SITA Standard Research Articles

Age, Sex, and Clinical Characteristics of Juvenile Open-Angle Glaucoma Patients in a Saudi Tertiary Hospital: A Retrospective Study of Surgical and Non-Surgical Outcomes.

Background/Objectives: Juvenile Open Angle Glaucoma (JOAG) is a condition that presents peculiar issues because it starts at a very early age and, in the end, causes substantial vision loss. This study aimed to analyze the age and gender distribution and treatment outcomes in JOAG patients. Methods: We carried out a retrospective study at King Abdul Aziz University Hospital, Riyadh, Saudi Arabia, from 2015 to 2022. We extracted data from the medical records. Visual acuity data were converted to the logarithm of the minimum angle resolution (LogMAR) for standardized analysis. The CARL ZEISS Humphrey 745i Field Analyzer/HFA II-i Visual Field Analyzer was used to perform visual field examinations under the 24-2 program SITA standard. Results: The study involved 45 JOAG patients (87 affected eyes) with a mean age of 26.91 years. Myopia was the prevailing trait (93%), and a family history of glaucoma was found in 51.1% of cases. Most of the patients presented with severe visual field defects in both eyes (right-57.1%, left-44.4%). Regarding visual acuity, we found that the majority of affected categories belonged to either mild or moderate in both eyes. Initial and final Intraocular pressure (IOP) measurements together showed a significant reduction (p < 0.001) and clearly demonstrated the need for IOP control. Surgical and non-surgical treatments significantly reduced IOP, with no gender or eye differences Conclusions: This research offers important data concerning JOAG demographics (age and gender), clinical picture, and treatment results. Though early-onset presents challenges, multidimensional therapeutic methods have great potential to get JOAG under control and maintain visual function. Additional research is needed to study the genetic causes of JOAG and assess the long-term treatment outcomes.

COMPARISON OF SITA STANDARD 24-2 WITH SITA FASTER 24-2C PROGRAM ON HUMPHREY FIELD ANALYZER IN ASSESSING VISUAL FIELD DEFECTS OF GLAUCOMA PATIENTS

Introduction &amp; ObjectivesIntroduction: Periodical perimetry examination to detect and determine the rate of glaucomaprogression continues to be a challenging task, because it depends on many factors. Besides, thereis now a paradigm shift which central visual field defects occur earlier. SITA Standard (SS) 24-2 isthe clinical standard for glaucoma examination, but there were studies reporting on the prevalenceof central visual field defects not detected. SITA Faster (SFR) 24-2C was developed to addresscurrent shortcomings, but the performance has yet to be formally and independently assessed.Objectives: To compare the global indices (Mean Deviation, Pattern Standard Deviation, Visual FieldIndex) and test duration between SS 24-2 and SFR 24-2C program.&#x0D; MethodsThis is an analytical observational study with a cross-sectional design. Subjects aged &gt;18 years whodiagnosed with glaucoma and whose visual fields unaffected by other condition besides glaucomawere included. All subjects underwent testing of both programs.&#x0D; ResultsThis study was conducted in 94 eyes of 66 patients. Comparison of global indices and test durationbetween the two programs was carried out by the Wilcoxon test. The mean results of MD and PSDglobal indices were not significantly different, however there was a difference in the mean VFI of1.5% between the two programs. The test duration of SFR 24-2C was 55.03% faster.&#x0D; ConclusionThere was no significant difference in the MD and PSD global indices, but there was a significantdifference in the VFI, as well as the test duration between the two programs.

COMPARISON OF SITA STANDARD 24-2 WITH SITA FASTER 24-2C PROGRAM ON HUMPHREY FIELD ANALYZER IN ASSESSING VISUAL FIELD DEFECTS OF GLAUCOMA PATIENTS

Introduction: Periodical perimetry examination to detect and determine the rate of glaucoma progression continues to be a challenging task, because it depends on many factors. Besides, there is now a paradigm shift which central visual field defects occur earlier. SITA Standard (SS) 24-2 is the clinical standard for glaucoma examination, but there were studies reporting on the prevalence of central visual field defects not detected. SITA Faster (SFR) 24-2C was developed to address current shortcomings, but the performance has yet to be formally and independently assessed. Objective: To compare the global indices (Mean Deviation, Pattern Standard Deviation, Visual Field Index) and test duration between SS 24-2 and SFR 24-2C program. Methods: This is an analytical observational study with a cross-sectional design. Subjects aged &gt;18 years who diagnosed with glaucoma and whose visual fields unaffected by other condition besides glaucoma were included. All subjects underwent testing of both programs. Results: This study was conducted in 94 eyes of 66 patients. Comparison of global indices and test duration between the two programs was carried out by the Wilcoxon test. The mean results of MD and PSD global indices were not significantly different, however there was a difference in the mean VFI of 1.5% between the two programs. The test duration of SFR 24-2C was 55.03% faster. Conclusion: There was no significant difference in the MD and PSD global indices, but there was a significant difference in the VFI, as well as the test duration between the two programs.

Evaluation of the Consistency of Glaucomatous Visual Field Defects Using a Clustered SITA-Faster Protocol

Frontloading SITA-Faster (SFR) visual fields (2 tests per eye on the same visit) has been shown to provide repeatable perimetric data at minimal time cost. This study reports the outcomes of using frontloaded SFR in the evaluation of pointwise visual field (VF) defects in a cohort of patients with glaucoma when transitioned from SITA-Standard (SS). Prospective, cross-sectional study. A total of 144 eyes of 91 patients with confirmed or suspected glaucoma who had an SS test on a previous visit. Two SFR tests (T1, T2) per eye on the same visit. Global sensitivity, reliability indices, and pointwise deviation map probability scores from the pattern deviation grid of each patient were compared across the 3 sequential tests to evaluate the consistency of VF defects. The mean age was 68.6 years, and 79.2% of patients had a diagnosis of glaucoma. There was no significant difference in mean deviation (MD) across the 3 tests (-5.83 decibels [dB], -5.28 dB, and -5.71 dB in SS, SFR1, and SFR2, respectively, repeated-measures analysis of variance [ANOVA], P= 0.48). The frontloaded SFR tests provided repeatable VFs that confirmed existing pointwise data on the SS in 4661 (62.3%) locations, reversed an SS defect in 614 (8.2%) locations, and demonstrated a new repeatable defect in 406 (5.4%) locations of the pattern deviation grid. A new defect of at least 3 contiguous points was identified in 20.1% of eyes. The non-repeatable points on the 2 SFR tests displayed no significant difference in the distribution of defect/nondefect points based on test order or peripheral versus central locations. There was no significant difference in the rate of obtaining at least 1 reliable test result between SS and the frontloaded SFR T1 and T2 (P= 0.77). Test duration significantly decreased from SS to SFR1/2 (379 vs. 160 vs. 158 seconds, P < 0.0001). Frontloading SFR tests can provide repeatable data for the evaluation of the consistency of pattern deviation defects in glaucoma, with no observable decline in performance from test fatigue. This is achieved at equivalent duration and reliability as a single SS test. Frontloading SFR may be helpful in increasing testing frequency/quantity to meet recommended guidelines for progression analysis. Proprietary or commercial disclosure may be found in the Footnotes and Disclosures at the end of this article.

Pointwise Visual Field Estimation From Optical Coherence Tomography in Glaucoma Using Deep Learning.

PurposeStandard automated perimetry is the gold standard to monitor visual field (VF) loss in glaucoma management, but it is prone to intrasubject variability. We trained and validated a customized deep learning (DL) regression model with Xception backbone that estimates pointwise and overall VF sensitivity from unsegmented optical coherence tomography (OCT) scans.MethodsDL regression models have been trained with four imaging modalities (circumpapillary OCT at 3.5 mm, 4.1 mm, and 4.7 mm diameter) and scanning laser ophthalmoscopy en face images to estimate mean deviation (MD) and 52 threshold values. This retrospective study used data from patients who underwent a complete glaucoma examination, including a reliable Humphrey Field Analyzer (HFA) 24-2 SITA Standard (SS) VF exam and a SPECTRALIS OCT.ResultsFor MD estimation, weighted prediction averaging of all four individuals yielded a mean absolute error (MAE) of 2.89 dB (2.50–3.30) on 186 test images, reducing the baseline by 54% (MAEdecr%). For 52 VF threshold values’ estimation, the weighted ensemble model resulted in an MAE of 4.82 dB (4.45–5.22), representing an MAEdecr% of 38% from baseline when predicting the pointwise mean value. DL managed to explain 75% and 58% of the variance (R2) in MD and pointwise sensitivity estimation, respectively.ConclusionsDeep learning can estimate global and pointwise VF sensitivities that fall almost entirely within the 90% test–retest confidence intervals of the 24-2 SS test.Translational RelevanceFast and consistent VF prediction from unsegmented OCT scans could become a solution for visual function estimation in patients unable to perform reliable VF exams.

Cluster Formation for Analyses of Glaucomatous Visual Field Defects in Central 10-2 Visual Field in Normal Tension Glaucoma Eyes.

PurposeTo develop a cluster system to analyze the retinal sensitivity loss of 68 test points in the central 10 degrees of standard automated perimetry (SAP) in eyes with normal tension glaucoma (NTG).Patients and MethodsPatients with NTG who met the following criteria were included: visual acuity ≥0.7, SAP-derived mean deviation ≥−15 dB, and pattern deviation probability plots with at least one point with a probability of <0.5% and/or two or more contiguous points with a probability of <1% that did not cross the horizontal meridian in the central 12 points of the 24-2 test points. SAP with the Swedish Interactive Threshold Algorithm Standard (SITA-S) 10-2 program (10-2) was performed within 6 months of the SITA-S 24-2. The averaged total deviation (TD) for each of the 68 test points in the 10-2 was calculated. Hierarchical cluster analyses were performed based on the deviation of the TDs of the test points, and a dendrogram was created. The number of clusters was determined following the Sturges’ rule.ResultsOne hundred and twenty-six eyes of 126 patients (61.9±11.4 years) were studied. Hierarchical cluster analysis of the TD values statistically obtained a dendrogram that divided the 68 test points into 7 clusters. Of these 7 clusters, 21 points belonging to the clusters in the papillomacular region included cluster 5. Cluster 5 was distributed above and below the horizontal meridian, which does not agree with the course of the retinal nerve fiber layer (RNFL).ConclusionThe hierarchical cluster analysis of the TD values stratified the 68 test points of the 10-2 into seven clusters. Considering the course of the RNFL, cluster 5 was divided into clusters of 5a and 5b, and consequently eight clusters were considered to be appropriate for detecting glaucomatous visual field defects in the central 10 degrees in NTG eyes.

Validation of the SITA faster strategy for the management of glaucoma.

To evaluate the SITA Faster strategy (SFR) in normal subjects and glaucoma patients. This randomized, controlled, cross-sectional study included 236 Visual fields (VFs) obtained from 59 subjects, grouped as controls, mild, moderate and severe glaucoma patients. All examinations were performed using the HFA-3 perimeter with the 24/2 program, adopting two strategies: the SITA Standard (SS) and SFR. Glaucoma severity was studied using continuous (mean defect -MD- and visual field index -VFI) and categorical (scoring systems from the AGIS and CIGTS studies) perimetric indices. There were no differences in the reliability indices obtained with both strategies when controls were compared to glaucoma patients. SFR significantly reduced the VF duration, saving 68% and 59.1% in glaucoma patients (60.8% in mild, 62.9% in moderate and 48.7% in severe glaucoma: p = 0.0004). The test duration was correlated with glaucoma severity, especially for the SFR (Spearman rho = -0.88, -0.82, 0.87 and 0.85 for the VFI, MD, AGIS and CIGTS, respectively). Although both strategies were correlated, the SS showed a greater severity of the defect in glaucoma patients (SS vs SFR VFI = 94.5 vs. 95, MD = -3.17 vs. -2.81, AGIS = 6 vs. 5, CIGTS = 4.85 vs. 3.41: p = 0.001). There was strong agreement between strategies, although this was lower in advanced glaucoma. The SFR strategy constitutes an adequate strategy to monitor glaucoma, especially in mild and moderate cases. Its speed allows more VFs to be assessed, as recommended in clinical practice guidelines.

Nomograms for Converting Perimetric Sensitivity From Full Threshold and SITA Fast to SITA Standard in Patients With Glaucoma and Healthy Subjects.

PurposeThe purpose of this study was to develop nomograms for converting Full Threshold (FT) and Swedish Interactive Threshold Algorithm (SITA) Fast (SF) tests to SITA Standard (SS) tests with the Humphrey Field Analyzer in patients with glaucoma and healthy subjects.MethodsOne eye each of 49 patients with glaucoma and 50 healthy subjects was tested in 4 and 2 sessions (each containing the 3 strategies), respectively, over 4 weeks. The difference between pointwise Best Available Estimate (BAE; mean of all FT tests) and SS sensitivity at each session was used to derive four nomograms. Nomogram accuracy was assessed by: (1) comparing the converted FT to actual SS sensitivity (omitting the test session used to derive the nomogram) and (2) comparing the distribution of the differences between the converted and actual SS sensitivity to the actual SS test-retest differences. The process was repeated for SF and healthy subjects.ResultsIn patients with glaucoma, 39.85% and 59.69% of the conversion differences from FT were within 1 dB and 2 dB of the mean, respectively. The respective figures for SF were 45.69% and 65.04%, and in healthy subjects, they were 54.34% and 76.48% for FT and 61.17% and 82.66% for SF. The difference in the mean conversion and test-retest differences was <0.5 dB for all comparisons, with an overlap in distributions ranging from 78.75% to 85.24. There was no association between conversion differences and BAE for either FT or SF in either subject group.ConclusionsNomograms to convert FT and SF tests to SS tests yield accuracies that are negligibly different from test-retest differences with SS.Translational RelevanceNomograms allow direct comparisons between different perimetric strategies for a more comprehensive assessment of visual field change.

Risk of Airborne COVID-19 Transmission While Performing Humphrey Visual Field Testing.

Designing and demonstrating an experiment that shows the risk of airborne transmission of COVID-19 between patients having visual fields analyzed is low. The aim was to investigate the possibility of airborne transmission of COVID-19 during Humphrey visual field testing in a real-world scenario. A particle counter was placed within the bowl of Humphrey visual field analyzer (HFA) before and after turning on the machine to ascertain the effect of the air current produced by the ventilation system on aerosols. A second experiment was run where the particle counter was placed in the bowl and recorded particulates, in the air, as a 24-2 SITA standard was performed by a mock patient and then again immediately after the patient had moved away. We measured aerosol particle counts sized ≤0.3 μm, >0.3≤0.5 μm, >0.5≤1 μm, >1≤2.5 μm, >2.5≤5 μm, and >5≤10 μm. Particulates of all sizes were shown to be significantly reduced within the bowl after turning the machine on, demonstrating that the air current produced by the HFA pushes air out of the bowl and it cannot stagnate. There was no significant difference in measurement of aerosol while there was a patient performing the test and immediately after they had moved away, suggesting that aerosols breathed out by the patient are not able to remain in suspension in the bowl because of the ventilation current. There is no significant difference between aerosol count in the bowl of a HFA before, during and after testing. This suggests the risk of airborne transmission of COVID-19 is low between subsequent patients. This is in keeping with manufacturer's guidance on Humphrey visual field testing.

Swedish Interactive Threshold Algorithm for central visual field defects unrelated to nerve fiber layer.

To evaluate the characteristic appearance of induced central visual field defects unrelated to the nerve fiber layer on standard automated perimetry using the Swedish Interactive Threshold Algorithm (SITA), and to compare the findings to the appearance on existing Full Threshold (FT) and FASTPAC (FP) algorithms. Thirty right eyes of 30 healthy young participants were examined using four Humphrey 24-2 program algorithms: FT, FP, SITA-Standard (SS), and SITA-Fast (SF). Central visual field defects were induced using a high-density white opacity filter centered on a plano lens. The test duration, fovea threshold, mean sensitivity (MS), mean deviation (MD), pattern standard deviation (PSD), visual field index (VFI), and defect size and depth were compared among all algorithms. The mean test duration was 21% to 71% shorter (p < 0.01), the fovea threshold 0.9 to 2.6dB higher (p < 0.05), MS 1.1 to 1.7dB higher (p < 0.05), MD 0.84 to 1.48dB higher, PSD 0.33 to 0.60 lower, and VFI 2% higher (p < 0.05) on SS and SF than on FT and FP. The defect size was approximately four points larger and the defect depth 127 to 156dB shallower on SS and SF than on FT and FP (p < 0.01). Central visual field defects unrelated to the nerve fiber layer were wider and shallower and global indices were higher on SITA than on conventional FT and FP. These findings indicate that careful attention is required when converting from FT and FP to SITA.

Assessment of retinal sensitivity using a time-saving strategy in normal individuals

BackgroundThe purpose of this study was to compare retinal sensitivities in normal individuals obtained using the Swedish Interactive Threshold Algorithm Standard (SITA-S) on the Humphrey field analyzer with those obtained using the Dynamic strategy on the Octopus.MethodsPrior to visual field examinations, the background luminance, stimulus size, and exposure time with the Octopus 101 were conformed to the Humphrey field analyzer II settings. Volunteers over 20 years of age without apparent ophthalmic abnormalities were examined with the SITA-S central 30-2 program followed by the Dynamic 32 program. Eye with corrected visual acuity ≥ 0.8, refraction ≥ −6.0 diopters, and fields with satisfactory levels of reliability in SITA-S and Dynamic were selected.ResultsSixty-seven eyes from 67 normal individuals of mean age 51.3 ± 16.3 (range 22–76) years satisfied the selection criteria and were analyzed. Mean retinal sensitivity was significantly (P < 0.0001) higher with SITA-S (29.0 ± 2.4 dB) than with Dynamic (26.8 ± 2.1 dB). Changes in retinal sensitivity with increasing age were significantly (P = 0.0003) greater with Dynamic (−0.09 ± 0.04 dB/year; 95% confidence interval [CI] −0.10 to −0.08 dB/year) than with SITA-S (−0.07 ± 0.04 dB/year, 95% CI −0.08 to −0.06 dB/year). When classifying the visual field into three areas (central, mid-peripheral, and peripheral), retinal sensitivities with SITA-S were significantly higher in all areas than with Dynamic (P < 0.0001 for all three areas).ConclusionDifferences in Dynamic and SITA-S strategies may contribute to the differences in retinal sensitivities observed in normal individuals.

Relationship between HEP perimetry and standard automated perimetry

Abstract Purpose To evaluate the relationship between Standard Automated Perimetry (SAP) performed with Humphrey perimeter (Carl Zeiss Meditec, EEUU) and a new white‐white perimetry tested with Heidelberg Edge Perimeter (HEP, Heidelberg Engineering, Alemania). Methods Fourty‐three subjects (healthy and with different levels of glaucomatous damage subjects) were prospectively and consecutively selected. Only one eye per subject was included in the study. All of them underwent at least one reliable perimetry with each device. 24‐2 SITA standard was used with Humphrey perimeter and 24‐2 ASTA standard algorithm was tested with HEP in all subjects. After checking the normal values of variables by Kolmogorov‐Smirnov test, Pearson’s correlation coefficients were calculated between global indices of both devices: mean deviation (MD), pattern standard deviation (PSD) and visual field index (VFI). Results Mean age was of 58.41±12.4 years. Subjects had mean IOP values of 18.24±3.6 mmHg. No differences were found in mean MD values (p=0.127): ‐2.82±4.8 dB and ‐1.54±2.6 dB between Humphrey and HEP, respectively. No differences were found in mean PSD values (p=0.290) between Humphrey (3.11±3.1) and HEP (2.52±1.9). The strongest correlations were observed between PSDs (0.788; p&lt;0.001) and between PSD with HEP and VFI (‐0.711; p&lt;0.001). Conclusion Both perimetries showed a good correlation between their indices. HEP tends to present MD and PSD values lower than Humphrey. Further studies are required to assess the clinical usefulness of HEP.

Comparison of Swedish Interactive Threshold Algorithm and Full Threshold Algorithm for Glaucomatous Visual Field Loss

To compare the prevalence of visual field loss, the sensitivity distribution, and the size and depth of glaucomatous visual field defects using the standard full threshold (FT) and the Swedish interactive threshold algorithm (SITA) standard (SS) procedures in patients with early or suspected glaucoma. Automated perimetry findings were retrospectively evaluated in 53 patients (105 eyes) with early or suspected glaucoma. The number of eyes judged to have glaucomatous visual field loss by SS (48 eyes) was significantly larger than what was found with FT (35 eyes), and 70 eyes were classified as pre-perimetric glaucoma. In these 70 eyes, there were many locations where the sensitivity was significantly higher with SS than with FT (intrasubject difference), and SS had less intersubject variability than FT at most locations. The cumulative decibel scores at the region of glaucomatous defects were larger with SS (206.2+/-103.3 dB) than with FT (162.1+/-87.5 dB) (p=0.02), which indicated that the depth of defects measured by SS was shallower than that by FT. The sizes of defects were significantly larger with SS (11.2+/-5.6) than with FT (9.7+/-5.1) (p<0.05). Glaucomatous defects were measured as being significantly shallower and larger with SS than with FT. In addition, the prevalence of visual field defect was higher with SS according to some of the criteria for glaucomatous visual field defects. These results might be related to the fact that SS strategy has a lower variability and to the Bayesian statistical properties of the SITA algorithm.

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.

Sensitivity and specificity of frequency‐doubling technology, tendency‐oriented perimetry, SITA Standard and SITA Fast perimetry in perimetrically inexperienced individuals

To evaluate the sensitivity and specificity of the screening modes of frequency-doubling technology (FDT), tendency-oriented perimetry (TOP), SITA Standard (SS) and SITA Fast (SF) in perimetrically inexperienced individuals. One eye of 64 glaucoma patients and 53 normal subjects who had never undergone automated perimetry were tested with programs C-20-5 (FDT), G1 (TOP) and 24-2 (SS and SF). The gold standard for glaucoma was the presence of a typical glaucomatous optic disc appearance on stereoscopic examination (judged by a glaucoma expert), and intraocular pressure (IOP) > 21 mmHg. The test order among strategies was randomized for each subject. To define an abnormal visual field, we applied three criteria for SS and SF and two criteria for TOP and FDT, all of which have been previously described in the literature. Sensitivities and specificities among the different criteria were compared using the Cochran test. Frequency-doubling technology showed the shortest mean test duration, followed by TOP, SF and SS (p < 0.05). Sensitivity ranges were 87.5-89.1% for SS, 92.2-93.8% for SF, 87.5-89.1% for TOP, and 82.8-85.9% for FDT (p = 0.34). Specificity ranges were 73.6-83% for FDT, 56.6-62.3% for TOP, 60.4-69.8% for SF and 66.0-71.7% for SS. The specificity obtained with criterion 2 for FDT (based on the presence of two or more abnormal locations regardless of the severity of abnormal points) was higher than those measured with the other strategies (p < 0.01). When testing individuals with no perimetric experience, moderate sensitivities and specificities should be expected, regardless of the strategy chosen.

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.

Converting to SITA-Standard from Full-Threshold Visual Field Testing in the Follow-up Phase of a Clinical Trial

To evaluate the impact of converting from Humphrey 24-2 full-threshold (FT) visual field (VF) testing to SITA-Standard (SS) VF testing during the follow-up phase of a clinical trial. VF data were obtained from 243 patients in the Collaborative Initial Glaucoma Treatment Study (CIGTS) who had follow-up visits in 2004. FT and SS VF tests were performed in random order on the same day. The average duration of the SS test (6.3 minutes) was shorter (P < 0.0001, paired t-test) than the FT test (11.8 minutes). The mean deviation did not differ between SS and FT testing. A small difference was found in the pattern SD (PSD) (P = 0.02). The mean CIGTS score from the FT test (4.5) was significantly lower (P < 0.0001) than the mean CIGTS score from the SS test (6.0). Although the two tests yielded identical Glaucoma Hemifield Test (GHT) results in 179 patients (76%), 16 patients had a normal GHT result on FT testing and an SS test result that was outside normal limits. Six patients had the reverse finding. The most significant factor associated with an increased (positive) difference between the CIGTS VF score generated from SS and FT testing was conducting the FT test first (P < 0.0001). Although SS and FT testing yielded very similar mean deviation results, the CIGTS VF score and GHT differed between SS and FT tests. Changing the approach used to measuring a study's primary VF outcome should be accompanied by a critical evaluation of the change's impact.

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.

Test–Retest Variability of Multifocal Visual Evoked Potential and SITA Standard Perimetry in Glaucoma

To investigate the test-retest variability of multifocal visual evoked potential (mfVEP) and threshold perimetry in glaucoma, and to examine the relationship between the two techniques. Data were recorded using the AccuMap mfVEP and SITA standard program of the Humphrey Field Analyzer. Data were obtained twice within a 4-week period from both eyes of 74 patients with varying amounts of glaucomatous visual field loss. The number of defective test locations (those falling beyond a given probability value of being normal) were calculated for mfVEP and SITA, using databases incorporated within the instruments software. Reliability measures and test times were recorded along with patient test preference. Both tests showed a large degree of test-retest variability in the number of defective test locations (95% limits of agreement for mfVEP and SITA being 13.39 and 9.88, respectively). A "fair to moderate" degree of spatial agreement was found between mfVEP and SITA. The number of mfVEP defective locations was dependent on the signal amplitude. No relationship was found between test-retest variability and the reliability indices for either test. The mean time taken to perform mfVEP and SITA standard was 33 and 20 minutes, respectively, and 73 of the 74 patients preferred the mfVEP test. Test-retest variability was found to be slightly greater for mfVEP. The processing of mfVEP signals needs to be changed to remove the relationship between the number of defective locations and signal amplitude. The majority of patients preferred mfVEP to conventional perimetry although mfVEP takes longer to perform.

Sensitivity and specificity of the swedish interactive threshold algorithm for glaucomatous visual field defects

Purpose To determine the sensitivity and specificity of two new visual field algorithms in detecting glaucomatous visual field defects: (1) Swedish interactive threshold algorithm (SITA) standard and (2) SITA fast. Design Prospective observational case series. Participants Ninety normal subjects and 82 glaucoma patients. Testing Central 30° fields were performed with the Humphrey visual field analyzer 30-2 program (Humphrey Systems, Dublin, CA) using full threshold, SITA standard, and SITA fast algorithms on the same day for two or more sessions within a 1-month period. Main outcome measures Sensitivity and specificity in detecting glaucomatous visual field defects with SITA standard and SITA fast using full threshold testing as the reference standard. Results The sensitivity of SITA standard and SITA fast in detecting glaucomatous defects overall was 98% and 95%, respectively. In the subset of mild glaucomatous field defects (26 patients), sensitivity of SITA standard was 92% versus 85% with SITA fast. Sensitivity was 100% for both algorithms in moderate to severe glaucomatous defects. Specificity for glaucoma defects using SITA standard and SITA fast was 96% for both algorithms. SITA standard reduced test-taking time from full threshold by 52% in normal subjects and 47% in glaucoma patients ( P < 0.001). SITA fast reduced test-taking time by 72% in normal subjects and 65% in glaucoma patients ( P < 0.001). Mean deviation values were 0.4 dB and 0.8 dB better in SITA standard and SITA fast fields, respectively, in normal subjects ( P < 0.001), and 0.7 dB and 1.2 dB in SITA standard and SITA fast fields, respectively, in glaucoma patients ( P < 0.001) compared with full threshold values. Conclusions The new algorithms for measuring visual fields, SITA standard and SITA fast, have excellent sensitivity and specificity for glaucomatous visual field loss with considerable savings in time.