Enlargement of optic nerve resembling orbital mass in case of optic neuritis.
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Adult↗
Biomedical subjects
Hisao Ohde
Publications and source records attributed to Hisao Ohde.
Discordance between subjective perimetric visual fields and objective multifocal visual evoked potential-determined visual fields in patients with hemianopsia.
PURPOSE: To investigate the concordance between subjectively and objectively acquired visual fields in patients with subjectively determined hemianopsia. DESIGN: Retrospective observational study. METHODS: Ten patients, six men and four women, ranging in age from 28 to 68 years, were studied. Goldmann or Humphrey perimeters were used to obtain the subjectively determined visual fields for up to 25 degrees of eccentricity, and the VERIS Scientific System (Electro-Diagnostic Imaging, San Francisco, California, USA) was used to record multifocal visual evoked potential [VEPs] (mfVEPs) to obtain the objective visual fields. Each of the 60 black-and-white segments of the checkerboard stimulus was alternated according to a binary m sequence. The first slices of the second-order kernels were extracted and analyzed. RESULTS: In five cases, the visual field loci where the mfVEPs were within normal limits corresponded to the scotomatous areas obtained by conventional perimetry. In these discordant cases, the lesions (e.g., arteriovenous malformation) were located in the occipital lobe. Two of these cases had a complete recovery of the subjective visual field. The lesions of the concordant cases were located outside the occipital lobe (e.g., pituitary adenoma). In these cases, no visual field improvement was seen. The temporal crescent syndrome was ruled out in patients with posterior lesions by computed tomography (CT) or magnetic resonance imaging (MRI) findings. CONCLUSIONS: In some patients with occipital lesions, the subjective and objective visual field results are discordant, and some of them will show a recovery of the visual field deficits.
Adult↗
Phototoxic effects of commercial photographic flash lamp on rat eyes.
BACKGROUND: To determine whether exposure of the cornea and retina of rats to flashes from a commercial photographic flash lamp is phototoxic. METHODS: Sprague-Dawley rats were exposed to 10, 100, or 1,000 flashes of the OPTICAM 16M photographic flash lamp (Fujikoeki, Japan) placed 0.1, 1, or 3 m from the eyes. Corneal damage was assessed by a fluorescein staining score, and the retinal damage by eletroretinography (ERG) and histology before and 24 h after exposure. RESULTS: Exposure of the eyes to 1,000 flashes at 0.1 m increased the fluorescein staining score significantly (P = 0.009, the Mann-Whitney test). Scanning electron microscopy (SEM) of the cornea showed a detachment of the epithelial cells from the surface after this exposure. The amplitude of the a-wave was decreased significantly by 23.0% (P = 0.026) of the amplitude before the exposure, and the b-wave by 19.7% (P = 0.0478) following 1,000 flashes at 0.1 m but not by the other exposures. TUNEL-positive cells were present in the outer nuclear layer only after the extreme exposure, but no significant decrease in retinal thickness was seen under any condition. The fluorescein staining score and ERGs recovered to control levels within 1 week. CONCLUSIONS: Light exposure to a photographic flash lamp does not induce damage to the cornea and retina except when they are exposed to 1,000 flashes at 0.1 m.
Animals↗
Microcirculation at optic disc rim is correlated with visual field defects in cases of anterior ischaemic optic neuropathy.
We report two cases of anterior ischaemic optic neuropathy in whom tissue blood flow at the disc rim was correlated with the visual field defect. Tissue blood flow of each eye was evaluated with Heidelberg retina flowmeter. Both cases experienced acute visual loss and an altitudinal hemianopsia associated with optic disc oedema in the affected eye. In each case, the tissue blood flow at the affected (upper or lower half) disc rim corresponding to visual field deficit was reduced compared with that at the opposite-sided half disc rim in the affected eye and with the corresponding area in the fellow eye. The reduction of blood flow in the affected half disc rim associated with the visual field defect demonstrated that retina flowmetry can detect differences in tissue blood flow between superior and inferior sectional disc rim areas as well as between eyes non-invasively.
Blood Flow Velocity↗
Novel 473-bp deletion in XLRS1 gene in a Japanese family with X-linked juvenile retinoschisis.
PURPOSE: To present the clinical features of two brothers with molecularly confirmed X-linked juvenile retinoschisis (xlRS) but with non-characteristic electrophysiological findings. METHODS: Comprehensive ophthalmological examinations were performed. The electroretinograms (ERGs) were recorded under ISCEV standards, and ERGs elicited by long-duration stimuli were also evaluated. Standard genetic analysis of peripheral blood leukocytes was performed. RESULTS: Molecular testing revealed a novel 473-bp deletion including exon 4 in the XLRS1 gene in both siblings. This resulted in a frameshift mutation and a premature termination at codon 78. The scotopic and photopic ERGs were reduced, but the "negative-type" ERG, characteristic of xlRS, was not observed. Flicker ERGs were also highly reduced. Long-duration stimuli elicited ERGs with a complete loss of the b-wave and a preservation of the off-response, i.e., negative-type ERG. The phenotype/genotype relationship was not determined. CONCLUSION: The consistency of the ERGs elicited by long-duration stimuli in xlRS patients suggests that this type of stimuli provides responses that are a better indicator for the progression or stage of the disease.
Adult↗
New method for detecting misrouted retinofugal fibers in humans with albinism by magnetoencephalography.
In humans with albinism, a large percentage of the ganglion cell axons from the temporal retina decussate abnormally in the chiasm and synapse in the contralateral LGN. The aim of this study was to determine whether the misrouting of the optic fibers can be detected by magnetoencephalography (MEG). Visually evoked magnetic fields (VEFs) were recorded from three patients with albinism. After monocular stimulation, the isofield contour maps of the VEFs showed a single current dipole pattern over the contralateral hemisphere in patients with albinism. These results clearly illustrated the reduced uncrossed retinofugal pathway of patients with albinism.
Adolescent↗
Optic disc excavation in the atrophic stage of Leber's hereditary optic neuropathy: comparison with normal tension glaucoma.
BACKGROUND: Abnormal optic disc excavations are reportedly seen in patients with Leber's hereditary optic neuropathy (LHON), a mitochondrial dysfunction disease. We examined the disc morphology in the eyes of patients with LHON at the atrophic stage and compared it to that in eyes with normal-tension glaucoma (NTG). METHODS: We studied 15 LHON patients with the 11778 mutation, 15 patients with NTG, and 25 normal subjects. The optic disc morphology was analyzed by Heidelberg retinal tomography (HRT). Ten parameters of the optic disc obtained by HRT were evaluated, including the diagnostic classification of glaucoma. RESULTS: Six of the nine morphological HRT parameters of the LHON patients, the exceptions being disc area, mean cup depth, and maximum cup depth, differed significantly from those of the normals. NTG patients had a significantly greater mean and maximum cup depth than LHON patients. The HRT glaucoma diagnostic software classified 22 (73%) of the 30 optic discs in LHON patients as glaucomatous. CONCLUSION: The optic discs at the atrophic stage of LHON eyes have glaucoma-like morphological changes. However, the cups were significantly deeper in NTG than LHON. The similarity in the optic disc findings in LHON and NTG suggests that alterations in mitochondrial function may be related to optic disc excavations.
Adolescent↗
ON-pathway disturbance in two siblings.
PURPOSE: To present two clinical cases diagnosed with predominant cone dystrophy and demonstrating early disturbance in the on-centre bipolar cells (ON-pathway). METHODS: Electrophysiological findings are presented in two siblings with predominant cone dystrophy. The subjects showed no remarkable ophthalmoscopic or fluorescein angiographic retinal changes, but demonstrated progressive visual disturbance during their 20s. RESULTS: The electroretinograms (ERGs) showed reduced dark-adapted responses but the positive component of the photopic ERG was absent. Response to 30 Hz flicker was severely reduced. Electroretinograms elicited by long-duration stimuli showed a loss of the b-wave, and the off-response was slightly reduced. In both patients, multifocal ERGs (m-ERGs) were more reduced within the central 10 degrees, where the ON-pathway is normally a major contributor. CONCLUSION: We conclude that these patients may be affected by an abnormality of the synapses of the cone receptors and that their decrease in vision might, at least initially, be due to selective ON-pathway dysfunction.
Adult↗
[The correlation between retinal circulation and function in branch retinal artery occlusion].
PURPOSE: To investigate retinal circulation and function in eyes with branch retinal artery occlusion(BRAO) using a scanning laser Doppler flow-meter (SLDF) and multifocal electroretinogram (mERG). METHODS: In juxtapapillary and paramacular areas close to the occluded artery of the affected eye and the corresponding area of the fellow eye, the mean flow measured by SLDF, indicating microcirculation, and the p-wave amplitude in the response of mERG, indicating retinal function, were determined in three patients with BRAO at the period of reperfusion. The ratios of the affected eye to fellow eye(a/f ratio) were calculated, and the ratios of the mean flow (Fa/f) were compared with those of the p-wave amplitude(Pa/f). RESULTS: In the juxtapapillary area, both Fa/f and Pa/f decreased consistently, but in the paramacular area, Pa/f were lower than Fa/f in all cases. CONCLUSIONS: Functional recovery is likely to be later in the paramacular area than in the juxtapapillary area in the course of recovery of retinal circulation.
Adult↗
Multifocal magnetoencephalogram applied to objective visual field analysis.
PURPOSE: To establish an objective visual field analysis by visual evoked magnetic fields. METHODS: Forty-eight focal areas of the visual field were stimulated by the visual evoked response imaging system (VERIS). The multifocal visual evoked magnetic fields (mfVEFs) of 11 healthy subjects were recorded. The output signals were recorded with VERIS, and the second-order kernel was calculated. The equivalent current dipoles (ECDs) were estimated, and the relative positioning of ECDs was determined by a magnetoencephalography (MEG) system. RESULTS: The mfVEFs consisted of either two- or three-peak waves. Large amplitude mfVEFs were elicited when the stimulus was confined to 6 degrees of the central visual field, but a strong response could not always be obtained between 6 degrees and 12 degrees. All ECDs were estimated to originate in the occipital striate cortex. The ECDs for the upper (lower) field stimulations were estimated to be on the lower (upper) cortex, while those for right (left) field stimulations were on the left (right) cortex. CONCLUSIONS: The locations of mfVEF peak ECDs were correlated with the stimulated visual field and generally matched the cruciform model. In combination with the multifocal technique, MEG can be used for objective visual field analysis.
Adult↗
Genetic variants of TP53 and EPHX1 in Leber's hereditary optic neuropathy and their relationship to age at onset.
PURPOSE: To determine whether genetic polymorphisms of the genes for oxidative stress and apoptosis cause the clinical variability in patients with Leber's hereditary optic neuropathy (LHON). METHODS: Eighty-seven unrelated Japanese LHON patients carrying the 11778 mitochondrial mutation were studied at the Keio University Hospital. Their mean age (+/-SD) was 25.0 +/- 13.0 years with a range 3 to 65 years. Eleven polymorphisms in nine genes were studied: seven genes related to oxidative stress (SOD2, GSTT1, GSTM1, EPHX1, NQO1, p22 PHOX, and NOS3), and two genes related to apoptosis (TP53 and CD95). Each genetic polymorphism was analyzed in relation to the age at onset and the final visual acuity. RESULTS: Among the oxidative stress-related polymorphisms, a significant association between Tyr113His in the EPHX1 gene and the age at onset of the disease was identified (P = 0.026). LHON patients who were homozygous for His113 developed the disease earlier than those without this genotype (21.9 vs. 27.9 years). Among the apoptosis-related polymorphisms, a significant association between Arg72Pro in the TP53 gene and the age at onset was identified (P = 0.007). LHON patients who were homozygous for Arg72 developed the disease earlier than those without this genotype (20.5 vs. 28.1 years). In addition, LHON patients with both genotypes developed the disease significantly earlier (17.5 years, P = 0.011). No associations were found between the final visual acuity and the genetic polymorphisms examined. CONCLUSION: Nuclear genetic polymorphisms related to oxidative stress or apoptosis may modify the age at onset of LHON.
Adolescent↗
Macular nerve fibers temporal to fovea may have a greater potential to recover function in patients with Leber's hereditary optic neuropathy.
PURPOSE: It is known that even after visual loss, younger patients with Leber's hereditary optic neuropathy (LHON) can recover vision. The purpose of this study was to determine the mean age at onset for LHON patients with and without visual recovery who carried the 11778 mutation, and to determine the pattern of central vision recovery. METHODS: Thirty-five LHON patients with the 11778 mutation of mitochondrial DNA who had visited the Keio University Hospital between 1980 and 1999 and were followed for 2 to 20 years, were the subjects of this retrospective study. The patients who had recovered vision were tested by Goldmann perimetry, Humphrey perimetry, and landmark-driven fundus microperimetry with a scanning laser ophthalmoscope (SLO). The fixation status was assessed by SLO microperimetry. RESULTS: Nine of the 35 patients (14 of 70 eyes) demonstrated a recovery of visual acuity to better than 0.3 in at least one eye. The mean age of disease onset was 15.9 +/- 4.6 years in patients with visual recovery and 25.5 +/- 8.9 years in patients without visual recovery. This difference in the mean age at onset was significant (P =.0001; Welch t-test). These 9 patients (14 eyes) showed fenestrated central scotomas in testing by Humphrey 10-2 threshold and SLO microperimetry. The nasal side of the central visual fields had a higher sensitivity than the temporal side in 7 of the 9 patients in Humphrey 10-2 threshold testing. Areas insensitive to 0 dB were detected on the nasal side of the central retina in these patients by SLO microperimetry, and fixation stability was related to the degree of clinical visual acuity. CONCLUSION: The LHON patients with the 11778 mutation and a younger age of onset were more likely to show visual recovery. The findings made by perimetry suggest that the nerve fiber bundles in the nasal field (retina temporal to the fovea) may have a greater potential to recover function in LHON patients.
Adolescent↗