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Biomedical subjects

Takahiro Kiuchi

Publications and source records attributed to Takahiro Kiuchi.

At least 19 recordsLinked to original sources
PubMed2006

Relationship of progression of visual field damage to postural changes in intraocular pressure in patients with normal-tension glaucoma.

PURPOSE: To evaluate whether postural changes of intraocular pressure (IOP) are associated with progression of visual field damage in patients with normal-tension glaucoma (NTG). DESIGN: Prospective, noncomparative, nonrandomized study. PARTICIPANTS: Sixty eyes of 33 patients with NTG. METHODS: Intraocular pressure, blood pressure (BP), and pulse rate (PR) were measured in both sitting and supine positions. Visual fields were examined using Humphrey Field Analyzer (HFA; Zeiss-Humphrey Instruments, Inc., San Leandro, CA). Changes in mean deviation (MD) per year (dB/year), that is, MD slope, were calculated by linear regression analysis of the HFA Statpac 2 program. MAIN OUTCOME MEASURES: The relationship between postural changes of IOP and MD slope was analyzed. The correlation between postural changes of IOP and cardiovascular parameters such as BP and PR also was analyzed. RESULTS: The IOP in the supine position was significantly higher than that in the sitting position (P<0.001, paired t test). There was no significant correlation between MD slope and sitting IOP (Pearson r = 0.172; P = 0.188), but a significant correlation was found between MD slope and supine IOP (r = -0.261; P = 0.043). The MD slope significantly correlated with IOP elevation caused by the postural change (r = -0.682; P<0.001). The systolic BP in the supine position correlated with postural changes of IOP (r = 0.364; P = 0.004), but other cardiovascular parameters did not correlate with IOP parameters. CONCLUSIONS: The progression of visual field damage in NTG is associated with IOP in the supine position and the magnitude of IOP elevation accompanying postural changes. These results suggest that deterioration in NTG may occur when patients are lying flat during sleep.

Aged↗
PubMed2006

Comparison of tacrolimus and mizoribine in a randomized, double-blind controlled study in patients with rheumatoid arthritis.

OBJECTIVE: To compare the efficacy and safety of tacrolimus and mizoribine in patients with rheumatoid arthritis (RA). METHODS: Adult patients with RA with an insufficient response to at least one disease modifying antirheumatic drug (DMARD) were randomized to receive 28 weeks of double-blind treatment with tacrolimus 3 mg once daily or mizoribine 50 mg three times daily. The primary efficacy endpoint was the American College of Rheumatology 20% (ACR20) response. Safety was evaluated by adverse events. RESULTS: A total of 204 patients were enrolled for study (103 in the tacrolimus group, 101 in the mizoribine group). Significantly more patients receiving tacrolimus achieved an ACR20 response compared with mizoribine (48.5 vs 10.0%, respectively; p = 0.001). Tacrolimus was also superior to mizoribine in ACR50 and ACR70 response rate, tender and painful joint counts, swollen joint counts and patient and physician assessments of pain, disease activity, and patient's physical function assessment based on the Modified Health Assessment Questionnaire (p < 0.001). Adverse events were more frequent in the tacrolimus group than the mizoribine group (65.0 vs 59.4%); however, there were no statistically significant differences between treatment groups. CONCLUSION: Tacrolimus improves RA symptoms to a significantly greater extent than mizoribine in patients with RA inadequately controlled with at least one prior DMARD. Tacrolimus has the potential to be a useful and highly effective treatment for RA.

Arthritis, Rheumatoid↗
PubMed2006

A multicenter randomized controlled trial to evaluate the effect of adjuvant cisplatin and 5-fluorouracil therapy after curative resection in cases of pancreatic cancer.

BACKGROUND: There have been few randomized controlled clinical trials until now to determine the effectiveness of adjuvant treatments for pancreatic cancer, and the results reported so far are inconsistent. METHODS: Patients with invasive ductal pancreatic cancer who underwent radical surgery with clear histological margins at 11 Japanese institutions were enrolled and randomly assigned to one of two groups: surgery-alone group (no further treatment after surgery) and the surgery + chemotherapy group [two courses of postoperative adjuvant systemic chemotherapy with cisplatin (80 mg/m(2), Day 1) and 5-fluorouracil (500 mg/m(2)/day, Days 1-5)]. Patients with a positive resectional margin or with resected distant metastases were excluded from the trial in order to minimize the influence of residual cancer. RESULTS: Between 1992 and 2000, 89 patients were randomized into the two arms of the trial (45 patients to the surgery + chemotherapy arm and 44 patients to the surgery-alone arm). Four patients in total were found to be ineligible (three in the surgery + chemotherapy group and one in the surgery-alone group). The baseline characteristics were comparable between the two groups. In the surgery + chemotherapy group, four patients did not receive the adjuvant treatment because of patient refusal. Toxicity was minor and acceptable among the eligible patients in the surgery + chemotherapy group. The estimated 5-year survival rates were 26.4% in the surgery + chemotherapy group and 14.9% in the surgery-alone group, and the median duration of survival was 12.5 months and 15.8 months, respectively. The recurrence rates at 5 years were 73.6 and 80.8%, respectively, in the surgery + chemotherapy and the surgery-alone groups. The differences in the survival and recurrence rates between the two groups were not statistically significant. CONCLUSIONS: Postoperative adjuvant chemotherapy using cisplatin and 5-fluorouracil was safe and well tolerated; however, no clear survival benefit could be demonstrated.

Aged↗
PubMed2006

Inadvertent insertion of an opposite-power intraocular lens.

An 82-year-old woman with age-related cataract and high myopia had uneventful phacoemulsification and intraocular lens (IOL) implantation. Preoperative visual acuity was 20/60 with -16.00 -3.00 x 70 and axial length was 29.29 mm. An IOL (MA60MA, Alcon) of +5.0 diopters (D) was selected with target refraction of -1.5 D. The next day, visual acuity was 20/15 with +5.50 -2.00 x 60. It was found that an IOL of -5.0 D was inadvertently inserted instead of +5.0 D because of an identical package appearance of the opposite-diopter IOLs except for a small negative sign before the diopter label. The -5.0 D IOL was surgically replaced with +5.0 D IOL, and visual acuity became 20/15 with -0.50 -2.00 x 70. When selecting an IOL for highly myopic patients, attention should be paid to the extreme resemblance of the package of opposite-diopter IOLs.

Aged, 80 and over↗
PubMed2006

Prospective intrapatient comparison of 6.0-millimeter optic single-piece and 3-piece hydrophobic acrylic foldable intraocular lenses.

PURPOSE: To compare postoperative performance and stability of 6.0-mm optic single- and 3-piece acrylic foldable intraocular lenses (IOLs). DESIGN: Prospective, randomized, self-controlled trial. PARTICIPANTS: Eighty eyes of 40 patients with bilateral senile cataracts. INTERVENTION: Phacoemulsification and IOL implantation were performed. One eye of a patient was randomly assigned to the SA60AT single-piece IOL, and the contralateral eye was allocated to the MA60AC 3-piece IOL. MAIN OUTCOME MEASURES: Best-corrected visual acuity (BCVA), spherical equivalent, aqueous flare intensity, anterior chamber depth, amount of IOL decentration and tilt, area of anterior capsule opening, and degree of posterior capsule opacification (PCO) were measured 2 days, 1 week, and 1, 3, 6, and 12 months after surgery. Specular microscopy was performed at 12 months postoperatively. RESULTS: In the SA60AT group, the anterior chamber depth did not show significant changes after surgery (P>0.05; paired t test), and the refraction remained highly stable throughout the 1-year study period. The MA60AC group showed significant shallowing of the anterior chamber (P<0.05) and a myopic shift (P<0.05) up to 1 month after surgery. There were no significant differences between the 2 groups (P>0.05) in BCVA, aqueous flare intensity, the amount of IOL decentration, IOL tilt, area of anterior capsule opening, and degree of PCO throughout the 12-month follow-up period. CONCLUSIONS: Both the SA60AT single-piece and MA60AC 3-piece lenses showed a minimum amount of decentration, tilt, anterior capsule contraction, and PCO. Although the MA60AC showed significant forward shift and myopic refractive changes after surgery, the SA60AT displayed little axial movement associated with highly stable refraction after surgery. This feature of the SA60AT should facilitate earlier spectacle prescription and quicker visual/social rehabilitation of patients after cataract surgery.

Acrylic Resins↗
PubMed2005

Effects of nebulized sodium cromoglycate on adult patients with severe refractory asthma.

Many patients with severe refractory asthma, which is insufficiently controlled by additional high-dose of inhaled corticosteroids, require oral corticosteroids and/or immunosuppressant. Clinicians should seek for suitable medications, for its' chronic use may induce high risk of side effects. The purpose of this study was to evaluate the efficacy and safety of nebulized sodium cromoglycate (3-4 times/day) in adult severe asthmatic patients with poorly controlled asthmatic symptoms, despite treatments with high-dose inhaled corticosteroids. Adult patients with severe asthma (n=251) were enrolled in a randomized clinical trial at 30 medical centers in Japan. Isotonic saline was used as placebo. The study was conducted for 10 weeks; with initial 2 weeks of observation followed by 8 weeks of treatments. Efficacy was primarily evaluated based on improvements in morning peak expiratory flow after treatment. All patients who applied inhalation of nebulized sodium cromoglycate (SCG group) or saline (Controls) were treated with high-dose of inhaled corticosteroids (median of beclomethasone dipropionate equivalent dose: 1600 microg/days) and second-line control therapy including oral corticosteroids. There was no significant difference in morning peak expiratory flow between SCG group and controls. However, when patients were stratified into atopic and non-atopic groups, morning peak expiratory flow had significantly improved in the atopic SCG group compared to atopic Controls. Additional inhalation of nebulized sodium cromoglycate with inhaled corticosteroids is effective even in patients with severe atopic asthma. This finding shows that nebulized sodium cromoglycate is expected to be new second-line therapeutic option in severe asthma.

Administration, Inhalation↗
PubMed2005

Corneal barrier function, tear film stability, and corneal sensation after photorefractive keratectomy and laser in situ keratomileusis.

PURPOSE: To compare corneal sensation, corneal barrier function, tear secretion, and tear film stability after photorefractive keratectomy (PRK) and laser in situ keratomileusis (LASIK). DESIGN: Prospective, nonrandomized clinical trial. METHODS: In a prospective study, 28 eyes of 15 patients underwent PRK and 115 eyes of 59 patients underwent LASIK to correct myopia. Corneal sensation, corneal epithelial barrier function, tear secretion, and tear film stability were examined preoperatively and 1 week and 1, 3, 6, and 12 months postsurgery. RESULTS: Both PRK and LASIK significantly compromised corneal sensation, increased epithelial barrier function, reduced tear secretion, and deteriorated tear film stability (P < .05, Wilcoxon signed-rank test). Deterioration of corneal sensation was significantly greater after LASIK than after PRK by 3 months postoperatively (P < .05, Wilcoxon rank sum test). Increases in corneal epithelial permeability were more prolonged after LASIK than after PRK. A significant intergroup difference in permeability was observed 1 month after surgery (P < .01). Tear breakup time was significantly shorter in the LASIK group than in the PRK group up to 3 months after surgery (P < .045). CONCLUSIONS: LASIK induces greater and more prolonged damage to corneal sensation, corneal barrier function, and tear film stability than PRK.

Adolescent↗
PubMed2005

Ocular higher-order wavefront aberration caused by major tilting of intraocular lens.

PURPOSE: To report a patient with a significant amount of ocular coma-like aberration that was caused by the tilting of an intraocular lens (IOL) who was treated successfully by IOL repositioning surgical procedure. DESIGN: Interventional case report. METHODS: At the Department of Ophthalmology, University of Tsukuba, a 52-year-old man complained of unclear and distorted vision in his left pseudophakic eye. The tilt and decentration of IOL were measured with the Scheimpflug videophotography system. Ocular and corneal wavefront aberrations were measured with the Hartmann-Schack aberrometer. RESULTS: The tilting angle was 28.87 degrees, and decentration was 1.78 mm. The ocular coma-like aberration was increased remarkably to 0.451 microm at 4.0 mm aperture diameter, and the simulated retinal image of a Landolt ring was blurred substantially. Ocular spheric-like, corneal coma-like, and corneal spheric-like aberrations were not increased. The IOL repositioning surgery significantly improved the IOL tilt, which resulted in the reduction of ocular coma-like aberration, recovery of simulated retinal image, and resolution of the patient's complaints. CONCLUSION: Major IOL tilting induces a large amount of ocular coma-like aberration, which deteriorates the patient's quality of vision.

Astigmatism↗
PubMed2005

Visual acuity measurements using Fourier series harmonic analysis of videokeratography data in eyes after penetrating keratoplasty.

PURPOSE: Fourier harmonic analysis can decompose videokeratography data into spherical power, regular astigmatism, and irregular astigmatism (asymmetry and higher-order irregularity). The aim of this study was to evaluate whether determination of cylinder power by Fourier analysis facilitates measurements of visual acuity and refraction in eyes after penetrating keratoplasty. DESIGN: Cross-sectional study. PARTICIPANTS: Sixty-six eyes of 56 subjects who had undergone penetrating keratoplasty. METHODS: Spectacle-corrected visual acuity was measured in 2 ways: by the conventional and the Fourier methods. In the conventional method, the refraction was determined subjectively by reference to the measurement results of the autokeratometer and autorefractometer. In the Fourier method, the magnitude and axis of regular astigmatism were calculated by Fourier analysis of the videokeratography data, and spherical lenses were adjusted until best spectacle-corrected visual acuity was attained. MAIN OUTCOME MEASURES: Logarithm of the minimum angle of resolution (logMAR) visual acuity and refraction used for correction. RESULTS: The spectacle-corrected visual acuity obtained with the Fourier method (logMAR, 0.23+/-0.32; Snellen equivalent, 20/34) was significantly better than that attained with the conventional method (logMAR, 0.31+/-0.29; Snellen equivalent, 20/41; P<0.001, paired t test). The cylinder power used for spectacle-corrected visual acuity measurements was significantly lower with the Fourier method (-2.41+/-1.26 diopters [D]) than with the conventional method (-3.53+/-1.64 D; P<0.001). The spherical equivalent at the final refraction was not different between groups (P = 0.207). CONCLUSIONS: Fourier analysis of videokeratography data significantly facilitates determination of refraction and measurement of best spectacle-corrected visual acuity in eyes with corneal irregular astigmatism, such as eyes that have undergone penetrating keratoplasty.

Adolescent↗
PubMed2005

Toxicological evaluation of micafungin ophthalmic solution in rabbit eyes.

There have been no reports of the topical application of micafungin to the eye. The aim of this study was to evaluate the safety of topical instillation of 0.1% micafungin ophthalmic solution in rabbit eyes. In New Zealand white rabbits (n = 6), 50 microL of 0.1% micafungin solution was topically instilled to 1 eye, and 50 microL of sterile saline was applied to the other eye. Both eyedrops were administered hourly from 7 A.M. for 7 days. Measurements were conducted on corneal thickness, intraocular pressure, endothelial cell density, and lactate dehydrogenase (LDH) activity of tear samples. The eyes were examined slit-lamp biomicroscopically and histopathologically. Topical micafungin application for 1 week did not induce any changes in intraocular pressure, endothelial cell density, and tear LDH. Corneal thickness after instillation was slightly, but significantly, smaller in the micafungin group than in the control group (P = 0.0156, paired t test), but this difference disappeared within 24 hours after the final instillation. Biomicroscopy and histopathology revealed no significant toxic influence of micafungin application on the cornea. Topical instillation of micafungin solution had no apparent toxicity to the cornea. These results warrant future studies on the efficacy of micafungin ophthalmic solution against corneal fungal infection.

Animals↗
PubMed2005

Central corneal thickness measurements using Orbscan II scanning slit topography, noncontact specular microscopy, and ultrasonic pachymetry in eyes with keratoconus.

PURPOSE: To compare corneal thickness measurements using Orbscan II scanning slit topography, Topcon SP-2000P noncontact specular microscopy, and ultrasonic pachymetry in eyes with keratoconus. METHODS: Central corneal thickness was measured in 22 eyes with keratoconus. Eyes with apparent corneal opacity were excluded. Scanning slit topography, noncontact specular microscopy, and ultrasonic pachymetry were used in this sequence. The acoustic equivalent correlation factor (0.92) was used for Orbscan readings. RESULTS: Three devices gave significantly different corneal thickness readings (P < 0.001, repeated-measure analysis of variance). Measurements with Orbscan scanning slit topography (449.5 +/- 43.2 [SD] mum) were significantly smaller than those of ultrasonic pachymetry (485.0 +/- 29.3 microm; P < 0.001, Tukey multiple comparison) and SP-2000P noncontact specular microscopy (476.7 +/- 28.3 microm; P = 0.002). There were significant linear correlations between ultrasonic pachymetry and scanning slit topography (Pearson correlation coefficient r = 0.741, P < 0.001), between scanning slit topography and noncontact specular microscopy (r = 0.880, P < 0.001), and between noncontact specular microscopy and ultrasonic pachymetry (r = 0.811, P < 0.001). CONCLUSION: In eyes with keratoconus, Orbscan II scanning slit topography system gave significantly smaller corneal thickness readings than the other 2 devices. Measurements taken by noncontact specular microscopy and ultrasonic pachymetry were comparable. Three devices showed significant linear correlations with one another.

Adult↗
PubMed2004

Residual bed thickness and corneal forward shift after laser in situ keratomileusis.

PURPOSE: To prospectively assess the forward shift of the cornea after laser in situ keratomileusis (LASIK) in relation to the residual corneal bed thickness. SETTING: Miyata Eye Hospital, Miyazaki, Japan. METHODS: Laser in situ keratomileusis was performed in 164 eyes of 85 patients with a mean myopic refractive error of -5.6 diopters (D) +/- 2.8 (SD) (range -1.25 to -14.5 D). Corneal topography of the posterior corneal surface was obtained using a scanning-slit topography system before and 1 month after surgery. Similar measurements were performed in 20 eyes of 10 normal subjects at an interval of 1 month. The amount of anteroposterior movement of the posterior corneal surface was determined. Multiple regression analysis was used to assess the factors that affected the forward shift of the corneal back surface. RESULTS: The mean residual corneal bed thickness after laser ablation was 388.0 +/- 35.9 microm (range 308 to 489 microm). After surgery, the posterior corneal surface showed a mean forward shift of 46.4 +/- 27.9 microm, which was significantly larger than the absolute difference of 2 measurements obtained in normal subjects, 2.6 +/- 5.7 microm (P<.0001, Student t test). Variables relevant to the forward shift of the corneal posterior surface were, in order of magnitude of influence, the amount of laser ablation (partial regression coefficient B = 0.736, P<.0001) and the preoperative corneal thickness (B = -0.198, P<.0001). The residual corneal bed thickness was not relevant to the forward shift of the cornea. CONCLUSIONS: Even if a residual corneal bed of 300 microm or thicker is preserved, anterior bulging of the cornea after LASIK can occur. Eyes with thin corneas and high myopia requiring greater laser ablation are more predisposed to an anterior shift of the cornea.

Adult↗
PubMed2004

Structural analysis of the cornea using scanning-slit corneal topography in eyes undergoing excimer laser refractive surgery.

PURPOSE: To review the time course of corneal anteroposterior shift and refractive stability after myopic excimer laser keratorefractive surgery. METHODS: We examined 65 eyes undergoing photorefractive keratectomy (PRK) and 45 eyes undergoing laser in situ keratomileusis (LASIK). Corneal elevation maps and pachymetry were obtained by scanning-slit corneal topography before; 1 week; and 1, 3, 6, and 12 months after surgery. RESULTS: Both PRK and LASIK induced significant forward shifts of the cornea. Corneal forward shift was progressive up to 6 months after PRK, but no progression was seen after LASIK. Progressive thinning and expansion of the cornea were not observed after either procedure. The amount of corneal forward shift showed a significant negative correlation with preoperative corneal thickness (r = -0.586; P < 0.01) and a significant positive correlation with the amount of myopic correction (r = 0.504; P < 0.01). A significant correlation was found between the amount of forward shift and the degree of myopic regression after surgery (r = -0.347; P < 0.05). CONCLUSION: Myopic PRK and LASIK induce significant forward shifts of the cornea, which are not true corneal ectasia. Eyes with thinner corneas and higher myopia requiring greater ablation are more predisposed to anterior protrusion of the cornea. Corneal forward shift was progressive up to 6 months after PRK but not progressive after LASIK. Forward shift of the cornea can be one of the factors responsible for myopic regression after surgery.

Adolescent↗
PubMed2004

Long-term changes in rabbit cornea after ionizing radiation.

PURPOSE: To investigate long-term changes in the cornea after ionizing irradiation in rabbits. METHODS: Mature albino rabbits (n = 4) were unilaterally irradiated with 20 Gy of x-rays. The contralateral eye served as a control. The rabbits were examined with slit-lamp biomicroscopy for 5 years. The eyes were then enucleated for histopathologic examinations with light microscopy and transmission electron microscopy. RESULTS: On biomicroscopy, there was no corneal abnormality during the 5-year follow-up period. On histopathology, no abnormality was observed in the corneal epithelium. In the endothelium, a vacuole-like structure was recognized by light microscopy, and transmission electron microscopy revealed marked enlargement of intercellular space and anamorphosis of the nuclei. CONCLUSION: Moderate x-ray irradiation to rabbit eye did not induce any long-term damage to the corneal epithelium, but the endothelium demonstrated persistent and irreversible damage, which was observed even 5 years after irradiation.

Animals↗
PubMed2004

Ocular higher-order aberrations and contrast sensitivity after conventional laser in situ keratomileusis.

PURPOSE: To investigate prospectively the relation between induced changes in higher-order aberrations of the eye and changes in contrast sensitivity by conventional laser in situ keratomileusis (LASIK) for myopia. METHODS: In 200 eyes of 110 consecutive patients (mean age, 32.7 +/- 8.4 years) undergoing LASIK, ocular aberrations and contrast sensitivity function were determined before and 1 month after surgery. The amount of myopic correction was 5.2 +/- 2.8 D (range, 1.0-13.0). Ocular higher-order aberrations were measured for a 4-mm pupil using the Hartmann-Shack wavefront analyzer (KR-9000PW; Topcon, Tokyo, Japan). The root mean square (RMS) of the third- and fourth-order Zernike coefficients was used to represent coma- and spherical-like aberrations, respectively. Total higher-order aberrations were calculated as the RMS of the third- and fourth-order coefficients. Contrast sensitivity and low-contrast visual acuity were measured. From the contrast sensitivity data, the area under the log contrast sensitivity function (AULCSF) was calculated. RESULTS: LASIK significantly improved logMAR best corrected visual acuity (Wilcoxon signed-rank test, P <0.001), but significantly reduced AULCSF (P <0.001) and low-contrast visual acuity (P=0.007). Total higher-order (P <0.001), coma-like (P <0.001), and spherical-like (P <0.001) aberrations were significantly increased after LASIK. The greater the amount of achieved myopia correction was, the more the changes in contrast sensitivity function and ocular higher-order aberrations were. The induced changes in AULCSF by LASIK showed significant correlations with changes in total higher-order (Pearson r=-0.221, P=0.003), coma-like (r=-0.205, P=0.006), and spherical-like (r=-0.171, P=0.022) aberrations. The changes in logMAR low-contrast visual acuity by surgery significantly correlated with changes in total higher-order (r=0.222, P=0.003), coma-like (r=0.201, P=0.007), and spherical-like (r=0.207, P=0.005) aberrations. CONCLUSIONS: Conventional LASIK significantly increases ocular higher-order aberrations, which compromise the postoperative contrast sensitivity function.

Adolescent↗
PubMed2004

UMIN--current status and future perspectives.

UMIN, fully funded by the Japanese government, is the largest and most versatile public academic information center for biomedical sciences in the world, and is considered as indispensable information infrastructure for the Japanese medical community. As of April 1st 2004, all Japanese national universities, including UMIN, will be incorporated as independent administrative entities. After the incorporation, each national university will have authority to determine its own budget, organization, etc. by itself, and will also be able to carry out profit-making business related to its activities under certain constraints. Thus we suspect that UMIN will inevitably be faced with a strong demand to undertake profit-making business at an early stage. Even in this case, we believe that UMIN should continue to provide its information services to the Japanese medical community free of charge as it has done, utilizing earnings from its profit-making business that services commercial companies, because the success of UMIN has depended on the cooperation and sympathy of the community in the past, and will continue to do so.

Academic Medical Centers↗