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Biomedical subjects

Y Kitazawa

Publications and source records attributed to Y Kitazawa.

286 records · Page 16Linked to original sources
PubMedDate not supplied

Holmium YAG laser sclerostomy ab externo for refractory glaucoma.

Ab externo thermal sclerostomy was performed with the holmium YAG (thulium, holmium, chromium-doped YAG crystal) laser in 21 eyes of 20 patients with refractory glaucoma. We used either the 5-fluorouracil (5-FU) or mitomycin C (MMC) antimetabolites in all cases. The rate of intraocular pressure (IOP) control defined as IOP < 21 mmHg regardless of whether antiglaucoma medication was applied postoperatively) was estimated by the life-table methods of Kaplan-Meier. The postoperative IOP control rate was 47.1% in the MMC-treated group at 57 months, and 14.3% in the 5-FU-treated group at 52 months. There were statistically significant differences in success rates between the MMC- and 5-FU-treated groups. We observed no clinically significant complications except excess filtration associated with a shallow anterior chamber in one case. This procedure is thought to have several advantages over more conventional filtration surgery; the operation time is shorter, and there is no need for intraocular manipulation, which means conjunctival trauma is minimal. However, the IOP control rate was substantially lower than that achieved via conventional trabeculectomy. Our results suggest that the selection of patients and the use of MMC is an important factor in maintaining successful filtration.

Adolescent↗
PubMedDate not supplied

Clinical evaluation of a new formula of timolol maleate (WP-934 ophthalmic solution). WP-934 Study Group.

We investigated the ocular hypotensive effect and possible adverse reactions of a new timolol maleate formula, WP-934 ophthalmic solution, which is timolol maleate solution dissolved in a reversible thermo-setting gel. Once-daily instillation of 0.25 or 0.5% WP-934 ophthalmic solution was administered in a prospective, randomized manner at 29 institutions for 8 weeks to patients with primary open-angle glaucoma or ocular hypertension, and for another 16 weeks in a limited number of these patients. Patients were closely monitored throughout the study by ophthalmic and systemic examinations, and by continuous evaluation of symptoms. The new timolol formula demonstrated a significant ocular hypotensive effect throughout the study period. Adverse effects were minor. WP-934 ophthalmic solution, timolol maleate dissolved in a reversible thermo-setting gel, has a significant ocular hypotensive effect in eyes with primary open-angle glaucoma and ocular hypertension.

Administration, Topical↗
PubMedDate not supplied

A comparative study of latanoprost (Xalatan) and isopropyl unoprostone (Rescula) in normal and glaucomatous monkey eyes.

Latanoprost (PhXA41, Xalatan) and isopropyl unoprostone (UF-021, unoprostone, Rescula) two new prostanoid derivatives, have been shown to reduce intraocular pressure (IOP) significantly in patients with glaucoma or ocular hypertension. This study was designed to compare the ocular hypotensive effects of latanoprost and unoprostone in cynomologus monkeys with glaucoma and characterizes the prostanoid's mechanisms of action in normal cynomolgus monkey eyes. Intraocular pressure was measured daily at 0, 0.5, and 1 hour and hourly for 5 additional hours during 1 baseline day, 1 vehicle-treated day, and 5 days of therapy with either 0.005% latanoprost or 0.12% unoprostone applied twice daily, at 9:30 AM and 3:30 PM, to the glaucomatous eye of eight monkeys with unilateral laser-induced glaucoma. Outflow facility was measured in six normal monkeys 3 hours prior to dosing and 1 hour after unilateral dosing with either drug. Aqueous humor flow rates were measured in six normal monkeys hourly for 4 hours on 1 baseline day and on 1 treatment day beginning 1 hour after administration of either drug to one eye. Intraocular pressure was significantly (P < 0.005) reduced after the first application for 4 hours with latanoprost and for 2 hours with unoprostone, up to 5.4 +/- 0.8 mm Hg (mean +/- SEM) (latanoprost) and 3.8 +/- 0.5 mm Hg (unoprostone). Intraocular pressure was significantly (P < 0.005) reduced for at least 18 hours following each PM dose of latanoprost. Intraocular pressure was not reduced (P > .05) 18 hours after each PM dose of unoprostone. An enhancement of the ocular hypotensive effect was observed from day 1 to day 5 with repeated dosing of either drug. Latanoprost produced a greater magnitude of IOP reduction for a longer duration of time than unoprostone after each application. Neither drug altered outflow facility or aqueous humor flow rates. Latanoprost and unoprostone appear to reduce IOP in monkeys by enhancing uveoscleral outflow. Latanoprost appears to be more efficacious and potent than unoprostone in reducing IOP in glaucomatous monkey eyes.

Administration, Topical↗
PubMedDate not supplied

Temporal modulation transfer function in normal-tension glaucoma patients.

A new screening test involving the Flicker System was used to measure temporal modulation transfer function in an effort to detect early-stage glaucoma. The study involved 64 normal-tension glaucomatous eyes and 65 normal control eyes. Patients with early-stage glaucoma (stage 0-1 of the Aulhorn-Greve classification) showed a significant modulation decrease in the 20-45 Hz range, compared to the modulation in normal eyes (P < 0.05). Patients with moderate stage glaucoma (stage 2-3) also exhibited significantly decreased modulation values in the 14-55 Hz range. In the 25-45 Hz range, the reduction of modulation in patients with diffuse visual defect was more profound than in those with localized or mixed defects. The results of the present study suggest the presence of diffuse visual function deficit in glaucoma.

Adult↗
PubMedDate not supplied

Effect of trabeculectomy on visual field in progressive normal-tension glaucoma.

The purpose of this study was to investigate the effectiveness of surgical treatment on the visual field in normal-tension glaucoma (NTG) eyes, and associated factors for visual field progression. Thirty-two patients (32 eyes) were enrolled in this retrospective study. Stepwise regression analysis was performed to correlate the visual field change with several clinical factors, such as intraocular pressure (IOP), and several IOP-unrelated parameters. Surgical reduction of IOP helps in preventing the progression of visual field damage in NTG eyes. The stepwise analysis revealed that better visual field prognosis was associated with higher preoperative IOP (P = 0.006) and the absence of diabetes mellitus (P = 0.04). The functional outcome in the lower IOP group was better when the patients were using Ca2+-channel blockers (P = 0.08); it was worse if disc hemorrhage appeared (P = 0.02). In conclusion, both IOP-related and unrelated factors are associated with visual field damage progression in NTG eyes. The functional prognosis in the eyes with low IOP depends on IOP-unrelated factors.

Adult↗
PubMedDate not supplied

Reproducibility of color Doppler imaging for orbital arteries in Japanese patients with normal-tension glaucoma.

The reproducibility of measurements by color Doppler imaging (CDI) were evaluated in Japanese patients with normal-tension glaucoma. Measurements were taken in the central retinal artery, the ophthalmic artery, and the short posterior ciliary arteries. Reproducibility was evaluated by calculating the coefficients of reproducibility for the peak systolic and end diastolic velocities and for the resistance index. The coefficient of reproducibility was calculated as magnitude of V1 - V2/¿(V1 + V2)/2¿ where V1 is the value of the first measurement and V2 is the value of the measurement taken 48 hours later. In calculating the resistance index of the orbital arteries, the central retinal artery and the short posterior ciliary artery temporal to the optic nerve both had coefficients of reproducibility of 0.04 +/- 0.04 (mean +/- standard deviation); the ophthalmic artery and the short posterior ciliary artery nasal to the optic nerve both had coefficients of reproducibility of 0.04 +/- 0.05. The high reproducibility of the CDI technique supports the validity of using CDI in a clinical setting to measure the hemodynamic parameters of small retrobulbar blood vessels.

Adult↗
PubMedDate not supplied

A new system to supply carbon dioxide safely to glaucoma patients.

PURPOSE: To develop a new system for safely supplying carbon dioxide (CO2) to open-angle glaucoma patients. METHODS: The orbital hemodynamics of 7 glaucoma patients were determined by color Doppler imaging under baseline conditions and during CO2 supplementation sufficient to increase the end-tidal CO2 partial pressure by 10%. Systemic conditions, including oxygen saturation and blood pressure, were monitored throughout the CO2 inhalation. RESULTS: Our results demonstrate that this new system enables us to supply CO2 in a safe, controlled manner to glaucoma patients. CONCLUSIONS: This new system will be useful for investigating the effects of vasodilation by CO2 on orbital blood flow.

Administration, Inhalation↗
PubMedDate not supplied

Prevalence of normal-tension glaucoma and primary open-angle glaucoma in patients with collagen diseases.

PURPOSE: To investigate the prevalence of normal-tension glaucoma (NTG) and primary open-angle glaucoma (POAG) in patients with collagen diseases and determine whether an immunocompromised condition is present in a subset of glaucoma patients. METHODS: Three glaucoma specialists prospectively examined patients with collagen diseases. The diagnostic process included applanation tonometry, slit-lamp examination, gonioscopy, direct ophthalmoscopy, and automated static perimetry. Twenty-four-hour intraocular pressure monitoring was done when necessary. Using the results of a population-based survey conducted in Japan, we calculated an expected number of cases of NTG and POAG, and compared these with the actual number of cases. RESULTS: Of the 153 patients with collagen diseases examined, we found 6 patients with NTG and 2 patients with POAG. Of these 8 patients, 2 with progressive systemic sclerosis (PSS), one with NTG, and the other, POAG, had a history of being on systemic steroidal therapy. The prevalence of NTG and POAG was significantly higher in women patients having collagen diseases as compared with normal women (P = .027). CONCLUSION: Women patients with collagen diseases are highly susceptible to NTG and POAG.

Adult↗
PubMedDate not supplied

Cataract development after trabeculectomy with mitomycin C: a 1-year study.

PURPOSE: To measure cataract changes quantitatively in the crystalline lens after trabeculectomy with mitomycin C and to identify associated clinical factors. METHODS: Forty-one consecutive trabeculectomy patients (41 eyes) were enrolled in this prospective study. The enrollment criteria were: phakic eye, no history of intraocular surgeries or inflammation, and no corneal opacification. The transparency of the lens was measured and analyzed by an anterior segment analysis system preoperatively and 1, 3, and 12 months postoperatively. Cataract development was correlated with clinical factors using a multivariate regression analysis. RESULTS: During the first postoperative month, changes occurred primarily in the anterior segment of the lens, but later, deeper lenticular areas also started to show an increase in light scattering intensity. Multivariate regression analyses demonstrated that some clinical factors were associated with cataract development. CONCLUSIONS: Slight cataractous changes develop after trabeculectomy with mitomycin C as early as 1 month postoperatively, and they gradually increase in extent and in intensity during the next 11 months.

Adult↗
PubMedDate not supplied

Efficacy and safety of latanoprost eye drops for glaucoma treatment: a 1-year study in Japan.

PURPOSE: To evaluate the intraocular pressure (IOP)-lowering effect and safety of latanoprost, a prostaglandin analogue, in patients with primary open-angle glaucoma or ocular hypertension. METHOD: One hundred and twenty-four Japanese patients with primary open-angle glaucoma or ocular hypertension were enrolled in this open-labeled study and were treated with 0.005% latanoprost once daily for 1 year. RESULTS: At all follow-up visits there was a significant (P < .001) reduction in IOP compared with the baseline value. After 1 year, the IOP was reduced by 5.4 +/- 2.9 (mean +/- SD) mm Hg from a baseline value of 23.5 +/- 2.2 mm Hg. No evidence of an upward drift in the IOP was observed during the treatment period. The most frequently reported adverse ocular events were mild conjunctival hyperemia and iris pigmentation. Very few adverse systemic events were observed. CONCLUSIONS: Latanoprost eye drops showed a marked and stable IOP-lowering effect during the 1-year treatment period. Furthermore, latanoprost was well-tolerated and should be a valuable contribution to the management of glaucoma.

Adult↗
PubMedDate not supplied

Association between watershed zone and visual field defect in normal tension glaucoma.

PURPOSE: To evaluate the association between the watershed zone and glaucomatous optic nerve head (ONH) damage. METHODS: We performed indocyanine green fluorescence angiography with a scanning laser ophthalmoscope in 54 eyes of 27 patients with normal tension glaucoma (NTG). RESULTS: We identified 7 eyes of 8 patients (14.8%) with a watershed zone not including the ONH, 32 eyes of 20 patients (59.3%) with the watershed zone partially including the ONH, and 10 eyes of 14 NTG patients (25.9%) with the watershed zone including the ONH. Of the 27 NTG patients, 10 patients (37.0%) had different types in each eye. CONCLUSIONS: In these patients, the mean deviation of visual field indices was greater in the eye with the watershed zone, which included a larger part of the ONH than in the contralateral eye. Conversely, the eye with the greater mean deviation had a watershed zone that included a larger part of the ONH. The location of the watershed zone appeared to influence the progression of the visual field defect.

Adolescent↗
PubMedDate not supplied

Effect of mitomycin C dissolved in reversible thermo-setting gel on the outcome of filtering surgery in the rabbit.

PURPOSE: Based on our previous report that showed enhanced transfer of mitomycin C to the sclera and the conjunctiva by dissolving the agent into a reversible thermo-setting gel, we conducted a study to investigate the efficacy of mitomycin C gel in the rabbit. METHODS: We subconjunctivally injected 0.1 mL of the mitomycin C gel solution containing several different amounts of the agent. Trephination was performed in the injected region 24 hours later. Intraocular pressure measurement, photography, and ultrasound biomicroscopic examination of the filtering bleb were conducted 1, 2, and 4 weeks postoperatively. RESULTS: The gel containing 3.0 microg or more mitomycin C significantly enhanced bleb formation and reduction in the intraocular pressure. CONCLUSIONS: The reversible thermo-setting gel seems to help the filtering bleb to survive in the rabbit and deserves further investigation as a new method of mitomycin C application.

Animals↗
PubMedDate not supplied

Spontaneous intraocular pressure reduction in normal-tension glaucoma and associated clinical factors.

PURPOSE: To investigate the intraocular pressure (IOP) reduction in certain normal-tension glaucoma (NTG) patients and clinical factors associated with this reduction. METHODS: Fifty-four NTG patients who met the following enrollment criteria were selected: IOP <21 mm Hg during a 24-hour pressure curve and throughout the subsequent 12 months; examined every 1 to 4 months for at least 3 years with no ocular hypotensive therapy. For each patient, the eye with the higher mean IOP during the 24-hour pressure curve was selected for this study. RESULTS: Six patients had an IOP reduction which was defined as a significant decrease (P <.05) of IOP over time, determined by the Spearman rank correlation coefficient method. These 6 eyes were rated positive for subsequent IOP reduction. The IOP reduction was correlated to clinical factors by means of a logistic multiple regression analysis (LOGIST procedure using PC-SAS), which demonstrated that the larger difference between the maximum IOP and the minimum IOP during the initial 24-hour pressure curve and the absence of disc hemorrhage showed significant correlation with IOP reduction (P =.026 and P =.013, respectively). The odds ratios were 2.05 per 1 mm Hg increase of difference between the maximum IOP and the minimum IOP during the initial 24-hour pressure curve and 1.13 for the absence of disc hemorrhage. CONCLUSIONS: The current study demonstrated that a significant reduction of IOP over time is not uncommon in NTG patients. One ninth of the NTG patients in this study showed a significant IOP reduction during a 3-year follow-up period.

Adult↗
PubMedDate not supplied

Influence of carteolol and timolol on IOP an visual fields in glaucoma: a multi-center, double-masked, prospective study.

The influences of Carteolol and Timolol eye drops on intraocular pressure (IOP) and visual fields were compared in a multi-center, double-masked, prospective study. Two-hundred and forty eyes of 120 patients were initially included in the study, and 142 eyes of 72 patients fulfilled all the criteria for final statistical analysis. Both drugs significantly reduced IOP. The visual fields in both treatment groups did not change during one year of treatment. In both groups some patients improved slightly, and others deteriorated slightly. This indicates that locally applied beta-blockers may efficiently stop further progression of visual field defects in cases with increased IOP and early visual field damage. There was no difference between Carteolol and Timolol in this regard. The side effects were minimal, and there were no differences in their frequency or intensity in the two treatment groups.

Adolescent↗
PubMedDate not supplied

Acute renal failure due to rhabdomyolysis associated with echovirus 9 infection: a case report and review of literature.

The occurrence of rhabdomyolysis and acute renal failure associated with viral infections is uncommon. We report a case of a 17-year-old female suffering from rhabdomyolysis caused by echovirus 9 in which the patient recovered after being treated for acute renal failure with hemodialysis. Among 42 cases of virus-induced rhabdomyolysis review in Japanese and English literatures, influenza virus is the most common cause of rhabdomyolysis, coxsackie virus tends to be next most common cause. Renal failure was recognized in 31 of the cases.

Acute Kidney Injury↗