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Yozo Miyake

Publications and source records attributed to Yozo Miyake.

At least 19 recordsLinked to original sources
PubMed2003

Retinal and optic disc atrophy associated with a CACNA1F mutation in a Japanese family.

OBJECTIVE: To describe retinal and optic disc atrophy and a progressive decrease of visual function in 2 Japanese brothers. Both had a mutation in the CACNA1F gene, the causative gene of incomplete congenital stationary night blindness (CSNB). METHODS: We studied observational case reports and performed comprehensive ophthalmologic examinations including best-corrected visual acuity, biomicroscopy, ophthalmoscopy, fundus photography, and electroretinography. Genomic DNA was extracted from the peripheral blood, and all 48 exons of the CACNA1F gene were directly sequenced. RESULTS: The 2 brothers had retinal and optic disc atrophy and a progressive reduction of visual acuity with increasing age. Although these clinical features are not typical of previous patients with incomplete CSNB, both patients had an in-frame mutation with deletion and insertion in exon 4 of the CACNA1F gene. In both patients, the bright-flash, mixed rod-cone electroretinogram had a negative configuration, a characteristic of incomplete CSNB. However, the full-field scotopic and photopic electroretinograms were nonrecordable, indicating severe, diffuse retinal malfunction, which is not typical in incomplete CSNB. CONCLUSION: These findings indicate that a mutation of the CACNA1F gene may be associated with retinal and optic disc atrophy with a progressive decline of visual function. Clinical Relevance In patients with retinal and optic disc atrophy associated with negative-type electroretinograms, a CACNA1F gene mutation should be considered.

Amino Acid Sequence↗
PubMed2003

Mapping posterior vitreous detachment by optical coherence tomography in eyes with idiopathic macular hole.

PURPOSE: To determine the relationship between posterior vitreous detachment and idiopathic macular hole. DESIGN: Observational case series. METHODS: In a prospective study, the posterior hyaloid face was scanned from the posterior pole to the far periphery by optical coherence tomography in 25 eyes (22 patients) with an idiopathic macular hole (stage 1 = 1, stage 2 = 7, stage 3 = 10, and stage 4 = 7), and a map of the posterior vitreous detachment was constructed. RESULTS: One eye with a stage 1 macular hole had a posterior vitreous detachment confined to the vascular arcade, but attached to the fovea. In all seven eyes at stage 2, the detached posterior hyaloid enlarged upward beyond the superior vascular arcade, but stopped at the margin of inferior vascular arcade. In two cases, the posterior vitreous detachment also extended temporally and superonasally. In all cases, the vitreous face remained attached to the fovea. Six of the 10 eyes at stage 3 had larger partial posterior vitreous detachment that extended not only upward, but also beyond the inferior vascular arcade, while in the other four eyes, the size and position of the posterior vitreous detachment was similar to stage 2 macular holes. However, unlike stage 2, the posterior vitreous detachment included the fovea in all eyes. All seven eyes with a stage 4 macular hole had complete posterior vitreous detachment that extended to the far periphery in all directions. CONCLUSION: There is a close correlation between the stage of the macular hole and the degree of posterior vitreous detachment. This close correlation suggests that progression of idiopathic macular hole is related to enlargement of the posterior vitreous detachment.

Aged↗
PubMed2003

Reduced oscillatory potentials of the full-field electroretinogram of eyes with aphakic or pseudophakic cystoid macular edema.

PURPOSE: To report reduced oscillatory potentials (OPs) in the full-field electroretinogram (ERG) of eyes with aphakic or pseudophakic cystoid macular edema (CME). DESIGN: Observational case series. METHODS: Bright white flash full-field ERGs were recorded from 19 eyes of 19 patients (ages, 53-84 years) with aphakic or pseudophakic CME. Seven of the cases had uncomplicated phacoemulsification (PE) with implantation of a posterior chamber intraocular lens (PC-IOL) and 6 had posterior capsular rupture during phacoemulsification and aspiration with implantation of a PC-IOL. Four additional patients had uncomplicated intracapsular cataract extraction (ICCE), and 2 had secondary anterior chamber intraocular lens after ICCE. Their fellow eyes without CME served as controls. Cystoid macular edema was diagnosed as clinically significant by slit-lamp examination and by fluorescein angiography. The grading for severity of CME was based on the fluorescein angiography. The visual acuity ranged from 20/200 to 20/16. RESULTS: There were no significant differences in the mean amplitudes and implicit times of the a-waves and b-waves between the affected eyes and the fellow eyes. The mean summed amplitude of the OPs was significantly reduced in the affected eyes (P =.0003, Wilcoxon signed rank test). This decrease was strongly correlated with visual acuity (r =.779, P <.0001). The mean implicit time of the first OP was significantly delayed in the affected eyes (P =.0089, Wilcoxon signed rank test). CONCLUSIONS: Because the peripheral retina contributes more significantly to full-field ERGs than the macula, the reduced OP amplitudes of the full-field ERGs in eyes with aphakic or pseudophakic CME suggest a functional impairment not only in the macula but also throughout the retina.

Aged↗
PubMed2003

Foveal thickness in occult macular dystrophy.

PURPOSE: Occult macular dystrophy (OMD) is an inherited macular dystrophy characterized by a progressive macular dysfunction without any visible fundus abnormality. We studied the foveal thickness in patients with OMD using optical coherence tomography (OCT). DESIGN: Observational case series. Foveal thickness by OCT images. METHODS: Foveal thickness obtained from 22 eyes of 11 patients with OMD was compared with that from 27 eyes of 20 age-matched normal controls. RESULTS: Mean foveal thickness in the patients group (96.5 +/- 19.5 microm) was significantly thinner than that in the normal controls (133.3 +/- 9.0 microm, P <.0001, Mann-Whitney U test). Eighteen of 22 eyes with OMD had foveal thickness that were thinner than the lower limit of the normal range. There was no statistically significant correlation between the foveal thickness and visual acuity, age, or duration from onset. CONCLUSION: These results demonstrated that there are significant anatomic changes in the macula of patients with OMD.

Adolescent↗
PubMed2003

Macular dystrophy in a Japanese family with fundus albipunctatus.

PURPOSE: To report a Japanese family with fundus albipunctatus and macular dystrophy associated with a mutation in the 11-cis retinol dehydrogenase (RDH5) gene. DESIGN: Observational case report. METHOD: Ophthalmic examinations and DNA analysis were performed. RESULTS: The fundi of a 56-year-old man and his 51-year-old sister showed numerous yellow-white punctata. He also had bull's-eye maculopathy and prepappillary arterial loops, whereas she did not, and his best-corrected visual acuity was impaired, whereas hers was normal. Their kinetic visual fields did, however, show central or paracentral scotoma, and both had tritanomalous color vision. Their scotopic electroretinograms were typical of fundus albipunctatus, and photopic electroretinograms were significantly reduced. A homozygous Gly107Arg mutation in the RDH5 gene was detected in both siblings. CONCLUSIONS: We suggest that the macular dystrophy is caused by the RDH5 gene mutation as a phenotype variation in fundus albipunctatus.

Alcohol Oxidoreductases↗
PubMed2003

Optical coherence tomography and focal macular electroretinogram in eyes with epiretinal membrane and macular pseudohole.

PURPOSE: To determine the morphology of macular pseudoholes (MPHs) and the relationship of morphology to macular function. DESIGN: Observational case series. METHODS: Optical coherence tomography (OCT) was performed on 42 eyes of 42 consecutive patients with an epiretinal membrane (ERM) and an MPH. The diameters of the MPH, and the thickness of the foveal and parafoveal retina were measured. Of these 42 eyes, focal macular electroretinograms (FMERGs) were recorded from 22 eyes of 22 patients with a 15 degree stimulus; FMERGs were also recorded with a 5 degree stimulus from 9 eyes of these 22 eyes. RESULTS: In 42 eyes, the mean +/- Standard deviation (SD) diameter (437.7 +/- 172.8 microm) and geometrical shape of the MPHs were not significantly correlated with the visual acuity. The MPHs were divided into 2 types from the OCT images at the base of MPHs; group A had normal thickness (100-199 microm; n = 29), and group B (n = 13) had thicknesses of >or= 200 microm, or thickness < 100 microm, or irregular base. The visual acuity in group A (logarithm of the minimum angle of resolution [log MAR] mean +/- SD:.083 +/-.144) was significantly better than group B (log MAR,.407 +/-.212, P <.0001). There was a significant reduction in the amplitude of all components of FMERGs elicited by the 15 degree stimulus in the affected eyes (mean +/- SE, A-wave: 1.26 +/-.12 microv, B-wave: 3.07 +/-.27 microv, oscillatory potentials: 1.23 +/-.25 microv) compared with the normal fellow eyes (A-wave: 1.58 +/-.13 microv, B-wave: 4.14 +/-.27 microv, oscillatory potentials: 2.35 +/-.29 microv). A significant correlation was found between the relative amplitudes of the B-wave elicited by the 5 degree stimulus and the visual acuity (r =.918, P =.0005). CONCLUSIONS: In eyes with an ERM and an MPH, the visual acuity is generally correlated with the OCT images. Macular function of eyes with an MPH resembles eyes with an ERM without an MPH. The effect of the ERM appears to be different on the base and parafovea of the MPHs.

Adult↗
PubMed2003

RDH5 gene mutations and electroretinogram in fundus albipunctatus with or without macular dystrophy: RDH5 mutations and ERG in fundus albipunctatus.

The aim of this study was to analyze the RDH5 gene in patients with fundus albipunctatus with and without macular dystrophy, and correlate the identified mutations with the electrophysiological results. Twenty-one patients from 19 unrelated Japanese families with fundus albipunctatus were examined. Ten unrelated patients had macular dystrophy. In 18 patients, either a homozygous or a compound heterozygous mutation in the RDH5 gene was identified. The bright-flash, mixed rod-cone ERG had a negative configuration with reduced a-wave amplitudes after a short period of dark-adaptation (20 or 30 min). After a prolonged dark-adaptation period (2 or 3 h), the waveform attained normal amplitudes in patients without macular dystrophy but the a-waves were still subnormal in patients with macular dystrophy. The photopic ERG responses were significantly reduced in patients with macular dystrophy, indicating that they also had cone dystrophy. The photopic ERGs were reduced in only some of the patients without macular dystrophy. In patients without macular dystrophy, the scotopic b-wave amplitudes were nonrecordable or significantly reduced after a short dark-adaptation period but then improved to normal levels. However, they did not fully recover in some patients with macular dystrophy. Three patients with macular dystrophy in whom a RDH5 gene mutation could not be detected by our routine method had atypical ERG responses. We conclude that RDH5 gene mutations cause a progressive cone dystrophy or macular dystrophy as well as night blindness. The clinical phenotype including electrophysiological responses varied among patients with the RDH5 gene mutations.

Adolescent↗
PubMed2003

Functional rescue of N-methyl-N-nitrosourea-induced retinopathy by nicotinamide in Sprague-Dawley rats.

PURPOSE: A single intraperitoneal injection of 60 mg/kg body weight of N-methyl-N-nitrosourea (MNU) into rats results in retinal degeneration over a 7-day period in all treated animals. The purpose of this study was to determine whether nicotinamide (NAM) can lead to a functional rescue of the MNU-induced retinopathy. METHODS: NAM, a water-soluble B-group vitamin (vitamin B( 3)), was administered immediately after MNU injection, and retinas were examined morphologically and functionally. RESULTS: Morphologically, 1000 mg/kg NAM completely suppressed and 50 mg/kg NAM partially suppressed the photoreceptor cell loss. Functionally, scotopic and photopic electroretinographic (ERG) recordings showed that both rod and cone photoreceptor cells were well protected from MNU damage by 1000 mg/kg NAM and partially protected by 50 mg/kg NAM. CONCLUSIONS: NAM can protect photoreceptor cells from MNU-induced retinopathy both structurally and functionally.

Alkylating Agents↗
PubMed2003

Function and morphology of macula before and after removal of idiopathic epiretinal membrane.

PURPOSE: To study the function and morphology of the macula of the eye before and after the removal of unilateral idiopathic epiretinal membrane (ERM). METHODS: Focal macular electroretinograms (fmERGs) elicited by a 15 degrees stimulus were recorded in 37 eyes of 37 patients with a unilateral ERM. The amplitudes of the a- and b-waves and the oscillatory potentials (OPs) were compared with the corresponding waves in the normal fellow eyes before and after removal of the ERM. In 29 eyes followed up for more than 6 months after surgery, the fmERGs and foveal and parafoveal thicknesses, measured by optical coherence tomography (OCT), were evaluated. RESULTS: Before surgery, the mean amplitudes of all components of the fmERGs were significantly smaller than in the fellow eyes, with the decrease largest for the OPs, followed by the b-waves and then the a-waves. The eyes with less severely reduced a-wave amplitude (>70% of the fellow eyes) had significantly lower b-wave to a-wave (b/a) ratios. After surgery, the amplitudes of the b-wave and OPs were still significantly smaller in the affected eyes. The mean foveal and parafoveal thicknesses were significantly less after surgery; however, the thickness was still more in the affected eyes. The decrease of the OPs remained after surgery and correlated with increased parafoveal thickness (r = -0.460, P = 0.011). CONCLUSIONS: The decreased fmERGs indicate that macular function is impaired in eyes with ERM. The decrease of the b-wave and OPs in the 29 eyes examined after vitrectomy may be due to the still thickened macular retina.

Aged↗
PubMed2002

Macular dystrophy in a 9-year-old boy with fundus albipunctatus.

PURPOSE: To report a 9-year-old boy with fundus albipunctatus and macular dystrophy. DESIGN: Observational case report. METHODS: A complete ophthalmic examination was performed. The 11-cis retinol dehydrogenase gene (RDH5) was examined by direct genomic sequencing. RESULTS: The fundi of the 9-year-old boy showed numerous yellow-white punctata as well as foveal atrophic lesions in both eyes. His corrected visual acuity was RE: 0.5 and LE: 0.3. Scotopic full-field electroretinograms were not present after 20 minutes of dark-adaptation but were normal after 3 hours of dark-adaptation. Full-field cone and 30-Hz flicker electroretinograms were normal; however, focal macular cone electroretinograms were significantly reduced. A compound heterozygous mutation of Tyr281His and Leu310GluVal in RDH5 was detected. CONCLUSION: We suggest that the macular dystrophy is caused by the RDH5 mutation as a phenotype variation in fundus albipunctatus.

Alcohol Oxidoreductases↗
PubMed2002

Enhanced S-cone syndrome with subfoveal neovascularization.

PURPOSE: To report a case of enhanced S-cone syndrome associated with subfoveal neovascularization. DESIGN: Observational case report. METHODS: A 23-year-old man, who was first examined at age 9 years, was found to have enhanced S-cone syndrome by clinical, electrophysiological, and molecular genetic examinations. RESULTS: At 9 years of age, a subfoveal neovascularization was present in his right eye and corrected visual acuity was RE: 0.15 and LE: 1.0. After he was 20 years old, cystoid changes in the macula of the left eye appeared and visual acuity, in the left eye, decreased from 1.0 to 0.02. CONCLUSION: The clinical course of enhanced S-cone syndrome is progressive, and we suggest that the subretinal neovascularization is a phenotypic variation of enhanced S-cone syndrome.

Adult↗
PubMed2002

Incomplete congenital stationary night blindness associated with symmetrical retinal atrophy.

PURPOSE: To describe a Japanese patient with incomplete congenital stationary night blindness (iCSNB) with atypical retinal atrophy and kinetic visual field defects. METHODS: An ophthalmologic examination was performed, and the CACNA1F gene was analyzed by direct genomic sequencing. RESULTS: The patient had a hemizygous Arg913stop mutation in CACNA1F and had electroretinographic changes that were typical of iCSNB. The fundus had atrophic retinal lesions around the inferior vascular arcades OU, and Goldmann kinetic perimetry showed relative scotomas in the corresponding areas. CONCLUSIONS: Although most patients with iCSNB show essentially normal fundi without visual field defects, this case demonstrated retinal atrophy associated with visual field defects indicating a phenotypic heterogeneity induced by the CACNA1F mutation.

Adult↗
PubMed2002

Novel de novo mutation in CRX gene in a Japanese patient with leber congenital amaurosis.

PURPOSE: To report a novel de novo mutation in the cone-rod homeobox (CRX) gene in a Japanese patient with Leber congenital amaurosis (LCA). METHODS: The CRX gene was analyzed by direct genomic sequencing in a patient with LCA and in his healthy parents. A complete ophthalmologic examination was performed on the family. RESULTS: A heterozygotic deletion of G at nucleotid 520 in CRX, predicting a frameshift in codon 174 and a premature termination of translation [Ala174(1-bp del)], was identified in the proband. The mutation was not present in his unaffected parents. CONCLUSION: A novel de novo mutation in CRX was found in a Japanese patient with LCA.

Adolescent↗
PubMed2002

Loss of stereopsis with optic chiasmal lesions and stereoscopic tests as a differential test.

OBJECTIVE: To identify and characterize the loss of stereopsis observed in patients with lesions of the optic chiasm. STUDY DESIGN: Cross-sectional study. PARTICIPANTS: Forty-three patients who had good visual acuity with orthophoria and without strabismologic histories were divided into two groups. Group 1 consisted of 13 patients with lesions involving the optic chiasm (regardless of their visual field loss) diagnosed by magnetic resonance imaging findings. Group 2 (control group) consisted of 30 patients who had large absolute visual field defects as a result of other causes, including 11 intracranial disorders other than optic chiasmal lesions, 11 cases of open-angle glaucoma, and 8 patients with lesions of the retina. METHODS: The stereoacuity and visual field in each case in group 1 (before and after surgery) and group 2 were assessed, and the results were compared. MAIN OUTCOME MEASURES: Stereoacuity was assessed by the Titmus stereo test (normal value for circle, 6/9; 80 seconds of arc) and by Lang-stereotest (normal value for circle, 3/3; 350 seconds of arc). Visual field was evaluated by Goldmann and Humphrey perimetry (conventional perimetry), the starlight test (binocular visual field test), and scanning laser ophthalmoscopic microperimetry (microperimetry). RESULTS: Before surgery, 11 of 13 cases (85%) in group 1 failed stereo tests, and after surgery, 5 of 13 cases (38%) in group 1 failed stereo tests. Before surgery, four patients who failed stereo tests showed no absolute scotoma by Humphrey or Goldmann analysis; after surgery, one patient who failed stereo tests showed no absolute scotoma by Humphrey or Goldmann analysis. However, starlight testing showed complete bitemporal hemianopsia only under binocular conditions, and microperimetry demonstrated a relative bitemporal hemianopsia at the fixating point. No patient failed in the Titmus circle test, but one patient in group 2 failed the Lang test (3%). The patients with chiasmal lesions significantly lost the ability of stereopsis compared with other diseases (group 1 [before or after surgery] vs. group 2, P < 0.001, Fisher's exact test). Conventional perimetry was unable to measure scotomas within 3 degrees of the fixation point, which is the key area for acute foveal stereopsis, because of an attached observational mirror. CONCLUSIONS: The difficulty with stereopsis in patients with lesions of the optic chiasm is most likely caused by the compression of the decussating optic nerve fibers resulting in the loss of an overlapping visual field at the fixation point. Stereo tests were demonstrated to be simple and effective adjunctive tests for suspected chiasmal compression.

Adolescent↗
PubMed2002

The relationship between age and intraocular pressure in a Japanese population: the influence of central corneal thickness.

PURPOSE: Previous cross-sectional Japanese studies have shown that intraocular pressure (IOP) decreases with age. However, central corneal thickness (CCT) variation should also be considered when examining the relationship between age and IOP, since tonometry has an inherent measurement error due to CCT variations. This study investigates the influence of CCT variation on the age-IOP relationship in a Japanese population. METHODS: The right eyes of 1317 subjects from 40 to 80 years old selected from a general population using a random sampling method were assessed in cross-section. The IOP was measured with a non-contact tonometer, and CCT was measured with a specular microscope. The relationships between age, IOP, and CCT were assessed using correlation analyses, while the relationship between age and IOP controlled for CCT, blood pressure, and body mass index was investigated using multivariate regression analyses. RESULTS: The mean (+/- SD) IOP value was 13.6 (+/- 2.6) mmHg in men and 13.3 (+/- 2.6) mmHg in women. The IOP correlated inversely with age in men (r = -0.14, p < 0.001), but showed only a marginal inverse correlation in women (r = -0.07, p = 0.066). The mean (+/- SD) CCT value was 518.3 (+/- 33.2) microm in men and 511.1 (+/- 33.0) microm in women. Only in men was an inverse correlation seen between CCT and age (r = -0.10, p = 0.009), but both genders had positive correlations between CCT and IOP (man: r = 0.44, p < 0.001; woman: r = 0.48, p < 0.001). In multivariate analyses, CCT was shown to have an effect on IOP measurement, however, it was shown that IOP still decreases with age in both sexes even when adjusted for CCT (p = 0.001). CONCLUSIONS: The IOP decreases with age in the Japanese, and CCT variation has practically no effect on the unique age-IOP relationship.

Adult↗
PubMed2002

Change in full-field ERGs after macular translocation surgery with 360 degrees retinotomy.

PURPOSE: One of the methods used in macular translocation (MT) surgery for subfoveal neovascularization is to create a temporary total retinal detachment followed by a 360 degrees retinotomy. The whole retina is then shifted from the original surface of the retinal pigment epithelium (RPE), resulting in an unusual retina and RPE complex. The purpose of this study was to assess retinal function after MT surgery. METHODS: Full-field electroretinograms (ERGs) were recorded before and 4 to 8 months (mean, 5.4 months) after MT surgery with a 360 degrees retinotomy in 15 consecutive patients with age-related macular degeneration (10 eyes), high myopia (4 eyes), and polypoidal choroidal vasculopathy (1 eye). Their ages ranged from 57 to 74 years. The angle of rotation of the retina ranged from 18 degrees to 45 degrees (mean +/- SE, 30 +/- 2 degrees). In addition to the recording of the standard rod and mixed rod-cone ERGs after 30 minutes of dark adaptation, the cone single flash and 30-Hz flicker ERGs were recorded immediately after a light-adapting background was turned on (LA(0)) and also after 10 minutes of light adaptation (LA(10)). RESULTS: The mean amplitude of the full-field ERGs was reduced after surgery by 44% for the rod response, by 24% for the mixed rod-cone b-wave, by 12% and 35% for the cone single-flash b-wave at LA(0) and 30-Hz flicker ERGs at LA(0), respectively. The mean implicit times were delayed by 8 msec for the rod response, by 2 msec for the mixed rod-cone oscillatory potential (OP1), by 4 msec for the cone single-flash b-wave at LA(0), and by 6 msec for the 30-Hz flicker at LA(0). CONCLUSIONS: These results demonstrated a functional alteration in both the rod and cone components of the ERGs for the entire retina after MT surgery.

Aged↗
PubMed2002

Focal macular electroretinograms before and after removal of choroidal neovascular lesions.

PURPOSE: To evaluate the changes in focal macular electroretinograms (fmERGs) after surgical removal of choroidal neovascular (CNV) lesions. METHODS: Fourteen patients (14 eyes) with subfoveal or juxtafoveal CNV associated with age-related macular degeneration and 1 patient with idiopathic CNV underwent vitrectomy and removal of the lesions. fmERGs elicited by a 15 degree stimulus were recorded before and 3 months after surgery. Optical coherence tomography (OCT) was performed to measure the foveal and parafoveal thickness before and 3 months after surgery. RESULTS: Preoperative fmERGs were markedly reduced in all eyes. The mean amplitude of the b-wave in 15 eyes recorded 3 months after surgery increased significantly (P = 0.0022, Wilcoxon signed rank test). In all eyes except two with nearly nonrecordable a- and b- waves, the mean b-wave-to-a-wave ratio after surgery increased significantly in all eyes (P = 0.0330, Wilcoxon signed rank test). The percentage increase in the b-wave amplitude correlated significantly with the percentage decrease in the mean parafoveal retinal thickness (r = 0.688, P = 0.0076). CONCLUSIONS: The decreased macular ERGs were partially recoverable in the early postoperative period. The decreased retinal edema after surgery may have contributed to this recovery.

Adult↗