Glaucoma Hemifield Test Research Articles

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.

Age-Related Losses of Retinal Ganglion Cells and Axons

Age-related losses in retinal nerve fiber layer (RNFL) thickness have been assumed to be the result of an age-dependent reduction of retinal ganglion cells (RGCs), but the published rates differ: age-related losses of RGCs of approximately 0.6%/year compared to 0.2%/year for thinning of the RNFL. An analysis of normative data for standard automated perimetry (SAP) sensitivities and optical coherence tomography (OCT) measures of RNFL thickness showed that the apparent disagreement in age-dependent losses of RGCs and axons in the RNFL can be reconciled by an age-dependent decrease in the proportion of the RNFL thickness that is composed of axons. The purpose of the present study was to determine whether the mechanisms of age-related losses that were suggested by the normative data can be confirmed with data from healthy, normal eyes. Data were obtained from visual fields (normal results in a Glaucoma Hemifield Test [GHT] on standard automated perimetry [SAP] 24-2 fields) and RNFL thickness measurements (standard OCT scan) of 55 patients (age range, 18-80 years; mean, 44.5 +/- 17.3). The SAP measures of visual sensitivity and OCT measures of RNFL thickness for one eye of each patient were used to estimate neuron counts by each procedure. The age-related thinning of RNFL was 0.27%/year when a constant axon density was used to derive axon counts from RNFL thickness, compared with 0.50%/year for the age-related loss of RGCs from SAP. In agreement with the model developed with normative clinical data, concordance between losses of axons and soma was achieved by an age-dependent reduction of 0.46%/year in the density of axons in the RNFL. The results suggest that the proportion of RNFL that is composed of RGC axons is not constant with age; rather, the proportion of the total thickness from non-neuronal tissue increases with age. If a similar compensation occurs in the RNFL thickness with axon loss from glaucoma, then a stage-dependent correction to translate OCT measurements to neuronal components is needed, in addition to the age-dependent correction.

Assessing Visual Field Clustering Schemes Using Machine Learning Classifiers in Standard Perimetry

To compare machine learning classifiers trained on three clustering schemes to determine whether distinguishing healthy eyes from those with glaucomatous optic neuropathy (GON) can be optimized by training with clustered data. Two machine learning classifiers-quadratic discriminant analysis (QDA) and support vector machines with Gaussian kernel (SVMg)-were trained separately using standard perimetry data from the Diagnostic Innovations in Glaucoma Study (DIGS), clustered using three clustering schemes on a training data set (123 eyes/123 glaucoma patients with GON; 135 eyes/135 normal control subjects). Trained classifiers were then applied to an independent data set containing 69 eyes of 69 glaucoma patients with early visual field loss and 83 eyes of 83 normal control subjects. Two control conditions were included: unclustered data and a random assignment of locations to clusters. Areas under the receiver operating characteristic (ROC) curve ranged from 0.85 (SVMg, thresholds clustered by Glaucoma Hemifield Test sectors) to 0.92 (QDA, thresholds clustered by Garway-Heath mapping) for the training data set. Use of clustered data showed no significant optimization of sensitivity over use of unclustered data, and no single clustering method resulted in significantly higher performance in the independent data set. Sensitivities tended to be higher with QDA than with SVMg, regardless of specificity cutoff and clustering QDA performed better with the early glaucoma data set than did the SVMg. Clustering may be advantageous when data-dimension reduction is needed-for example, when combining field results with other high-dimensional data (e.g., structural imaging data)-but it is not necessary for visual field data alone.

Reproducibility of Visual Field End Point Criteria for Standard Automated Perimetry, Full-Threshold, and Swedish Interactive Thresholding Algorithm Strategies: Diagnostic Innovations in Glaucoma Study

To compare the interthreshold and intrathreshold strategy agreement of visual field end point criteria for standard automated perimetry (SAP) with the full-threshold (FT) algorithm and the Swedish interactive threshold algorithm (SITA). Prospective, longitudinal cohort study. The interstrategy group included a randomly selected eye of 173 participants in the Diagnostic Innovations in Glaucoma Study who had undergone FT algorithm and SITA analysis within three months (sequence 1, FT + SITA). Intrastrategy agreement for the FT algorithm (sequence 2, FT + FT) was tested for 44 (25.4%) participants who had undergone FT analysis within one year of the FT used in the interstrategy pairing, and for 89 patients (51.4%) who had undergone SITA analysis within one year before (sequence 3, SITA + SITA). Four different end point criteria using Statpac II indices were tested. Interstrategy agreement was compared with intrastrategy agreement using kappa statistics. FT + SITA agreement (kappa) for pattern standard deviation (PSD) < 1% was 0.82; for PSD < 5%, the kappa value was 0.64; and for four or more pattern deviation plot points, the kappa value was 0.43. Agreement with glaucoma hemifield test (GHT) results was significantly higher (P < .01) for FT + FT (kappa = 0.94) than FT + SITA (kappa = 0.67), and approached significance (P = .07) when comparing FT + FT with SITA + SITA (kappa = 0.77). GHT results were more likely to be abnormal on the SITA analysis than on the FT analysis. No other significant differences were found. To minimize misinterpreting abnormal GHT results on SITA as evidence of change when switching strategies, both SITA and FT should be performed and compared within a short period. Other indices are comparable between the two strategies.

Learning effect of Humphrey Matrix perimetry

Background: Humphrey Matrix perimetry is a recent development in automated perimetry that uses frequency-doubling technology (FDT).We evaluated the learning effect of Humphrey Matrix perimetry with a full-threshold 30-2 strategy. Methods: Twenty-four patients with primary open-angle glaucoma and early visual field defects as assessed by standard automated perimetry and 24 healthy control subjects participated. All subjects had no prior experience with FDT visual field tests. Humphrey Matrix perimetry using a full-threshold 30-2 strategy was performed 3 times within 1 month.Various visual field indices were compared across multiple tests. Results: Mean deviation (MD) showed a larger defect at the first test than at the second and third tests ( p < 0.001), and the mean total improvement of the MD was 2.80 decibels (dB) in the glaucoma group and 1.71 dB in the control group. Pattern standard deviations (PSDs) were decreased as the tests were repeated, but test duration, fixation losses, and false-positive or false-negative rate were not changed significantly. Additionally, the Glaucoma Hemifield Test (GHT) showed unstable results. Interpretation: In patients naive to the FDT test, Humphrey Matrix perimetry showed a large learning effect on MD and PSD among the various visual field indices. The GHT results of Humphrey Matrix perimetry showed a large instability.

Clinical characteristics of eyes demonstrating atypical patterns in scanning laser polarimetry

To characterize which clinical features are associated with the occurrence of atypical birefringence patterns (ABP) occasionally seen with scanning laser polarimetry (SLP). Sixty-one subjects, including glaucoma patients, glaucoma suspects, and normal subjects, underwent a full clinical examination, standard visual field (VF) test, and a GDx-VCC SLP examination. One eye was selected from each patient. The magnitude of ABP was determined in two independent ways: using a support vector machine analysis (typical scan score (TSS)) and by a masked experienced observer. We assessed whether the magnitude of ABP was correlated with age, gender, the refractive state of the eye, corneal polarization axis and magnitude, GDx global parameters (TSNIT and NFI), and the VF status, as evident from glaucoma hemifield test (GHT), mean deviation (MD), and the pattern standard deviation (PSD). Of the 61 study eyes, 27 (44%) showed an ABP, based on a TSS cutoff (<82.5). A very high correlation was found between the TSS score and the masked experienced observer score (r(2)=0.80; P<0.001). The following clinical parameters were found, on bivariate analysis, to be significantly correlated with the presence of an ABP: age (r(2)=0.086; P=0.02); corneal polarization magnitude (r(2)=0.069; P=0.04); TSNIT (r(2)=0.16; P<0.001). The presence and magnitude of ABP did not seem to be closely correlated with most clinical parameters. A low, but statistically significant, correlation was found for age and corneal polarization magnitude (r(2)=0.086 and 0.069, respectively). A low-medium correlation was found for TSNIT (r(2)=0.16); however, we speculate that this might represent a confounding effect, rather than an underlying association. We conclude that none of the clinical parameters investigated in this study appears to be strongly correlated with the presence of an ABP on SLP scans performed using the commercially available GDx-VCC.

The Influence of Learning Effect on Frequency Doubling Technology Perimetry (Matrix)

To determine learning effect in healthy patients without perimetric experience, tested with the frequency doubling technology perimetry, with the new model Matrix. Frequency doubling technology in the 30-2 threshold mode was performed on 37 healthy subjects. Each subject was tested twice in different sessions. The test always began with the right eye (RE) and continued with the left eye (LE). To evaluate learning effect the results of the REs at the first session were compared with those of the LE. The following parameters were evaluated: foveal threshold (FT), reliability indexes, mean defect (MD), pattern standard deviation (PSD), glaucoma hemifield test (GHT), duration of examination. At the first session the average values of RE were FT=30.81 db, MD=-1 db, PSD=3.01 db, and duration of the examination=383.27 "and of LE were FT=30.73, MD=-0.79 db, PSD=2.97 db, and duration of examination 382.62." At the second session the average values of RE were FT=32.22 db, MD=+0.16 db, PSD 2.75 db, and duration of examination=374.97 db. The reliability was different and the GHT between the RE and LE in the first and second session was also different. A learning effect was observed between the first and the second sessions and the results of the GHT appeared improved. This above all should be taken into account when considering the clinical use of this test to avoid erroneous diagnostic conclusions.

Discriminating Ability of Humphrey Matrix Perimetry in Early Glaucoma Patients

Purpose: To determine the discriminating ability of some parameters provided by Humphrey Matrix perimetry for early glaucoma detection. Methods: A prospective cross-sectional study was performed. Sixty-five primary open-angle glaucoma patients with early-stage visual field defects on standard automated perimetry (mean deviation = –1.98 ± 1.93 dB) and 56 healthy subjects were included. All subjects performed the Humphrey Matrix perimetry with a threshold 30-2 strategy. The receiver operating characteristic (ROC) curve was constructed for each parameter and calculated the area under the ROC curve (AUC) to seek the best discriminating parameter for early glaucoma detection. Results: The AUCs of Humphrey Matrix perimetry with the mean deviation, pattern standard deviation, Glaucoma Hemifield Test, number of points that have a p < 5% in pattern deviation plot (PDP) and number of points that have a p < 1% in PDP were 0.795, 0.808, 0.689, 0.985 and 0.946, respectively. Conclusion: Humphrey Matrix perimetry allowed accurate discrimination between normal and early glaucomatous eyes. The number of points that had a p < 5% in PDP was the best discriminating parameter for early glaucoma detection using Humphrey Matrix perimetry.

Detecting Visual Function Abnormalities Using the Swedish Interactive Threshold Algorithm and Matrix Perimetry in Eyes With Glaucomatous Appearance of the Optic Disc

To compare the ability of 24-2 frequency-doubling perimetry (FDP-Matrix) with standard automated perimetry with the Swedish interactive threshold algorithm (SAP-SITA) in detection of visual function abnormalities in patients with glaucomatous-appearing optic discs (GAOD). This observational case-control study included 80 patients with GAOD and 54 control subjects diagnosed by masked assessment of optic disc stereoscopic photographs. Abnormal visual function at SAP-SITA and FDP-Matrix testing required consistent abnormalities in 2 visual field examinations, determined using the glaucoma hemifield test outside 99% normal limits, pattern standard deviation outside 95% normal limits, or 3 contiguous points in the pattern deviation probability plot outside 95% normal limits (at least 1 P<1%) within the same hemifield. The FDP-Matrix and SAP-SITA detected abnormal visual function in 51% and 44%, respectively, of GAOD eyes (P = .26), and both perimetry techniques identified 11% of healthy eyes as abnormal. Agreement between FDP-Matrix and SAP-SITA was moderate (kappa = 0.49), as only 35% of GAOD eyes and 2% of healthy eyes had both visual field test results flagged as abnormal. The FDP-Matrix detected abnormal visual function in more eyes with GAOD than did SAP-SITA, although this difference was not significant. Each visual field test tended to identify different subsets of eyes with GAOD as abnormal. Combination of these perimetry techniques may improve the detection of visual function abnormalities in patients with glaucoma.

Comparing Multifocal VEP and Standard Automated Perimetry in High-Risk Ocular Hypertension and Early Glaucoma

To compare the diagnostic performance of multifocal visual evoked potential (mfVEP) and standard automated perimetry (SAP), in eyes with high-risk ocular hypertension or early glaucoma. Both eyes of 185 individuals with high-risk ocular hypertension or early glaucoma were evaluated. Subjects ranged in age from 37 to 87 (mean +/- SD: 61 +/- 11 years). Pattern-reversal mfVEPs were obtained by using VERIS (Electro-Diagnostic Imaging, San Mateo, CA) with a four-electrode array and were analyzed with custom software. SAP visual fields (SITA-standard; Carl Zeiss Meditec, Inc., Dublin, CA) were obtained within 22.3 +/- 27.0 days of the mfVEP. Stereo disc photographs and Heidelberg Retina Tomograph (HRT) images were obtained during one visit, which was within 24.8 +/- 50.4 days of the mfVEP and 33.1 +/- 62.9 days of the SAP visual field. Abnormalities on the mfVEP were defined by using a variety of cluster criteria: SAP with pattern standard deviation (PSD) P </= 0.05 or glaucoma hemifield test (GHT) outside normal limits, according to OHTS criteria (SAP-OHTS). In separate analyses cluster criteria were used to determine SAP abnormalities. Disc photographs were graded as either glaucomatous optic neuropathy (GON) or normal by two independent masked experts, and disagreements were adjudicated by a third masked expert. The overall Moorfields regression analysis (MRA) result from the HRT was used as a separate diagnostic classification. All eyes classified as "borderline" by the MRA were assigned to the normal category (i.e., "within normal limits"). Sensitivity for mfVEP or SAP was defined as the percentage of GON eyes that had an abnormality on the functional test. Specificity for mfVEP or SAP was defined as the percentage of eyes with normal optic disc structure that had normal functional test results. Disc photographs from 50% of eyes were graded GON. Both eyes were graded GON in 71 (38%) of the 185 subjects. Exactly half as many eyes were abnormal by HRT MRA. The average SAP mean deviation (MD) was +0.3 +/- 2.1 dB; average PSD was 2.3 +/- 1.9 dB. By OHTS criteria, 83 (22%) of the 370 eyes had an abnormal SAP. Depending on the cluster criterion used, the proportion of eyes with an abnormal SAP ranged from 8% to 26% and with an abnormal mfVEP, from 14% to 45%. A criterion with an estimated specificity in normal subjects of 91% resulted in 102 (28%) eyes with an abnormal mfVEP. For criteria with estimated specificities of 95% and 99%, respectively, 88 (24%) eyes and 52 (14%) eyes had an abnormal mfVEP. Agreement between SAP and mfVEP ranged from 75% to 81%. The sensitivity of SAP-OHTS to detect GON (using the disc photograph as diagnostic standard) was 29%, whereas specificity was 84%. Sensitivity of the mfVEP to detect GON, for cluster criteria with disc structure specificity between 84% and 87%, ranged from 28% to 32%. When the HRT MRA was used as the diagnostic standard, sensitivities of both functional tests to detect GON increased to 42%. The diagnostic performance of mfVEP was similar to that of SAP. However, the two modalities agreed in only approximately 80% of eyes, suggesting that they may detect slightly different functional deficits.

Changes in the visual field following laser in situ keratomileusis for myopia

To assess the changes of the visual field (VF) caused by transient intraocular pressure (IOP) peaks during laser in situ keratomileusis (LASIK) surgery for myopia using automated perimetry. This prospective study involved 94 eyes of 94 patients who underwent a conventional LASIK procedure. A complete eye examination was carried out in which the IOP measurement, and Humphrey 24-2 SITA standard VF were tested prior to LASIK and 6 and 12 months after LASIK. Patients were divided into two subgroups according to their refractive error. VF global indices, Glaucoma Hemifield Test and the number of depressed points deviating at p < 5%, p < 2%, p < 1% and p < 0.5% on the Pattern Deviation probability maps were compared using the analysis of variance. In the low myopia group, there were no significant differences in the analysed variables, except a slight decrease in mean deviation (MD) when comparing results prior to and 6 months following LASIK (p = 0.036; anova) that returned to baseline values at 12 months after surgery. In the moderate and high myopia group, there were no statistically significant differences in any of the variables analysed. No significant correlation was found between the transitory reduction in MD and any of the variables studied. In patients with low myopia, the VF undergoes a transitory increase in diffuse defects 6 months after surgery, with spontaneous recovery at 12 months after LASIK procedure. Possible explanations for these findings are discussed.

Retinal Nerve Fiber Layer Thickness and Visual Sensitivity Using Scanning Laser Polarimetry with Variable and Enhanced Corneal Compensation

To compare the strength of the structure-function association between scanning laser polarimetry-measured retinal nerve fiber layer (RNFL) thickness and visual sensitivity. Two methods of corneal compensation were evaluated, variable corneal compensation (VCC) and enhanced corneal compensation (ECC). Observational case series. One hundred twenty-seven glaucoma (repeatable abnormal visual fields [VF] by pattern standard deviation and/or glaucoma hemifield test) or glaucoma suspect (glaucomatous-appearing discs by photograph assessment without field defects) participants in the University of California, San Diego Diagnostic Innovations in Glaucoma Study. One eye of each participant was imaged using GDx VCC and GDx ECC on the same day. Visual fields tested using the Humphrey Field Analyzer (with Swedish interactive threshold algorithm) were obtained within 6 months of imaging. The associations (R2) using linear and logarithmic regression between RNFL thicknesses measured in 6 sectors (inferior, inferotemporal, temporal, superotemporal, superior, nasal) with VCC and ECC and VF sensitivities (decibel threshold measurements) measured in 6 corresponding sectors were compared. Comparisons were made using paired t tests on the log-transformed absolute values of regression residuals. Using GDx VCC, 32 scans had a typical scan score (TSS) < or = 78 (lowest quartile) and no ECC scans had TSS<86. Most RNFL thickness measurements obtained using GDx VCC were significantly greater than those measured using GDx ECC. Regional structure-function associations (R2) ranged from 0.03 (temporal RNFL) to 0.22 (superotemporal RNFL) for VCC and from 0.01 (temporal RNFL) to 0.26 (superotemporal RNFL) for ECC. Associations generally were slightly stronger for ECC than for VCC, although these differences were only significant for inferotemporal RNFL (R2 = 0.19 and 0.11, for ECC and VCC, respectively). The RNFL thickness associations with VF sensitivity are stronger using ECC compared with VCC, suggesting that ECC provides a better cross-sectional representation of visual function than VCC.

Trained Artificial Neural Network for Glaucoma Diagnosis Using Visual Field Data

To evaluate and confirm the performance of an artificial neural network (ANN) trained to recognize glaucomatous visual field defects, and compare its diagnostic accuracy with that of other algorithms proposed for the detection of visual field loss. SITA Standard 30-2 visual fields, from 100 glaucoma patients and 116 healthy participants, formed the data set. Our ANN was a previously described fully trained network using scored pattern deviation probability maps as input data. Its diagnostic accuracy was compared to that of the Glaucoma Hemifield Test, the Pattern Standard Deviation index at the P<5% and <1%, and also to a technique based on the recognizing clusters of significantly depressed test points. The included tests had early to moderate visual field loss (median MD=-6.16 dB). ANN achieved a sensitivity of 93% at a specificity level of 94% with an area under the receiver operating characteristic curve of 0.984. Glaucoma Hemifield Test attained a sensitivity of 92% at 91% specificity. Pattern Standard Deviation, with a cut off level at P<5% had a sensitivity of 89% with a specificity of 93%, whereas at P<1% the sensitivity and specificity was 72% and 97%, respectively. The cluster algorithm yielded a sensitivity of 95% and a specificity of 82%. The high diagnostic performance of our ANN based on refined input visual field data was confirmed in this independent sample. Its diagnostic accuracy was slightly to considerably better than that of the compared algorithms. The results indicate the large potential for ANN as an important clinical glaucoma diagnostic tool.

The Effect of Atypical Birefringence Patterns on Glaucoma Detection Using Scanning Laser Polarimetry with Variable Corneal Compensation

The purpose of this study was to investigate the effect of the presence of atypical birefringence patterns, as measured by the typical scan score (TSS), on the diagnostic accuracy of a scanning laser polarimeter (the GDx VCC; Carl Zeiss Meditec, Inc., Dublin, CA) assessed by receiver operating characteristic (ROC) curves for discriminating between glaucoma and healthy eyes. Two hundred thirty-three glaucomatous eyes (repeatable abnormal visual fields by pattern standard deviation [PSD] and/or glaucoma hemifield test [GHT]) from 153 patients with glaucoma and 104 eyes from 71 healthy participants enrolled in the UCSD Diagnostic Innovations in Glaucoma Study (DIGS) were imaged using the GDx VCC. An ROC regression model was used to evaluate the influence of the covariates TSS; disease severity, defined as standard automated perimetry (SAP) mean deviation [MD]; and age in years on the diagnostic accuracy of the GDx parameters nerve fiber indicator [NFI], TSNIT (temporal, superior, nasal, inferior, temporal) average thickness, superior average thickness, inferior average thickness, and TSNIT standard deviation. Areas under the ROC curve were calculated for specific levels of the covariates according to the results provided by the model. TSS and SAP MD significantly affected the diagnostic accuracy of each investigated GDx VCC parameter. Low TSSs, indicating the presence of atypical scans, were associated with decreased accuracy. For NFI, ROC curve areas ranged from 0.749 (when TSS = 20) to 0.904 (when TSS = 100). A similar influence of TSS was found for other parameters. In addition, diagnostic accuracy increased with increasing disease severity. For instance, for NFI, ROC curve areas ranged from 0.853 (when SAP MD = -3) to 0.954 (when SAP MD = -15). The diagnostic accuracy of GDx VCC parameters is affected by disease severity and is adversely affected by the presence of atypical retardation patterns (i.e., decreasing TSS). GDx VCC scans with atypical scan patterns should be interpreted with caution when used in clinical practice.

Assessment of a Race-specific Normative HRT-III Database to Differentiate Glaucomatous From Normal Eyes

To determine if a new, normative, race-specific database enhances the ability of confocal scanning laser ophthalmoscopy to differentiate normal from glaucomatous eyes. One eye of eligible normal and glaucoma patients was enrolled. All subjects underwent a complete ophthalmologic examination, standard achromatic perimetry (SITA-SAP, 24-2), and confocal scanning laser ophthalmoscopy [Heidelberg retinal tomograph (HRT-II)] within 1 month of enrollment. Racial groups were defined by self-report. Glaucoma was defined by the existence of reproducible SAP loss (pattern standard deviation <5% and/or Glaucoma Hemifield Test outside normal limits) on 2 consecutive fields. Normal subjects had 2 normal visual fields (pattern standard deviation >5% and Glaucoma Hemifield Test within 97% normal limits) and a normal clinical examination. HRT-II examinations were exported to the HRT-III software, which includes a large race-specific normative database consisting of 733 white and 215 black eyes. Moorfields regression analysis (MRA) for the most abnormal optic disc sector was compared between the HRT-II (MRA2) and the HRT-III software before (MRA3-B) and after (MRA3-A) adjustment for race. Sectors outside the 99.9% confidence interval limits ("outside normal limits") were determined to be abnormal. We enrolled 124 black (52 glaucoma, 72 normal) and 96 white (32 glaucoma, 64 normal) subjects. Mean age was 51+/-13 years and 50+/-16 years for blacks and whites, respectively (P = 0.45). Visual field mean deviation was -7.3+/-6.7 db for glaucomatous eyes and -0.4+/-1.1 db for normal eyes (P < 0.001). Sensitivity and specificity for the HRT-II was 71.9% and 95.3%, respectively, for white subjects and 50.0% and 98.6%, respectively, for black subjects. Using the expanded HRT-III database, analysis yielded a sensitivity of 81.3% and specificity of 93.8% for whites and a sensitivity of 71.2% and specificity of 86.1% for blacks. After an adjustment for black ethnicity was made in the HRT-III program, the sensitivity and specificity for blacks was 65.4% and 90.3%, respectively. A new, larger, race-specific HRT-III database increases sensitivity while maintaining specificity for whites and increases sensitivity but decreases specificity for blacks. New software and databases based on race require careful scrutiny before use in clinical practice.

Frequency-Doubling Perimetry: Comparison With Standard Automated Perimetry to Detect Glaucoma

To compare second generation frequency-doubling perimetry (FDP) with standard automated perimetry (SAP) to detect glaucomatous visual field abnormalities. Prospective, cross-sectional, controlled observational study. Fifty eyes of 50 patients with glaucoma with confirmed SAP visual field abnormalities and 42 eyes from 42 normal control subjects were studied. Swedish Interactive Thresholding Algorithm (SITA) standard 24-2 SAP and FDP visual fields were performed. The correlation of global indices and the number of defects on total deviation (TD) and pattern deviation (PD) plots were compared. The spatial concordance of FDP and SAP defect locations was determined. In patients with glaucoma, significant correlations of mean deviation (MD) and pattern standard deviation (PSD) were found between SAP and FDP (P < .001 for MD and P < .001 for PSD), but not in the normal group. FDP had significantly greater defect scores than SAP on total deviation and PD plots in the glaucoma group (P = .028 and P = .01, respectively). In comparison with SAP, sensitivity and specificity of FDP were 92% and 98% with glaucoma hemifield test criteria and 98% and 93% with PSD <5% criteria, respectively. Similarly high diagnostic precision was found with MD and PSD (at 95% specificity; MD and PSD sensitivity was 82% and 90%, respectively). The location of defects within 12 hemifield clusters found with FDP agreed moderately well with those detected with SAP (kappa = .48). FDP and SAP perform similarly in their ability to detect visual field defects in early to moderate glaucoma. Larger and deeper defects detected with FDP suggests the possibility of earlier detection at high specificity.

Comparison of Visual Field Defects Using Matrix Perimetry and Standard Achromatic Perimetry

To compare visual field (VF) defects found by Swedish interactive thresholding Algorithm (SITA) perimetry and Matrix perimetry, a new VF device that utilizes frequency doubling technology in a 24-2 test pattern. Prospective cross-sectional study. Fifty eyes from 50 subjects with SITA field defects were recruited for an observational study. Swedish Interactive Threshold Algorithm and Matrix VF testing were performed on patients from a glaucoma practice. To evaluate the learning effect on the performance of the VF, we tested subsets of each group who had previous experience with standard automated perimetry (SAP). Test duration, mean threshold, mean deviation (MD), pattern standard deviation (PSD), glaucoma hemifield test, and number of abnormal points on the pattern deviation plot were evaluated for each device. Test duration was significantly shorter for Matrix (SITA, 357.0+/-85.6 seconds; Matrix, 319.5+/-16.5 seconds; P = 0.0002, paired t-test). Thirty-six percent of eyes with SITA VF defects showed a normal Matrix field. In 30 of 32 eyes (94%) where both devices showed VF defects, the defects were congruent. Mean threshold value was significantly lower with Matrix compared to SITA (P<0.0001, paired t-test), as was MD (-5.34+/-5.42 dB, -4.14+/-5.29 dB, respectively; P = 0.03, paired t-test). There was no significant difference in PSD between the 2 devices (P = 0.78, paired t-test). Matrix delineated significantly smaller (P = 0.005, Wilcoxon's test) and deeper (P<0.001, Wilcoxon's test) defects than those found with SITA. Similar results were observed in the subgroups with prior SAP experience. The Matrix examination did not detect 36% of abnormal SITA fields. Matrix field defects were smaller and deeper than those appearing in SITA perimetry.

Assessment of False Positives with the Humphrey Field Analyzer II Perimeter with the SITA Algorithm

To evaluate the effects of false-positive (FP) response errors on mean deviation (MD), pattern standard deviation (PSD), glaucoma hemifield test (GHT), and test duration in the Humphrey Field Analyzer's (HFA II) Swedish Interactive Threshold Algorithm (SITA; Carl Zeiss Meditec, Inc., Dublin, CA). Five individuals with glaucoma (ages 52, 63, 69, 77, and 78 years) and five individuals with normal, healthy eyes (ages 25, 34, 43, 45, and 52 years), participated in the study. Each subject was experienced in automated perimetry and performed multiple, monocular baseline SITA-standard (SITA-S) 24-2 visual field tests. In addition, normal subjects completed SITA-S 24-2 field examinations in which known frequencies of FP error were introduced (0%, 5%, 10%, 20%, or 33% frequency). Likewise, the subjects with glaucoma completed visual field examinations with 0%, 20%, and 33% error introduced during the test. Reported FP errors were significantly lower than the introduced frequency of error. The SITA algorithm more accurately identified FP errors when the MD and PSD diverged from normal. Test duration increased as introduced error frequencies increased. The Statpac single-field analyses indicated that two thirds of the tests with introduced errors produced a "low-patient-reliability" determination. HFA II SITA-S underestimates patients' FP errors, particularly among normal patients. High FP error frequencies can have adverse effects on MD and PSD, leading clinicians and researchers to an inaccurate determination of the amount and severity of visual field loss.

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.

Detecting Early Functional Damage in Glaucoma Suspect and Ocular Hypertensive Patients With the Multifocal VEP Technique

To determine whether the multifocal visual evoked potential (mfVEP) technique can detect early functional damage in ocular hypertensive (OHT) and glaucoma suspect (GS) patients with normal standard achromatic automated perimetry (SAP) results. Twenty-five GS patients (25 eyes), 25 patients with OHT (25 eyes), and 50 normal controls (50 eyes) were enrolled in this study. All GS, OHT and normal control eyes had normal SAP as defined by a pattern standard deviation and mean deviation within the 95% confidence interval and a glaucoma hemifield test within normal limits on the Humphrey visual field 24-2 program. Eyes with GS had optic disc changes consistent with glaucoma with or without raised intraocular pressure (IOP), and eyes with OHT showed no evidence of glaucomatous optic neuropathy and IOPs >or=22 mm Hg. Monocular mfVEPs were obtained from both eyes of each subject using a pattern-reversal dartboard array with 60 sectors. The entire display had a radius of 22.3 degrees. The mfVEPs, for each eye, were defined as abnormal when either the monocular or interocular probability plot had a cluster of 3 or more contiguous points with P<0.05 and at least 2 of these points with P<0.01. The mfVEP results were abnormal in 4% of the eyes from normal subjects. Abnormal mfVEPs were detected in 20% of the eyes of GS patients and 16% of the eyes of OHT patients. Significantly more mfVEP abnormalities were detected in GS patients than in normal controls. However, there was no significant difference in mfVEP results between OHT patients and normal controls. The mfVEP technique can detect visual field deficits in a minority of eyes with glaucomatous optic disks and normal SAP results.