Wavelet decomposition analysis in the two-flash multifocal ERG in early glaucoma: a comparison to ganglion cell analysis and visual field.

PURPOSE: To further improve analysis of the two-flash multifocal electroretinogram (2F-mfERG) in glaucoma in regard to structure-function analysis, using discrete wavelet transform (DWT) analysis. METHODS: Sixty subjects [35 controls and 25 primary open-angle glaucoma (POAG)] underwent 2F-mfERG. Responses were analyzed with the DWT. The DWT level that could best separate POAG from controls was compared to the root-mean-square (RMS) calculations previously used in the analysis of the 2F-mfERG. In a subgroup analysis, structure-function correlation was assessed between DWT, optical coherence tomography and automated perimetry (mf103 customized pattern) for the central 15°. RESULTS: Frequency level 4 of the wavelet variance analysis (144 Hz, WVA-144) was most sensitive (p < 0.003). It correlated positively with RMS but had a better AUC. Positive relations were found between visual field, WVA-144 and GCIPL thickness. The highest predictive factor for glaucoma diagnostic was seen in the GCIPL, but this improved further by adding the mean sensitivity and WVA-144. CONCLUSIONS: mfERG using WVA analysis improves glaucoma diagnosis, especially when combined with GCIPL and MS.

Ganglion cell layer segmentation and the two-flash multifocal electroretinogram improve structure function analysis in early glaucoma.

PURPOSE: To improve structure-function analysis in primary open-angle glaucoma (POAG) by including the two-global flash multifocal electroretinogram (2F-mfERG) and macular ganglion cell layer segmentation. METHODS: Twenty-five glaucoma patients (six pre-perimetric (PPG), 19 POAG) and 16 controls underwent 2F-mfERG, optical coherence tomography (OCT), and standard automated perimetry (SAP). For 2F-mfERG, the root mean square was calculated for the focal flash response at 15-45 ms (DC) and the global flash responses at 45-75 ms (IC1) and 75-105 ms (IC2). For OCT, macular total thickness (mT) and ganglion cell-inner plexiform layer (GCIPL) thickness were analysed. Values from the central 10° and 15° of 2F-mfERG were compared to the corresponding areas from OCT and visual field. RESULTS: Both PPG and POAG had significantly lower mfERG responses in the central 10° and 15° than the control group. Of the glaucoma patients, 30.7% (three PPG, five POAG) showed central mfERG and GCIPL reduction without a SAP defect in the central 15 degrees. Four patients had a central SAP defect associated with a reduced GCIPL without any detectable dysfunction on mfERG. MfERG DC and IC2 were larger with increased mT (p ≤ 0.02), but GCIPL only related positively to IC2 (p = 0.027). SAP sensitivity also increased with thicker mT but not with GCIPL (p < 0.03 and p = 0.35). DC, IC2, and GCIPL could best differentiate glaucoma from control (AUC values: 0.897, 0.903, and 0.905). CONCLUSIONS: Structure function analysis in glaucoma can be improved when the GCIPL thickness as well as the 2F-mfERG is included as these measures complement information obtained by SAP.

Structural and functional changes in glaucoma: comparing the two-flash multifocal electroretinogram to optical coherence tomography and visual fields.

PURPOSE: To correlate multifocal electroretinogram (mfERG) findings in the macular area of glaucoma patients with automated perimetry (visual fields) and with optical coherence tomography (OCT). METHODS: A two-global flash mfERG (VERIS™) was recorded in 20 eyes with primary open-angle glaucoma. The root mean square was calculated, and three response epochs were analysed: the direct component (15-45 ms) and two induced components (IC-1 at 45-75 ms and IC-2 at 75-105 ms). The central 10° of the mfERG was compared to the central 10° of the OCT and of the visual field. Responses grouped in a superior and in an inferior semicircle, extending between 10° and 20°, were also compared to the corresponding areas of the OCT and of the visual fields. In addition, the area of the papillomacular bundle was also analysed separately. RESULTS: In glaucoma patients, mfERG responses showed a significant positive association with retinal thickness in the central 10° for IC2 (p = 0.001) and a trend for IC1 (p = 0.066). A significant association was found between the central IC1 and IC2 of the mfERG and corresponding perimetric sensitivities expressed in linear units (p < 0.01). The OCT showed a positive association with visual field sensitivities (p < 0.05) in all areas examined (p < 0.05). Separation of the papillomacular bundle area did not improve structure-function association further. CONCLUSIONS: In our study, mfERG showed a statistically significant correlation with perimetric sensitivity measured in linear units and with structural macular changes detected with time-domain OCT.

What are the options of psychophysical approaches in glaucoma?

The article attempts to provide useful information on psychophysical tests in glaucoma management. This includes the suitability of various glaucoma screening methods, optimum screening parameters for glaucoma detection, and methods for glaucoma follow-up. There is clear evidence that perimetry methods using temporal modulation show a larger area under the curve than standard perimetry methods for the detection of glaucoma. Once the disease is established, there is no significant advantage for flickering stimulus targets. In most cases pattern standard deviation (sLV), or the number of points with a total deviation at the 5% probability level, are best for the identification of glaucoma suspects. If early diagnosis and glaucoma screening is requested, perimetry methods with temporal modulation show a larger area under the curve than standard perimetry methods. In the course of the disease, standard automated perimetry is still the method of choice for functional follow-up.

Applying a New Automated Perimetry Pattern Based on the Stimulus Distribution of the Multifocal ERG to Improve Structure-Function Investigation in Glaucoma.

PURPOSE: To validate a new automated perimetry pattern (mf103 pattern) for the investigation of retinal structure-function relationships in glaucoma in comparison to the standard G2 pattern and to relate either field's performance to optical coherence tomography (OCT). METHODS: Automated perimetry data from the mfERG103 pattern were compared with the standard G2 pattern in glaucoma patients (18) and controls (15). The results of both (mean defect (MD) and mean sensitivity (MS)) were compared with optical coherence tomography (OCT): retinal nerve fiber layer (RNFL) thickness, macular thickness (mT), and ganglion cell analysis (GCIPL). Nine patients were followed up after one year. RESULTS: G2 pattern and mf103 pattern did not differ significantly in MD or MS. The mf103 pattern associated significantly with more RNFL sectors in both MD and MS (p < 0.01 and p < 0.05, resp.). GCIPL thickness was not significantly associated with either SAP protocols. Both protocols remained comparable after one-year follow-up. CONCLUSIONS: G2 and mf103 pattern can both differentiate patients from controls with no significant difference in performance. RNFL thickness defects correlated better with mf103 than G2 with POAG. The mfERG-103 perimetry pattern can be used to establish structure-function correlations in glaucoma and may enable a more direct comparison with objective electrophysiological data.

Validation of a new static perimetric thresholding strategy (GATE).

AIMS: To validate the EyeSuite version of German Adaptive Threshold Estimation (GATE), a new thresholding algorithm for automated static perimetry. METHODS: Specification of agreement and its clinical evaluation as validation criteria. Comparison of local differential luminance sensitivity (DLS) and test time values between the prototype version of GATE (GATEp) and a clinical trial version, implemented in EyeSuite (GATEe), by means of modified Bland-Altman plots. All examinations were performed on the Octopus 900 perimeter (Haag-Streit Inc., Köniz, Switzerland). Visually impaired patients (anterior ischaemic optic neuropathy [n=3], glaucomatous optic neuropathy [n=15], (post-)chiasmal visual pathway lesion [n=6], retinitis pigmentosa [n=6]) were either tested with grid 30A (30° excentricity, 83 test locations) or grid 84NO (90° excentricity, 109 test locations, patients with RP only). RESULTS: The comparison of local DLS values showed good-to-acceptable agreement between GATEp and GATEe (bias <2 dB, limits of agreement [LOA] <5 dB) and very good repeatability for GATEp (bias <0.5 dB, LOA<3 dB). Median test times for GATEp and GATEe were 7.8  and 8.8 min for the 30° grid and 6.7  and 7.8 min for the 90° grid. CONCLUSIONS: GATEp and GATE, implemented in the commercially available EyeSuite software package (GATEe), show good agreement regarding local differential luminance sensitivity. GATEe can thus be also recommended for clinical practice. CLINICAL TRIAL NUMBER: NCT01265628.

Normal values for Octopus tendency oriented perimetry in children 7 through 13 years old.

BACKGROUND: The purpose of this study was to determine age-dependent values for mean sensitivity, mean deviation, and loss variance for normal children age 6 through 13 years, using the Octopus 301 perimeter and the Tendency Oriented Perimetry 32 (TOP-32) program. METHODS: Healthy children from 6 through 13 years of age with a visual acuity of 20/20 OU and at least 60 arc seconds of stereopsis were recruited. They were tested on the Octopus 301 perimeter using the TOP-32 program, and each eye was tested twice during one session. Results for all four tests were averaged for each subject, and the average was used for statistical analysis. The main outcome measures were mean sensitivity, mean deviation, and loss variance by age. The test duration, learning and fatigue effects, and the influence of false positive responses on the average mean sensitivity were also analyzed. RESULTS: There were 142 subjects tested. Six-year-old children showed high intersubject variability and were excluded (N=23). The average age of the remaining 7- to 13-year-old cohort (N=119) was 9.8 +/- 1.7 years. The average test duration was 2.9 +/- 0.3 min. The average mean sensitivity was 28.7 +/- 1.9 dB. The mean sensitivities for tests 1 through 4 were 28.14, 28.63, 28.96, and 28.92 dB, respectively. The average mean deviation was 0.4 +/- 1.9 dB. The slope of the regression line for mean sensitivity vs age was -0.018 +/- 0.165 dB/year, which was not significantly different from zero (two-tailed t test, p=0.83). The false positive catch trial rate was high (mean 26%) and was independent of age. When the data from subjects who had more than two false positive catch trial responses on any one test were eliminated, the mean sensitivity decreased to 28.3 +/- 1.9 dB. CONCLUSIONS: When testing patients age 7 through 13 years on the Octopus 301 perimeter using the TOP-32 program, comparison against the programmed normal mean sensitivity value for 20-year-old subjects (29.0 dB) is appropriate. During a sequence of four tests, both learning and fatigue effects are evident. The false positive response rate is naturally high regardless of age, and children should not be overencouraged to respond during testing.