Muneyoshi Kaneko

Correlation between photopic negative response and retinal nerve fiber layer thickness and optic disc topography in glaucomatous eyes.

PURPOSE To investigate whether there is a significant correlation between the photopic negative response (PhNR) of the electroretinogram (ERG) and retinal nerve fiber layer thickness and optic disc topography in glaucomatous eyes. METHODS Ninety-nine eyes of 53 patients with open-angle glaucoma (OAG) and 30 eyes of 28 normal volunteers were studied. Photopic ERGs were elicited by red stimuli (644 nm, 1600 cd/m(2)) on a blue background (470 nm, 40 cd/m(2)). The mean deviation (MD) of the visual field was obtained by static visual field analyses. The topography of the optic nerve head was determined by confocal scanning laser ophthalmoscopy. The retinal nerve fiber layer thickness (RNFLT) around the optic nerve head was measured with a scanning laser polarimeter. RESULTS The amplitude of the PhNR and the PhNR/b-wave ratio decreased with an increase in visual field defects. The logarithmic values of the PhNR amplitude and PhNR/b-wave amplitude ratio were significantly correlated with the MD better than the linear values. The PhNR amplitude and PhNR/b-wave amplitude ratio were significantly correlated with the RNFLT and the rim area of the optic disc and with the cup/disc area ratio. These correlations were higher when expressed linearly than when stated logarithmically. The sensitivity and specificity were 77% and 90% for the PhNR amplitude and 70% and 87% for the PhNR/b-wave amplitude ratio when the optimal cutoff values were used. Although the a-wave amplitude correlated with the MD, the a-wave amplitudes of most of the patients fell within the normal range. The correlation between the b-wave amplitude and MD was not significant. CONCLUSIONS The PhNR amplitudes correlate with the decrease in function and morphology of retinal neurons in eyes with OAG. The linear relationship between the PhNR and the structural parameters indicates that inner retinal function declines proportionately with neural loss in eyes with glaucoma.

Photopic Negative Response of Focal Electoretinograms in Glaucomatous Eyes

PURPOSE To determine the clinical importance of the photopic negative response (PhNR) of the focal electoretinogram (fERG) for diagnosing glaucoma. METHODS Fifty-nine eyes of 38 patients with open-angle glaucoma (OAG), 12 glaucoma suspects, and 32 eyes of 32 normal controls were studied. The fERGs were elicited by a 15 degrees stimulus spot on the macula region, the supero-temporal, and infero-temporal regions of the macula. The mean of the visual sensitivity was measured by standard automated perimetry (SAP). The optimal cutoff amplitudes of the focal PhNR and ratios of the focal PhNR/b-wave amplitudes that discriminated glaucomatous eyes from normal eyes were obtained from the receiver operating characteristic curves. RESULTS The amplitudes of the PhNR were significantly smaller in patients with OAG than in normal controls (P < 0.00001). A curvilinear relationship was found between the mean sensitivity (dB, on log scale) and the PhNR amplitude, and between the mean sensitivity and the PhNR/b-wave amplitude ratio. After converting the mean sensitivity from a logarithmic to a linear scale, the amplitude of the PhNR and PhNR/b-wave ratio were linearly correlated with the SAP-determined visual sensitivity in all retinal areas (r = .428-0.544, P < 0.0001). When the optimal cutoff values were used, the sensitivity and specificity of the PhNR/b-wave amplitude ratio were 98.3% and 90.1%, respectively. CONCLUSIONS The reduction of the focal PhNR amplitude was associated with a local decrease in the retinal sensitivity in OAG. The high sensitivity and specificity suggest that the focal PhNR can be used to detect functional loss in OAG.

Sensitivity and Specificity of Photopic Negative Response of Focal Electoretinogram to Detect Glaucomatous Eyes

Aims To determine the sensitivity and specificity of the photopic negative response (PhNR) of the focal electroretinograms (ERG; focal PhNR) to detect glaucomatous eyes with different degrees of visual field defects. Methods One-hundred and fourteen eyes of 114 patients with open angle glaucoma and 42 eyes of 42 normal controls were studied. The focal ERGs were elicited by a 15° stimulus spot centred on the macula, and on the supero-temporal and on the infero-temporal areas of the macula. The receiver operating characteristic curves were determined to obtain optimal cut-off values. Eyes were classified as being glaucomatous when their focal PhNRs were less than the cut-off values in either retinal area (combined criterion). Results The focal PhNR amplitudes were significantly reduced with an advance in the stage of glaucoma. In early glaucoma, the sensitivities of the PhNR measured for each retinal area ranged from 58.1% to 80.7%. The sensitivities were significantly increased to 90.6% and 96.9% for the focal PhNR amplitude and the focal PhNR/b-wave amplitude ratio, respectively, when the combined criterion was employed. The specificity was >90%. Conclusions Focal PhNRs have diagnostic ability in detecting early glaucoma with high sensitivity and specificity, especially when the combined criterion is used.

Comparison of Photopic Negative Response of Full-Field and Focal Electroretinograms in Detecting Glaucomatous Eyes

Purpose. To compare the photopic negative response (PhNR) of the full-field electroretinogram (ERG) to the PhNR of the focal ERGs in detecting glaucoma. Methods. One hundred and three eyes with glaucoma and 42 normal eyes were studied. Full-field ERGs were elicited by red stimuli on a blue background. The focal ERGs were elicited by a 15° white stimulus spot centered on the macula, the superotemporal or the inferotemporal areas of the macula. Results. In early glaucoma, the areas under the receiver operating characteristic curves (AUCs) were significantly larger for the focal PhNR (0.863–0.924) than those for the full-field PhNR (0.666–0.748) (P < .05). The sensitivity was significantly higher for the focal PhNR than for the full-field PhNR in early (P < .01) and intermediate glaucoma (P < .05). In advanced glaucoma, there was no difference in the AUCs and sensitivities between the focal and full-field PhNRs. Conclusions. The focal ERG has the diagnostic ability with higher sensitivity in detecting early and intermediate glaucoma than the full-field ERG.

Alterations of Photopic Negative Response of Multifocal Electroretinogram in Patients with Glaucoma

Abstract Purpose: To determine the effect of glaucoma on the multifocal electroretinograms (ERGs) (mfERGs) elicited by low-frequency stimuli. Methods: Forty-four patients with open-angle glaucoma and 15 normal subjects were studied. The stimulus frequency was 6.25 Hz, and the stimulus was a circle with a 6.8° radius that was centered on the fovea (center). MfERGs were also elicited by a quarter of an annulus placed around the macula (superior/temporal; inferior/temporal; superior/nasal; and inferior/nasal quadrants). The radius of the inner border of the annulus was 6.8° and that of the outer border was 20°. The actual sensitivity was determined by standard automated perimetry. The thickness of the ganglion cell complex (GCC) was measured by optical coherence tomography. Results: The mfERGs consisted of a negative wave (N1) followed by a positive wave (P1), and followed by a slow negative wave (N2). There were no significant differences in the response densities of N1 and P1 between the normal control and glaucomatous eyes in any areas. The N2 response density was significantly reduced with the severity of glaucoma in the center. There was a significant reduction even at an early stage of glaucoma compared to control values. In the center, the N2 response density was significantly correlated with the GCC thickness and mean sensitivity. However, in other stimulus areas, there was no significant reduction of any components of the mfERGs. Conclusions: These results suggest that the N2 component of the slow-sequence mfERGs is affected by glaucoma in the central retinal area. Regional variations in the contribution of the retinal ganglion cell activity to the N2 should be considered when examining the mfERGs in glaucoma patients.

Regional Variations in Correlation between Photopic Negative Response of Focal Electoretinograms and Ganglion Cell Complex in Glaucoma

Abstract Purpose: To determine regional variations in a structure-function relationship, we correlated the the photopic negative response (PhNR) of the focal electoretinogram (ERG) with the ganglion cell complex (GCC) thickness in different retinal regions in patients with open angle glaucoma (OAG). Methods: Fifty-one eyes of 51 OAG patients (OAG group) and 17 eyes of 17 normal volunteers (control group) were studied. The OAG patients had different degrees of glaucoma ranging from early to advanced stages. The focal ERGs were elicited by a white, 15° hemispherical stimulus placed superior or inferior to the fovea. Focal ERGs were also elicited by a half annulus placed superior or inferior to the macular region. The diameter of the inner border of the annulus was 15° and that of the outer border was 30°. The average GCC thickness in areas corresponding to the location of the stimuli was measured in SD-OCT images. Results: The PhNR amplitude and PhNR/b-wave amplitude ratio were significantly correlated with the GCC thickness in the superior and inferior hemispherical areas (p < 0.0001). These ERG parameters were weakly correlated with the GCC thickness in the superior and inferior semi-annular areas (p < 0.05). There were significant differences in the slopes of the regression lines plotting the GCC thickness and the PhNR amplitude or the PhNR/b-wave amplitude ratio between the spherical and semi-annular areas (superior: p < 0.01, inferior: p < 0.0005). Conclusions: The thinning of the GCC affects the RGC function measured by the PhNR more strongly in the central retinal area than in the surrounding retinal areas.

Electrical Responses from the Inner Retina of Rats with Streptozotocin-induced Early Diabetes Mellitus☆

PURPOSE To evaluate behavior of the scotopic threshold response (STR) and the oscillatory potential (OP) in the electroretinogram (ERG) in streptozotocin (STZ)-induced diabetic rats (DM rats). METHODS The amplitude of the STR and the OP 3, the implicit time of the STR, and the peak latency of the OP 3 of the DM rats were measured. RESULTS No significant differences were observed in the mean amplitude or the mean implicit time of the STR between the control and the DM rats. On the other hand, the mean peak latency of OP 3 of the DM rats was significantly prolonged up to 125% of the control rats (p < 0.01), although there were no significant differences between the two groups in the mean OP 3 amplitude. CONCLUSIONS Although both STR and OP were of inner retinal origin, their behavior was different in DM rats. This result supported some reports describing how dopaminergic amacrine cells generate OP and glycinergic or GABAergic amacrine cells generate STR. In the early stage of diabetic retinopathy, there may be not only minor ischemia but also disorder of neurotransmission of the amacrine cells in the inner retinal layers.

A case of Churg-Strauss syndrome and central retinal artery occlusion with good visual recovery

Here we report a case of Churg–Strauss syndrome (CSS) and central retinal artery occlusion (CRAO), with good visual recovery. A 58-year-old Japanese man with CSS experienced acute painless loss of vision in his right eye. CRAO was diagnosed by fundoscopic findings (retinal whitening with a cherry-red spot). Steroid pulse therapy (methylprednisolone at 1 g daily for 3 days) followed by combined treatment with prednisolone (30 mg/day) and cyclophosphamide (150 mg/day) was administered; his visual acuity recovered to 20/30 in 1 month, and no recurrence has occurred for 1 year. Steroid pulse therapy may be effective for CRAO in CSS patients.

[Scotopic threshold response in noninsulin-dependent diabetes mellitus patients with good HbA1c level and ophthalmoscopically intact fundus].

PURPOSE To evaluate behavior of the scotopic threshold response(STR) and the oscillatory potentials(OPs) of the electroretinogram in noninsulin-dependent diabetes mellitus(NIDDM) patients without retinal abnormalities. METHODS The STR and the OP 1-3 were recorded from 15 eyes of 15 NIDDM patients aged from 45 to 63 years old with good HbA1c level and ophthalmoscopically intact fundus. As a control group, 8 eyes of 8 age-matched normal subjects were used. The amplitude and the implicit time of the STR as well as the amplitudes and the peak latencies of OP 1-3 were measured. RESULTS The mean amplitude and the mean implicit time of the STR in the NIDDM group did not differ significantly from those in the control group. The mean amplitudes and the mean peak latencies of the OP 1-3 also showed no significant differences between the NIDDM and control groups. CONCLUSIONS The STR in NIDDM patients remains normal with good HbA1c level and ophthalmoscopically intact fundus.