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Biomedical subjects

G Tomita

Publications and source records attributed to G Tomita.

At least 19 recordsLinked to original sources
PubMed1999

Optic disc changes in normotensive persons with unilateral exfoliation syndrome: a 3-year follow-up study.

BACKGROUND: If, at the time of glaucoma diagnosis, the intraocular pressure (IOP) is higher and the initial field loss more advanced in glaucomatous eyes with than without exfoliation, the cause of the optic disc damage has been suggested to be the high IOP associated with the exfoliation syndrome (EXS). We decided to investigate whether EXS alone, without the contributory effect of measured raised IOP, is a risk factor for optic nerve damage. METHODS: Twenty-two non-glaucomatous, normotensive persons with clinically unilateral EXS were examined for IOP, visual fields (Octopus G1) and disc topography (Imagenet, Topcon) and followed up for 3 years. RESULTS: At the start, the paired exfoliative (E) and non-exfoliative (NE) eyes did not differ in IOP, disc, rim, or cup areas, or cup volumes. They differed in R/D (rim/disc) radius ratio in the inferior section of the optic disc. During the follow-up period, the IOP increased in the E and the NE eyes, and changes indicative of nerve fiber loss were measured in both eyes. In those (n=14) in whom the IOP in the two eyes was equal throughout the follow-up period, disc changes took place only in the E eye. CONCLUSION: The exfoliative process in itself may be a risk factor for optic disc changes.

Aged↗
PubMed1999

Peripapillary atrophy in primary angle-closure glaucoma: a comparative study with primary open-angle glaucoma.

PURPOSE: To investigate the characteristics of peripapillary atrophy in primary angle-closure glaucoma and to compare peripapillary atrophy in primary angle-closure glaucoma with that in primary open-angle glaucoma. METHODS: Twenty-one eyes (of 21 patients) with chronic primary angle-closure glaucoma that had no evidence of an acute attack or combined-mechanism glaucoma and 31 eyes (31 patients) with primary open-angle glaucoma were enrolled in this study. The cup-to-disk area ratio and the visual field mean deviation were matched in both groups. The prevalence of peripapillary atrophy and peripapillary atrophy-to-disk area ratio of eyes with primary angle-closure glaucoma and eyes with primary open-angle glaucoma were compared. The correlation between the peripapillary atrophy area and the cup-to-disk area ratio or the mean deviation was also evaluated. RESULTS: Eight (38%) of 21 eyes with primary angle-closure glaucoma and 21 (68%) of 31 eyes with primary open-angle glaucoma had peripapillary atrophy. The peripapillary atrophy-to-disk area ratio averaged 0.16 in primary angle-closure glaucoma and 0.41 in primary open-angle glaucoma. There were statistically significant differences regarding the prevalence of peripapillary atrophy (P = .048) and peripapillary atrophy-to-disk area ratio (P = .005) between the two groups. There was no significant correlation between the peripapillary atrophy area and the cup-to-disk area ratio or the mean deviation in primary angle-closure glaucoma. In contrast, the peripapillary atrophy-to-disk area ratio significantly correlated with the cup-to-disk area ratio (P = .003) and the mean deviation (P = .0001) in primary open-angle glaucoma. CONCLUSIONS: The peripapillary atrophy in primary angle-closure glaucoma has a different relationship to the structural and functional optic disk changes than that in primary open-angle glaucoma. Different mechanisms seem to be involved in the development of the optic disk damage in the two types of glaucoma.

Adult↗
PubMed1999

Localized wedge-shaped defects of retinal nerve fiber layer and disc hemorrhage in glaucoma.

OBJECTIVE: To evaluate frequencies of localized wedge-shaped defects of the retinal nerve fiber layer (RNFL) in eyes with and without disc hemorrhage in normal-tension glaucoma (NTG) and primary open-angle glaucoma (POAG). This study also aims to define a topographic correlation between disc hemorrhage and localized RNFL defects in POAG. DESIGN: Cross-sectional study. PARTICIPANTS AND CONTROLS: The authors studied 83 eyes of 83 patients with NTG (male/female = 23/60; age, 58.8+/-12.9 years) and 20 eyes of 20 patients with POAG (male/female = 9/11; age, 61.6+/-11.4 years); subjects in both groups had developed new disc hemorrhage at the time of enrollment. The authors randomly selected 45 eyes of 45 patients with NTG (male/female = 20/25; age, 62.0+/-9.3 years) and 24 eyes of 24 patients with POAG (male/female = 13/11; age, 56.3+/-14.5 years) with no history of disc hemorrhage during the follow-up period of more than 2 years. METHODS: Visual field in the patients with POAG was matched to that of the patients with NTG regarding global indices for both the hemorrhage and the nonhemorrhage groups. Localized wedge-shaped defects of RNFL were identified by scanning laser ophthalmoscopy using an argon-blue laser. MAIN OUTCOME MEASURES: The frequency of localized RNFL defects and the relationship between the locations of disc hemorrhages and localized RNFL defects were determined. RESULTS: Localized wedge-shaped defects of RNFL occurred significantly more often in the hemorrhage group than in the nonhemorrhage group in both NTG (Fisher's exact probability test, P < 0.0001) and POAG (P < 0.05) patients. Regardless of the presence of disc hemorrhage, there was no significant difference in the frequency of localized RNFL defects between patients with NTG and those with POAG. Most disc hemorrhages were present in the vicinity of the border between localized RNFL defects and relatively healthy-looking RNFL in both patients with POAG and those with NTG. CONCLUSION: Disc hemorrhage is associated with localized damage of RNFL in both NTG and POAG.

Cross-Sectional Studies↗
PubMed1999

Disc hemorrhage and peripapillary atrophy in apparently healthy subjects.

PURPOSE: We estimated the prevalence of disc hemorrhage and peripapillary atrophy in apparently healthy subjects. METHODS: We reviewed consecutive plain color fundus photographs of 12,140 eyes of 6,070 subjects (male/female=4,079/1,991) who visited a health consultation center. RESULTS: We analyzed 11,934 eyes of 5,967 subjects with good quality of photographs. Disc hemorrhage was found in 36 eyes of 35 subjects (0.6%). The prevalence of disc hemorrhage was significantly greater in women 60 years of age or older (Fisher's exact test, p=0.0004). The prevalence of peripapillary atrophy (zone Beta, zone Alpha), and suspected glaucomatous excavation in eyes with disc hemorrhage was 66.7%, 86.1% and 25.0%, respectively, and significantly greater than that (29.1%, 52.9% and 1.7%) in eyes without disc hemorrhage (Fisher's exact test, p<0.0001). CONCLUSIONS: Disc hemorrhage is more frequent in women over 60 years of age and is significantly associated with peripapillary atrophy in otherwise apparently healthy Japanese people.

Adult↗
PubMed1998

[Diagnostic capabilities of a classification program of the Heidelberg retina tomograph for early glaucomatous changes].

We investigated the diagnostic capabilities of a new glaucoma diagnostic softwave (classification program) of the Heidelberg retina tomograph for early glaucoma. Thirty eyes of 30 patients with early glaucoma (average visual field mean deviation = -3.7 dB) and 30 eyes of 30 normal subjects were enrolled. The criterion for early glaucomatous change was a visual field defect appearing earlier than Aulhorn classification stage II without considering the disc configuration. The diagnostic ability of three glaucoma specialists for the same eyes was evaluated using the Heidelberg retina tomograph analysis map. The agreement of two or three glaucoma specialists was accepted as the final judgment. Sensitivity, specificity, and diagnostic precision were calculated for all evaluations. The agreement between the classification program and glaucoma specialists was calculated with kappa statistics. Sensitivity, specificity, and diagnostic precision of the classification program were 80%, 83% and 82%, respectively. Those of the by glaucoma specialists were 83%, 90% and 87%, respectively. The agreement between the classification program and glaucoma specialists was excellent (kappa 0.73, % agreement 86.7%). The classification program will aid the diagnosis of early glaucomatous damage with high sensitivity and specificity.

Adult↗
PubMed1998

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

In order to evaluate the association between the watershed zone and glaucomatous optic damage, we performed indocyanine green fluorescence angiography with a scanning laser ophthalmoscope in 54 eyes of 27 patients with normal tension glaucoma. The visual field indices were measured with a Humphrey Field Analyzer. We identified 8 eyes (14.8%) of 7 patients with a watershed zone not including the optic nerve head (type I), 32 eyes (59.3%) of 20 patients with the zone partially including the optic nerve head (type II), and 14 eyes (26.0%) of 10 patients with the zone including the optic nerve head (type III). Of the total of 27 patients, 10 patients (37.0%) had different types in each eye. In these patients, the mean deviation (MD) of visual field indices was worse in the eye with the watershed zone which included a larger part of the optic disc than in the contralateral eye (p < 0.05). Conversely, the eye with worse MD than the contralateral eye had a watershed zone which included a larger part of the optic disc than the other eye (p < 0.05). The location of watershed zone appeared to influence the progression of the visual field defect.

Adult↗
PubMed1998

Transscleral cyclophotocoagulation with the diode laser for neovascular glaucoma.

BACKGROUND AND OBJECTIVE: To compare the outcome of transscleral cyclophotocoagulation (TSCPC) using a diode laser with that of TSCPC using an Nd:YAG laser in neovascular glaucoma. PATIENTS AND METHODS: The surgical outcome of diode laser TSCPC was retrospectively compared with that of free-running mode Nd:YAG laser (FR-YAG) TSCPC and continuous-wave mode Nd:YAG laser (CW-YAG) TSCPC. Twenty-one eyes of 21 patients in the diode laser group, 9 eyes of 9 patients in the FR-YAG group, and 9 eyes of 9 patients in the CW-YAG group were treated. RESULTS: The Kaplan-Meier life-table analysis revealed that the probability (mean +/- standard error) of successful intraocular pressure control with diode laser TSCPC at 3 years postoperatively was 47.2 +/- 12.6% per operation and 55.9 +/- 16.3% per eye. Compared with the CW-YAG TSCPC, the diode laser TSCPC had a significantly higher probability of success throughout the follow-up period. Diode laser TSCPC was associated with improvements or preservation of visual acuity in 16 of 21 eyes (76%), and was the best of the three laser sources. Postoperative complications were minor following diode laser TSCPC. CONCLUSION: Diode laser TSCPC appears to be as effective as FR-YAG TSCPC and better than CW-YAG TSCPC for treating neovascular glaucoma.

Ciliary Body↗
PubMed1998

Correlation of the peripapillary atrophy area with optic disc cupping and disc hemorrhage.

PURPOSE: To investigate the association of the peripapillary atrophy area with disc cupping area and disc hemorrhage in subjects who underwent ocular examination as part of a routine physical examination. METHODS: We reviewed plain color fundus photographs taken of 12,140 eyes of 6,070 subjects as part of a routine health examination. The refractive error in these eyes was not known. Using a computerized image analysis system, we measured the area of peripapillary atrophy (zone beta), the optic disc, and optic disc cupping by means of planimetry in 8,842 eyes of 4,421 subjects with fundus images of good quality. RESULTS: The ratio of cup area to disc area was significantly greater in eyes with peripapillary atrophy (0.36 + 0.09) than in eyes without peripapillary atrophy (0.34 + 0.07), and the ratio of peripapillary atrophy area to disc area was significantly greater in eyes with disc hemorrhage (0.26 + 0.34) than in those without disc hemorrhage (0.09 + 0.18). Moreover, in eyes with peripapillary atrophy, the ratio of cup area to disc area was significantly larger in eyes with disc hemorrhage (0.48 + 0.08) than in those without disc hemorrhage (0.36 + 0.09). These results remained statistically unchanged even after "glaucomatous" eyes were excluded from the study. CONCLUSION: Peripapillary atrophy appears to be associated with a higher degree of cupping of the optic disc and disc hemorrhage, and the results suggest an association between peripapillary atrophy and glaucomatous optic neuropathy.

Female↗
PubMed1998

Retinal nerve fiber layer thickness within the area of apparently normal visual field in normal-tension glaucoma with hemifield defect.

PURPOSE: To evaluate changes in nerve fiber layer (NFL) thickness in areas with apparently normal retinal sensitivity in eyes with normal-tension glaucoma (NTG) with hemifield dominant visual field defects. METHODS: The prospective clinical study consisted of 17 eyes from 17 patients with NTG in whom superior or inferior hemifield dominant defects based on the Humphrey visual field of central 30 degrees were present, and 10 normal eyes from 10 control subjects matched in age and refractive error. The retinal NFL thickness was evaluated with a scanning laser polarimeter. Mean NFL thickness measurements in the defined ring in four quadrants (superior, inferior, nasal, and temporal) were obtained. To facilitate visual field and NFL thickness correspondence, the total deviation (TD) plot of the visual field was divided into four 90 degrees quadrants, using Wirtschafter's scheme to match the four quadrants examined by laser polarimetry. RESULTS: The mean NFL thickness in the unaffected quadrant, i.e., the quadrant within the area corresponding to the hemifield with apparently normal visual field in eyes with NTG, was significantly thinner than the average NFL thickness of the superior and inferior quadrants in the normal eyes. In eyes with NTG, the NFL thickness in the affected quadrant also was significantly thinner than that in the unaffected quadrant. In the unaffected quadrant, visual field TD (the sum of the TD values within this quadrant) showed a significant correlation with the ratio of NFL thickness in the unaffected quadrant to that in the nasal quadrant. CONCLUSION: Early changes in the retinal nerve fiber layer may already exist even in the unaffected area of the visual field in eyes with NTG with hemifield dominant visual field defects.

Adult↗
PubMed1997

The associations of optic disc hemorrhage with retinal nerve fiber layer defect and peripapillary atrophy in normal-tension glaucoma.

OBJECTIVE: The purpose of the study is to elucidate a topographic correlation between optic disc hemorrhages and retinal nerve fiber layer defects as well as peripapillary atrophy in normal-tension glaucoma (NTG). DESIGN: The authors prospectively studied the relation between the precise locations of disc hemorrhages and retinal nerve fiber layer defects in the first part of the study. The authors also compared morphometrically the peripapillary atrophy and the optic disc in eyes with disc hemorrhage with eyes without a history of disc hemorrhage in age-matched patients in the second part of the study. PARTICIPANTS: In part 1, 42 patients with NTG (male/female = 11/31; age, 56.8 +/- 14.2 years) in whom new disc hemorrhages developed were enrolled. In part 2, 51 randomly selected age-matched patients with NTG without a history of disc hemorrhage (male/female = 16/35; age, 55.7 +/- 12.5) were examined. MAIN OUTCOME MEASURE: In part 1, retinal nerve fiber layer defects were observed by scanning laser ophthalmoscopy using an argon-blue laser. In part 2, the area, angular extent, and radial extent of zone beta of peripapillary atrophy and the structural parameters of optic disc were measured by scanning laser tomography using a diode laser. RESULTS: In part 1, the authors detected 64 disc hemorrhages in 48 eyes of 42 patients; retinal nerve fiber layer defects were shown in 47 (97.9%) of 48 eyes by scanning laser ophthalmoscopy. Of 64 disc hemorrhages, 51 (79.7%) coincided with retinal nerve fiber layer defects in location. These 51 hemorrhages were present on the border (41.2%) or adjacent to the border (58.8%) between the retinal nerve fiber layer defect and the apparently healthy-looking retinal nerve fiber layer. In part 2, the prevalence, area, angular extent of zone beta, and ratio of zone beta area to disc area were significantly greater in the disc hemorrhage group than in the nonhemorrhage group, even though there were no significant differences in disc parameters between the two groups. CONCLUSIONS: Disc hemorrhage is associated closely with retinal nerve fiber layer defect in location and the size of peripapillary atrophy in NTG.

Adult↗
PubMed1997

High-pass resolution perimetry and a Humphrey Field Analyzer as indicators of glaucomatous optic disc abnormalities. A comparative study.

BACKGROUND: The "neural capacity (NC)" of high-pass resolution perimetry (HRP) may be correlated to the neuroretinal rim area of the optic disc. The authors compared HRP with conventional differential light sensitivity (DLS) perimetry in terms of correlation with glaucomatous optic disc changes. METHODS: Thirty-seven eyes of 37 normal-tension glaucoma (NTG) patients were examined. The authors used an Ophthimus system for HRP and a Humphrey Field Analyzer (HFA) for DLS perimetry. The total rim area and the area of temporal, superior, nasal, and inferior quadrants were determined using a confocal laser tomographic scanner. Quadrant NC (QNC) was calculated using the resolution thresholds corresponding to a given quadrant. Quadrant mean deviation (QMD) was calculated from the total deviations of HFA. RESULTS: In all eyes, NC and MD showed significant correlations with total rim area (Spearman rank correlation coefficient [rs] = 0.375, P < 0.05 for NC; rs = 0.336, P < 0.05 for MD). A significant correlation was observed in 21 eyes with early visual field changes (rs = 0.469, P < 0.05), but not in 16 eyes with advanced visual field changes. Both QNC and QMD showed significant correlations with inferior rim area (rs = 0.575, P < 0.01 for QNC; rs = 0.431, P < 0.01 for QMD). However, no significant correlations were found between QNC or QMD and superior rim area. CONCLUSIONS: The NC may relate to glaucomatous optic disc changes better than does MD in NTG, especially in eyes with early-stage visual field changes.

Adult↗
PubMed1996

In vivo detection of perineural circular arterial anastomosis (circle of Zinn-Haller) in a patient with large peripapillary chorioretinal atrophy.

PURPOSE: In vivo visualization of perineural circular arterial anastomosis (circle of Zinn-Haller) has been considered impossible because of the arterial circle's location in the sclera. We investigated whether the circle of Zinn-Haller could be detected in a glaucoma patient who had a large area of temporal peripapillary chorioretinal atrophy. METHODS: We performed both scanning laser Doppler flowmetry and indocyanine green angiography with a scanning laser ophthalmoscope in the same patient. RESULTS: In the area of peripapillary atrophy, a circumferential vascular loop consistent with a portion of the circle of Zinn-Haller could be detected by the two imaging methods. CONCLUSION: The circle of Zinn-Haller can be visualized in vivo because of the peripapillary atrophy.

Arteries↗
PubMed1996

Correlation between peripapillary atrophy and optic nerve damage in normal-tension glaucoma.

PURPOSE: To investigate the correlation between peripapillary atrophy and visual field defects as well as optic nerve head configurations in patients with normal-tension glaucoma (NTG). METHODS: Topographic measurements for peripapillary atrophy and optic nerve head using confocal scanning laser tomography and automated static threshold perimetry were performed on 102 eyes of 51 patients with NTG. Peripapillary atrophy was divided into (1) a central zone (zone Beta) with visible, large choroidal vessels and sclera, and (2) a peripheral zone (zone Alpha) with irregular hyper- and hypopigmentation. The area, angular extent around the disc, and radial extent of each zone were measured. RESULTS: The area and extent of zone Beta increased significantly with increasing visual field defects expressed in terms of mean deviation, corrected pattern standard deviation, central visual field defects within 5 degrees of fixation, and superior hemifield defects (r = 0.3770-0.5291, P < 0.01). The angular extent of zone Beta represented localized field defects better (r = 0.5217, P < 0.001) than diffuse field defects (r = -0.3770, P < 0.01). Zone Beta significantly correlated with optic nerve head topography. Intraindividual right-left-side differences of corrected pattern standard deviation showed the highest correlation with the side differences of zone Beta area (r = 0.6305, P < 0.001). The location of visual field defects correlated significantly with the location of peripapillary atrophy (chi-square = 9.0484, P = 0.011). Zone Alpha was not significantly correlated with visual field defects or optic nerve head configurations (P > 0.05). CONCLUSION: Peripapillary atrophy is significantly associated with functional and structural optic nerve damage in NTG.

Adult↗
PubMed1996

[Temporal modulation transfer function in normal-tension glaucoma patients].

In an attempt to detect patients in an early stage of glaucoma, a new screening test, the Flicker System, by which temporal modulation transfer function is evaluated, was performed in 64 normal-tension glaucoma patients and 65 normal eyes. The early stage of glaucoma, i.e., stage 0-1 of Aulhorn-Greve's classification, showed a significant decrease of the modulation in the range from 20 to 45 Hz in comparison with normal eyes (p value < 0.05). The moderate stage of glaucoma of stages 2-3 also revealed significantly decreased values of the modulation in the range from 14 to 55 Hz. In the range from 25 to 45 Hz, the reduction of modulation in the glaucoma with diffuse visual defect was more profound than in glaucoma with localized or mixed defects. The results seem to be compatible with the presence of diffuse visual function deficit in glaucoma.

Adult↗
PubMed1996

Optic disc topography before and after trabeculectomy in advanced glaucoma.

BACKGROUND AND OBJECTIVE: To analyze changes in the optic disc topography after filtration surgery. PATIENTS AND METHODS: Laser scanning tomography was performed in 10 eyes of 9 patients (mean age 65.6 +/- 8.1 years; age range 55 to 75 years) after a mean follow-up of 3.7 months, and in 8 eyes of 7 patients (mean age 63.1 +/- 7.6 years; age range 55 to 75 years) after a mean follow-up of 13.1 months. RESULTS: Preoperatively, the mean intraocular pressure (IOP) was 24.4 +/- 6.9 mm Hg with maximal medication. Postoperatively at 3.7 months it was 11.0 +/- 2.2 mm Hg, and at l2.1 months it was l3.6 +/- 2.8 mm Hg. An initial reduction in IOP of more than 30 percent at 3.7 months was achieved without medication in all but 1 eye. After 12.1 months, an IOP reduction of more than 30 percent was achieved in 6 of 8 eyes (1 with medication), while 2 eyes had IOP reductions of less than 15 percent (< or = 3 mm Hg) despite medication. In the 6 eyes, the optic disc cup volume showed a decrease of more than 30 percent, while the 2 eyes without marked IOP reductions had slight increases in cup volume. Of the 2 eyes without marked decreases in cup size, 1 had normal-tension glaucoma and 1 experienced an increase in IOP of more than 25 mm Hg during the first postoperative week. CONCLUSION: The postoperative IOP should be kept low enough to permit reversal of optic disc changes.

Aged↗
PubMed1996

["Neural capacity" index correlates with neuroretinal rim area of glaucomatous eyes better than light sensitivity].

We compared the relationship between the neuroretinal rim area and the neural capacity (NC) index of high-pass resolution perimetry (HRP) and the differential light sensitivity (DLS) of a Humphrey Field Analyzer (HFA). Subjects were 40 eyes of 27 normal-tension glaucoma (NTG) patients. The total rim area and the area of its temporal, superior, nasal, and inferior quadrants were determined with a confocal laser tomographic scanner. Mean local NC (MLNC) was calculated using the resolution thresholds corresponding to the quadrant. Mean local DLS (MLDLS) was calculated using the data of program 30-2 of HFA. In a total of 40 eyes, NC and mean deviation were significantly correlated with the total rim area (rs = 0.422, p < 0.01: rs = 0.360, p < 0.05, respectively). NC was also significantly correlated with the total rim area in 19 eyes with early visual field changes, but not in 21 eyes with advanced changes. MLNC was significantly correlated with the superior and inferior rim areas, and MLDLS was significantly correlated with the inferior rim area. These results indicate that indices of HRP may relate to glaucomatous optic disc changes better than those of HFA in NTG, especially in patients with early visual field defects.

Adult↗
PubMed1996

Relationship of nerve fiber layer defects and parafoveal visual field defects in glaucomatous eyes.

To evaluate the relationship between nerve fiber layer defects (NFLD) and parafoveal visual field defects in glaucomatous eyes, 23 eyes of 20 patients with open-angle glaucoma were studied by scanning laser ophthalmoscope (SLO). Only eyes in which the NFLD reached the temporal raphe in either hemisphere were used. We defined three topographic parameters of NFLD: 1) the angle (theta, degrees) of line 'A' from the optic disc center to the foveal pit, and line 'B' from the disc center to a point of the NFLD at the disc edge nearest line 'A'; 2) a horizontal distance (D1, mm) along the temporal raphe between the foveal pit and the internal edge of the NFLD; and 3) a vertical distance (D2, mm) between the foveal pit and either the superior or inferior internal edge of the NFLD. We defined the nearest defect location (in degrees from the fovea) as the nearest location with sensitivity loss of at least 6 dB (Humphrey visual field program 10-2). A highly significant correlation was found between each of the NFLD parameters and the nearest defect location (P < 0.001). The NFLD parameters we defined may be helpful for evaluating parafoveal visual function in glaucoma.

Adult↗