Masaki Tanito

Shimane University, Matsu, Shimane Prefecture, Japan

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Publications (96)296.18 Total impact

  • Masaki Tanito, Ichiya Sano, Akihiro Ohira
    Acta ophthalmologica 10/2014; · 2.44 Impact Factor
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    ABSTRACT: PurposeA possible association has been reported between exfoliation syndrome (EX) and various ocular and systemic vascular disorders; however, it is unclear if there is an association between EX and central retinal vein occlusion (CRVO). Because latent deposits of exfoliation materials might not be recognized during slit-lamp examination, an ocular biopsy is required to establish a precise diagnosis. We evaluated a possible association between EX and CRVO using lysyl oxidase-like 1 (LOXL1) gene variants as alternative markers for EX.Methods The allelic and genotypic frequencies of three LOXL1 variants (rs1048661, rs3825942, and rs2165241) were determined in 68 consecutive Japanese patients with CRVO [15 with exfoliation syndrome (EX+) and 53 without exfoliation syndrome (EX−)] and 90 control patients with cataract without EX (CT).ResultsThe frequencies of the rs1048661 and rs3825942 variants showed borderline difference between the CRVO and CT groups (p = 0.04085 and p = 0.06088, respectively, for allelic frequencies, and p = 0.06838 and p = 0.03482, respectively, for genotypic frequencies). Compared with the CT group, subgroup analysis showed that the CRVO EX+ group had significant differences in the allelic and genotypic frequencies of rs1048661 (p = 0.0006447 and p = 0.0001392, respectively) and had borderline differences in the allelic and genotypic frequencies of rs3825942 (p = 0.03403 and p = 0.07341, respectively), while the CRVO EX− group did not (p = 0.1324–0.6306). Subgroup analysis showed that the frequencies of rs2165241 did not differ between the CRVO and CT groups.Conclusions When the LOXL1 variants were used as disease markers for clinically undetectable EX, there was no association between CRVO and EX. The results suggested that the LOXL1 variants, which are well-established markers for EX, are not likely genetic markers for CRVO in Japanese subjects.
    Acta ophthalmologica 08/2014; · 2.44 Impact Factor
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    ABSTRACT: To estimate the melatonin suppression index (MSI), which may reflect the nonvisual photoreception function, through commercially available foldable, clear and yellow-tinted intraocular lenses (IOLs). The MSIs for 13 IOL models (6 clear IOLs, 7 yellow-tinted IOLs) with three lens powers were calculated based on previously reported data about the melatonin suppression spectrum, spectral intensity of a 20-W white fluorescent lamp and spectral transmission of IOLs in wavelengths from 300 to 800 nm. The models tested were the SA60AT and SN60AT (Alcon Japan); the VA-60BBR, YA-60BBR, and NM-1 (Hoya); the AU6K and AN6K (Kowa); the N4-18B and N4-18YG (Nidek); the X-60 and NX-60 (Santen); and the KS-3Ai and KS-AiN (Staar Japan). The MSIs of the clear IOLs ranged from 1.12 to 1.18 mW cm(-2) sr(-1) and those of the yellow-tinted IOLs from 0.74 to 1.01 mW cm(-2) sr(-1). All yellow-tinted IOLs had significantly lower MSIs (P < 0.0001-0.0021) than the clear IOLs; the %MSI cutoff values for yellow-tinted IOLs compared to the clear IOLs were 11.4-36.2 %. The MSIs of the six clear IOLs did not differ based on lens powers (P = 0.2159-0.6144). Except for one IOL model, all yellow-tinted IOLs had a lower MSI with higher lens powers compared to those with lower lens powers (P < 0.0001-0.0055). Compared to phakic eyes (MSI, 1.03 mW cm(-2) sr(-1)), the MSIs of the clear IOLs were higher (%MSI cutoff, -14.6 to -8.4 %), whereas those of the yellow-tinted IOLs were lower (2.6-28.1 %). Compared to aphakic eyes (MSI, 1.21 mW cm(-2) sr(-1)), the MSIs of the clear (2.1-7.4 %) and yellow-tinted (16.7-38.6 %) IOLs were lower. Yellow-tinted IOLs absorb more circadian rhythm-associated light than clear IOLs. The difference in the lens power is significantly related to the MSI value in some yellow-tinted IOLs. To correlate the current data with the clinical relevance of these findings, the percent loss of the MSI leading to a circadian rhythm disorder needs to be clarified.
    Japanese Journal of Ophthalmology 04/2014; · 1.27 Impact Factor
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    ABSTRACT: Macular pigment is a defense system against phototoxic damage of the retina by visible light. It is still under debate whether or not macular pigment optical density (MPOD) levels decline with age, because the age effect varied depending on the technique used to measure MPOD levels. Resonance Raman spectroscopy (RRS) is an objective method to measure MPOD, and studies using RRS showed a drastic age-related decline of MPOD levels; however, since RRS measurements are influenced by cataracts, it has been argued that the age-related decline of RRS measurements is an artifact from lens changes in aged subjects. In the present study, MPOD levels were measured with RRS in pseudophakic eyes, and the effects of age and other factors on MPOD levels were investigated. The subjects included 144 patients with no fundus disorders who received cataract surgery with untinted intraocular lens implantation. MPOD levels were measured in 144 eyes using integral RRS 1 day post surgery. Factors potentially associated with MPOD levels such as age, gender, smoking habits, body mass index, diabetes, glaucoma, axial length, pupil diameter, spherical equivalent refractive error, and foveal thickness were examined by multiple regression analysis. The macular pigment RRS levels ranged from 776 to 11,815 Raman counts, with an average level of 4,375 ± 1,917 (standard deviation [SD]) Raman counts. Multiple regression analysis revealed that age and axial length were significantly correlated with low MPOD values (regression coefficient of -59 for age and -404 for axial length, respectively). No significant correlations were observed for other factors. After removing the potentially confounding effect of age-related lens yellowing on the RRS measurements, age remained a significant patient parameter for lowered MPOD levels. MPOD levels were found to decline by more than 10 % each decade. Axial length was also a negative predictor of MPOD levels. Since the present study included only patients aged 50 years and older, the effects of age and other factors on MPOD levels for younger subjects remain unknown.
    Albrecht von Graæes Archiv für Ophthalmologie 03/2014; · 1.93 Impact Factor
  • Acta ophthalmologica 01/2014; · 2.44 Impact Factor
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    ABSTRACT: To elucidate Japanese trends for perioperative disinfection and antibiotic selection during cataract surgeries.
    Clinical ophthalmology (Auckland, N.Z.) 01/2014; 8:2013-8.
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    ABSTRACT: The Glaucoma Stereo Analysis Study (GSAS), a cross sectional multicenter collaborative study, used a stereo fundus camera to assess various morphological parameters of the optic nerve head (ONH) in glaucoma patients and investigated the relationships between these parameters and patient characteristics.
    PLoS ONE 01/2014; 9(6):e99138. · 3.53 Impact Factor
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    ABSTRACT: To report the reproducibility profile of optic nerve head parameters obtained by computer software-assisted fundus photoplanimetry. Fundus photographs obtained during a population-based health survey (Sakurae Study) were planimetrically analyzed using newly developed computer software, CDSketch. The parameters assessed included vertical and horizontal cup-to-disc (C/D) ratios, superior and inferior rim-to-disc (R/D) ratios, disc and cup vertical-to-horizontal (V/H) ratios, and disc-macular distance-to-disc diameter (DM/DD) ratio. For intraobserver and interobserver agreement assessments, we calculated the coefficients of variation (CVs) and intraclass correlation coefficients (ICCs) of the mean of three measurements obtained by one observer and a one-time measurement by three observers, respectively. The intraobserver CVs were between 2.4 % (DM/DD ratio) and 11.0 % (inferior R/D ratio), and the ICCs were between 0.868 (cup V/H ratio) and 0.976 (DM/DD ratio); all intraobserver ICCs had almost perfect agreement (>0.81). The interobserver CVs were between 2.6 % (disc V/H ratio) and 18.0 % (inferior R/D ratio), and the ICCs were between 0.762 (cup V/H ratio) and 0.930 (DM/DD ratio); the interobserver ICCs were categorized as substantial (0.61-0.80) for the inferior R/D and cup V/H ratios and as almost perfect for the other five parameters. The consistent profiles of the planimetric parameters suggest the suitability of software-assisted photoplanimetry for assessing optic disc characteristics in glaucoma clinical study and practice.
    Japanese Journal of Ophthalmology 10/2013; · 1.27 Impact Factor
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    ABSTRACT: PURPOSE. To report the efficacy of systemic prostaglandin E1 (PGE1) monotherapy for treating acute central retinal artery occlusion (CRAO). METHODS. The best-corrected visual acuity (BCVA) and side effects were evaluated retrospectively in 10 consecutive eyes (9 patients; mean age, 61.3 years) with acute CRAO treated with PGE1 monotherapy. The protocol included intravenous injection of 40 μg PGE1 twice daily (80 μg/day) for 5 days then oral PGE1 three times daily (30 μg/day) for at least 1 month. In four eyes, the retinal vessel diameters were assessed on serial fundus photographs. RESULTS. The mean time-to-treatment was 7.1 hours (range, 1-18 hours). The mean ± standard deviation logarithm of the minimum angle of resolution (logMAR) BCVAs at baseline and 1 month after initiation of therapy were 2.67 ± 0.54 (range, 3.00-1.70) and 0.52 ± 0.62 (range, 2.00- -0.18), respectively (P=0.005); the BCVA improved by 1.0 or more logMAR unit at 1 month in all eyes. The BCVA improvement was correlated negatively with the time-to-treatment (ρ= -0.655, P=0.0492), but was not correlated with age (ρ= -0.473, P=0.156) and did not differ between genders (P=0.0871). Compared with baseline, the mean changes in the vessel diameters in four cases were 151.1% (range, 115.1%-188.0%) in the arteries and 191.0% (range, 127.2%-246.4%) in the veins 1 day after initiation of therapy. Angialgia during injection was the only side effect. CONCLUSIONS. Systemic administration of PGE1 for acute CRAO rapidly restores retinal blood flow by its vasodilatory effects, improves VA, is well tolerated with few side effects, and requires no special training.
    Investigative ophthalmology & visual science 04/2013; · 3.43 Impact Factor
  • Masaki Tanito, Akihiro Ohira
    Acta ophthalmologica 02/2013; · 2.44 Impact Factor
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    ABSTRACT: Oxidative stress has been suspected of contributing to the pathogenesis of pterygia. We evaluated the immunohistochemical localization of the markers of oxidative stress, that is, the proteins modified by 4-hydroxyhexenal (4-HHE) and 4-hydroxynonenal (4-HNE), which are reactive aldehydes derived from nonenzymatic oxidation of n-3 and n-6 polyunsaturated fatty acids, respectively. In the pterygial head, labeling of 4-HHE- and 4-HNE-modified proteins was prominent in the nuclei and cytosol of the epithelium. In the pterygial body, strong labeling was observed in the nuclei and cytosol of the epithelium and proliferating subepithelial connective tissue. In normal conjunctival specimens, only trace immunoreactivity of both proteins was observed in the epithelial and stromal layers. Exposures of ultraviolet (330 nm, 48.32 ± 0.55 J/cm(2)) or blue light (400 nm, 293.0 ± 2.0 J/cm(2)) to rat eyes enhanced labeling of 4-HHE- and 4-HNE-modified proteins in the nuclei of conjunctival epithelium. Protein modifications by biologically active aldehydes are a molecular event involved in the development of pterygia.
    Oxidative Medicine and Cellular Longevity 01/2013; 2013:602029.
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    Acta ophthalmologica 08/2012; · 2.44 Impact Factor
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    ABSTRACT: To explore the fundus photoplanimetric distribution of the optic nerve head in a population-based health survey conducted in Sakurae area, in Shimane, Japan(the Sakurae Study). After the exclusion of poor quality images from the 1660 right eye-fundus photos obtained from the Sakurae Study in 1991, 1583 photos were digitized, and then were planimetrically analyzed using a newly developed computer software, CDSketch. The parameters calculated included vertical and horizontal cup-to-disc (C/D) ratios, superior and inferior rim-to-disc (R/D) ratios, disc and cup vertical-to-horizontal (V/H) ratios, and disc-macular distance-to-disc diameter (DM/DD) ratio. For the vertical and horizontal C/D, superior and inferior R/D, disc and cup V/H, and DM/DD ratios, mean values were calculated to be 0.58, 0.59, 0.20, 0.18, 1.11, 1.09, 2.60, respectively, and median values were calculated to be 0.58, 0.59, 0.19, 0.18, 1.11, 1.09, 2.57, respectively; no parameter showed any remarkably skewed distribution. The vertical C/D ratio was positively correlated with the cup V/H ratio, but was not correlated with the disc V/ H ratio. The vertical and horizontal C/D, and the disc and cup V/H ratios were negatively correlated with the DM/DD ratio. The distributions of the various optic nerve head parameters and their correlations in the Sakurae Study are reported. Both mean and median values of the vertical C/D ratio were approximately 0.6 in this study population. These values were larger than the previously reported C/D ratios obtained by direct ophthalmoscopic observations and/or by subjective methods.
    Nippon Ganka Gakkai zasshi 08/2012; 116(8):730-9.
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    ABSTRACT: Our purpose was to determine whether either lutein or zeaxanthin supplementation affects macular pigment concentration/optical density (MPOD) in healthy Japanese individuals. Twenty-two healthy volunteers were randomized to either 10 mg of orally administered lutein or zeaxanthin daily for up to 3 months. MPOD levels were measured by resonance Raman spectrophotometry (RRS) and one-wavelength autofluorescence imaging (AFI) at baseline and 1, 2, and 3 months after the start of supplementation. MPOD levels measured with each method were correlated significantly at all time points. MPOD(RRS) and MPOD(AFI) levels increased >20 % from baseline at 2 and 3 months after lutein supplementation. By multiple regression analyses, the refractive error was correlated positively with MPOD(RRS) levels at baseline, whereas age and sex were not significant. In the lutein group, MPOD(RRS) levels significantly increased from baseline at all time points in individuals without high myopia exceeding -4 diopters, whereas the increase was not observed in individuals with high myopia. In the zeaxanthin group, MPOD(RRS) levels remained unchanged in those with and without high myopia. MPOD(RRS) and MPOD(AFI) levels correlated significantly with each other. In normal healthy Japanese individuals without high myopia, lutein supplementation increased MPOD levels within the fovea more effectively than did zeaxanthin.
    Japanese Journal of Ophthalmology 06/2012; 56(5):488-96. · 1.27 Impact Factor
  • Acta ophthalmologica 06/2012; · 2.44 Impact Factor
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    ABSTRACT: Toevaluate the effect of removing epiretinal membranes (ERMs) on visual function and vision-related quality of life (VR-QOL) for 12 months postoperatively. Idiopathic ERMs were removed during vitrectomy in 26 eyes. The VR-QOL was evaluated using a self-administered 25-item National Eye Institute Visual Function Questionnaire before (baseline) and 3 and 12 months postoperatively. During the same periods, the best-corrected visual acuity (BCVA), central macular thickness (CMT), and metamorphopsia score were recorded. At baseline and months 3 and 12, the logMAR BCVAs (mean ± SEM) were 0.41 ± 0.05, 0.17 ± 0.04 (P = 0.0001 versus baseline), and 0.10 ± 0.03 (P < 0.0001 versus baseline, P = 0.0016 versus month 3), respectively; the CMTs (μm) were 402 ± 18, 312 ± 9 (P < 0.0001 versus baseline), and 300 ± 7 (P < 0.0001 versus baseline, P = 0.0544 versus month 3); and the metamorphopsia scores were 202 ± 29, 137 ± 27 (P = 0.0186 versus baseline), and 108 ± 26 (P = 0.0005 versus baseline, P = 0.0218 versus month 3). In 23 (88%) of 26 eyes, the BCVA improved more than 0.1 logMAR unit at month 12. The improved BCVA was correlated with improvements in two subscales (r = -0.405 to -0.574, P = 0.0041-0.0427) at month 3; the improved metamorphopsia score was correlated with the improved composite score (r = -0.552, P = 0.0058) and three subscales (r = -0.458 to -0.507, P = 0.0113-0.0219) at month 12. Removing ERMs improved visual function, anatomy, and the VR-QOL. Three months postoperatively, the improved BCVA was the most important factor related to the improved VR-QOL, although the simultaneous cataract surgery might have had a confounding effect. The improved metamorphopsia was the important factor associated with improved VR-QOL 12 months postoperatively.(www.umin.ac.jp/ctr number, UMIN000000617).
    Investigative ophthalmology & visual science 04/2012; 53(6):3054-8. · 3.43 Impact Factor
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    ABSTRACT: Caveolin-1 (Cav-1), an integral component of caveolar membrane domains, is expressed in several retinal cell types, including photoreceptors, retinal vascular endothelial cells, Müller glia, and retinal pigment epithelium (RPE) cells. Recent evidence links Cav-1 to ocular diseases, including autoimmune uveitis, diabetic retinopathy, and primary open angle glaucoma, but its role in normal vision is largely undetermined. In this report, we show that ablation of Cav-1 results in reduced inner and outer retinal function as measured, in vivo, by electroretinography and manganese-enhanced MRI. Somewhat surprisingly, dark current and light sensitivity were normal in individual rods (recorded with suction electrode methods) from Cav-1 knock-out (KO) mice. Although photoreceptor function was largely normal, in vitro, the apparent K(+) affinity of the RPE-expressed α1-Na(+)/K(+)-ATPase was decreased in Cav-1 KO mice. Cav-1 KO retinas also displayed unusually tight adhesion with the RPE, which could be resolved by brief treatment with hyperosmotic medium, suggesting alterations in outer retinal fluid homeostasis. Collectively, these findings demonstrate that reduced retinal function resulting from Cav-1 ablation is not photoreceptor-intrinsic but rather involves impaired subretinal and/or RPE ion/fluid homeostasis.
    Journal of Biological Chemistry 03/2012; 287(20):16424-34. · 4.65 Impact Factor
  • Masaki Tanito, Feng Li, Robert E Anderson
    Advances in experimental medicine and biology 01/2012; 723:137-43. · 1.83 Impact Factor
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    ABSTRACT: The involvement of local and systemic oxidative stress in intraocular pressure (IOP) elevation and optic nerve damage has been hypothesized in the pathogenesis of glaucoma. To test this, we measured the systemic levels of prooxidants and antioxidants by analyzing the blood biochemistry in patients with glaucoma. Peripheral blood samples were collected from Japanese patients with primary open-angle glaucoma (PG) (n = 206), exfoliation syndrome (EX) (n = 199), and controls (n = 126). Plasma levels of lipid peroxides, ferric-reducing activity, and thiol antioxidant activity were measured by diacron reactive oxygen metabolites (dROM), biological antioxidant potential (BAP), and sulfhydryl (SH) tests, respectively, using a free radical analyzer. In the PG, EX, and control groups, the mean ± standard deviation values were 355±63, 357±69, and 348±56 (U. Carr), respectively, for dROM; 1,951±282, 1,969±252, and 2,033±252 (µmol/L), respectively, for BAP (µmol/L); and 614±98, 584±91, and 617±99 (µmol/L), respectively, for SH. The differences in the BAP values were significant between the PG and control groups (p = 0.0062), for SH between the EX and control groups (p = 0.0017), and for SH between the PG and EX groups (p = 0.0026). After adjustment for differences in age and sex among groups using multiple regression analysis, lower BAP values were correlated significantly with PG (p = 0.0155) and EX (p = 0.0049). Higher dROM values with and without glaucoma were correlated with female gender, and lower SH values with older age. There were no significant differences between the higher (≥21 mmHg) and lower (<21 mmHg) baseline IOPs in the PG group or between the presence or absence of glaucoma in the EX group. Lower systemic antioxidant capacity that measured by ferric-reducing activity is involved in the pathogenesis of PG and EX.
    PLoS ONE 01/2012; 7(11):e49680. · 3.53 Impact Factor
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    ABSTRACT: To investigate surgical outcomes after pars plana implantation of the Ahmed glaucoma valve (ppAGV). The intraocular pressure, corneal endothelial damage and post-surgical complications of 31 consecutive refractory glaucoma eyes of 26 subjects who underwent ppAGV were prospectively studied at two centers. Cell density (CD) at the central cornea decreased by 3.5 ± 15.0 and 10.2 ± 18.9% at 6 and 12 months, respectively. The CD loss at 1 year was comparable with the loss after cataract surgery alone (6.5 ± 8.5%, P = 0.441). Hexagonality (Hex) changed little, from 41.5 ± 15.6% at baseline to 41.8 ± 14.9% (P = 0.976) at 6 months and 41.6 ± 10.2% (P = 0.58) at 12 months. The coefficient of variation of the central corneal endothelium area (CV) changed from 40.7 ± 9.0% at baseline to 45.7 ± 12.6% (P = 0.078) at 6 months and 45.5 ± 11.2% (P = 0.013) at 12 months. Concomitant cataract surgery was a significant risk factor for CD loss. The probabilities of success or qualified success at 1 year were 66.1 and 83.6%, respectively. Most of the posterior segment complications, which were noted in 6 of 31 eyes (19%), were self-limiting, except for 2 eyes (6%) that developed retinal detachment as a consequence of kissing choroidal detachment. Corneal endothelial damage was minimal, and the success probability was relatively high after ppAGV in refractive glaucoma cases.
    Japanese Journal of Ophthalmology 12/2011; 56(2):119-27. · 1.27 Impact Factor

Publication Stats

2k Citations
296.18 Total Impact Points

Institutions

  • 2001–2014
    • Shimane University
      • • Department of Ophthalmology
      • • Faculty of Medicine
      Matsu, Shimane Prefecture, Japan
  • 2005–2012
    • University of Oklahoma Health Sciences Center
      • Dean McGee Eye Institute
      Oklahoma City, OK, United States
  • 2011
    • Seirei Hamamatsu General Hospital
      Hamamatu, Shizuoka, Japan
  • 2002–2009
    • Kyoto University
      • • Graduate School of Medicine / Faculty of Medicine
      • • Institute for Virus Research
      Kyoto, Kyoto-fu, Japan
  • 2004–2005
    • Shiga University of Medical Science
      Ōtu, Shiga, Japan
    • University Hospital Medical Information Network
      Edo, Tōkyō, Japan