Biomedical subjects

M Araie

Publications and source records attributed to M Araie.

At least 109 records · Page 6Linked to original sources

PubMed1995

[Effect of topical timolol on microcirculation in the rabbit optic nerve head evaluated with a laser speckle microcirculation analyser].

The effect of topical 0.5% timolol on the microcirculation in albino rabbit optic nerve head (ONH) tissue was examined using a laser speckle microcirculation analyser. In the first experiment, normalized blue (NB) in ONH, a quantitative index of peripheral blood flow in ONH, intraocular pressure (IOP), blood pressure (BP) and pulse rate (PR) were measured under general anesthesia before, and 30, 60, 90 and 120 minutes after a 20 microliters instillation of timolol in one eye and a placebo in the other eye in a masked randomized manner. In the second experiment, one eye of another group of rabbits received timolol twice daily for 20 days and a placebo in the fellow eye in a randomized masked manner. The NB in ONH and IOP were measured before treatment and 2 hours after the last instillation on the 20th day. After a single instillation of timolol, PR showed a maximum reduction of 11% and the IOP in the timolol-treated eyes showed a maximum decrease of 18%, but the NB in ONH and BP did not show any significant change during the experiment. After the 20-day treatment, IOP showed a maximum decrease of 28% in the timolol-treated eyes and 17% in the placebo-treated eyes. The NB in the timlol-treated eyes increased significantly (p < 0.01), but in the placebo-treated eyes it showed no significant change. Thus, the long-term use of topical timolol may increase peripheral blood flow in ONH tissue in the living rabbit eye.

Administration, Topical↗

PubMed1995

Influence of myopic refraction on visual field defects in normal tension and primary open angle glaucoma.

It is known that the prevalence of normal tension glaucoma (NTG) or primary open angle glaucoma (POAG) is higher in the myopic population and that the prevalence of myopia and NTG is higher in Japan than in western countries. To evaluate the influence of myopic refractive error in the central 10 degrees of the visual field in NTG eyes, the data obtained from NTG eyes with the Humphrey Visual Field Analyzer were analyzed in comparison with data from POAG eyes. One hundred and twenty eyes of 86 NTG patients and 197 eyes of 138 POAG patients whose ages were 65 years or younger were included in this study. All of them had clear ocular media, refractive power less than +1.0 diopter and no myopic degeneration in the fundus. Multiple linear regression analysis was performed with the dependent variable of the deviation of the measured threshold value from the normal reference value (TD; STATPAC 2), and independent variables of myopic refractive power and the mean deviation (MD; STATPAC 2) as an index of the disease stage at each test point of the Humphrey 10-2 program and at the most central 12 test points of the 30-2 program. Myopic power was found to have a significant positive correlation with the depression in the lower cecocentral area in both NTG and POAG eyes, while only in NTG eyes it had a significant negative correlation with the depression in the upper arcuate area extending just nasal to the fixation point.

Aged↗

PubMed1995

[Effect of topical carteolol on tissue circulation in rabbit optic nerve head evaluated with the laser speckle microcirculation analyser].

The effect of topical 2% carteolol on the tissue circulation in the albino rabbit optic nerve head (ONH) was studied using a laser speckle microcirculation analyser. In the first experiment, normalized blur (NB), the quantitative index of peripheral blood flow rate in the ONH, intraocular pressure (IOP), blood pressure (BP) and pulse rate (PR) were measured under general anesthesia before, and 30, 60, 90, and 120 minutes after a 20 microliters instillation of carteolol in one eye and a placebo in the other eye in a masked randomized manner. In the second experiment, one eye of another group of rabbits received carteolol twice daily for 20 days and the fellow eye a placebo in a randomized masked manner. The NB in the ONH and the IOP were measured before treatment and 2 hours after the last instillation on the 20th day. After a single instillation of carteolol, PR showed a maximum reduction of 14% and the IOP in the carteolol-treated eyes showed a maximum decrease of 22%, while NB in ONH and BP did not show any significant change during the experiment. After 20-day treatment, IOP showed a maximum decrease of 25% in the carteolol-treated eyes and 17% in the placebo-treated eyes. The NB showed a significant increase of 16% (p < 0.01) in the carteolol-treated eyes and 10% (p < 0.05) in the placebo-treated eyes. This indicates that long-term use of topical carteolol increases peripheral blood flow in ONH tissue in the living rabbit eye.

Administration, Topical↗

PubMed1995

[Noninvasive two-dimensional analysis of iridial circulation using the laser speckle phenomenon].

We have developed an apparatus using the laser speckle phenomenon for noninvasive two-dimensional measurement of the peripheral circulation of the iris. The normalized blur of the speckle pattern (NB-value) was adopted as an index of the blood velocity in the tissue. It was found that the average NB-value of the pigmented rabbit iris was gradually increasing from pupil margin to periphery. The coefficient of variation of the NB-value in the middle area of the iridial width was the smallest. The coefficient of reproducibility of the NB-value measured in the same area twice at 5-minute intervals was 8.8%, and that at 24-hour intervals was 14.1%. The NB-value of the iris showed a good correlation (r = 0.57, p < 0.0072 n = 20) with the iridial blood flow rate measured at the same time by the microsphere technique when intraocular pressure was adjusted to 20 mmHg or 40 mmHg. This result suggests that the NB-value can be useful for quantitative assessment not only of the blood velocity but also of the blood flow rate in the iridial tissues.

Animals↗

PubMed1995

[An apparatus using laser speckle phenomenon for noncontact two-dimensional analysis of microcirculation in optic nerve head or choroid in human eyes].

The previously reported apparatus using the laser speckle phenomenon for noncontact two-dimensional analysis of the fundus peripheral circulation was improved so that peripheral circulation in the optic nerve head (ONH) or choroid in human eyes can be measured on a real-time basis. The fundus was illuminated by a diode laser spot and its image speckle was detected with an area sensor. The NB value, a quantitative index of blood velocity, was calculated by the logic board every 0.125 sec successively for 7 sec. Using this apparatus, the NB averaged over the measurement field located in the temporal site of ONH, free of visible surface vessels (NBONH), and that located in the posterior choroid (NBCh) were measured in normal human eyes. The coefficients of reproducibility of 5-minute interval measurements were 11.7% for the NBONH averaged over 5 pulses (mean NBONH) and 8.7% for the NBONH averaged over 5 pulses (mean NBCh), and those of 24-hour interval measurements were 13.0% for the former and 9.7% for the latter, respectively. The average of pulsatile component of NBONH was 38.4% of mean NBONH and that of NBCh was 26.6% of mean NBCh.

Adult↗

PubMed1995

Visual field damage proximal to fixation in normal- and high-tension glaucoma eyes.

To compare in more detail the central visual field damage in normal-tension glaucoma (NTG) and high-tension glaucoma (HTG) eyes, a pointwise inner-group comparison of the data obtained with the Humphrey 10-2 was carried out in 68 NTG cases with maximum intraocular pressure (IOP) of < or = 21 mmHg and 62 HTG cases with maximum IOP of > or = 25 mmHg. All eyes had the usual field defects, with a mean deviation of > or = -15 dB (MD, STATPAC). Age, refraction and MD were matched between the two groups. Total deviation (TD, STATPAC), the difference between the measured threshold and the age-corrected normal reference at each test point of the 10-2 program, was used for pointwise inter-group comparisons. The data were analyzed with Wilcoxon rank-sum test and logistic discriminant analysis. The latter method was also applied to the data of the 30-2 program to confirm the results obtained with the 10-2 program. The comparisons using the different methods and programs gave consistent results. For a given amount of overall visual field damage in the two types of glaucoma, a superior arcuate area extending down to the horizontal meridian just nasal to the fixation point was significantly more depressed and an area inferior to the horizontal meridian and inferior temporal to the fixation point significantly less depressed in NTG eyes. HTG eyes were significantly more diffusely damaged in the central 10-degree visual field. NTG and HTG may have unique patterns of central visual field damage. These differences may implications in following NTG patients and studying the pathogenesis of this glaucoma.

Fixation, Ocular↗

PubMed1995

Color vision deficit in normal-tension glaucoma eyes.

Color vision deficit in 26 eyes with normal-tension glaucoma (NTG) is compared with that in 21 eyes with primary open angle glaucoma (POAG) using the color perimetry method developed by Iijima et al. Subjects had visual field defects confined to either the upper or the lower hemifield as determined by conventional white-on-white perimetry, and the stage of disease was relatively early with an average mean deviation (MD) of -7 dB. Except for intraocular pressure, there were no significant differences between NTG and POAG subjects in age, refraction, MD, and mean total deviation for spared and damaged hemifield. In the spared hemifield, the incidence of blue-yellow abnormality was significantly different between the two diseases (P = 0.01); in only 11% of the present NTG eyes versus 52% of the POAG eyes in the present study. In the damaged hemifield, however, the blue-yellow abnormality was found in about 75% of the eyes, whether NTG or POAG. This finding may further shed light on the pathogenesis of open angle glaucoma.

Adult↗

PubMed1994

Factors contributing to the progression of visual field damage in eyes with normal-tension glaucoma.

PURPOSE: To evaluate the contribution of various factors on the progression of visual field damage in normal-tension glaucoma. METHODS: Follow-up data of 56 eyes of 56 patients with normal-tension glaucoma, all of whom had an early stage of the disease with a mean deviation of -5 decibels or greater and were followed without therapy, were analyzed using regression analysis of survival data based on the Cox proportional hazards model. Factors studied were age, sex, presence or absence of diabetes or family history of glaucoma, refraction, systolic and diastolic pressures, cup:disc ratio, ratio of area of parapapillary atrophy to disc area, the mean deviations of the studied and contralateral eyes, and intraocular pressure and occurrence of disc bleeding during follow-up, both of which were treated as time-dependent variables. The progression of visual field damage was based on the glaucoma change probability analysis. RESULTS: Cup:disc ratio, ratio of area of parapapillary atrophy to disc area, and intraocular pressure were found to have significant influence on the progression of visual field damage in normal-tension glaucoma. CONCLUSION: Intraocular pressure may be involved in the development of normal-tension glaucoma. However, further prospective studies are needed to determine the validity of such a conclusion.

Female↗

PubMed1994

Movement of carboxyfluorescein across the isolated rabbit iris-ciliary body.

The movement of carboxyfluorescein across the isolated iris-ciliary body of the albino rabbit was analyzed using an Ussing chamber under short-circuit conditions with carboxyfluorescein concentrations ranging from 10 to 100 microM. At a concentration of 50 microM, the outward permeability (from the aqueous to the stromal side) was 4.0 +/- 0.2 x 10(-6) cm/sec and the inward permeability (from the stromal to the aqueous side) was 1.3 +/- 0.2 x 10(-6) cm/sec (Mean +/- SE, N = 6). The former was significantly greater than the latter (P < 0.001). Inward movement of carboxyfluorescein showed a linear increase in relation to the concentrations tested. Neither ouabain (100 microM), 2,4-dinitrophenol (10 microM) nor probenecid (100 microM) significantly inhibited the inward movement of carboxyfluorescein. The net outward movement of carboxy-fluorescein became saturated, as concentration was increased, and a Lineweaver--Burke plot gave an apparent Km of 28 microM and Vmax of 0.67 x 10(-9) mole/hr/cm2. In addition, outward carboxyfluorescein movement was significantly inhibited by ouabain (100 microM), 2,4-dinitrophenol (10 microM), probenecid (100 microM), iodipamide (1.0 mM), hippurate (1.0 mM), low temperature or low external Na+ concentration. These results suggest that outward carboxyfluorescein movement across the tissue largely depends on carrier-mediated active transport, while inward movement occurs by passive diffusion.

Animals↗

PubMed1994

[Influence of refraction on the visual field defects in normal tension glaucoma and primary open angle glaucoma eyes].

The prevalence of normal tension glaucoma (NTG) or primary open angle glaucoma (POAG) is higher in myopic populations and the prevalence of myopia and NTG is relatively high in the Japanese. To evaluate the influence of myopic refractive error on the central visual field defect in NTG eyes, the data obtained from NTG eyes with the Humphrey Visual Field Analyser were analysed in comparison with those from POAG eyes. One hundred and twenty NTG eyes and one hundred and ninety-seven POAG eyes were included. All of them had clear ocular media, but no myopic degeneration in the fundus. Multiple linear regression analysis was performed with a dependent variable of the deviation of the measured threshold value from normal reference value (total deviation, STATPAC) and independent variables of refractive error and mean deviation (STATPAC). Myopic power was found to be positively correlated with the depression in the lower papillo-macular area in both NTG and POAG eyes, and it was negatively correlated with the depression in an upper arcuate area extending just nasal to the fixation only in NTG eyes.

Adult↗

PubMed1994

[Effects of long-term application of bunazosin hydrochloride eye drops on the aqueous flow rate and blood-aqueous barrier permiability in rabbit eyes].

We investigated the effects of long-term instillation of bunazosin hydrochloride--alpha 1 specific adrenergic antagonist--on the aqueous humor dynamics and blood-aqueous barrier in rabbit eyes. We examined intraocular pressure, aqueous flow rate, and blood-aqueous barrier permiability for albumin after four weeks application of 0.05% bunazosin. The effect of bunazosin on blood-aqueous barrier destruction by laser iridophotocoagulation was also examined. During four weeks, bunazosin reduced the intraocular pressure by 1.7 +/- 0.6 mmHg (mean +/- SEM). Continuous application of bunazosin had no significant influence on aqueous flow rate and fluorescein isothiocyanate-labeled rabbit albumin (FITC-Alb) concentration in the anterior chamber. Bunazosin had no effect on the rise of the FITC-Alb concentration after iris photocoagulation, but the intraocular pressure in bunazosin treated eyes was significantly lower than in control eyes one hour after photocoagulation.

Adrenergic alpha-Antagonists↗

PubMed1994

Noncontact, two-dimensional measurement of retinal microcirculation using laser speckle phenomenon.

PURPOSE: To report a new apparatus for noncontact, two-dimensional measurement of retinal microcirculation using the laser speckle phenomenon and to demonstrate that this apparatus can document known or expected changes in retinal blood flow. METHODS: The rabbit fundus was illuminated by an argon (blue) laser spot (0.62 x 0.62 mm), and its image speckle was detected with an image sensor. The difference between the average of the speckle intensity (Imean) and the speckle intensity for successive scannings was calculated, and the ratio of Imean to this difference was defined as normalized blur (NB), a quantitative index of blood velocity in the retinal microcirculation. The results were displayed on a color monitor showing the two-dimensional variation of the NB level in the measurement area. Using this apparatus in the rabbit, the NB in the retinal field free of visible surface vessels was determined and compared with the retinal blood flow rate measured using the microsphere technique in the same eye simultaneously. In addition, the effect of the ocular perfusion pressure (OPP) on NB was studied. In the above experiments, a stepwise reduction in OPP was introduced by elevating the intraocular pressure manometrically. RESULTS: The relative decrease in the average NB (NBav) over the field measured, with the reduction in OPP, showed significant correlation with the relative change in the blood flow rate determined using the microsphere technique (r = 0.59, P < 0.001). Although NBav in the retina was little affected by OPP change when OPP was greater than 50 mm Hg, NB decreased along with OPP at levels less than 50 mm Hg. CONCLUSIONS: The NBav showed significant correlation with the retinal blood flow rate determined with microsphere technique. Retinal microcirculation under various conditions can be studied two dimensionally and noninvasively in the living eye with the present apparatus.

Animals↗

PubMed1994

Endogenous acetylcholine concentrations in rat iris-ciliary body.

The technique of microwave irradiation, whereby enzymes are inactivated within milliseconds, was employed to accurately determine the in vivo acetylcholine (ACh) concentration in the iris-ciliary body (ICB). Rats were sacrificed by microwave irradiation at 9.5 kW at 2,450 MHz for 0.9 seconds. The eyes were enucleated, the ICBs isolated and 10 ICBs from 10 eyes were treated as one sample. ACh levels were determined using high performance liquid chromatography in an immobilized-enzyme reactor. Endogenous ACh levels in the rat ICB were 58.8 +/- 5.0 nmoles (8.58 +/- 0.73 micrograms) per gram tissue protein (mean +/- SE, 9 samples). A single instillation of 5 microliters of 0.05% atropine in one eye of an animal lowered the ACh level in the ICB of the eye (P < 0.02).

Acetylcholine↗

PubMed1994

Posterior chamber intraocular lens implantation in filtered or nonfiltered glaucoma eyes.

Cataract extraction and posterior chamber intraocular lens (PC-IOL) implantation was carried out in 45 glaucoma eyes that had undergone glaucoma filtering surgery (Group A), and in 47 glaucoma eyes in which intraocular pressure (IOP) was well controlled with medication (Group B). To analyze the effects of PC-IOL implantation on the control of IOP and the functioning of the filtering bleb, a life-table analysis using the Kaplan-Meier method was carried out. In Group A the probability that IOP control will not worsen at 2 years was 56 +/- 12 (SE)% in eyes where a functioning filtering bleb had existed preoperatively. The probability that the filtering bleb was not cicatrized at 2 years postoperatively was 44 +/- 11 (SE)%. In Group B the postoperative IOP on the first postoperative day was significantly higher than the preoperative level in primary open angle glaucoma (POAG) eyes, while no such difference was seen in primary angle closure glaucoma (PACG) eyes. The postoperative IOP was significantly lower than the preoperative level from 3 to 6 months postoperatively in POAG eyes and from 1 to 12 months postoperatively in PACG eyes. Medication did not differ significantly pre- and postoperatively. In 64 +/- 11 (SE)% of POAG and 63 +/- 15% of PACG eyes the IOP control did not worsen at 2 years. In 70% of the eyes the IOP control improved postoperatively, and was maintained for 2 years with the probability of 44 +/- 12 (SE)%.

Aged↗

PubMed1994

Endogenous catecholamine concentrations in rat iris-ciliary body.

Endogenous catecholamine concentrations in the rat iris-ciliary body (ICB) were determined using the technique of microwave irradiation, whereby enzymes are inactivated within milliseconds, and high performance liquid chromatography. Rats were sacrificed by microwave irradiation at 9.5 kW at 2450 MHz for 0.9 seconds. The eyes were enucleated, the ICBs isolated, and 10 ICBs from 10 eyes were treated as one sample. Endogenous norepinephrine levels in the rat ICB were 19.5 +/- 2.3 nmol per gram tissue protein (mean +/- SE, 7 samples), while endogenous dopamine levels were 3.2 +/- 0.2 nmol. Epinephrine could not be detected. A single instillation of 5 microliters of 0.05% apraclonidine, an alpha-2 agonist, in one eye of an animal raised the NE level in the ICB of the treated eye by 8% compared to that in the untreated fellow eye (P < 0.05).

Adrenergic alpha-Agonists↗

PubMed1994

[Visual field defects in normal tension glaucoma and primary open angle glaucoma. Comparison in the late stage of disease].

To compare the visual field defects in the late stage of disease between normal-tension glaucoma (NTG) and primary open angle glaucoma (POAG), measurements taken with the 30-2 and 10-2 threshold program of the Humphrey Visual Field Analyzer were analysed by statistical methods including logistic discriminant analysis. Thirty-four eyes of 34 NTG cases and 63 eyes of 63 POAG cases whose mean deviation (MD) given by STATPAC was equal to or less than -15 dB were included and there was no significant difference in MD, refraction, or age between the two groups. The analyses demonstrated that the upper arcuate area was significantly more depressed in POAG and the inferior Bjerrum area was significantly more depressed in NTG eyes. It was also shown that the lower papillo-macular area was less affected in NTG than in POAG eyes.

Discriminant Analysis↗

PubMed1994

[Sectorization of the central 10 degrees visual field in open-angle glaucoma].

In an attempt to determine an optimal sector pattern of the central 10 degrees visual field in glaucoma, we applied the VARCLUS procedure, a new clustering algorithm provided by SAS Institute, to 379 glaucoma visual fields of the central 10-2 program of the Humphrey visual field analyzer. The subjects were 211 normal-tension glaucoma (NTG) and 168 primary open angle glaucoma (POAG) eyes with early to moderately advanced stages of visual field defects. The 68 2-degree grid test points in the central 10 degrees visual field were divided into 10 sectors. The sector pattern was compatible with the projection of nerve fiber layers and no sectors extended over the horizontal meridian. Comparison of the mean of total deviation in the sector of 76 eyes of 76 POAG patients with the maximum intraocular pressure: (IOP) > or = 25 mmHg (high-tension group) and 85 eyes of 85 NTG patients with the maximum IOP < or = 18 mmHg (low-tension group) revealed that four sectors nasal superior to the fixation were significantly more damaged in the low-tension group. We suggest that the sector pattern obtained here is useful in studying the visual field of glaucoma and that the damaging processes in the optic nervehead are not the same in the high-tension and low-tension groups.

Aged↗

PubMed1994

[An apparatus using the laser speckle phenomenon for non-invasive two-dimensional analysis of retinal microcirculation].

A new instrument using the laser speckle phenomenon for non-invasive two-dimensional analysis of the retinal microcirculation was developed. The fundus was illuminated with an argon laser spot and its image speckle was detected with an area sensor. The difference between the average of output data (Imean) and output data for successive scannings of the image speckles at the sensor plane was calculated and integrated to give Dmean, and Imean/Dmean is defined as normalized blur (NB), which is a quantitative index of blood flow velocity. The results were displayed in color graphics showing the two-dimensional variation of the NB level in the area of interest. The NB had a good correlation with the speed of rotation of the ground glass in a range between 5 and 120 mm/sec. Using this instrument, the effect of intraocular pressure (IOP) on the microcirculation of the rabbit retina was studied. The coefficient of reproducibility was 9.2% when measured in the same area twice at 5-minute intervals. A stepwise reduction in the ocular perfusion pressure (OPP) was introduced by elevating the IOP manometrically. The NB in the retina was little affected by OPP change when OPP was above 50 mmHg, but below this value the NB decreased as the OPP decreased.

Animals↗