Matrix Frequency Doubling Technology Research Articles

Does the apodized diffractive intraocular lens Acrysof ReSTOR NaturalTM interfere with FDT Matrix perimetry results?

To compare the effect of an apodized diffractive intraocular lens (IOL) (Acrysof ReSTOR Natural) and its yellow counterpart (Natural IQ) on frequency doubling technology (FDT) perimetry results. This study included 37 eyes from 22 patients at the 'Centro Oftalmológico Tranjan' who had undergone uncomplicated phacoemulsification and intraocular lens implantation (17 Acrysof ReSTOR Natural, 20 Natural IQ) performed by the same surgeon, at least three months prior to the study. Patients were subject to frequency doubling technology Matrix Perimeter testing. The patients were between 41 to 79 years old (mean, 70.78 +/- 9.83) in the Natural IQ and 49 to 81 years old (mean, 67.11+/- 11.48) in the Acrysof ReSTOR Natural group, and the mean IOP was 13.64 +/- 2.02 mmHg in the Natural IQ 12.94 +/- 1.39 mmHg in the Acrysof ReSTOR Natural group. The mean pupillary diameter under scotopic conditions was 6.63 +/- 1.16 mm in the Natural IQ group and 7.20 +/- 1.8 mm in the Acrysof ReSTOR Natural group (p=0.20). The mean deviation was -1.83 +/- 3.46 dB in the Natural IQ group and -1.77 +/- 3.94 dB in the Acrysof ReSTOR Natural group (p=0.28). The pattern standard deviation was 3.49 +/- 0.79 dB in the Natural IQ group and 3.20 +/- 0.86 dB in the Acrysof ReSTOR Natural group (p=0.27). There was no difference in the results of FDT Matrix perimetry in eyes that received apodized diffractive IOLs implant or eyes that received monofocal intraocular lens implant.

Learning effect in visual field testing of healthy subjects using Humphrey Matrix frequency doubling technology perimetry

To evaluate the learning effect of frequency doubling technology (FDT) perimetry using the Humphrey Matrix perimeter in healthy subjects with no perimetric experience. One eye of 28 healthy adults who had no history of visual field testing underwent three Matrix tests using 24-2 programme with full-threshold strategy. The results of the first session were compared with those of the second, and the third sessions. Learning effect was defined as an improvement at results for duration, perimetric indices, and the number of points with a P<5 and <1% in the total and pattern deviation maps. Anderson's criteria were applied to define abnormal examinations. The mean in the mean deviation global index was -7.40+/-1.49 dB in the first session, -4.64+/-0.97 dB in the second session, and -3.29+/-0.93 dB in the third session. Pattern standard deviations were decreased as the tests were repeated (P<0.01). Test duration, fixation losses, false negative, and the number of points with a P<5 and <1% in the total and pattern deviation maps rate were also changed significantly (P<0.05). Among the criteria suggested by Anderson, the Glaucoma Hemifield Test performed better in all session tests. The false-positive rates ranged from 50% (95% confidence intervals [CI] 30.6-69.4%) to 64% (95% CI 44.1-81.4%) for the first session, 29% (95% CI 13.2-48.7%) to 54% (95% CI 33.9-72.5%) for the second session, and from 18% (95% CI 6.1-36.9%) to 32% (95% CI 15.9-52.4%) for the third session. The results of this study show that the learning effect for Humphrey Matrix FDT perimetry must be considered in normal individuals with no perimetric experience.

Frequenzverdopplungsperimetrie

Glaucoma is a disease in which death of retinal ganglion cells is associated with loss of visual function. The gold standard for visual field testing has been standard automated perimetry (SAP). However, up to 30-50% of retinal ganglion cells must be lost before a scotoma is detected with SAP. Therefore, investigators have been interested in finding diagnostic techniques that would allow earlier detection of visual field loss than that detected by standard white-on-white perimetry. Frequency-doubling technology (FDT) has been suggested as a promising technique that may detect glaucomatous ganglion cell damage earlier than SAP by targeting a sparsely spaced subsystem of Mgamma retinal ganglion cells where cell damage is less masked by redundancy. The second generation of FDT perimetry, the Matrix FDT, was released with the intention of improving the spatial resolution of visual field defects. In this article we present FDT and discuss data that compare FDT with standard white-on-white perimetry.

Interpretation of the Humphrey Matrix 24-2 test in the diagnosis of preperimetric glaucoma

To define the diagnostic precision of the Humphrey Matrix 24-2 test and to determine a clinically applicable cutoff criterion for the inclusion of preperimetric glaucoma. Eyes with preperimetric glaucoma (99 eyes) were defined as having normal standard automated perimetry (SAP) results and a glaucomatous optic nerve head, along with one or more optical coherence tomography (OCT) parameters flagged as <0.05 or a retinal nerve fiber layer (RNFL) defect on red-free fundus photographs. Normal controls (122 eyes) were defined as having a normal optic disc and RNFL with normal SAP. Receiver-operating characteristic (ROC) curves were constructed to determine the best-discriminating parameter of the frequency-doubling technology (FDT) Matrix. The sensitivity, specificity, and hit ratio of all available criteria were calculated from the FDT Matrix. Pattern standard deviation (PSD) showed a larger area under the ROC curve (AUC) (0.767) than mean deviation (MD) (0.619). A pattern deviation plot (PDP) analysis by modified Anderson criteria showed the highest discriminating power, with a sensitivity of 75.76%, followed by a PSD cutoff value of 3.14 dB (sensitivity, 73.74%). FDT Matrix seems to be a valuable clinical tool in the detection of preperimetric glaucoma. Among the parameters of the FDT Matrix, PDP analysis by modified Anderson criteria may provide a reliable cutoff criterion.

Performance of Humphrey Matrix Frequency Doubling Technology Perimetry and Standard Automated Perimetry Global Indices

Purpose: To evaluate and compare the diagnostic performance of Humphrey Matrix frequency doubling technology perimetry (Matrix) global indices with standard automated perimetry (SAP) for glaucoma discrimination. Methods: Forty-seven healthy and 63 glaucomatous subjects were included in this study. Glaucoma was defined as having glaucomatous optic disc and glaucomatous visual field defect. Correlations of mean deviation (MD) and pattern standard deviation (PSD) between Matrix and SAP were evaluated. Areas under receiver operating characteristic curves (AUCs) for discriminating healthy from glaucoma, sensitivity, and cut-off value at fixed specificity of MD and PSD were determined in Matrix and SAP. Results: MD and PSD from Matrix were highly correlated with SAP data in glaucomatous eyes (r =0.80, 0.69 p

Visual Function-Specific Perimetry to Identify Glaucomatous Visual Loss Using Three Different Definitions of Visual Field Abnormality

To compare the most recent versions of standard automated perimetry (SAP), short-wavelength automated perimetry (SWAP), and frequency-doubling technology (FDT) using three definitions of visual field (VF) abnormality: single-test abnormality, abnormality confirmed by the same test, and abnormality confirmed by a different test. Data obtained from one eye of each of 174 patients with glaucoma and 164 age-matched healthy control subjects from the Diagnostic Innovations in Glaucoma Study and African Descent and Glaucoma Evaluation Study were included, based on the appearance of the optic disc on stereophotographs. Each participant had two reliable 24-2 SAP-SITA, SWAP-SITA, and Matrix FDT tests. Receiver operating characteristic (ROC) curves were generated for the PSD of each test to equate the tests at 90% and 95% specificity. SAP, SWAP, and FDT were compared under each definition of VF abnormality by assessing the sensitivities, the agreement between tests and the overlap in deficit location at these set specificities. The tests were also compared using the machine-derived PSD. At a set specificity of 95%, single-test sensitivities of 30% (SAP), 29% (SWAP), and 28% (FDT) were observed (all P > 0.05). Sensitivities ranged from 24% to 27% (all P > 0.05) when same-test confirmation was used and from 20% to 23% (all P > 0.05) when different-test confirmation was used. SAP/SAP sensitivity was higher than all different-test combinations (all P < 0.05), and SWAP/FDT sensitivity was lower than all same-test combinations (all P < 0.05). Confirming VF abnormality is important and optimal when an abnormal SAP is confirmed by a subsequent SAP or SWAP test.

Learning Effect of Humphrey Matrix Frequency Doubling Technology Perimetry in Patients With Ocular Hypertension

To evaluate the learning effect of Frequency Doubling Technology (FDT) perimetry using the Humphrey Matrix-FDT perimetry (Matrix) 24-2 full-threshold program on patients with ocular hypertension experienced with standard automated perimetry. Twenty-four patients with ocular hypertension underwent 5 full-threshold Matrix tests at intervals of 5+/-2 days. Learning effect was defined as an improvement at results for duration, perimetric indices, foveal sensitivity, Glaucoma Hemifield Test, and the number of points with a P<5% and <1% in the total and pattern deviation maps. Eccentricity, hemifield, and quadrant sensitivities were also addressed as sources of differences in learning effect. Test-retest variability was also calculated for each repetition as the mean of the point-to-point interindividual standard deviations. A learning effect was demonstrated for mean defect (P=0.031, analysis of variance) and foveal sensitivity (P=0.009) and it only affected the first test for both parameters. All the other parameters did not show any significant learning effect. The effect was independent from eccentricity and quadrant or hemifield sensitivities. The results of this study demonstrate that the learning effect for Matrix-FDT is mild and it may affect only the first test. Caution is needed in the analysis of the first Matrix-FDT examination and retest may be advisable in the presence of low mean defect.

Relationship Between Humphrey 30-2 SITA Standard Test, Matrix 30-2 Threshold Test, and Heidelberg Retina Tomograph in Ocular Hypertensive and Glaucoma Patients

To evaluate the relationship between global indices of Humphrey standard automated perimetry (SAP, 30-2 SITA standard test), Humphrey Matrix frequency doubling technology (FDT, 30-2 threshold test), and Heidelberg Retina Tomograph (HRT II) parameters and measure the level of agreement among these 3 tests in classifying eyes as normal or abnormal. The study included 1 eye of 29 ocular hypertensive and 56 glaucoma patients with a mean age of 60.9+/-10.5 years. All subjects had reliable visual fields and HRT measurements performed within a 2-week period. The eyes were classified as normal/abnormal according to visual field criteria and Moorfields regression analysis (MRA). Correlations between visual field indices (mean deviation and pattern standard deviation) and HRT parameters were analyzed using Spearman correlation coefficient (r) and the agreement between the tests in classifying eyes was defined with kappa value. FDT Matrix mean deviation and pattern standard deviation parameters were found to be highly correlated with those of SAP (r=0.66 and 0.69, respectively). Visual field indices showed statistically significant correlations with cup area, rim area, cup/disc (C/D) area, linear C/D, cup shape, mean retinal nerve fiber layer thickness and retinal nerve fiber layer area parameters (P<0.05). Fifty-eight patients (68.2%) had abnormal results at least with 1 of the tests and 21 subjects (24.7%) had abnormal results with all 3 tests. The kappa values were 0.6 for SAP and Matrix (P<0.001), 0.33 for SAP and MRA (P=0.002), and 0.31 for Matrix and MRA (P=0.004). FDT Matrix results are highly comparable with SAP in the assessment of glaucoma. Visual field global indices show statistically significant, but low-moderate correlations with most of the HRT parameters. The agreement among MRA and visual fields for abnormality is fair. Either HRT or visual fields may show the first evidence of glaucomatous damage; therefore, the combination of optic nerve head parameters and visual field results could improve glaucoma diagnosis and follow-up.

Diagnostic Accuracy of the Matrix 24-2 and Original N-30 Frequency-Doubling Technology Tests Compared with Standard Automated Perimetry

To compare the diagnostic accuracy of the Matrix frequency-doubling technology (FDT) 24-2, first-generation FDT N-30 (FDT N-30), and standard automated perimetry (SAP) tests of visual function. One eye of each of 85 glaucoma patients and 81 healthy controls from the Diagnostic Innovations in Glaucoma Study was included. Evidence of glaucomatous optic neuropathy on stereophotographs was used to classify the eyes. Matrix FDT 24-2, first-generation FDT N-30, and SAP-SITA 24-2 tests were performed on all participants within 3 months. Receiver operating characteristic (ROC) curves were generated and used to determine sensitivity levels at 80% and 90% specificity for mean deviation (MD), pattern standard deviation (PSD), number of total deviation (TD), and pattern deviation (PD) points triggered at less than 5% and 1%. The tests were compared using the best parameter for each test (that with the highest area under the ROC curve) and with the PSD. The best parameters were MD for SAP (0.680), PSD for FDT N-30 (0.733), and number of TD less than 5% points for FDT 24-2 (0.774). Using the best parameter, the area under the ROC curve was significantly larger for FDT 24-2 than for SAP (P = 0.01). No statistically significant differences were observed between SAP and FDT N-30 (P = 0.21) and FDT N-30 and FDT 24-2 (P = 0.26). Similar results were obtained when the PSD was used to compare the tests, with the exception that the area under the ROC curve for the FDT N-30 test (0.733) was significantly larger than that of the SAP-SITA (0.641; P = 0.03). The performance of the Matrix FDT 24-2 was similar to that of the first-generation FDT N-30. The Matrix FDT 24-2 test was consistently better than SAP at discriminating between healthy and glaucomatous eyes. Further studies are needed to evaluate the ability of the Matrix FDT 24-2 to monitor glaucoma progression.

Accuracy of Combined GDx-VCC and Matrix FDT in a Glaucoma Screening Trial

To assess the advantage in glaucoma screening of the use of scanning laser polarimetry with customized cornea compensation (GDx-VCC) combined with Matrix Frequency Doubling Technology (M-FDT) testing. In a nonpopulation-based prepublicized trial, self-recruited white participants were screened for glaucoma with GDx-VCC, with M-FDT, and by independent clinical examination. Cases with possible glaucoma as found with any of the screening methods underwent a detailed clinical investigation to verify or exclude glaucoma. Sensitivity, specificity, accuracy, likelihood ratios, and predictive values were calculated using different threshold criteria for GDx-VCC alone, M-FDT alone, and for various combinations. Of the 233 attendees, 181 participants (345 eyes) successfully underwent the GDx-VCC and M-FDT measurements. Thirty-nine eyes of 24 participants had glaucoma (11.3% prevalence among eyes tested successfully). All but 2 of the glaucomatous eyes had only early damage. Evaluated separately, the criterion GDx-VCC NFI (normal threshold < or =30) performed best, with 97.0% specificity, 88.8% accuracy, and 25.6% sensitivity; but with only 8.5 positive likelihood ratio (PLR). For paired criteria, the best combination of GDx-VCC-screening test with M-FDT-screening test provided 99.6% specificity, 91.3% accuracy, and 28.6 PLR. For NFI combined with GDx-VCC nerve fiber bundle defect criterion, specificity was 99.0%, accuracy 89.6%, and PLR 18.0. However, the sensitivities in the 2 cases fell to 12.0% and 18.0%. For a triple combination of M-FDT-screening test with the latter pair of criteria, sensitivity increased to 41.7% and PLR (13.6) still remained clinically useful. In a self-recruited white population with relatively high risk for mild glaucomatous damage, a combination of GDx-VCC together with M-FDT could usefully be employed for mass glaucoma screening.

Localized Retinal Nerve Fiber Layer Defects and Visual Field Abnormalities by Humphrey Matrix Frequency Doubling Technology Perimetry

To investigate the ability of frequency doubling technology (FDT) perimetry to identify eyes with a localized retinal nerve fiber layer (RNFL) defect and normal Humphrey C30-2 SITA-Standard visual field (HVF). Retrospective case-control study. Fifty-four eyes were divided into two groups, an abnormal (n = 29) and a normal (n = 25) FDT perimetry group. Approximation of the RNFL defect to the macula (angle alpha) and width of the defect (angle beta) were measured by RNFL photograph and compared between two groups. Angle alpha and angle beta were significantly different between two groups (P < .001 by Mann-Whitney U test, respectively). A multivariate logistic regression analysis demonstrated that only angle beta was significantly associated with FDT perimetry abnormalities (P = .002). Only 53.7% of the eyes with a localized RNFL defect and normal HVF had visual field abnormalities identified by FDT perimetry. Width of the RNFL defect was more strongly associated with FDT perimetry abnormalities than location of the defect.

Comparison of Standard Automated Perimetry with Matrix Frequency-Doubling Technology in Patients with Resolved Optic Neuritis

To examine performance characteristics of frequency-doubling perimetry (FDP) in comparison with standard automated perimetry (SAP) in patients with resolved optic neuritis in a short-term follow-up study. Comparative consecutive case series. Twenty patients with resolved optic neuritis and 20 healthy volunteers participated in this study. The subjects were patients who recovered normal vision (1.0 or better) after optic neuritis. The Swedish interactive thresholding algorithm 30-2 program was used for SAP and a full-threshold 30-2 program was used for FDP. Using both forms of perimetry, the mean deviation (MD), pattern standard deviation (PSD), and the percentage of abnormal points significantly depressed <0.5% in the total deviation probability plot were compared. The visual fields were divided into 5 zones, and the mean sensitivity in each zone in affected eyes was compared with that in healthy eyes of the volunteers within 2 weeks of vision recovery and in follow-up after 2 weeks and 2 and 5 months. Standard automated perimetry and FDP showed general depression in the fovea and extrafoveal areas. Correlations between SAP and FDP were statistically significant for MD (Pearson r>0.75; P<0.001) and PSD (r>0.6; P<0.005). Defects detected with FDP were larger than with SAP in 14 eyes (70 %). In follow-up after 2 weeks and again after 2 and 5 months, FDP indicated slower improvement in visual field defects in the fovea and extrafoveal areas, whereas SAP indicated rapid improvement in these defects. Frequency-doubling perimetry is at least comparable with and potentially more sensitive than SAP in detecting visual field defects in resolved optic neuritis. This short-term follow-up study in patients with resolved optic neuritis suggests that FDP detects characteristics of slower recovery more effectively than SAP in the fovea and extrafoveal areas. These properties may allow more accurate detection of visual field defects and may prove advantageous for monitoring of patients with resolved optic neuritis.

Humphrey Matrix Frequency Doubling Technology Perimetry and Optical Coherence Tomography Measurement of the Retinal Nerve Fiber Layer Thickness in Both Normal and Ocular Hypertensive Subjects

The purpose of this study was to determine by means of the Humphrey Matrix frequency doubling technology (FDT) perimetry and the optical coherence tomography (OCT) retinal nerve fiber layer (RNFL) thickness measurement whether functional and/or structural differences exist between normal and ocular hypertensive (OHT) subjects. One eye of 60 consecutive normal individuals and 60 OHT subjects was enrolled in this prospective observational comparative case series study. All subjects were examined at either the Ophthalmology Clinic, University of Chieti-Pescara, Chieti, Italy or the Department of Ophthalmology, S. Maria della Misericordia Hospital, Udine, Italy. All subjects underwent a full ophthalmic examination, including visual acuity, slit-lamp biomicroscopy, central corneal thickness ultrasound pachymetry measurement, achromatic automated perimetry, Matrix FDT perimetry, stereoscopic optic nerve head photography, and OCT. Matrix FDT perimetry mean deviation (MD), pattern standard deviation, glaucoma hemifield test, and 12 OCT RNFL thickness parameters were examined. Student t test, Bonferroni correction for multiple comparisons and receiver operator characteristics curve areas (AUROCs) were used to find any discrimination function between healthy and OHT eyes. Sensitivities at 83% and 92% specificities were reported. The FDT MD scores ranged from -1.10 to +3.80 decibels (db) in normal individuals and from -4.75 to +3.20 db in OHT subjects. The comparison between the average MD in the 2 groups showed a statistically significant difference (P=0.024). OCT showed a statistically significant difference between the 2 groups when examining the ratio between the inferior and the superior mean RNFL thickness (P=0.004). For OCT, the parameter with the largest AUROC for discriminating between healthy and hypertensive eyes was the ratio between the mean inferior and superior RNFL thickness (AUROC=0.85, sensitivity=75% at specificity=83%, sensitivity=67% at specificity=92%). For Matrix FDT perimetry, the parameter with the largest AUROC was MD (AUROC=0.78, sensitivity=67% at specificity=83%, sensitivity=58% at specificity=92%). Our results suggest that OHT eyes having a normal achromatic automated perimetry and a normal clinical disc appearance cannot be differentiated from normal eyes using conventional OCT parameters. When analyzing the ratio between inferior and superior average RNFL thickness, however, a significant difference is evident between healthy and hypertensive eyes. Using Matrix FDT perimetry, a significant difference in MD seems to exist between these 2 groups of eyes. The AUROCs confirm that OCT Iavg/Savg and Matrix FDT MD show the greatest sensitivity and specificity among the examined OCT and Matrix FDT parameters.

Threshold and Variability Properties of Matrix Frequency-Doubling Technology and Standard Automated Perimetry in Glaucoma

To compare test results from second-generation Frequency-Doubling Technology perimetry (FDT2, Humphrey Matrix; Carl-Zeiss Meditec, Dublin, CA) and standard automated perimetry (SAP) in patients with glaucoma. Specifically, to examine the relationship between visual field sensitivity and test-retest variability and to compare total and pattern deviation probability maps between both techniques. Fifteen patients with glaucoma who had early to moderately advanced visual field loss with SAP (mean MD, -4.0 dB; range, +0.2 to -16.1) were enrolled in the study. Patients attended three sessions. During each session, one eye was examined twice with FDT2 (24-2 threshold test) and twice with SAP (Swedish Interactive Threshold Algorithm [SITA] Standard 24-2 test), in random order. We compared threshold values between FDT2 and SAP at test locations with similar visual field coordinates. Test-retest variability, established in terms of test-retest intervals and standard deviations (SDs), was investigated as a function of visual field sensitivity (estimated by baseline threshold and mean threshold, respectively). The magnitude of visual field defects apparent in total and pattern deviation probability maps were compared between both techniques by ordinal scoring. The global visual field indices mean deviation (MD) and pattern standard deviation (PSD) of FDT2 and SAP correlated highly (r > 0.8; P < 0.001). At test locations with high sensitivity (>25 dB with SAP), threshold estimates from FDT2 and SAP exhibited a close, linear relationship, with a slope of approximately 2.0. However, at test locations with lower sensitivity, the relationship was much weaker and ceased to be linear. In comparison with FDT2, SAP showed a slightly larger proportion of test locations with absolute defects (3.0% vs. 2.2% with SAP and FDT2, respectively, P < 0.001). Whereas SAP showed a significant increase in test-retest variability at test locations with lower sensitivity (P < 0.001), there was no relationship between variability and sensitivity with FDT2 (P = 0.46). In comparison with SAP, FDT2 exhibited narrower test-retest intervals at test locations with lower sensitivity (SAP thresholds <25 dB). A comparison of the total and pattern deviation maps between both techniques showed that the total deviation analyses of FDT2 may slightly underestimate the visual field loss apparent with SAP. However, the pattern-deviation maps of both instruments agreed well with each other. The test-retest variability of FDT2 is uniform over the measurement range of the instrument. These properties may provide advantages for the monitoring of patients with glaucoma that should be investigated in longitudinal studies.