Perimetry In Glaucoma Research Articles

Correlation of Binocular Perimetry Screening using imo, a Portable Head Mounted Perimeter with 10-2 Standard Automated Perimetry for Early Glaucoma with Central Visual Field Defects.

The screening program using imo strongly correlates with 10-2 Standard automated perimetry in detecting central visual field defects in early glaucoma, highlighting its potential as a valuable tool for efficient screening and severity quantification. To investigate the correlation between abnormalities within the central 10° of the screening program using imo, a portable head-mounted perimeter, and 10-2 standard automated perimetry in early-stage glaucoma with central visual field defects. This retrospective study included early glaucoma with (26 eyes) and without (38 eyes) central visual field defects. The correlation between the numbers of abnormal points within the central 10° of the imo screening program and those in the probability plot of 10-2, and mean total deviation and pattern deviation, were analyzed. The imo screening program demonstrated sensitivity (80%) and specificity (98.7%) in detecting abnormalities, with a 91.6% agreement rate of 10-2. The mean number of anomalies in the 10-2 plot (pattern deviation) with P<1% was 0.85, 7.75, and 9.69 (95% confidence interval: 0.18-1.51, 5.38-10.1, and 6.89-12.5, respectively) for no, one, and two anomalies in the imo screening program, respectively. The number of anomalies with P<1% was significantly higher when the imo screening program detected one anomaly versus none (P<0.01), and two versus one (P<0.05). Mean total deviation values were -1.15, -7.5, and -15.2 (95% confidence interval: -2.32 to 0.03, -11.21 to -3.78, and -19.7 to -10.6, respectively), while mean pattern deviation values were -1.57, -9.0, and -16.0 (95% confidence interval: -2.57 to -0.57, -12.5 to -5.49, and -21.4 to -10.7, respectively), for no, one, and two anomalies in the imo screening program, respectively. The imo portable head-mounted perimeter was found to correlate with 10-2 standard automated perimetry in glaucoma patients with central visual field defects and has the potential to shorten visual field testing times.

Diagnostic Power and Reproducibility of Objective Perimetry in Glaucoma.

An objective perimetry method provides four 30-2 style reports in 8 minutes. These comprise sensitivity and delay reports for both eyes. A combined report format shows comparable diagnostic power to two forms of automated perimetry. To compare objective perimetry with two forms of standard automated perimetry (SAP) in glaucoma. The study cohort contained 40 persons with glaucoma (PwG) and 94 normal control subjects. The PwG had both perimetric and pre-perimetric eyes. Multifocal pupillographic objective perimetry was performed with the objectiveField Analyser® (OFA®), which independently assesses the visual fields of both eyes concurrently. Its OFA30 test assessed the central ±30°, and the OFA15 test assessed the central ±15°, both providing 30-2 style reports. The OFA tests were repeated two weeks apart to assess test-retest variability (TRV). OFA was compared with Matrix and HFA-SITA fast 24-2 threshold testing. Diagnostic power was quantified as area under receiver operating characteristic curves (AUROC). Test durations, Mean Defects and Pattern Standard Deviations of the 4 tests were compared. At a median of 4.09±0.02 minutes/eye the OFA tests were quicker than SAP (all P≤0.0001), 2 minutes/eye if OFA per-region sensitivities and delays are considered separately. The %AUROCs for OFA, Matrix and HFA were not significantly different, averaging 93±3% (mean±SD) in perimetric eyes, and 73±6% in pre-perimetric eyes. For moderate to severe fields OFA TRV was less than published results for SAP. OFA30 mean defects were significantly correlated between repeats (r=0.91), and with OFA15 (r=0.93, both P<0.0001). OFA provides extra functional measures in the form of per-region delays, and between-eye asymmetries. Both the OFA wide-field and macular tests provided comparable diagnostic power to SAP and better TRV in damaged eyes.

Comparing a Head-Mounted Smartphone Visual Field Analyzer to Standard Automated Perimetry in Glaucoma: A Prospective Study.

Wang et al compare an FDA-registered head-mounted smartphone device (PalmScan VF2000) with standard automated perimetry (SAP) in glaucoma patients and find that the head-mounted device may not fully recapitulate SAP testing. This study prospectively compared visual field testing using the PalmScan VF2000 Visual Field Analyzer, a head-mounted smartphone device, with standard automated perimetry (SAP). Patients with glaucoma undergoing Humphrey Field Analyzer SAP testing were asked to complete in-office PalmScan testing using a Samsung S5 smartphone in a virtual reality-style headset. Glaucoma severity was defined as SAP mean deviation (MD) >-6 dB for mild, between -6 and -12 dB for moderate, and <-12 dB for severe. Global parameters MD and pattern SD from PalmScan and SAP were compared using t -tests and Bland-Altman analyses. Bland-Altmann analyses of PalmScan and SAP MD were conducted for the superonasal, superotemporal, inferonasal, and inferotemporal visual field quadrants. The repeatability of PalmScan was assessed using Spearman's correlations and intraclass correlation coefficients (ICCs). Fifty-one patients (51 eyes) completed both SAP and PalmScan testing and met the criteria for analysis. Compared with SAP, global MD and pattern SD measurements from PalmScan differed by an average of +0.62±0.26 dB (range: -3.25 to +4.60 dB) and -1.00±0.24 dB (range: -6.03 to +2.77 dB), respectively, while MD scores from individual visual field quadrants differed by as much as -6.58 to +11.43 dB. The agreement between PalmScan and SAP in classifying glaucoma severity was 86.3% across all eyes. PalmScan and SAP identified the same quadrant as having the worst visual field defect in 66.7% of eyes. Despite advantages in cost and accessibility, the PalmScan head-mounted perimetry device may not be able to fully recapitulate SAP testing.

Prospective Comparison of VisuALL Virtual Reality Perimetry and Humphrey Automated Perimetry in Glaucoma.

Automated perimetry plays an important role in the diagnosis and monitoring of glaucoma patients. The purpose of this study is to prospectively determine parity between Humphrey visual field analyzer (HVFA) perimetry (the current gold standard) and the VisuALL virtual reality perimeter (VRP). In this prospective fully paired diagnostic accuracy study, patients with stable, long-term HVFA visual fields (horizontal dots for ≥4 consecutive visits on progression analysis) with preperimetric, mild, moderate, or severe visual field loss were familiarized with the VRP and then tested using its proprietary software. These results were used for point-by-point comparison with a contemporaneous HVFA test. This study was approved by the Institutional Review Board (IRB) of the University of the Incarnate Word, San Antonio, Texas, United States of America (IRB approval #20-06-002). The prospective study analyzed 43 eyes of 24 glaucoma patients. Spearman's correlation of mean deviation (MD) revealed a strong correlation between HVFA and VRP with rs(41) = 0.871, p < 0.001. The overall mean difference in locus-locus sensitivity between the devices was -0.4 ± 1.5 dB but varied for different visual field locations and glaucoma severity. The parity between the VRP and HVFA was remarkably strong for mild and moderate glaucoma. Given its portability, ease of use, space efficiency, and low cost, the VRP presents a viable alternative. Automated perimetry, specifically the HVFA, has been the gold standard for visual field assessment since its introduction. The recent COVID-19 pandemic has illuminated the advantages of the VRP, allowing for safer visual assessment for both patient and clinician alike. Our study hopes to establish parity between these systems, allowing for the efficient integration of a novel head-mounted perimetry system that can safely diagnose and monitor glaucomatous progression in clinical practice. Investigation of parity between Olleyes VisuALL virtual reality perimetry (VRP) and existing standard HVFA perimetry is essential to the diagnosis and management of glaucoma. Linear correlations between the two were established from 43 glaucomatous eyes. Parity was strong for mild and moderate glaucoma, presenting VRP as a viable alternative. Griffin JM, Slagle GT, Vu TA, et al. Prospective Comparison of VisuALL Virtual Reality Perimetry and Humphrey Automated Perimetry in Glaucoma. J Curr Glaucoma Pract 2024;18(1):4-9.

Detectability of Visual Field Defects in Glaucoma Using Moving Versus Static Stimuli for Perimetry.

We have previously shown that using moving, instead of static, stimuli extends the effective dynamic range of automated perimetry in glaucoma. In this study, we further investigate the effect of using moving stimuli on the detectability of functional loss. We used two experimental perimetry paradigms to test 155 subjects with a diagnosis of glaucoma or glaucoma suspect, and 34 healthy control subjects. One test used stimuli moving parallel to the average nerve fiber bundle orientation at each location; the other used static stimuli. Algorithms were otherwise identical. Sensitivities to moving stimuli were transformed to the equivalent values for static stimuli based on a Bland-Altman plot. The proportions of locations outside age-corrected normative limits were compared, and test-retest variability was compared against defect depth for each stimulus type. More tested locations were below the fifth percentile of the normative range for that location using static stimuli. However, among locations abnormal according to standard clinical perimetry on the same day, 19.2% were abnormal using static stimuli, versus 20.5% using moving stimuli (P = 0.372). Test-retest variability was 44% lower for moving stimuli across the range of defect depths. When compared with static automated perimetry and expressed on a common scale, moving stimuli extend the effective dynamic range and decrease variability, without decreasing the detectability of known functional defects. Moving stimuli provide a method to improve known problems of current clinical perimetry.

Dealing with perimetric variability in clinical practice

AbstractThe perimetric follow‐up of glaucoma patients seems a complex task. However, with a limited number of basic rules, it can be done well organized and efficiently. We first address the why would we do perimetry in glaucoma follow‐up. After that, we focus on the how. What is the optimal timing of visual fields? Which variables should be monitored? How do we define a change? What is rate‐of‐progression? How can we incorporate age and glaucoma stage in our decision making?

Long- and Short-Term Variability of Perimetry in Glaucoma.

PurposeTest–retest variability in perimetry consists of short-term and long-term components, both of which impede assessment of progression. By minimizing and quantifying the algorithm-dependent short-term variability, we can quantify the algorithm-independent long-term variability that reflects true fluctuations in sensitivity between visits. We do this at locations with sensitivity both < 28 dB (when the stimulus is smaller than Ricco's area and complete spatial summation can be assumed) and > 28 dB (when partial summation occurs).MethodsFrequency-of-seeing curves were measured at four locations of 35 participants with glaucoma. The standard deviation of cumulative Gaussian fits to those curves was modeled for a given sensitivity and used to simulate the expected short-term variability of a 30-presentation algorithm. A separate group of 137 participants was tested twice with that algorithm, 6 months apart. Long-term variance at different sensitivities was calculated as the LOESS fit of observed test–retest variance minus the LOESS fit of simulated short-term variance.ResultsBelow 28 dB, short-term variability increased approximately linearly with increasing loss. Long-term variability also increased with damage below this point, attaining a maximum standard deviation of 2.4 dB at sensitivity 21 dB, before decreasing due to the floor effect of the algorithm. Above 30 dB, the observed test–retest variance was slightly smaller than the simulated short-term variance.ConclusionsLong-term and short-term variability both increase with damage for perimetric stimuli smaller than Ricco's area. Above 28 dB, long-term variability constitutes a negligible proportion of test–retest variability.Translational RelevanceFluctuations in true sensitivity increase in glaucoma, even after accounting for increased short-term variability. This long-term variability cannot be reduced by altering testing algorithms alone.

Understanding the role of microperimetry in glaucoma.

The present narrative review attempts to provide an overview on the use of microperimetry or fundus-driven perimetry in glaucoma, considering the clinical use, the different strategies and limits compared to standard automated perimetry. An electronic database (PubMed and Medline) search was performed of articles of any type published in the English language between 1998 and 2020 with a combination of the following terms: microperimetry, glaucoma, primary open-angle chronic glaucoma, visual field, Humphrey visual field, fundus automated perimetry. All the original articles, case reports, and short series analyzed were included in the present review, offering an excursus on the strengths and limitations characterizing the use of microperimetry in glaucomatous patients. The characteristics of a recently introduced fundus-driven perimetry Compass (CMP; Centervue, Padua, Italy) were also included. Although there remain several contradictions regarding routine use of microperimetry and the restricted research on this topic limits our ability to draw firm conclusions, microperimetry may be preferable in cases of localized retinal nerve fiber layer defects in patients with primary open-angle glaucoma and normal visual field. However, standard automated perimetry remains the gold standard for monitoring glaucoma, especially in patients with diffuse retinal nerve fiber layer impairment and visual field defects. The newly introduced Compass device can potentially provide a more accurate structural-functional evaluation than standard automated perimetry and can therefore produce superior testing reliability.

Performance of iPad-based threshold perimetry in glaucoma and controls.

Independent validation of iPad visual field testing software Melbourne Rapid Fields (MRF). To examine the functionality of MRF and compare its performance with Humphrey SITA 24-2 (HVF). Prospective, cross-sectional validation study. Sixty glaucomas mean deviation (MD:-5.08±5.22); 17 pre-perimetric, 43 HVF field defects and 25 controls. The MRF was compared with HVF for scotoma detection, global indices, regional mean threshold values and sensitivity/specificity. Long-term test-retest variability was assessed after 6 months. Linear regression and Bland Altman analyses of global indices sensitivity/specificity using (ROC) curves, intraclass correlations. Using a cluster definition of three points at <1% or two at 0.5% to define a scotoma on HVF, MRF detected 39/54 abnormal hemifields with a similar threshold-based criteria. Global indices were highly correlated between MRF and HVF: MD r2 = 0.80, PSD r2 = 0.77, VFI r2 = 0.85 (all P < 0.0001). For manifest glaucoma patients, correlations of regional mean thresholds ranged from r2 = 0.45-0.78, despite differing array of tested points between devices. ROC analysis of global indices showed reasonable sensitivity/specificity with (AUC) values of MD:0.89, (PSD:0.85) and (VFI:0.88). MRF retest variability was low with (ICC) values at 0.95 (MD and VFI), 0.94 (PSD). However, individual test point variability for mid-range thresholds was higher. MRF perimetry, despite using a completely different test paradigm, shows good performance characteristics compared to HVF for detection of defects, correlation of global indices and regional mean threshold values. Reproducibility for individual points may limit application for monitoring change over time, and fixation monitoring needs improvement.

Comparison of Saccadic Vector Optokinetic Perimetry and Standard Automated Perimetry in Glaucoma. Part I: Threshold Values and Repeatability.

PurposeWe evaluated threshold saccadic vector optokinetic perimetry (SVOP) and compared results to standard automated perimetry (SAP).MethodsA cross-sectional study was done including 162 subjects (103 with glaucoma and 59 healthy subjects) recruited at a university hospital. All subjects underwent SAP and threshold SVOP. SVOP uses an eye tracker to monitor eye movement responses to stimuli and determines if stimuli have been perceived based on the vector of the gaze response. The test pattern used was equivalent to SAP 24-2 and stimuli were presented at Goldmann III. Average and pointwise sensitivity values obtained from both tests were compared using Pearson's correlation coefficient. Two versions of SVOP were evaluated.ResultsA total of 124 tests were performed with SAP and SVOP version 2. There was excellent agreement between mean threshold values obtained using SVOP and SAP (r = 0.95, P < 0.001). Excluding the blind spot, correlation between SVOP and SAP individual test point sensitivity ranged from 0.61 to 0.90, with 48 of 54 (89%) test points > 0.70. Overall SVOP showed good repeatability with a Pearson correlation of 0.88. The repeatability on a point-by-point basis ranged from 0.66 to 0.98, with 45 of 54 points (83%) > 0.80. Repeatability of SAP was 0.87, ranging from 0.69 to 0.96, with 47 of 54 (87%) points > 0.80.ConclusionEye-tracking perimetry is repeatable and compares well with the current gold standard of SAP. The technique has advantages over conventional perimetry and could be useful for evaluating glaucomatous visual field loss, particularly in patients who may struggle with conventional perimetry.Translational RelevanceSuprathreshold SVOP already is in the field. To our knowledge, this is the first report of threshold SVOP and provides a benchmark for future iterations.

Pathogenesis of Orderly Loss of Nerve Fibers in Glaucoma

Chronic Glaucoma, commonly known as glaucoma, is a misunderstood disease since given a separate entity in the 1850s. Currently, there are many conflicting views of glaucoma but on one issue we have complete agreement: the million or so densely packed nerve fibers (NFs) in the optic nerve head (ONH) are being destroyed in an orderly tandem fashion from peripheral to central, never randomly–a pathognomonic feature. The orderly destruction of NFs is perhaps the only lead we have in solving the mystery of glaucoma, but rarely discussed. If the NFs were not destroyed in a predictable orderly sequence, the role of perimetry in glaucoma would be meaningless. Various theories have been postulated regarding the pathogenesis of glaucoma, but none of them have addressed the crucial question of orderly destruction of NFs, which can’t be ignored. For any glaucoma theory to prevail, it must incorporate the issue of the orderly destruction of NFs otherwise it will be of no value. The ‘cupping’ theory dating back 160 years and the more recent theories like apoptosis, neurodegeneration, vascular pressure and others fail to answer the question of orderly loss of NFs in glaucoma. This article examines the prevalent theories of glaucoma in the context of orderly loss of NFs and attempts to describe the hypothesis of the sinking disc and severance of nerve fibers corroborating with orderly loss in glaucoma.

Methodology and reporting of diagnostic accuracy studies of automated perimetry in glaucoma: evaluation using a standardised approach.

To evaluate methodological and reporting quality of diagnostic accuracy studies of perimetry in glaucoma and to determine whether there had been any improvement since the publication of the Standards for Reporting of Diagnostic Accuracy (STARD) guidelines. A systematic review of English language articles published between 1993 and 2013 reporting the diagnostic accuracy of perimetry in glaucoma. Articles were appraised for methodological quality using the 14-item Quality assessment tool for diagnostic accuracy studies (QUADAS) and evaluated for quality of reporting by applying the STARD checklist. Fifty-eight articles were appraised. Overall methodological quality of these studies was moderate with a median number of QUADAS items rated as 'yes' equal to nine (out of a maximum of 14) (IQR 7-10). The studies were often poorly reported; median score of STARD items fully reported was 11 out of 25 (IQR 10-14). A comparison of the studies published in 10-year periods before and after the publication of the STARD checklist in 2003 found quality of reporting had not substantially improved. Methodological and reporting quality of diagnostic accuracy studies of perimetry is sub-optimal and appears not to have improved substantially following the development of the STARD reporting guidance. This observation is consistent with previous studies in ophthalmology and in other medical specialities.

Effect of a Variability-Adjusted Algorithm on the Efficiency of Perimetric Testing

Variability in perimetry increases with the amount of damage, making it difficult for testing algorithms to efficiently converge to the true sensitivity. This study describes a variability-adjusted algorithm (VAA), in which step size increases with variability. Contrasts were transformed to a new scale wherein the SD of frequency-of-seeing curves remains 1 unit for any sensitivity. A Bayesian thresholding procedure based on the existing Zippy Estimation by Sequential Testing (ZEST) algorithm was simulated on this new scale, and results converted back to decibels. The root-mean-squared (RMS) error from true sensitivity based on these simulations was compared against that achieved by ZEST using the same number of presentations. The procedure was repeated after limiting sensitivities to 15 dB or higher, the lower limit of reliable sensitivities using standard white-on-white perimetry in glaucoma, for both algorithms. When the true sensitivity was 35 dB, with starting estimate also 35 dB, RMS errors of the algorithms were similar, ranging from 1.39 dB to 1.60 dB. When true sensitivity was instead 20 dB, with starting estimate 35 dB, VAA reduced the RMS error from 7.43 dB to 3.66 dB. Limiting sensitivities at 15 dB or higher reduced RMS errors, except when true sensitivity was near 15 dB. VAA reduces perimetric variability without increasing test duration in cases in which the starting estimate of sensitivity is too high; for example, due to a small scotoma. Limiting the range of possible sensitivities at 15 dB or higher made algorithms more efficient, unless the true sensitivity was near this limit. This framework provides a new family of test algorithms that may benefit patients.

Luminance and colour variant pupil perimetry in glaucoma.

This study investigated the diagnostic utility for glaucoma of multifocal pupillographic objective perimetry stimuli targeting different components of the pupillary response: cortically derived colour responses and subcortical luminance responses. Observational cross-sectional study undertaken at the Australian National University. Thirty-five eyes of 24 glaucoma subjects and 46 eyes of 23 normal subjects. Subjects were tested with three multifocal pupillographic objective perimetry stimulus variants. The luminance-only variant (YYbal) utilized yellow stimuli on a yellow background; mixed colour and luminance protocols utilized green stimuli on a red background (RGbal, RG). Stimuli of 33 ms duration were presented at mean intervals of 4 s/region. Pupil constriction amplitude and time to peak. Area under the receiver operating characteristic curve was the main measure of sensitivity and specificity for glaucoma. Colour and luminance protocols were more accurate at differentiating glaucoma subjects from normal subjects than the luminance-only protocol, and produced the largest reductions in amplitudes. This type of protocol also produced the highest overall sensitivity and specificity for glaucoma (receiver operating characteristic % area under the curve: severe, 100%; moderate, 94.4%; mild, 71.0%). Pattern deviations tended to produce higher area under the receiver operating characteristic curves in eyes classified as mild. Significant differences in the means of the six worst amplitude deviations were observed between normal and severe glaucoma subjects only. Stimuli targeting both cortical pupillary colour response and subcortical pupillary luminance response components produced higher diagnostic accuracy than stimuli targeting subcortical pupillary luminance responses alone. Inclusion of constriction latencies further improved accuracy.

A Comparison of False-negative Responses for Full Threshold and SITA Standard Perimetry in Glaucoma Patients and Normal Observers

To compare false-negative (FN) rates for Full Threshold (FULL) and Swedish Interactive Threshold Algorithm (SITA) Standard automated perimetry in healthy control subjects and glaucoma patients. One eye of 19 glaucoma patients and 5 normal control subjects underwent 5 visual field examinations within 6 weeks on the Humphrey Field Analyzer II using the 24-2 FULL and SITA testing procedures. The order of presentation of test procedures was counterbalanced across participants. We obtained FN response procedures that presented stimuli 9 dB greater than a previously determined threshold value at specific locations in the visual field (FULL) or up to 20 dB greater than the threshold value (SITA), and evaluated whether the patient responded to these suprathreshold stimuli. We compared the percentage of FN responses for the FULL and SITA tests before (Peridata output) and after postprocessing of data. The percentage of FNs was almost twice as high for FULL testing compared with the 2 SITA analyses. The SD of FN percentages was half as large for SITA postprocessing compared with FULL and SITA Peridata procedures. Because the distributions were not normally distributed, a Kruskal-Wallis analysis of variance was performed and revealed a statistically significant difference (H=13.094, P<0.001) for FN percentages among the 3 evaluations. FULL test procedures yield about twice as many FNs as SITA procedures. This may be related to the SITA method of testing for FN in relatively normal areas as opposed to any location (even if it has low sensitivity) with FULL. Because FN responses can be due to either high variability in damaged areas or pathologic variations, these revised FN procedures provide greater assistance in properly interpreting visual field results.

Frequency-Doubling Technology Perimetry for Detection of the Development of Visual Field Defects in Glaucoma Suspect Eyes

While standard automated perimetry (SAP) remains the reference standard for evaluation of visual field (VF) defects in glaucoma, this study demonstrates that frequency-doubling technology (FDT) perimetry is effective in monitoring visual field progression and may detect the onset of visual field defects earlier than SAP. To compare detection of the development of VF defects, rate of change of VF loss, and risk factors for progression between SAP and matrix FDT perimetry in glaucoma suspect and ocular hypertensive eyes. A total of 113 glaucoma suspect and ocular hypertensive eyes from 76 patients with normal SAP and FDT perimetry results at baseline were prospectively followed up for SAP and FDT perimetry testing at approximately 4-month intervals for 30 months or longer. Patients were consecutively enrolled and followed up from January 2, 2008, to February 28, 2012, at the Hong Kong Eye Hospital, Chinese University of Hong Kong. Visual field progression was defined by the development of VF defects confirmed by 3 or more consecutive examinations at a cluster of 3 or more (less conservative) or 4 or more (more conservative) locations. The rates of change of mean deviation and pattern standard deviation were evaluated with linear mixed models and the risk factors for VF progression were computed with Cox proportional hazard models. During a median study period of 3.4 years, 8.0% of eyes developed VF defects detected by FDT perimetry, 6.2% by SAP, and 4.4% by both using the less-conservative criteria. The detection dropped to 6.2%, 4.4%, and 2.7%, respectively, when the more-conservative criteria were applied. The rate of change of pattern standard deviation was significantly faster for FDT perimetry than SAP (P < .001). Baseline average retinal nerve fiber layer thickness and the number of clock hours of abnormal retinal nerve fiber layer measurement were associated with increased risk for VF progression for both SAP and FDT perimetry. Frequency-doubling technology perimetry would be useful to monitor the onset of VF defects in glaucoma and may detect VF defects not evident in SAP.

Functional relationship between retinal sensitivity threshold values assessed by standard automated perimetry in glaucoma

ObjectiveTo study the correlation between the sensitivity threshold values of the different points assessed by the Humphrey Visual Field Analyzer (24-2 Swedish interactive threshold algorithm [SITA] standard strategy) in glaucoma patients. Subjects, material and methodsProspective cross-sectorial study. One-hundred and four eyes of 104 glaucoma patients, defined by the appearance of the optic nerve head, were evaluated. Retinal threshold sensitivity points of standard automated perimetry (SA) with SITA Standard 24-2 program were obtained. The upper and the lower hemifields were studied separately. Pearson correlation coefficients were calculated between the mean threshold sensitivity value at each point of the visual hemifield and the rest of the threshold points in the same hemifield. ResultsPerimetric correlation maps between retinal threshold sensitivity values in the same hemifield were obtained. Most of the points showed moderate to high correlations (r≥0.65. p<0.001) with neighboring points and distant points in the same hemifield. ConclusionsThere is a functional relationship between neighboring and distant points in Humphrey Visual Field Analyzer (SITA Standard 24-2) in glaucoma patients. This correlation is related to the anatomical arrangement of ganglion cell axons. This fact enables perimetric patterns of glaucoma defects to be obtained.

Towards Patient-Tailored Perimetry: Automated Perimetry Can Be Improved by Seeding Procedures With Patient-Specific Structural Information

To explore the performance of patient-specific prior information, for example, from structural imaging, in improving perimetric procedures. Computer simulation was used to determine the error distribution and presentation count for Structure-Zippy Estimation by Sequential Testing (ZEST), a Bayesian procedure with prior distribution centered on a threshold prediction from structure. Structure-ZEST (SZEST) was trialled for single locations with combinations of true and predicted thresholds between 1 to 35 dB, and compared with a standard procedure with variability similar to Swedish Interactive Thresholding Algorithm (SITA) (Full-Threshold, FT). Clinical tests of glaucomatous visual fields (n = 163, median mean deviation -1.8 dB, 90% range +2.1 to -22.6 dB) were also compared between techniques. For single locations, SZEST typically outperformed FT when structural predictions were within ± 9 dB of true sensitivity, depending on response errors. In damaged locations, mean absolute error was 0.5 to 1.8 dB lower, SD of threshold estimates was 1.2 to 1.5 dB lower, and 2 to 4 (29%-41%) fewer presentations were made for SZEST. Gains were smaller across whole visual fields (SZEST, mean absolute error: 0.5 to 1.2 dB lower, threshold estimate SD: 0.3 to 0.8 dB lower, 1 [17%] fewer presentation). The 90% retest limits of SZEST were median 1 to 3 dB narrower and more consistent (interquartile range 2-8 dB narrower) across the dynamic range than those for FT. Seeding Bayesian perimetric procedures with structural measurements can reduce test variability of perimetry in glaucoma, despite imprecise structural predictions of threshold. Structural data can reduce the variability of current perimetric techniques. A strong structure-function relationship is not necessary, however, structure must predict function within ±9 dB for gains to be realized.

High‐ versus low‐density multifocal pupillographic objective perimetry in glaucoma

Multifocal pupillographic objective perimetry was compared using 24 and 44 regions per visual field. Experimental design in a university setting. Twenty-seven normal control and 36 age-matched glaucoma patients. The four test variants differed in the mean interval between stimuli: 4, 1 or 0.25 s; and the number of visual field regions tested within the central 60 degrees: 24 or 44. All subjects had their diagnostic status confirmed by optical coherence tomography, two forms of perimetry and slit-lamp biomicroscopy. Both eyes were measured concurrently in 2.73 ± 0.45 min/eye (mean ± standard deviation), and tests were repeated about 2 weeks apart. The main outcome measures were: (i) mean change in light sensitivity due glaucoma; and (ii) areas under Receiver Operator Characteristic plots for detecting glaucoma. For all four variants, consensual responses, female gender and age produced small but significant sensitivity differences, and sensitivity declined with age by ≤-0.27 dB/decade (all P < 0.0003). The best diagnostic accuracy (area under curve 93.2 ± 3.89%) was produced by the one-presentation/s 44-region protocol. Across the four protocols, the effect of repeat testing was small (all methods ≤0.15 dB). Presentation rate had little effect, but increasing the tested density from 24 to 44 regions/field improved diagnostic power. Given that multifocal pupillographic objective perimetry also provides information on response delay and afferent versus efferent defects at every visual field region, it may be a useful adjunct to perimetry.

Retinal Nerve Fiber Layer Atrophy Is Associated With Visual Field Loss Over Time in Glaucoma Suspect and Glaucomatous Eyes

To compare prospectively detection of progressive retinal nerve fiber layer thickness (RNFL) atrophy identified using time-domain optical coherence tomography with visual field progression using standard automated perimetry in glaucoma suspect and preperimetric glaucoma patients or perimetric glaucoma patients. Prospective, longitudinal clinical trial. Eligible eyes with 2 years or more of follow-up underwent time-domain optical coherence tomography and standard automated perimetry every 6months. The occurrence of visual field progression was defined as the first follow-up visit reaching a significant (P < .05) negative visual field index slope over time. RNFL progression or improvement was defined as a significant negative or positive slope over time, respectively. Specificity was defined as the number of eyes with neither progression nor improvement, divided by the number of eyes without progression. Cox proportional hazard ratios were calculated using univariate and multivariate models with RNFL loss as a time-dependent covariate. Three hundred ten glaucoma suspect and preperimetric glaucoma eyes and 177 perimetric glaucoma eyes were included. Eighty-nine eyes showed visual field progression and 101 eyes showed RNFL progression. The average time to detect visual field progression in those 89 eyes was 35 ± 13months, and the average time to detect RNFL progression in those 101 eyes was 36 ± 13months. In multivariate Cox models, average and superior RNFL losses were associated with subsequent visual field index loss in the entire cohort (every 10-μm loss; hazard ratio, 1.38; P= .03; hazard ratio, 1.20; P= .01; respectively). Among the entire cohort of 487 eyes, 42 had significant visual field index improvement and 55 had significant RNFL improvement (specificity, 91.4% and 88.7%, respectively). Structural progression is associated with functional progression in glaucoma suspect and glaucomatous eyes. Average and superior RNFL thickness may predict subsequent standard automated perimetry loss.