Full Threshold Strategy Research Articles

Repeatability of a Virtual Reality Headset Perimeter in Glaucoma and Ocular Hypertensive Patients.

The VisuALL S is an automated, static threshold, virtual reality-based perimeter for mobile evaluation of the visual field. We examined same-day and 3-month repeatability. Adult participants with a diagnosis of glaucoma or ocular hypertension underwent two VisuALL 24-2 Normal T- Full threshold strategy tests at baseline and one additional exam at 3months for each eligible eye. Spearman, intraclass correlation coefficients (ICCs), and Bland-Altman plots were used to assess the correlation of individual point sensitivities and mean deviation (MD) among three tests. Eighty-eight eyes (44 participants) were included. Average age was 68.1 ± 14.3 years, and 60.7% were male. VisuALL MD was highly correlated between tests (intravisit: r = 0.89, intervisit: r = 0.82; P < 0.001 for both). Bland-Altman analysis showed an average difference in intravisit MD of -0.67dB (95% confidence interval [CI], -6.04 to 4.71dB) and -0.15dB (95% CI, -8.04 to 7.73dB) for intervisit exams. Eight-five percent of pointwise intravisit ICCs were above 0.75 (range, 0.63 to 0.93), and 65% of pointwise intervisit ICCs were above 0.75 (range, 0.55 to 0.91). VisuALL demonstrated high correlation of MD between tests and good repeatability for individual point sensitivities among three tests in 3months, except at the points around the blind spot and superiorly. The preliminary reproducibility results for VisuALL are encouraging. Its portable design makes it a potentially useful tool for patients with glaucoma, enabling more frequent assessments both at home and in clinical settings.

Classification and Statistical Trend Analysis in Detecting Glaucomatous Visual Field Progression

Aim To evaluate the agreement between different methods in detection of glaucomatous visual field progression using two classification-based methods and four statistical approaches based on trend analysis. Methods This is a retrospective and longitudinal study. Twenty Caucasian patients (mean age 73.8 ± 13.43 years) with open-angle glaucoma were recruited in the study. Each visual field was assessed by Humphrey Field Analyzer, program SITA standard 30-2 or 24-2 (Carl Zeiss Meditec, Inc., Dublin, CA). Full threshold strategy was also accepted for baseline tests. Progression was analyzed by using Hodapp–Parrish–Anderson classification and the Advanced Glaucoma Intervention Study visual field defect score. For the statistical analysis, linear regression (r2) was calculated for mean deviation (MD), pattern standard deviation (PSD), and visual field index (VFI), and when it was significant, each series of visual field was considered progressive. We also used Progressor to look for a significant progression of each visual field series. The agreement between methods, based on statistical analysis and classification, was evaluated using a weighted kappa statistic. Results Thirty-eight visual field series were analyzed. The mean follow-up time was 6.2 ± 1.53 years (mean ± standard deviation). At baseline, the mean MD was −7.34 ± 7.18 dB; at the end of the follow-up, the mean MD was −9.25 ± 8.65 dB; this difference was statistically significant (p < 0.001). The agreement to detect progression was fair between all methods based on statistical analysis and classification except for PSD r2. A substantial agreement (κ = 0.698 ± 0.126) was found between MD r2 and VFI r2. With the use of all the statistical analysis, there was a better time-saving. Conclusions The best agreement to detect progression was found between MD r2 and VFI r2. VFI r2 showed the best agreement with all the other methods. GPA2 can help ophthalmologists to detect glaucoma progression and to help in treatment decisions. PSD r2 was the worse method to detect progression.

Macular sensitivity in areas of capillary nonperfusion in nonproliferative diabetic retinopathy

Aim The aim of this study was to correlate the visual field changes in the central macular area with the areas of capillary nonperfusion seen in fluorescein angiogram in patients with nonproliferative diabetic retinopathy (NPDR). Patients and methods This study included 40 eyes of 32 patients with NPDR attending the Ophthalmic Outpatient Clinic of El-Minia University Hospital during the period from January 2012 to July 2013. All patients were subjected to automated perimetry using a Topcon perimeter. A full-threshold strategy was applied for the central 10° field (program 10–2) fluorescein angiography using the IMAGE Net 2000 fundus camera. Results This study included 40 eyes of 32 patients between 50 and 70 years of age with a mean of 59.3 ± 7.6 years. Of them, there were 12 (37.5%) male and 20 (62.5%) female patients. All patients were noninsulin-dependent diabetic patients with a mean duration of 16.6 ± 5.4 years; 20 (62.5%) patients were hypertensive and 12 (37.5%) were normotensive. Twenty eyes had a rate of 0 dB corresponding to areas of capillary nonperfusion. Sixteen eyes showed a rate of 0 dB less than the areas of capillary nonperfusion. Four eyes showed relatively good retinal sensitivity (rate of 0 dB = 0) despite the presence of definite areas of capillary nonperfusion. The mean sensitivity in these areas ranged between 10.38 ± 1.47 and 12.91 ± 1.43 dB. Conclusion There is a significant correspondence between macular capillary nonperfusion and central field sensitivity in patients with NPDR.

A Novel Distribution of Visual Field Test Points to Improve the Correlation between Structure–Function Measurements

To create a new visual field (VF) test grid centered at the optic disc (disc-centered field [DCF]) and to infer the combination of VF test points (structure-function field [SFF]), taken from the DCF and the conventional fovea-centered 24-2 grid (24-2) of standard automated perimetry, which yields the strongest sectorial correlation between structure-function measurements of retinal nerve fiber layer (RNFL) thickness and VF sensitivity. In 50 eyes with ocular hypertension or open angle glaucoma, the DCF and 24-2 VF were measured with a humphrey field analyzer II (Full Threshold strategy) and RNFL thickness was measured with Stratus optical coherence tomography. test points from the DCF and 24-2 VF Were combined and divided into 12 sectors according to the spatial distribution of the RNFL. A novel VF for structure-function studies was established using the following criteria: each sector must contain at least one or two test points (depending on the sector's location), and the combination of test points which yields the strongest structure-function correlation is selected. The SFF consisted of 40 test points. The structure-function correlation for the SFF was compared with the standard 24-2 VF; a multiple-comparison test for dependent groups was carried out using a percentile bootstrap method, which indicated that the sector correlation coefficients in the SFF were significantly higher than those in the 24-2 VF. The SFF, with fewer test locations, has a stronger structure-function correlation than the 24-2 VF. This improved correlation may help clinicians to better interpret functional measurements in relation to structural measurements.

Visual Fields, Visual Acuity, and Driving Performance in Patients with Pituitary Adenoma before and after Surgery

We evaluated the prognosis of visual fields, visual acuity, and fitness to drive and the phenomenon of statokinetic dissociation in patients with pituitary adenoma who undergo surgery. In patients with pituitary adenoma, visual requirements for on road driving performance and the role of statokinetic dissociation have not been evaluated previously. Twenty-eight patients (56 eyes) with pituitary adenoma were included in the study over a period of 5 years and consecutively examined before and after surgery by the same ophthalmologist. Preoperatively, out of 56 eyes, we found visual field defects in 31 eyes (55%) and visual acuity impairment in 23 eyes (41%). Postoperatively, 24 out of 28 patients (86%) met the legal binocular visual requirements for driving a car in Germany. In 31 eyes with visual field defects (VFD), 64% of VF improved after surgery. Visual acuity impairment was reduced postoperatively in 75%, 10% remained unchanged, and 15% deteriorated, but 2/3 of these improved after second surgical intervention. All 28 patients were legally fit to drive postoperatively. Statokinetic dissociation was evaluated in 22 eyes with reliable static and kinetic double examination, performed on the same day. In 16 eyes (73%), computerised static perimetry (Octopus perimetry, central 30°, full threshold strategy) showed considerably more severe VFD than kinetic perimetry (i.e., statokinetic dissociation was ascertained). From this study we conclude that 60% of patients with pituitary adenoma can hope for significant improvement of visual function (64% in VF, 75% in visual acuity) after surgery, and driving permission can often be regained. Due to statokinetic dissociation, kinetic perimetry should be complemented by automated static perimetry.

Differences of optic disc appearance between normal tension and high tension glaucoma patients

The term glaucoma is used to cover a wide range of diseases, whose main feature is optic neuropathy. According to the level of intraocular pressure (IOP), the open angle glaucoma is arbitrarily divided into high tension glaucoma (HTG) and normal tension glaucoma (NTG). The aim of this study was to investigate the differences of optic disc cup appearance between patients with NTG and HTG. Prospective study included 30 patients (60 eyes) with NTG and 30 patients (60 eyes) with HTG. IOP was measured by Goldmann applanation tonometry. Examination of optic disc head was performed by indirect ophthalmoscopy with Volk 90 D superfield lens through a dilated pupil to observe qualitative and quantitative parameters. Visual fields were examined in all patients with the Octopus program G1, full threshold strategy (Octopus 500 EZ, Interzeag, Switzerland). Vertical form of optic disc cup was present in 11 eyes with NTG (18.3%) and three eyes with HTG (5%) (p < 0.05). A disc with localized tissue loss (polar notching) on the inferior pole was observed in eight eyes with NTG (13.3%) and in one eye with HTG (1.7%) (p < 0.01). Uniformly enlarged, round cup was more frequent in patients with HTG than NTG: 93.3% and 68.3% respectively (p < 0.05). The perceived differences indicate a complex multifactorial nature of glaucoma disease and a possible existence of two pathophysiological ways of optic disc changes within the same basic disease.

Learning Effect of Humphrey Matrix Frequency Doubling Technology Perimetry in Patients with Open-Angle Glaucoma

To evaluate the learning effect of frequency doubling technology (FDT) perimetry using the Humphrey Matrix perimeter in patients with open-angle glaucoma with no perimetric experience. One eye each of 30 glaucoma patients who had no history of visual field testing underwent 3 Matrix tests using 24-2 program with full-threshold strategy. The parameters investigated to detect learning effect were test duration, reliability indexes, mean deviation (MD), pattern standard deviation (PSD), and the number of points with a p of <5% and <1% in the total and pattern deviation maps. MD showed a larger defect at the first test (-13.64 +/- 1.63 dB) than at the second (-12.68 +/- 1.45 dB) and third (-11.69 +/- 1.48 dB) tests (p<0.05). A statistically significant reduction (p<0.05) in the number of points with a p <5% and <1% in the total deviation map was observed when repeating the examination. The values of test duration, PSD, fixation losses, false-positive rate, false-negative rate, and number of points with a p <5% and <1% in the pattern deviation map were not changed significantly (p>0.05). Humphrey Matrix FDT perimetry showed a statistically significant learning effect on MD and the number of significantly depressed points of the total deviation map in glaucoma patients with no perimetric experience. It is probably necessary to obtain at least 3 repetitions to rule out the presence of a learning effect in such patients before providing useful results.

Relationship between frequency‐doubling perimetry indices and optic nerve head parameters measured with the Heidelberg retina tomograph 3

Abstract Purpose To determine the relationship between the indices of frequency‐doubling perimetry (FDT) and the optic disc parameters measured with the Heidelberg Retina Tomograph (HRT) 3 in glaucoma patients. Methods 74 eyes of 74 glaucoma patients were prospective and consecutively selected. All of them had intraocular pressure higher than 21 mmHg, and reproducible glaucomatous visual field loss in standard automated perimetry. FDTs were performed with a Humphrey FDT perimeter using the C‐20‐5 full threshold strategy. Participants underwent imaging of the optic disc with the HRT3. The Kolmogorov Smirnov test was applied to check the data were normally distributed. Pearson correlations were calculated between FDT indices (mean deviation and pattern standard deviation) and global stereometric HRT3 parameters. Results Mild to moderate significant correlations (p&lt;0.05) were observed between the FDT indices and most HRT3 parameters. The strongest correlation was found between the mean deviation of FDT and FSM discriminant function of HRT3 (0.525). Pattern standard deviation had the strongest correlation with rim area (‐0.431). Conclusion Optic nerve head parameters measured with HRT3 showed reasonable agreement with FDT indices in glaucoma patients.

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.

Comparing the Full-Threshold and Swedish Interactive Thresholding Algorithms for Short-Wavelength Automated Perimetry

To compare the Swedish interactive thresholding algorithm (SITA) with the full-threshold (FT) strategy for short-wavelength automated perimetry (SWAP). One eye of 286 patients with glaucomatous optic neuropathy (GON) and 289 age-matched participants without GON from the Diagnostic Innovations in Glaucoma Study (DIGS) and the African Descent and Glaucoma Evaluation Study (ADAGES) were classified with optic disc stereophotographs taken within 6 months of visual field testing, conducted within a 3-month period. Six parameters were derived per test, including pattern standard deviation (PSD) and the number of pattern deviation plot (PDP) points triggered at <1%. Receiver-operating characteristic (ROC) analysis equated the tests for specificity (80%, 90%, and 95%). Sensitivities of parameters with the highest area under the curve (AUC) and STATPAC (Carl Zeiss Meditec, Inc., Dublin, CA) PSD were compared. Agreement, severity, and test duration between algorithms were assessed. Sensitivities were not different between algorithms using PSD. With PDP <1%, SWAP-FT was more sensitive (35%) than SWAP-SITA (29%) at 95% specificity (P<0.05). Sensitivity and specificity using the STATPAC PSD at 95% (P<5%) and 99.5% (P<0.05%) was similar between algorithms. Severity correlated significantly between algorithms (P<0.001), although there was bias for SWAP-SITA to suggest more severe loss. SWAP-SITA required significantly less test time than did SWAP-FT (P<0.001). Mean differences in PSD, PDP <1%, and MD between algorithms were not clinically significant. Both algorithms performed similarly when equated for specificity. The reduced test duration makes SWAP-SITA the better choice. Testing with both algorithms within a short period is recommended for confirmation of results when switching from FT to SITA.

Repeatability of Automated Perimetry: A Comparison between Standard Automated Perimetry with Stimulus Size III and V, Matrix, and Motion Perimetry

Standard automated perimetry (SAP) shows a marked increase in variability in damaged areas of the visual field. This study was conducted to test the hypothesis that larger stimuli are associated with more uniform variability, by investigating the retest variability of four perimetry tests: standard automated perimetry size III (SAP III), with the SITA standard strategy; SAP size V (SAP V), with the full-threshold strategy; Matrix (FDT II), and Motion perimetry. One eye each of 120 patients with glaucoma was examined on the same day with these four perimetric tests and retested 1 to 8 weeks later. The decibel scales were adjusted to make the test's scales numerically similar. Retest variability was examined by establishing the distributions of retest threshold estimates, for each threshold level observed at the first test. The 5th and 95th percentiles of the retest distribution were used as point-wise limits of retest variability. Regression analyses were performed to quantify the relationship between visual field sensitivity and variability. With SAP III, the retest variability increased substantially with reducing sensitivity. Corresponding increases with SAP V, Matrix, and Motion perimetry were considerably smaller or absent. With SAP III, sensitivity explained 22% of the retest variability (r(2)), whereas corresponding data for SAP V, Matrix, and Motion perimetry were 12%, 2%, and 2%, respectively. Variability of Matrix and Motion perimetry does not increase as substantially as that of SAP III in damaged areas of the visual field. Increased sampling with the larger stimuli of these techniques is the likely explanation for this finding. These properties may make these stimuli excellent candidates for early detection of visual field progression.

Comparison of Different Analytic Algorithms for Interpretation of the Swedish Interactive Threshold Algorithm Strategy

OBJECTIVETo compare 4 analytic algorithms for interpretation of the Swedish Interactive Threshold Algorithm.INTRODUCTIONAnalytic algorithms were initially developed for interpretation of standard automated perimetry (using a full threshold strategy). The Swedish interactive threshold algorithm is a novel strategy that was developed to shorten test duration.METHODSOne hundred forty-three printouts of normal and glaucomatous patients were analyzed using Caprioli’s (strict, moderate and liberal) criteria and Anderson’s modified criteria for perimetric defect. Areas under the receiver operator characteristics (ROC) curves, sensitivity, and specificity for each criteria were calculated.RESULTSCaprioli’s strict and Anderson’s modified criteria presented similar sensitivity (94.5% and 92.3%, respectively) and specificity (63.5% and 61.5%, respectively). Caprioli’s liberal criteria were more sensitive (98.9%) and less specific (42.5%) than the other three criteria.CONCLUSIONBoth Caprioli’s and Anderson’s modified criteria can be used for interpretation of the Swedish interactive threshold algorithm.

Evaluation of Threshold Estimation and Learning Effect of two Perimetric Strategies, Sita Fast and Clip, in Damaged Visual Fields

The threshold estimation, learning effect, and between-algorithm differences of the Fast Swedish Interactive Thresholding Algorithm (SITA Fast), of the Humphrey Field Analyzer (HFA), and the Continuous Light Increment Perimetry (CLIP) strategy of the Oculus Twinfield perimeter were evaluated in damaged visual fields. Twenty-one glaucomatous patients with damaged visual fields (MD worse than -8 dB) underwent Oculus Full Threshold (FT), Humphrey FT, SITA Fast, and CLIP 30-2 perimetric examinations. All the tests were repeated in a second session at least 3 days later. The point-wise differences in absolute sensitivity and of the total deviation plot values between FT and fast algorithms, between fast algorithms and the learning effect were evaluated (Wilcoxon test and Bland-Altman analysis). The average point-wise sensitivity difference between SITA Fast and HFA FT strategy (0.84 dB) was significantly lower than that found between CLIP and Oculus FT strategy (1.71 dB). Between-algorithm point-wise differences of the total deviation plot values of the fast strategies were not significantly different. Learning effect for SITA Fast (0.67 dB) was higher than that found for CLIP (0.39 dB). Test time for SITA (367+/-71 sec) and CLIP (453+/-98 sec) were about 55% and 35%, respectively, shorter (p<0.001) than those found with FT algorithms. The acceptance for fast algorithms and particularly for CLIP was significantly better. The two fast strategies, even though using very different algorithms, showed good threshold estimation compared to FT strategies with a consistent time saving in damaged visual fields.

Correlación entre los índices globales de la perimetría automatizada convencional y los parámetros topográficos papilares (Heidelberg Retina Tomograph II)

To correlate the optic nerve head topographic parameters measured by the Heidelberg Retina Tomograph II (HRT) with the perimetric indices of standard automated perimetry (SAP). This study included 101 normal subjects, 247 ocular hypertensive eyes (increased intraocular pressure with normal SAP) and 102 glaucomatous subjects (IOP above 21 mm Hg and abnormal standard automated perimetry). Only one eye was randomly chosen from each subject for the study. The visual field was evaluated by means of Humphrey Field Analyzer (24-2 full threshold strategy). The HRT II (Heidelberg Engineering) was used to acquire and measure the optic disc topographic parameters. Pearson correlations between topographic data and perimetric indices were performed for the total sample and each group of patients. The distribution of values obtained in the samples was normal. A significant correlation was found between several optic disc parameters and the global indices of SAP. Rim area, rim volume, cup/disc area ratio, rim/disc area ratio, cup shape measurement, RNFL cross-sectional area, and discriminant functions FSM and RB, showed the strongest correlation with the visual field indices in the total and glaucoma groups (RIM AREA: total group: r=0.32; p=4.14x10(-11)/glaucoma group: r=0.28; p=0.004. RIM VOLUME: total group: r=0.26; p=1.55x10(-7)/glaucoma group: r=0.26; p=0.006). The ocular hypertensive group showed few significant correlations. The correlations found between standard automated perimetry and HRT defined topographic parameters allow a better understanding of glaucomatous damage and make decision-making easier.

Visual field testing with the new Humphrey Matrix: a comparison between the FDT N‐30 and Matrix N‐30‐F tests

To determine if the N-30-F test with the new Humphrey Matrix instrument is comparable to the traditional frequency-doubling technology (FDT) N-30 test. A sample of 47 eyes from 47 patients (five normal subjects, 27 with ocular hypertension and 15 with glaucoma) underwent visual field (VF) testing with standard automated perimetry, and with FDT, using the FDT N-30 program, and the Matrix N-30-F program (using the same 19 tested points, full-threshold strategy, but with an enhanced algorithm to reduce testing time). The plots, mean deviation (MD), pattern standard deviation (PSD), defect locations and test time were compared. The agreement between the two tests was shown to be good, except for subjects with large VF defects, in which greater PSD values were observed with the FDT test, whereas the Matrix test gave a higher MD and number of abnormal test locations in the total deviation plot. A lack of agreement was also found for the number of abnormal test locations on the pattern deviation plot at any VF loss severity level. The test time for the Matrix test was significantly shorter. The FDT N-30 and Matrix N-30-F tests proved to be comparable in cases of early to moderate VF defects.

Full threshold vs. Swedish interactive threshold algorithm (SITA) em pacientes glaucomatosos submetidos à perimetria computadorizada pela primeira vez

To compare the Full Threshold (FT) and SITA Standard (SS) strategies in glaucomatous patients undergoing automated perimetry for the first time. Thirty-one glaucomatous patients who had never undergone perimetry underwent automated perimetry (Humphrey, program 30-2) with both FT and SS on the same day, with an interval of at least 15 minutes. The order of the examination was randomized, and only one eye per patient was analyzed. Three analyses were performed: a) all the examinations, regardless of the order of application; b) only the first examinations; c) only the second examinations. In order to calculate the sensitivity of both strategies, the following criteria were used to define abnormality: glaucoma hemifield test (GHT) outside normal limits, pattern standard deviation (PSD) <5%, or a cluster of 3 adjacent points with p<5% at the pattern deviation probability plot. When the results of all examinations were analyzed regardless of the order in which they were performed, the number of depressed points with p<0.5% in the pattern deviation probability map was significantly greater with SS (p=0.037), and the sensitivities were 87.1% for SS and 77.4% for FT (p=0.506). When only the first examinations were compared, there were no statistically significant differences regarding the number of depressed points, but the sensitivity of SS (100%) was significantly greater than that obtained with FT (70.6%) (p=0.048). When only the second examinations were compared, there were no statistically significant differences regarding the number of depressed points, and the sensitivities of SS (76.5%) and FT (85.7%) (p=0.664). SS may have a higher sensitivity than FT in glaucomatous patients undergoing automated perimetry for the first time. However, this difference tends to disappear in subsequent examinations.

Análisis de la distribución de anillo neurorretiniano por sectores mediante láser confocal de barrido en el diagnóstico del glaucoma

To evaluate the diagnostic ability of the Moorfields regression analysis (MRA; neuroretinal rim sector-based analysis) by means of confocal scanning laser. 200 eyes were included in this study: 101 normal subjects and 99 glaucoma patients (standard automated perimetry with glaucomatous defects -MD or CPSD with p<0.02 or a cluster of three or more points with p<0.05 or a cluster of two or more points with p<0.01 or abnormal Glaucoma Hemifield Test). All subjects underwent a full ophthalmic evaluation, visual field evaluation by means of a Humphrey Field Analyzer, 24-2 full threshold strategy, and optic disc topography by Heidelberg retina tomograph (HRT-II). The outcome parameters were sensitivity and specificity of the MRA for each sector. The highest sensitivity in detecting structural defects based on MRA (p<0.05) was observed in the nasal-superior sector (48%) and nasal-inferior sector (45%); however the highest specificity was found in the temporal-superior (98%) and inferior (98%) sectors. The highest sensitivity for MRA (p<0.01) was found in the temporal-inferior sector (31%) and nasal-superior sector (30%) while the temporal-superior and inferior-sectors showed the highest specificity (100%). The diagnosis of glaucoma based on the presence of any sector alteration showed sensitivity figures of 67% with p<0.05 and 46% with p<0.01 and specificity values of 84% with p<0.05 and 96% with p<0.01. The analysis of the distribution of the neuroretinal rim by means of HRT-II contributes effectively to the diagnosis of glaucoma based on perimetry in a sample derived from a Spanish population.

Conventional Perimetry, Short-Wavelength Automated Perimetry, Frequency-Doubling Technology, and Visual Evoked Potentials in the Assessment of Patients with Multiple Sclerosis

To evaluate the diagnostic power of conventional, achromatic, automated perimetry (CAP), short-wavelength automated perimetry (SWAP), frequency-doubling technology (FDT) perimetry, and visual evoked potentials (VEP) in a group of patients with multiple sclerosis (MS) with or without a history of optic neuritis. Thirty eyes of 15 patients (5 male, 10 female, average age 38+/-7 years) with confirmed diagnosis of MS underwent CAP, SWAP (Humphrey 750-II VFA, program central 30-2, full-threshold strategy), FDT perimetry (program N-30), and pattern VEPs. Sixteen eyes (53.3%) had no history of ocular involvement and a negative ophthalmologic examination. They were matched with a control group of 10 healthy volunteers (4 male, 6 female, average age 31+/-10 years). The mean deviation (MD) and the pattern standard deviation (PSD) of the two groups were compared (t-test). Fourteen eyes (46.7%) had, on the contrary, a history of optic neuritis. Inside this group, the MD and the PSD of the three techniques were correlated (Spearman's rank test), in order to investigate whether any significant differences might be revealed by these techniques in pointing out the total amount of visual field damage. When comparing MS patients without signs or symptoms of ocular involvement and a control group, no significant differences were found for CAP MD, CAP PSD, and FDT PSD. Significant differences were found, on the contrary, for SWAP MD (p=0.0014), SWAP PSD (p=0.0001), and FDT MD (p=0.0001). When considering the MD and the PSD of the three techniques in the group of MS patients who had a history of optic neuritis, a significant correlation was found only between CAP MD and SWAP MD (r=0.0057), with a tendency by SWAP to reveal a higher rate of visual field loss. The other correlations were not significant. According to predefined criteria, the group of asymptomatic subjects had abnormal CAP in 1 eye (6.25%), abnormal SWAP in 9 (56.2%), abnormal FDT in 11 (68.7%), and abnormal VEPs in 7 (43.7%). The combined use of all techniques allowed us to identify silent optic nerve impairment in 15 (93.7%) eyes. Short-wavelength automated perimetry and FDT perimetry are two non-conventional perimetric techniques that were mainly developed for the early detection of glaucomatous damage. The results of this study demonstrate their efficacy also in detecting early visual field deficits in MS patients without clinical signs of optic neuropathy. Frequency doubling perimetry, in particular, proved to be an easy, fast, and sensitive technique in the assessment of patients with MS. Our results also suggest that subclinical visual involvement in MS can be better diagnosed using multiple (neurophysiologic and psychophysical) tests.

Continuous Light Increment Perimetry Compared to full Threshold Strategy in Glaucoma

Continuous light increment perimetry (CLIP) is an improved testing strategy for automated static perimetry designed to save test time and enhance patient compliance. CLIP uses a modified ramp stimulus where stimulus intensity is continuously increased according to patient reaction time, starting from a subthreshold intensity until recognition. The test is constantly modified according to patient performance. As CLIP showed good results in normal subjects in previous studies, the authors now compared CLIP to the standard 4/2-full threshold (4/2) strategy in glaucoma patients. Fifty-two patients with glaucomatous visual field defects (mean sensitivities 2.9 to 18.4 dB), all with perimetric experience, were tested with CLIP (three times) and 4/2 in a randomized fashion. Tests were performed at 55 test locations within the central 30 degree visual field (24-2 area) using the Twinfield perimeter. Average mean sensitivity was significantly higher for CLIP than for 4/2 (t test, p<0.0001). Absolute scotomas and extension of scotomas were comparable for both strategies, whereas CLIP found less deep relative scotomas in some cases. Mean test time was significantly shorter for CLIP (5.6 min) compared to 4/2 (8.9 min) (Wilcoxon signed rank test, p<0.0001). Patient acceptance was better for CLIP than for 4/2. CLIP showed comparable results to 4/2 with excellent patient acceptance. Mean sensitivities are 1.8 dB higher than for 4/2; similar results were found previously in normal subjects. CLIP was able to save a mean 38% of test time compared to full threshold strategy with good reproducibility.

Evaluation of Two Humphrey Perimetry Programs: Full Threshold and SITA Standard Testing Strategy for Learning Effect

To compare learning effect of Swedish interactive threshold algorithm (SITA) standard strategy with full threshold testing. Thirty-nine medical students with no experience in visual field testing had full threshold (FT) and SITA standard for either right or left eyes. They were chosen in such a way that 20 (Group I) had FT for right and SITA for left eyes and 19 (Group II) had SITA standard for right and FT for left eyes. It was designed to have both strategies on same person whereby eliminating inter-individual variability. Visual field testing was repeated in the same week of the first test on the same subject with the same strategy that was chosen for that eye. The authors found an improvement in mean deviation (MD) and pattern standard deviation (PSD) of first and second testings correspondingly for FT (MD from -3.04 to -2.55; PSD from -2.60 to -2.29) and SITA standard (MD from -2.86 to -2.20; PSD from 2.25 to 2.10) and changes were statistically significant (p<0.05). To analyze learning effect of visual field testings, we calculated percentage change in MD and PSD for full threshold and SITA standard strategy. The percentage changes in visual field parameters were significantly lower in SITA standard strategy testing for MD (p=0.02) and PSD (p=0.01). This study shows that a learning effect is present for both strategies and SITA standard may have a reduced learning effect compared to FT.