Biomedical subjects

Yozo Miyake

Publications and source records attributed to Yozo Miyake.

At least 73 records · Page 4Linked to original sources

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↗

PubMed2002

ABCA4 gene mutations in Japanese patients with Stargardt disease and retinitis pigmentosa.

PURPOSE: To evaluate photoreceptor cell-specific adenosine triphosphate (ATP)-binding cassette transporter (ABCA4) gene mutations in Japanese patients with Stargardt disease (STGD) and the correlation of these mutations to clinical phenotypes. METHODS: Serum was obtained from 10 unrelated Japanese patients with STGD and 96 unrelated Japanese patients with autosomal recessive retinitis pigmentosa (arRP). All 50 ABCA4 gene exons of the patients with STGD were screened for mutations by a combination of single-strand conformation polymorphism analysis and polymerase chain reaction (PCR) direct-sequencing techniques. By restriction enzyme digestion, primer extension analysis, and PCR direct sequencing techniques, the patients with arRP were screened for three segregated, presumably null ABCA4 gene mutations observed in Japanese patients with STGD. RESULTS: Three novel, presumably null mutations of the ABCA4 gene, IVS7-45_952delinsTCTGACC, IVS12+2T-->G, and 1894delA, were identified. The Arg2149stop mutation that had been found in a white patient with STGD in a prior study was also found in a Japanese patient. Two arRP-affected siblings and two unrelated patients with STGD were found to be homozygous for the same IVS12+2T-->G mutation, and three other arRP-affected siblings were carriers of the IVS12+2T-->G mutation and/or the IVS7-45_952delinsTCTGACC mutation. These three siblings with arRP showed only atrophic degeneration in the macula early after the onset of the disease, and STGD had been diagnosed. CONCLUSIONS: Three novel ABCA4 gene mutations were identified in Japanese patients with STGD and arRP. Mutations in the ABCA4 gene can cause panretinal degeneration that changes its clinical appearance from STGD to arRP over time.

ATP-Binding Cassette Transporters↗

PubMed2002

[Establishment of the concept of new clinical entities--complete and incomplete form of congenital stationary night blindness].

I summarized our long-term study to prove that the complete and incomplete types of congenital stationary night blindness (CSNB) are different clinical entities and that the latter is a newly identified disease which has never been reported in the past. CSNB with normal fundi and negative electroretinogram (ERG) showing selective reduction of the b-wave was previously known as the "Schubert-Bornschein type". For the sake of convenience, we classified the disease into two types according to the absence or the presence of rod function: complete CSNB and incomplete CSNB. The hereditary mode of the former is X-linked recessive and autosomal recessive, while that of the latter is X-linked recessive. They are never found together in a single family. We found several additional differences between the two types, including ERG oscillatory potentials, cone mediated ERG, and refractive errors, all leading us to hypothesize that the two types are not variants of a single disease but are the sum of two different clinical entities. Our hypothesis has recently been proven true by molecular genetical analysis. Namely, the mutated gene in X-linked recessive complete CSNB was found in the nyctalopin (NYX) gene, while that in incomplete CSNB was found in the calcium channel (CANCA1F) gene which encodes the retina-specific calcium channel alpha 1-subunit. These results proved that complete and incomplete CSNB are different clinical entities and that the latter is the first disease of the eye which discloses mutation of this region. We classified 90 patients to include 49 complete and 41 incomplete types. Fifteen incomplete CSNB patients underwent gene analysis and they all showed mutation of the CACNA1F gene. We also examined for gene mutation in several patients who had progressive retinal disease and negative ERG and found two siblings with CANA1F gene mutation. This finding indicates that the mutation of the CACNA1F gene can also cause progressive retinal disease in addition to incomplete CSNB. Gene analysis of 11 patients with complete CSNB was performed and 6 revealed mutation of the NYX gene. The remaining 5 patients showed neither NYX nor CACNA1F gene mutation, suggesting they are of autosomal recessive complete CSNB where gene mutation has not been identified. The comparison of our phenotype and genotype diagnosis indicated that a precise ERG analysis can provide correct differentiation between complete and incomplete types. Other clinical findings include moderately low visual acuity in both types, high or moderate myopia in complete CSNB, and wide distribution from myopia to hyperopia in incomplete CSNB. Pathophysiology studies using clinical patients and animal models suggested that complete CSNB has a complete defect of the ON-bipolar cells or their synapses in the rod and cone visual pathways, leaving the OFF pathway intact (OFF-retina). On the other hand, the incomplete CSNB has an incomplete defect of the ON and OFF bipolar cells or their synapses in the rod and cone visual pathways. The macular function is relatively well preserved in both types, which was shown by focal macular ERG. The incomplete CSNB patients seldom complain of night blindness, which causes us to overlook this disease because we then tend not to perform ERG testing. This disease is not so rare and clinicians should be more aware of its existence. The incomplete CSNB is a new hereditary retinal disease detected by Japanese investigators just like the Oguchi disease, and it has much unknown pathophysiology which needs to be identified in the future. Since the namings of complete and incomplete CSNB may be misunderstood as indicating functional classification of one disease, it has been proposed internationally to change the name "complete type" to CSNB1 and that of "incomplete type" to CSNB2.

Humans↗

PubMedDate not supplied

A case of sectorial benign flecked retina.

PURPOSE: A case of sectorial benign flecked retina not associated with an RDH5 gene mutation is reported. METHODS: A 51-year-old woman showed multiple yellow-white flecks in both eyes similar to those of benign flecked retina but in only the upper half of the retina. We carried out clinical, electrophysiological, and molecular genetic examinations of the patient. RESULTS: Visual acuity was 20/20 OD and 20/20 OS. Fluorescein angiography showed diffuse irregular hypofluorescence that did not correspond to the flecked lesions. A Goldmann-Weeker adaptometer test revealed that the visual threshold of the upper retina was approximately 0.6 to 0.8 log units higher than that of the lower retina. No mutations of the RDH5 gene were detected in exons 2-5 or in the flanking intron sequences. CONCLUSIONS: To our knowledge, this is the first report of sectorial benign flecked retina, and the flecks may not be caused by an RDH5 gene mutation.

Alcohol Oxidoreductases↗

PubMedDate not supplied

Visual acuity in a community-dwelling Japanese population and factors associated with visual impairment.

PURPOSE: The aim of this study was to describe the distribution of visual acuity and investigate the predictors of visual impairment in a Japanese population. METHODS: Best-corrected visual acuity was measured in 2263 subjects aged 40-79 years randomly selected from a local community. Relations between visual impairment and possible risk factors were investigated. RESULTS: Among these subjects, 41 individuals (1.8%) were identified as visually impaired (best-corrected visual acuity in the better eye <0.5). Both sexes in the older age groups had a higher frequency of visual impairment (Mantel-Haenszel chi-square test: P<0.001). A multiple logistic regression indicated that an increase in age of 10 years [odds ratio (OR) 3.9; 95% confidence interval (CI) 2.3-6.7] and myopia (OR 2.9; 95%CI 1.4-6.0) were independent risk factors for visual impairment. Individuals with the highest level of education (college or higher) had a lower risk of visual impairment (OR 0.1; 95%CI 0-0.7) compared to individuals with the lowest level of education. CONCLUSIONS: As expected, visual impairment increased with advancing age, although the prevalence of visual impairment in our population was lower than in other surveys. Racial and regional differences and differences in study design may be responsible for discrepancies between surveys. It is noteworthy that myopia was a significant risk factor for visual impairment, although the reasons for this association are uncertain and need further investigation.

Adult↗

PubMedDate not supplied

Autosomal dominant cone-rod dystrophy with R838H and R838C mutations in the GUCY2D gene in Japanese patients.

PURPOSE: To describe the clinical phenotypes of two Japanese families with autosomal dominant cone-rod dystrophy (CORD) caused by an R838H or R838C mutation. METHODS: Complete ophthalmological examinations were performed on three affected individuals from two Japanese families with autosomal dominant CORD. One family had an R838H mutation, and the other family had an R838C mutation in the GUCY2D gene. The tests included best-corrected visual acuity, slit-lamp and fundus examinations, fundus photography, electroretinography, Goldmann kinetic perimetry, and automated light- and dark-adapted static perimetry. RESULTS: The three patients showed essentially normal fundus or little pigmentary change in the maculae by indirect ophthalmoscopy, and only fluorescein angiography revealed clear atrophy of the retinal pigmented epithelium around the fovea. Central or paracentral scotoma was detected by the Goldmann kinetic visual field test. Electroretinography as well as light-adapted and dark-adapted two-color perimetry showed more severe impairment of cone than of rod function. The clinical features in our patients resembled those in Caucasian families with R838H or R838C mutations. CONCLUSIONS: The R838H and R838C mutations in GUCY2D cause CORD in the Japanese population. These mutations can cause a similar clinical phenotype in other races.

Adult↗

PubMedDate not supplied

High prevalence of myopia in Japanese patients with multiple evanescent white dot syndrome.

PURPOSE: To compare the incidence of refractive errors in Japanese patients with multiple evanescent white dot syndrome (MEWDS) with that in age- and sex-matched controls. METHODS: Fifty Japanese patients with MEWDS (11 males and 39 females; ages, 15-58; mean 29.9 years) were studied retrospectively. The refractive errors (spherical equivalent) in the patients were compared with those of 150 age- and sex-matched controls. RESULTS: The mean refractive error in the patient group was -5.30 +/- 4.58 diopters (D) which was significantly greater than that in the controls (-2.57 +/- 2.94 D, P = 0.0005). Twenty-two (44.0%) of the 50 MEWDS patients had refractive errors >-6.00 D; whereas 14 (9.3%) of 150 normal subjects had this degree of myopia. This difference was statistically significant ( P < 0.005). CONCLUSION: Japanese patients with MEWDS tend to be highly myopic.

Adolescent↗

PubMedDate not supplied

Relationship between astigmatism and aging in middle-aged and elderly Japanese.

PURPOSE: To study the effect of aging on astigmatism in adult Japanese. METHODS: Measurements of refractive errors and keratometry were performed on 2161 randomly selected subjects (aged 40-79 years). The relation between age and the net value in diopters (D) of astigmatism was evaluated with a trend test. The relation between age and the polar value was also examined by linear regression analysis. RESULTS: The mean (+/-SD) value of total and corneal astigmatism was -0.97 +/- 0.72 D and -0.86 +/- 0.63 D, respectively, and the net value of both increased with age (P trend < 0.001). The prevalence of either type of astigmatism also increased with age, according to the Cochran-Mantel-Haenzel test (P < 0.0001 for total and P < 0.01 for corneal astigmatism). The prevalence of against-the-rule astigmatism increased with age for either type of astigmatism (P < 0.0001 for total, P < 0.0001 for corneal). According to the analysis of polar values by age, the regression coefficient (+/-SE) for total and corneal astigmatism was -0.024 +/- 0.002 (P < 0.0001) and -0.028 +/- 0.002 (P < 0.0001), respectively. There was no statistical difference between these two regression coefficients. CONCLUSIONS: The prevalence of astigmatism increases and the axis turns to against-the-rule with age. The result of the linear regression analysis indicates that the age-related change in astigmatism is mainly associated with changes in the cornea.

Adult↗

PubMedDate not supplied

Unique characteristics of two types of retinitis pigmentosa patients with different rod sensitivities.

PURPOSE: To determine the psychophysical differences between two types of retinitis pigmentosa (RP) patients with different rod sensitivities. METHODS: Thirty-five RP patients with a visual acuity of > or =0.7 or better were classified by cone-rod perimetry into type 1, those with undetectable rod sensitivity, and type 2, those with measurable rod sensitivity. Their symptoms, age at onset of symptoms, cone and rod sensitivity, and full-field electroretinograms (ERGs) were compared. RESULTS: The age when the symptoms of night blindness were first noticed was 13.1 +/- 3.3 years (mean +/- SD) for type 1 and 34.5 +/- 14.4 years for type 2 patients (P = 0.0001). One of nine type 1 patients (11%) and 10 of 26 type 2 patients (38%) did not have any symptoms of night blindness. The average rod sensitivity within the central 10 degrees was 43.7 +/- 12.0 dB for type 2 patients with night blindness, and 54.8 +/- 6.4 dB for type 2 patients without night blindness (P = 0.014). One of nine (11%) type 1 patients and 9 of 23 (39%) type 2 patients had recordable ERGs (P = 0.13). CONCLUSIONS: These findings indicate that the two types of RP patients, distinguished by their rod sensitivity, have different psychophysical characteristics of the visual system. The course of the disease process and the long-term prognosis for these two types of patients are different.

Adolescent↗

PubMedDate not supplied

Optical coherence tomography before and after vitrectomy with internal limiting membrane removal in a child with optic disc pit maculopathy.

BACKGROUND: The pathogenesis of optic disc pit maculopathy is still unknown, although recent optical coherence tomographic (OCT) analyses have made a great contribution to clarifying its morphological appearance. The best treatment for this disease is also controversial. CASE: We report on a 7-year-old girl with optic disc pit maculopathy associated with a separation of the internal limiting membrane (ILM) near the optic disc. OBSERVATIONS: The OCT images before treatment showed a conduit from the perineural space to the schisislike separation of the sensory retina with a dome-shaped separation of the ILM. A serous detachment (SD) in the macula, centered on the fovea, was also present. In OCT images after laser photocoagulation, the conduit appeared to be closed, but the SD was still present. Vitrectomy with ILM removal and gas tamponade resulted in a marked reduction of the SD in the macular area. Focal macular electroretinograms and visual acuity demonstrated a recovery of macular function. CONCLUSION: The dome-shaped separation of the ILM suggested that the vitreous might be exerting a tractional force on the optic disc pit, and vitrectomy with ILM peeling released the traction on the optic disc pit.

Basement Membrane↗

PubMedDate not supplied

Charles Bonnet syndrome associated with a first attack of multiple sclerosis.

BACKGROUND: We treated a rare case of Charles Bonnet syndrome (CBS) manifested during temporary blindness in both eyes caused by optic neuritis associated with a first attack of multiple sclerosis (MS). CASE: A 66-year-old Japanese woman became completely blind for 3 months due to optic neuritis after a first attack of MS. During the blind period, she experienced vivid visual hallucinations for about 2 weeks. OBSERVATIONS: The patient had no psychiatric disorders or cognitive impairments; therefore, the visual hallucinations during the period of blindness were indicative of CBS. Unexpectedly, the hallucinations disappeared without treatment following her recovery of vision. CONCLUSIONS: Although rare, visual impairment during a first attack of MS can be associated with visual hallucinations indicative of CBS. The hallucinations can disappear spontaneously with the recovery of vision without treatment.

Aged↗

PubMedDate not supplied

Ultrasound biomicroscopic findings in hallerman-streiff syndrome.

PURPOSE: To demonstrate the usefulness of ultrasound biomicroscopy in detecting the morphological changes in the lens caused by the spontaneous absorption of lens material and to detect fundus abnormalities in a patient with Hallermann-Streiff syndrome. METHODS: Case report of an infant diagnosed at the age of 2 months as having Hallermann-Streiff syndrome. RESULTS: Spontaneous lens absorption occurred during the course of follow-up and was detected only by ultrasound biomicroscopy after the patient was prepared for cataract surgery. The changes in the anterior chamber depth and lens shapes were documented by ultrasound biomicroscopy. Retinal folds that were barely observable by conventional ophthalmoscopy because of a dense cataract were clearly shown by ultrasound biomicroscopy. CONCLUSIONS: Ultrasound biomicroscopy can be used to examine the lenses of eyes that are not observable with conventional optical instruments. Ultrasound biomicroscopy can also be used to study the posterior segment of microphthalmic eyes. We recommend preoperative ultrasound biomicroscopy to prevent unnecessary anesthesia and surgical preparation.

Abnormalities, Multiple↗

PubMedDate not supplied

Refractive errors and factors associated with myopia in an adult Japanese population.

PURPOSE: To investigate the refractive status and factors associated with myopia by a population-based survey of Japanese adults. METHODS: A total of 2168 subjects aged 40 to 79 years, randomly selected from a local community, were assessed in a cross-sectional study. The spherical equivalent of the refractive error was calculated and used in a multiple logistic regression analysis to evaluate the relationships between myopia and possible related factors. RESULTS: The mean (+/- SD) of the spherical equivalent was -0.70 +/- 1.40 diopters (D) in men, and -0.50 +/- 1.44 D in women. Based on +/- 0.5 D cutoff points, the prevalence of myopia, emmetropia, and hypermetropia were 45.7%, 40.8%, and 13.5% in men, and 38.3%, 43.1%, and 18.6% in women, respectively. A 10-year increase in age was associated with reduced risk of myopia [men: odds ratio (OR) = 0.53, 95% confidence interval (CI): 0.44-0.62; women: OR = 0.65, 95% CI: 0.54-0.78]. In men, myopia was significantly associated with higher education (high school: OR = 1.6, 95% CI: 1.1-2.3; college: OR = 2.0, 95% CI: 1.3-3.1) and management occupations (OR = 1.6, 95% CI: 1.0-2.4). For women, high income (OR = 1.5, 95% CI: 1.1-2.2), and clerical (OR = 1.5, 95% CI: 1.0-2.4) and sales/service occupations (OR = 1.7, 95% CI: 1.1-2.6) were also associated with myopia. CONCLUSIONS: The prevalence of myopia in a Japanese population was similar to that in other Asian surveys but higher than in black or white populations. Our study confirmed a higher prevalence of myopia among younger vs. older populations, and a significant association with education levels and socioeconomic factors.

Adult↗

PubMedDate not supplied

Age-related change in contrast sensitivity among Japanese adults.

PURPOSE: To evaluate the age-related change in contrast sensitivity seen in a middle-aged to elderly Japanese population. METHODS: Contrast sensitivity and visual acuity were measured in subjects aged 40 to 79 years randomly recruited from a community in Aichi prefecture near Nagoya, Japan. Contrast sensitivity tests were performed using the Vistech contrast sensitivity test chart (VCTS 6500). The results were statistically analyzed relative to age. RESULTS: A statistically significant decrease in contrast sensitivity was seen with advancing age at each spatial frequency (Cochran-Mantel-Haenszel: P<.001). This trend was detected even when the subjects were limited to only those having a corrected visual acuity of 1.0 or better (Cochran-Mantel-Haenszel: P<.001). Overall, 9.4% of the eyes with good visual acuity had poor contrast sensitivity at a high spatial frequency, while in the 70-79-year-old group, the percentage with poor contrast sensitivity reached 21.1%. CONCLUSIONS: The age-related decrease in contrast sensitivity was confirmed at all frequencies in our population, even when adjusted for visual acuity. Our results suggest that contrast sensitivity tests, especially at high frequencies, assess aspects of visual function that cannot be determined in the elderly population from visual acuity tests alone.

Adult↗

PubMedDate not supplied

Preoperative electroretinogram and postoperative visual outcome in patients with diabetic vitreous hemorrhage.

PURPOSE: To determine whether the single-flash electroretinogram (ERG) can predict the postoperative outcome in diabetic cases where massive vitreous hemorrhage precludes fundus observation. METHODS: Eighty-five diabetic patients (105 eyes) who underwent vitrectomy due to dense vitreous hemorrhage were studied retrospectively. Eyes with postoperative complications were excluded. Preoperative ERGs (mixed cone-rod ERG with maximum flash intensity) were classified as: Group A, the b-wave/a-wave ratio (b/a ratio) was > or =1.0 and the oscillatory potentials (OPs) were clearly recordable (22 eyes); Group B, the b/a ratio was > or =1.0 and the OPs were markedly reduced (33 eyes); and Group C, the b/a ratio was <1.0 (50 eyes). RESULTS: The postoperative visual acuity in Group C (hand motion to 1.5) was significantly worse than in Group A (0.4-.2) (P<.01) or Group B (0.08-1.0) (P<.01). Thick preretinal membrane causing retinal traction around the optic disc was found intraoperatively in 1 eye (4.5%) in Group A, 9 eyes (27.3%) in Group B, and 28 eyes (56.0%) in Group C (P=.0132). CONCLUSION: Our findings suggested that the configuration of the single-flash ERG can provide important preoperative information for a functional prognosis following vitrectomy in diabetic patients with vitreous hemorrhage.

Adult↗

PubMedDate not supplied

Negative electroretinograms in pericentral pigmentary retinal degeneration.

The clinical presentation and electrophysiological findings are described of three consecutive cases with pericentral pigmentary retinal degeneration. The responses to bright flashes after dark adaptation showed negative waveform shape in all cases. Rod responses were strongly reduced compared with cone responses. Cone electroretinograms elicited by long-duration stimuli showed greater loss of the on-response than the off-response. The ratio of the on-response amplitude to off-response amplitude of these patients (0.52 +/- 0.12; mean +/- SD, n = 6) was significantly smaller than that of normal subject (0.83 +/- 0.21; mean +/- SD, n = 8) (Mann-Whitney U-test, P < 0.01). The electrophysiological findings of these cases suggest a greater defect of inner retinal function, especially in transmission between photoreceptors and depolarizing bipolar cells.

Aged↗