BCVA) was 20/50. After eight injections of infliximab and 10 months after the first injection, her foveal thickness was decreased to 293 mum and the visual acuity improved to 20/20. There was no recurrence of macular edema during the infliximab injections. However, the infliximab injection was stopped because the patient developed pneumonia. Eight months after stopping the infliximab injection, her foveal thickness increased to 494 mum. To treat the RA, her orthopedists began weekly subcutaneous injections of etanercept, a fusion protein of a section of the TNF receptor and immunoglobulin. Five months later, the foveal thickness had decreased to 260 mum, and the visual acuity remained at 20/25(+). Because TNF-alpha is known to break down the blood-retinal barrier, the improvements in our case suggest that TNF-alpha plays a role in the pathogenesis of macular edema in some patients with BRVO.
    Clinical Ophthalmology 01/2010; 4:667-70.