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E Chihara

Publications and source records attributed to E Chihara.

At least 19 recordsLinked to original sources
PubMed2005

The preoperative intraocular pressure level predicts the amount of underestimated intraocular pressure after LASIK for myopia.

AIMS: To evaluate the statistical significance of the parameters that affect underestimation of intraocular pressure (IOP) after laser in situ keratomileusis (LASIK) for myopia. METHODS: In this prospective case series study, patient age, axial length, preoperative corneal curvature, preoperative central corneal thickness (CCT), preoperative IOP, and ablation depth were studied to determine whether they affect the underestimation of IOP in the right eyes of 100 consecutive patients who underwent LASIK. RESULTS: The preoperative IOP was the most important parameter for an amount of underestimated Goldmann applanation tonometric IOP (GAT) and non-contact tonometric IOP (ncIOP) at 1 month (r = 0.654, p<0.0001, R(2) = 0.427, and r = 0.694, p<0.0001, R(2) = 0.481, respectively) and 3 months (r = 0.637, p<0.0001, R(2) = 0.406, and r = 0.726, p<0.0001, R(2) = 0.527, respectively). Patient age was statistically significant for underestimating the GAT at 1 month, and both the ablation depth and CCT were statistically significant parameters for underestimating the ncIOP at 1 month and at 3 months by stepwise multiple regression analysis (F>4.000). However, these parameters had small bivariate correlation coefficients, and were considered as minor parameters. CONCLUSION: Preoperative IOP is the most important parameter that affects an underestimation of IOP after LASIK for myopia. Eyes with a higher true IOP have a larger underestimation of the IOP after LASIK for myopia. From these results, the importance of the modulus of elasticity on IOP measurements was discussed.

Adult↗
PubMed2001

Surgical outcome of combined trabeculotomy and cataract surgery.

PURPOSE: To evaluate the efficacy of combined trabeculotomy and cataract surgery in lowering intraocular pressure and improving visual acuity in adults with primary open-angle glaucoma. PATIENTS AND METHODS: A consecutive series of 141 eyes with primary open-angle glaucoma or ocular hypertension was prospectively recruited. One hundred five eyes with visual field defects were treated by trabeculotomy combined with phacoemulsification and intraocular lens implantation (TPI group), and 36 eyes without visual field defects underwent cataract surgery (PI group). Patients in the TPI and PI groups were followed for more than 6 months after surgery (578.1 +/- 35.8 days and 616.0 +/- 58.5 days, respectively). The intraocular pressure reductions after surgery were compared between the groups to evaluate the effect of combined trabeculotomy and cataract surgery. Visual acuity and the complication rate in the two groups were secondary outcomes. The success probabilities of both groups were evaluated by Kaplan-Meier life table analysis with log rank test. RESULTS: A significant intraocular pressure reduction was observed in the TPI and PI groups up to 3 years and up to 1 year and 6 months after surgery, respectively; the magnitude of the reduction was significantly larger in the TPI group up to 3 years after surgery. The success probabilities of TPI group for intraocular pressure control under 21, 17, and 15 mm Hg were 95.8%, 58.7%, and 30.0%, respectively, 1 year after surgery, and 84.9%, 29.5%, and 13.5%, respectively, 3 years after surgery; the success probabilities were significantly higher than those of the PI group. Of 105 eyes, 104 (99.0%) had visual acuity equal to or better than the baseline acuity 3 months after combined trabeculotomy and cataract surgery. CONCLUSION: Combined trabeculotomy and cataract surgery normalizes intraocular pressure and improves visual acuity in adults with glaucoma and coexisting cataract.

Aged↗
PubMed2001

Slope analysis of the optic disc in eyes with ocular hypertension and early normal tension glaucoma by confocal scanning laser ophthalmoscope.

AIMS: To determine whether quantitative differences in sector based slope can differentiate between eyes with ocular hypertension with and without glaucomatous disc changes and eyes with normal tension glaucoma with glaucomatous disc changes. METHODS: Seventy six eyes with ocular hypertension or early glaucomatous disc changes were consecutively categorised into three groups: 22 eyes with ocular hypertension and no glaucomatous disc changes (OHND); 35 with ocular hypertension and glaucomatous disc changes (OHD); and 19 with normal ocular tension and glaucomatous disc changes (NTD). Twenty eyes served as controls. The average total slope angle and sector based slope angle of the cup, total contour area, effective area, neuroretinal rim area, half depth area, cup to disc ratio, contour variation, mean contour depth, average depth, volume below, half depth volume, and contour tilt were evaluated with a confocal scanning laser ophthalmoscope. RESULTS: The earliest changes in eyes with OHND or OHD started in the slope at the nasal inferior sector (p<0.05), followed by the superior and temporal superior sectors (p<0.05). The mean slopes in eyes with NTD and OHD were steeper than in controls (p<0.05). Statistically significant differences were found between controls and disease groups in the half depth area, mean contour depth, and half depth volume. The cup to disc ratios in eyes with OHD and NTD were greater than in eyes with OHND; the volume below was greater in eyes with NTD than in eyes with OHND and OHD. CONCLUSIONS: The steep slope in the nasal inferior section is the first indicator of glaucomatous nerve defects in many eyes. The half depth parameters, half depth area, and half depth volume may be useful for distinguishing ocular hypertension with and without glaucomatous disc changes.

Adult↗
PubMed2001

[Clinical evaluation of roxatidine acetate hydrochlorides as a preanesthetic medication].

Roxatidine acetate hydrochloride capsule is slowly absorbed from the gastrointestinal tract, and its acid suppressive effect on the stomach is long-lasting compared with other H2-blockers. The reduction of gastric juice in perioperative period is considered advantageous for patients not only because it decreases the risk for aspiration pneumonia but also because it reduces the risk of bronchial spasm induced by gastroesophageal reflux of acidic gastric content. The effects of single oral administration of roxatidine acetate hydrochloride 150 mg at night before the operation on the volume and pH of gastric juice were investigated during anesthesia using two types of anesthetic agents (isoflurane and propofol) in 93 patients of three age groups (group Y: age 20-40, group M: age 41-64, group O: age 65 <). The effect of roxatidine on reduction of gastric juice was found at the time of anesthetic induction and 2 hours after the induction in any age group with either anesthetic agent. The serum concentration of roxatidine at the time of induction was much higher in group O. The value of residual concentration of roxatidine 20 hours after oral intake was estimated from the intraoperative measurements of serum concentration. The results suggest that single administration at night before the operation is sufficient for the oldest group, but an additive dose is recommended for the younger groups.

Adult↗
PubMed2001

[Pseudo-disc-pits.macular syndrome].

BACKGROUND: Optical coherence tomography(OCT) permits the noninvasive analysis of cross-sectional tomograms of ocular tissue in vivo. CASE: A 67-year-old woman presented with abnormal feeling in the left eye. An ophthalmoscopic examination revealed retinal edema in the macular vascular arcades and radial folds on the fovea. Optic disc pits were not demonstrated ophthalmoscopically or by fluorescein angiography(FAG). OCT disclosed separations in the inner and outer layers of the edematous retina, retinal detachment on the fovea, and cystic schisis(pseudo-pits) beneath the inner limiting membrane of the disc which seemed to be connected with the separation of the inner layers of the retina. CONCLUSION: OCT demonstrated cystic schisis-like pits(pseudo-pits) which were not recognized ophthalmoscopically or by FAG, and the cystic schisis seemed to communicate with the inner separation of the retina. Therefore, we prefer to call such cases pseudo-disc-pits macular syndrome instead of optic disc pit macular syndrome.

Aged↗
PubMed2001

Tranilast inhibits TGF- A1 secretion without affecting its mRNA levels in conjunctival cells.

The present study was conducted to assess the effect of Tranilast, a drug developed as anti-keloid and anti-hypertrophic scar agent, on the level of transforming growth factor- A1 (TGF- A1) mRNA, and on TGF- A1 secretion in Chang Conjunctiva cells. TGF- A1 mRNA was not detected in Chang Conjunctiva cells by Northern blot analysis, but reverse transcriptase-polymerase chain reaction (RT-PCR) analysis confirmed the presence of TGF- A1 mRNA. Tranilast, whereas the drug had no effect on the levels of TGF- A1 mRNA and cellular protein, time- and dose-dependently inhibited TGF- A1 secretion from Chang Conjunctiva cells in the enzyme-linked immunosorbent assay (ELISA) analysis. TGF- A1 is suggested to cause fibroblast proliferation, that obstructs aqueous humor filtration route after glaucoma filtration surgery. Tranilast, potentially inhibiting TGF- A1 secretion, therefore, could be a promising drug to prevent from scarring after glaucoma filtration surgery.

Adult↗
PubMed1998

[Analysis of diabetic optic neuropathy with a topographic laser scanning system].

Optic disc topography was done with a 3-dimensional scanning laser ophthalmoscope in 53 eyes of 53 diabetic patients and compared with that of 34 control eyes. In diabetic eyes, the parameters for contour variation of the optic nerve head was significantly greater than in control eyes. The cup of the disc, on the other hand, did not increase or decrease in diabetic eyes. The area of the neuroretinal rim area, and the tissue volume of the neuroretinal rim area was increased in eyes with pre-proliferative retinopathy, and proliferative retinopathy, respectively. The cup of the disc was not enlarged in diabetic eyes in spite of discrete signs of retinal nerve fiber layer defects. Topographic features of eyes with diabetic optic neuropathy were very different from those with glaucomatous optic neuropathy in spite of the similar appearance of retinal nerve fiber layer defects.

Diabetic Neuropathies↗
PubMed1998

Age and increased incidence of "forward bowing" of the iris in normal eyes.

PURPOSE AND METHODS: The incidence of forward bowing of the iris, width of the iridocorneal angle, and distance between the apex of the angle and the scleral spur were studied using high-frequency (50 MHz) ultrasound B-scan images in 90 normal eyes from Japanese volunteers. RESULTS: The incidence of forward bowing of the iris, defined as a 120-micron anterior shifting of the posterior profile of the iris, increased from 0% in subjects under 31 years old to 50% in subjects 71 years of age and older. The iridocorneal angle was significantly narrower and the distance between the apex of the angle and the scleral spur was significantly less in eyes with forward bowing. Of the risk factors (age, axial length, sex, and corneal curvature), age (p = 0.0005) was the most significant risk factor for forward bowing of the iris. CONCLUSION: Forward bowing of the iris is not uncommon in the elderly. Half of the Japanese subjects in this study 71 years of age and older had this condition, even though they had no optic nerve atrophy or elevation in intraocular pressure (IOP) at the time of examination.

Adult↗
PubMed1997

Severe myopia as a risk factor for progressive visual field loss in primary open-angle glaucoma.

The optic nerve head in severely myopic eyes may be particularly vulnerable to glaucomatous damage. To study this hypothesis, we examined 122 primary open-angle glaucoma eyes with fair to good control of the intraocular pressure and a sign of baseline optic nerve damage. Then, parameters for the progression of the visual field defects were evaluated by multivariate analysis. A high mean intraocular pressure (p = 0.007) and a large refractive error (p = 0.023) were significant risk factors for subsequent visual field loss. A high baseline cup-to-disk ratio (p = 0.100) was a marginal risk factor. Nonsignificant parameters included patient age (p = 0.692), the use of beta-adrenergic antagonists (p = 0.384), gender (p = 0.831) and left versus right side (p = 0.977). When the refractive error was used to subclassify patients into severely myopic (< or = -4 dpt), mildly myopic (-0.25 to -4 dpt), or emmetropic and hyperopic (> or = 0 dpt), only severe myopia was a significant risk factor for progressive visual field loss. Severe myopia, but not mild myopia, is a significant risk factor for subsequent visual field loss in patients with primary open-angle glaucoma.

Adolescent↗
PubMed1996

Surgical results and complications of trabeculectomy with intraoperative application of mitomycin C.

Trabeculectomy is reportedly less effective in aphakic eyes, secondary glaucoma, juvenile patients, and eyes with a history of unsuccessful glaucoma surgery. We evaluated the surgical effects and complications of trabeculectomy with the adjunctive use of mitomycin C, an antiproliferative drug, in a number of refractory cases. Forty patients (50 eyes) with refractory glaucoma were treated with trabeculectomy and the adjunctive use of mitomycin C and were followed postoperatively for at least 3 months. The mean follow-up period was 13.6 +/- 7.5 months (range: 3 to 31 months). In 43 eyes (86%), intraocular pressure was well controlled at < or = 21 mmHg. Complications included corneal epithelial damage (30 eyes), shallow anterior chamber (20 eyes), hyphema (19 eyes), choroidal detachment (18 eyes), leakage of aqueous humor from the conjunctival wound (4 eyes), and endophthalmitis (1 eye). The results of trabeculectomy with intraoperative use of mitomycin C in this series of procedures demonstrates that this can be a useful and effective treatment; however, mitomycin C may cause transient decreased visual acuity due to inhibited wound healing and the resultant overfiltration.

Adolescent↗
PubMed1994

Covariation of optic disc measurements and ocular parameters in the healthy eye.

To understand the variations in optic disc topography that may affect the local susceptibility of nerve fibers to glaucomatous damage, we evaluated the correlations between optic disc topography and selected ocular parameters in 210 normal eyes of healthy Japanese. In the total study group, eyes with a longer axial length had a longer distance between the disc and foveola, a larger index of ovalness and a larger disc (P < 0.01). A longer disc-foveola distance correlated with a larger index of ovalness (P < 0.01). The optic discs of severely myopic eyes had a considerably different structure from other eyes. Eyes with a tilted optic disc were unique in that the area of the optic disc was not large despite a positive correlation with long axial length (P < 0.01) a long disc-foveola distance (P < 0.01), and a large index of ovalness (P < 0.01). Eyes with a rotated optic disc were another special case. This eye type correlated in a contradictory fashion with two parameters: a large axial length (P < 0.01) and a short disc-foveola distance (P < 0.01). These findings suggest that changes in optic disc topography or susceptibility to glaucomatous damage correlate with selected ocular parameters but are not completely parallel.

Anthropometry↗
PubMed1994

Right atrial pressure and forearm blood flow during prolonged exercise in a hot environment.

Right atrial pressure (RAP) at rest is known to be reduced by an increase in skin blood flow (SkBF) in a hot environment. However, there is no clear evidence that this is so during exercise. To clarify the effect of the increase in SkBF on RAP during exercise, we measured forearm blood flow (FBF) (as an index of SkBF) and RAP continuously using a Swan-Ganz catheter in five male volunteers exercising on a cycle ergometer at 60% of peak aerobic power for 50 min in a hot environment (30 degrees C, relative humidity 20%). Cardiac output increased from 5.5 +/- 0.2 l/min at rest to 17.9 +/- 1.2 l/min (mean +/- SE, P < 0.01) in the first 10 min of exercise and then remained steady until the end of exercise. FBF did not change significantly during the first 5 min, but then increased from 2.7 +/- 0.5 ml/100 ml per min at rest to 10.8 +/- 1.7 ml/100 ml per min (P < 0.001) by 25 min as pulmonary arterial blood temperature (Tb) rose from 37.0 +/- 0.1 degrees C to 38.1 +/- 0.1 degrees C (P < 0.001). FBF then reached a plateau, despite a continuing increase in Tb. RAP increased significantly from 4.3 +/- 0.8 to 7.6 +/- 1.2 mm Hg (P < 0.001) during the first 5 min of exercise and then gradually declined to 6.1 +/- 1.0 mm Hg by 25 min (P < 0.001 vs. 5 min) and further to 5.7 +/- 1.0 mm Hg by 50 min, a value not significantly higher than at rest.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1994

Right atrial pressure and ANP release during prolonged exercise in a hot environment.

To investigate the relationship between right atrial pressure (RAP) and atrial natriuretic peptide (ANP) release during prolonged exercise in a hot environment (30 degrees C, 20% relative humidity), we studied with a Swan-Ganz catheter five male volunteers exercising on a cycle ergometer at 60% of peak aerobic power for 50 min. The ANP level increased from 14 +/- 3 (SE) to 69 +/- 10 pg/ml (P < 0.001) during the first 10 min of exercise as RAP rose from 4.3 +/- 0.8 to 6.9 +/- 1.1 mmHg (P < 0.001). The 10-min ANP level was significantly correlated with RAP (r = 0.88, P < 0.05) but not with heart rate, pulmonary arterial blood temperature, plasma norepinephrine, or plasma epinephrine. The 10-min RAP value was inversely correlated with blood volume (r = -0.98, P < 0.01) and also with stroke volume (r = -0.96, P < 0.01). In the next 20 min of exercise, ANP continued to increase to 101 +/- 12 pg/ml (P < 0.02 vs. 10 min) and remained at this level until 50 min of exercise, whereas RAP decreased and reached a level not significantly different from baseline at 50 min (5.7 +/- 1.0 mmHg; P < 0.01 vs. 10 min). This dissociation of ANP and RAP may have been related to the significant increases from the 10-min values of heart rate, blood temperature, norepinephrine (all P < 0.01), and epinephrine (P < 0.02) during the same period. These results suggest that ANP release is primarily controlled by atrial distension at the onset of exercise but that other stimulators may be involved thereafter.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1994

Egress route of emulsified 20 centistokes silicone oil from anterior chamber of rabbit.

Silicone oil is used in recent clinical practice, however, it may cause adverse reactions in the eyes. When the high viscosity silicone oil is contaminated with low molecular weight silicone oil, the contamination may cause ocular toxicity or elevation of the intraocular pressure. To obtain information on the distribution of this preparation, emulsified 20 centistokes silicone oil was injected into the anterior chamber of rabbit eyes. The silicone oil droplets were visualized by light and electron microscopy by using oil soluble phthalocyanine blue. This copper containing dye remains in the tissue after removal of the silicone oil by organic solvents. Two and 4 weeks after an injection, the silicone emulsion was observed as numerous small vacuoles with blue precipitate at the margin of vacuoles within elongated trabecular endothelial cells, fibroblasts along the route of uveoscleral outflow and cells of the iris. Three hours after the injection, only a few vacuoles were present in these cells. These results demonstrated that the emulsified silicone oil leaves the anterior chamber through the conventional and unconventional routes. Phagocytosis by the trabecular endothelial cells and fibroblasts along the uveoscleral route caused an accumulation of the emulsified silicone oil in these cells. With chronic exposure to emulsified silicone oil, changes in the trabecular meshwork may lead to a reduction in the outflow of aqueous humor and cause glaucoma.

Animals↗
PubMed1993

Assessment of optic disc topography with scanning laser ophthalmoscope.

Evaluation of the topography of the optic disc is of clinical importance to assess the degree of nerve damage. We conducted a study in 17 glaucomatous and 20 control subjects with a scanning laser ophthalmoscope (SLO; Rodenstock) and compared the results with those in conventional photographs. A tomographic image of the cup area in control subjects and the neuroretinal rim area in glaucomatous subjects obtained with the SLO was smaller than that in photographs taken with a conventional camera (P < 0.05 and P < 0.01 respectively). In both the control and glaucoma groups, the optic disc area obtained with the SLO was significantly smaller than that in conventional photographs (P < 0.01). The coefficient of variation of the optic disc parameters studied with the SLO range from 4.2% to 9.1%. A correlation between the optic disc indices studied with SLO and the mean defect of the visual field was statistically significant. The tomographic images obtained by the SLO permit accurate assessment of optic nerve damage.

Fundus Oculi↗
PubMed1993

Retinal nerve fiber layer defect as an early manifestation of diabetic retinopathy.

PURPOSE: An incidence of and risk factors for retinal nerve fiber layer defect were investigated in patients with type II diabetes mellitus and compared with that of age-matched control subjects. METHODS: The authors photographed the retinal nerve fiber layer of the right eye in each of 137 patients with diabetes and 144 healthy control subjects. The level of diabetic retinopathy ranged from levels 1 (no microaneurysm) to 4 (eyes with localized intra-retinal microvascular abnormalities or venous beading). Risk factors for the nerve fiber layer defect analyzed were age of patients, visual acuity, axial length, optic disc size, glycosylated hemoglobin, systolic blood pressure, and level of diabetic retinopathy. RESULTS: Defects of the retinal nerve fiber layer were found in 6/30 (20%) eyes with level 1 retinopathy, 8/14 (57%) eyes with level 2 retinopathy, 24/47 (51%) eyes with level 3 retinopathy, and 36/46 (78%) eyes with level 4 retinopathy. These defect incidences were significantly higher than that of the control group, which had 5/144 (3.5%) defects (P < or = 0.001). Risk factors for this nerve defect were level of diabetic retinopathy (P = 0.002), high systolic blood pressure (P = 0.0232), and patient's age (P = 0.0478). Not correlated with the incidence of the retinal nerve fiber layer defect were visual acuity, disc size, axial length, and glycosylated hemoglobin level at the time of examination. CONCLUSION: These findings suggest that the retinal nerve fiber layer defect is common in patients with early diabetic retinopathy. Risk factors for this defect were higher level of diabetic retinopathy, systemic hypertension, and advanced age.

Adult↗