Swedish Interactive Threshold Algorithm Research Articles

Visual Field Prediction: Evaluating the Clinical Relevance of Deep Learning Models

Two novel deep learning methods using a convolutional neural network (CNN) and a recurrent neural network (RNN) have recently been developed to forecast future visual fields (VFs). Although the original evaluations of these models focused on overall accuracy, it was not assessed whether they can accurately identify patients with progressive glaucomatous vision loss to aid clinicians in preventing further decline. We evaluated these 2 prediction models for potential biases in overestimating or underestimating VF changes over time. Retrospective observational cohort study. All available and reliable Swedish Interactive Thresholding Algorithm Standard 24-2 VFs from Massachusetts Eye and Ear Glaucoma Service collected between 1999 and 2020 were extracted. Because of the methods' respective needs, the CNN data set included 54 373 samples from 7472 patients, and the RNN data set included 24 430 samples from 1809 patients. The CNN and RNN methods were reimplemented. A fivefold cross-validation procedure was performed on each model, and pointwise mean absolute error (PMAE) was used to measure prediction accuracy. Test data were stratified into categories based on the severity of VF progression to investigate the models' performances on predicting worsening cases. The models were additionally compared with a no-change model that uses the baseline VF (for the CNN) and the last-observed VF (for the RNN) for its prediction. PMAE in predictions. The overall PMAE 95% confidence intervals were 2.21 to 2.24 decibels (dB) for the CNN and 2.56 to 2.61 dB for the RNN, which were close to the original studies' reported values. However, both models exhibited large errors in identifying patients with worsening VFs and often failed to outperform the no-change model. Pointwise mean absolute error values were higher in patients with greater changes in mean sensitivity (for the CNN) and mean total deviation (for the RNN) between baseline and follow-up VFs. Although our evaluation confirms the low overall PMAEs reported in the original studies, our findings also reveal that both models severely underpredict worsening of VF loss. Because the accurate detection and projection of glaucomatous VF decline is crucial in ophthalmic clinical practice, we recommend that this consideration is explicitly taken into account when developing and evaluating future deep learning models.

24-2 SITA Standard versus 24-2 SITA Faster in Perimetry-Naive Normal Subjects

To compare the Swedish Interactive Thresholding Algorithm (SITA) Standard (SS) and SITA Faster (SFR) strategies in normal individuals undergoing standard automated perimetry (SAP) for the first time. Randomized, comparative, observational case series. Seventy-four perimetry-naive healthy individuals. All individuals underwent SAP 24-2 testing with the Humphrey Field Analyzer III (model 850 Zeiss) using the SS and SFR strategies. One eye of each individual was tested. Test order between strategies was randomized, and an interval of 15 minutes was allowed between the tests. The following variables were compared: test time, foveal threshold, false-positive errors, number of unreliable tests, mean deviation (MD), visual field index (VFI), pattern standard deviation (PSD), glaucoma hemifield test (GHT), and number of depressed points deviating at P < 5%, P < 2%, P < 1%, and P<0.5% on the total and pattern deviation probability maps. Specificity of the SS and SFR strategies were compared using Anderson's criteria for abnormal visual fields. The SFR tests were 60.4% shorter in time compared with SS (P < 0.001) and were associated with a significantly lower PSD (1.75 ± 0.80 decibel [dB] vs. 2.15 ± 1.25 dB; P= 0.016). There were no significant differences regarding the MD, VFI, foveal threshold, GHT, and number of points depressed at P < 5%, P < 2%, P<1%, and P < 0.5% on the total deviation and pattern deviation probability maps between SS and SFR. When all exams were analyzed and any of Anderson's criteria was applied, the specificity was 68% with SFR and 61% with SS (P= 0.250). The specificities observed with SFR and SS when only the first or second exams were analyzed were also similar (63% vs. 64% and 72% vs. 58%, respectively, P > 0.05). The SS and SFR were associated with similar specificities in perimetry-naive individuals. The SFR did not increase the number of depressed points in the total and pattern deviation probability maps. Ophthalmologists should be aware that both strategies are associated with disturbingly high false-positive rates in perimetry-naive individuals. Proprietary or commercial disclosure may be found after the references.

One-Year Efficacy and Safety of Omidenepag Isopropyl in Patients with Normal-Tension Glaucoma.

Purpose: To retrospectively evaluate the 1-year efficacy and safety of single-agent of omidenepag isopropyl in patients with normal-tension glaucoma (NTG). Methods: One hundred patients (100 eyes) newly administered omidenepag isopropyl were enrolled. Intraocular pressure (IOP) was compared at baseline and 3, 6, 9, and 12 months after administration. The mean deviation values at baseline and 12 months measured using the Humphrey visual field test (30-2 Swedish Interactive Threshold Algorithm standard) were compared. Adverse reactions and dropouts were observed. Results: IOP significantly decreased from 15.5 ± 2.7 mmHg at baseline to 13.3 ± 2.5 mmHg after 3 months, 13.7 ± 2.3 mmHg after 6 months, 13.9 ± 2.4 mmHg after 9 months, and 13.7 ± 2.3 mmHg after 12 months (P < 0.0001). There was no significant difference in the mean deviation values at baseline (-3.66 ± 3.49 dB) and after 12 months (-3.41 ± 3.80 dB). Adverse reactions occurred in 9 patients (9.0%): conjunctival hyperemia (n = 6), eye pain (n = 1), iritis (n = 1), and blepharitis (n = 1). Twenty-one patients (21.0%) discontinued administration because of changes in medication (n = 7), interruption of visits (n = 5), adverse reactions (n = 4), and others. Conclusions: After administering omidenepag isopropyl, the IOP in patients with NTG decreased within 1 year, visual fields were maintained, and safety was satisfactory. Omidenepag isopropyl can be used as the first-line medication for patients with NTG.

The role of optical coherence tomography angiography in moderate and advanced primary open-angle glaucoma.

To evaluate the relationship between structure and function in moderate and advanced primary open-angle glaucoma (POAG) and to determine the accuracy of structure and vasculature for discriminating moderate from advanced POAG. In this cross-sectional study, 25 eyes with moderate and 40 eyes with advanced POAG were enrolled. All eyes underwent measurement of the thickness of circumpapillary retinal nerve fiber layer (cpRNFL) and macular ganglion cell complex (GCC), and optical coherence tomography angiography (OCTA) of the optic nerve head (ONH) and macula. Visual field (VF) was evaluated by Swedish interactive threshold algorithm and 24-2 and 10-2 patterns. The correlation between structure and vasculature and the mean deviation (MD) of the VFs was evaluated by a partial correlation coefficient. The area under the receiver operating characteristic curve (AUC) was applied for assessing the power of variables for discrimination moderate from advanced POAG. Including all eyes, whole image vessel density (wiVD) of the ONH area, and vessel density (VD) in the inferior quadrant of perifovea were the parameters with significant correlation with the mean deviation (MD) of the VF 24-2 in OCTA of the ONH and macula (r = .649 and .397; p < .05). The greatest AUCs for discriminating moderate and advanced POAG belonged to VD of the inferior hemifield of ONH area (.886; 95% CI (.805, .967)), and VD in the inferior quadrant of perifovea (.833; 95% CI (.736, .930)) without statistically significant difference (.886 Versus .833; p = .601). Among vascular parameters of the ONH area, wiVD had the strongest correlation with the MD of the VF 24-2 while VD of the inferior hemifield of the ONH area had the greatest AUC for discriminating moderate and advanced POAG. Vessel density in the inferior quadrant of perifovea had a significant correlation with the MD of VF 24-2 and also the greatest AUC for discriminating moderate and advanced POAG.

Differences in visual field loss pattern when transitioning from SITA standard to SITA faster

Swedish Interactive Threshold Algorithm (SITA) Faster is the most recent and fastest testing algorithm for the evaluation of Humphrey visual fields (VF). However, existing evidence suggests that there are some differences in global measures of VF loss in eyes transitioning from SITA Standard to the newer SITA Faster. These differences may be relevant, especially in glaucoma, where VF changes over time influence clinical decisions around treatment. Furthermore, characterization of differences in localizable VF loss patterns between algorithms, rather than global summary measures, can be important for clinician interpretation when transitioning testing strategies. In this study, we determined the effect of transitioning from SITA Standard to SITA Faster on VF loss patterns in glaucomatous eyes undergoing longitudinal VF testing in a real-world clinical setting. Archetypal analysis was used to derive composition weights of 16 clinically relevant VF patterns (i.e., archetypes (AT)) from patient VFs. We found switching from SITA Standard to SITA Faster was associated with less preservation of VF loss (i.e., abnormal AT 2–4, 6–9, 11, 13, 14) relative to successive SITA Standard exams (P value < 0.01) and was associated with relatively greater preservation of AT 1, the normal VF (P value < 0.01). Eyes that transition from SITA Standard to SITA Faster in a real-world clinical setting have an increased likelihood of preserving patterns reflecting a normal VF and lower tendency to preserve patterns reflecting abnormal VF as compared to consecutive SITA Standard exams in the same eye.

Relationship between visual acuity and visual field and its reproducibility in patients with retinitis pigmentosa.

To investigate the association between visual acuity (VA) and visual field (VF) and its reproducibility in patients with retinitis pigmentosa (RP). The study cohort comprised 227 eyes of 227 patients with RP. The reproducibility of two Humphrey VF tests (10-2 Swedish Interactive Threshold Algorithm [SITA] tests) performed within a period of 3 months was calculated using the root mean squared error (RMSE) of each VF test point's sensitivity. The association between the logarithm of the minimum angle of resolution (logMAR) VA and VF sensitivity was investigated. Additionally, the relationship between RMSE and age, fixation loss, false positives, false negatives, and logMAR VA was determined. The association between visual sensitivity and VA was most tight at the fovea, and it became weak toward the peripheral region in an eccentric manner. VF reproducibility appreciably increased as VA decreased. In particular, reproducibility was significantly decreased when logMAR VA was >0.5 compared with logMAR VA ≤ 0. Reproducibility of VF tests decreases with a decrease in VA. Careful consideration is necessary when a patient's logMAR VA is >0.5.

Classification of Visual Field Abnormalities in Highly Myopic Eyes without Pathologic Change

To develop a classification system of visual field (VF) abnormalities in highly myopic eyes with and without glaucoma. Secondary analysis of VF data from a longitudinal cohort study. One thousand eight hundred ninety-three VF tests from 1302 eyes (825 individuals). All participants underwent VF testing (Humphrey 24-2 Swedish interactive threshold algorithm standard program; Carl Zeiss Meditec) and detailed ophthalmic examination. A comprehensive set of VF defect patterns was defined via observation of the 1893 VF reports, literature review, and consensus meetings. The classification system comprised 4 major types of VF patterns, including normal type, glaucoma-like defects (paracentral defect, nasal step, partial arcuate defect, arcuate defect), high myopia-related defects (enlarged blind spot, vertical step, partial peripheral rim, nonspecific defect), and combined defects (nasal step with enlarged blind spot). A subset (n= 1000) of the VFs was used to evaluate the interobserver and intraobserver agreement and weighted κ values of the classification system by 2 trained readers. The prevalence of various VF patterns and their associated factors were determined. The classification of VF in highly myopic eyes and its associated risk factors. We found that normal type, glaucoma-like defects, high myopia-related defects, and combined defects accounted for 74.1%, 10.8%, 15.0%, and 0.1% of all unique VF tests, respectively. The interobserver and intraobserver agreements were > 89%, and the corresponding κ values were 0.86 or more between readers. Both glaucoma-like and high myopia-related VF defects were associated with older age (odds ratios [ORs], 1.07 [95% confidence interval (CI), 1.04-1.10; P < 0.001] and 1.06 [95% CI, 1.04-1.10; P < 0.001]) and longer axial length (ORs, 1.65 [95% CI, 1.32-2.07; P < 0.001] and 1.37 [95% CI, 1.11-1.68; P= 0.003]). Longer axial length showed a stronger effect on the prevalence of glaucoma-like VF defects than on the prevalence of high myopia-related VF defects (P= 0.036). We propose a new and reproducible classification system of VF abnormalities for nonpathologic high myopia. Applying a comprehensive classification system will facilitate communication and comparison of findings among studies.

Faster algorithms to measure visual field using the variational Bayes linear regression model in glaucoma: comparison with SITA-Fast

AimsTo compare the visual field (VF) test results measured with the Swedish Interactive Threshold Algorithm Fast (SITA-Fast) and newly developed variational Bayes linear regression visual field (VBLR-VF) Fast or VBLR-VF...

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.

Visual Field Loss Impacts Vision-Specific Quality of Life by Race and Ethnicity: The Multiethnic Ophthalmology Cohorts of California Study

To assess the impact of visual field loss (VFL) on vision-specific quality of life (VSQOL) by race, ethnicity, and age. Pooled analysis of cross-sectional data from 3 population-based, prospective cohort studies. The Multiethnic Ophthalmology Cohorts of California Study (MOCCaS) participants included 6142 Latinos, 4582 Chinese Americans, and 6347 Black Americans from Los Angeles County. A total of 17 071 adults aged 40 years and older completed comprehensive interviews and ophthalmic examinations from 2000 to 2018. VFL was measured using the Humphrey Swedish Interactive Threshold Algorithm Standard 24-2 test as decibels (dB) of mean deviation (MD). Multivariable linear regression was used to evaluate the impact of VFL in the better-seeing eye on self-reported VSQOL scores, adjusting for sociodemographic and clinical covariables. Hierarchical modeling was performed to determine the best-fit model after considering main effects and interactions by race, ethnicity, and age. The VSQOL scores were measured using the 25 Item National Eye Institute Visual Function Questionnaire (NEI-VFQ-25). Item response theory was used to model vision-related task and well-being composite scores, and classical test theory was used to calculate 11 vision subscales. The impact of VFL on VSQOL varied by race and ethnicity. Five-point reductions in task and well-being scores were reached after mild-to-moderate VFL for Latinos (6.7 dB and 7.5 dB), mild-to-moderate VFL for Chinese Americans (7.0 dB and 8.7 dB), and moderate-to-severe VFL for Black Americans (10.1 dB and 12.9 dB), respectively. Differences met statistical significance when comparing Latinos and Black Americans (P < 0.001). Visual field loss had the largest effect on driving among all participants. Driving difficulties were the only VSQOL outcome modified by age; participants aged 65 years and older scored 0.487 lower points per MD of VFL (P<0.001). Subscales most affected by VFL included role function, mental health, and dependency. Race and ethnicity modified the impact of VFL on VSQOL, even after adjusting for sociodemographic covariates. In MOCCaS, Latinos and Chinese Americans reported a greater change in VSQOL than Black Americans for the same level of VFL. Future work should assess whether findings were due to socioeconomic or cultural differences in perception of visual function.

Testing the eligibility of glaucoma patients for potential gene therapy among a clinic population.

Glaucoma patients who deteriorate despite standard treatment may benefit from novel gene therapies. Key inclusion criteria for a glaucoma gene therapy trial were devised. A retrospective chart review in a glaucoma clinic population was conducted. Feasibility of gene therapy inclusion criteria and factors associated with progression and fast progression < -1 decibels/year (dB/y) were evaluated. Three hundred and seventy-four primary open-angle glaucoma patients all of whom had performed at least five Swedish interactive threshold algorithm standard visual fields within a 58-month period. Two definitions were applied to characterize visual field progression rate using Guided Progression Analysis for an individual patient based on A, the eye with the greatest visual field loss, or B, the eye with the most rapid progression rate. Mean rate of visual field progression was -0.50dB/y (Definition A) and -0.64dB/y (Definition B). 19.0% (A) and 21.9% (B) of eyes, 71 (A) and 82 (B) eyes, were 'fast progressors' (< -1dB/y). 37 (A) and 43 (B) eyes met the putative gene therapy inclusion criteria (≥ 50years; mean deviation ≤ -4 to ≥ -12 or ≤ -20dB, progression rate between -1 and -4dB/y). Beta blockers (Odds ratio (OR) with 95% Confidence Intervals (CI): 2.84 (1.39-5.80); p = 0.004) (A), (OR (95%CI): 2.48 (1.30-4.75); p = 0.006) (B) and alpha agonists (OR (95%CI): 2.18 (1.14-4.17); p = 0.02) (A), (OR (95%CI) 2.00 (1.08-3.73); p = 0.028) (B) were significantly associated with fast progression. A substantial proportion (10%) of patients in this clinic population would meet recommended gene therapy inclusion criteria.

An observational study of the correlation between axial length and retinal nerve fibre layer thickness in myopic eyes in a tertiary care centre in south india

Objective: To assess the correlation between axial length and retinal nerve fibre layer (RNFL) thickness in myopic eyes in a tertiary care hospital in a two-year period (August 2017 to June 2019). Methods: Institutional ethics committee approval was obtained. Written and informed consent was obtained from all the participants. One hundred eyes of 58 patients were screened. Myopic patients with > -0.50 D myopia in the age group of 18 to 40 years with intraocular pressure (IOP) <20 mm Hg were included in the study. Patients with a history of ocular trauma, glaucoma, ocular surgeries, optic nerve or macular diseases, pathological myopia, and media opacities were excluded from the study. An ophthalmic evaluation was done by assessing the visual acuity, IOP, slit-lamp examination, and perimetry using Humphrey field analyser II (Swedish interactive threshold algorithm SITATM testing strategy). After dilating the pupils with Tropicamide plus, posterior segment evaluation was done using a 90 D lens with slit lamp bio-microscopy as well as indirect ophthalmoscopy and 20 D lens. The axial length was measured using Lenstar LS 900. Optical Coherence Tomography (OCT) images were obtained using a 3 D OCT 1 Maestro machine by a single observer. Results: There was a statistically significant association between axial length and RNFL thickness in myopic eyes (P = 0.0003). As the axial length of the eyeball increases, the RNFL thickness decreases in all four quadrants except the temporal quadrant, producing a statistically significant negative correlation (r = -0.3551). Conclusion: There is a statistically significant association between axial length and RNFL thicknesses in all quadrants except the temporal quadrant. The negative correlation between axial length and RNFL thickness would be useful in avoiding misdiagnosis of glaucoma since RNFL thickness is low in both glaucoma and myopia.

Comparing Five Criteria for Evaluating Glaucomatous Visual Fields

No consensus exists on the relative superiority among criteria for evaluating glaucomatous visual field (VF) damage. We compared the sensitivities and specificities of 5 criteria-Glaucoma Hemifield Test (GHT), Hoddap-Anderson-Parrish 2 (HAP2), Foster, United Kingdom Glaucoma Treatment Study (UKGTS), and Low-pressure Glaucoma Treatment Study (LoGTS)-across various levels of functional and structural glaucomatous damage. Retrospective cross-sectional study. This single-center study included patients with suspect or known glaucoma with reliable VF (Humphrey 24-2 Swedish Interactive Thresholding Algorithm) and optical coherence tomography (OCT; Spectralis, Heidelberg Engineering) examinations within a 4-month period. One eye per patient was included. The level of functional and structural damage was defined by mean deviation (MD) and by an OCT score, respectively. We created the OCT score by counting the number of abnormal (MD percentile [P] <1%) global and sectoral averages of optic nerve head MRW, circumpapillary RNFL thickness, and macular GCL thickness. We inferred specificities and sensitivities from positive rates of the criteria in patients with low glaucomatous damage (MD at P ≥ 10% or OCT score = 0) and with higher damage (MD at P < 10% or OCT score > 0), respectively. We included 1230 patients. In patients with low glaucomatous damage, HAP2 and UKGTS had higher positive rates, suggesting lower specificities, whereas GHT, Foster, and LoGTS had lower positive rates, suggesting higher specificities. In patients with higher glaucomatous damage, HAP2 and UKGTS had higher positive rates, indicating higher sensitivities, whereas GHT, Foster, and LoGTS had lower positive rates, indicating lower sensitivities. No criteria had uniformly superior performance. Selection of criteria should consider the degree of damage anticipated and the desire for either higher sensitivity or specificity.

Topical Medication Adherence and Visual Field Progression in Open-angle Glaucoma: Analysis of a Large US Health Care System.

Précis:Modeling of visual field and pharmacy data (Kaiser Permanente, 2001 to 2014) from open-angle/pseudoexfoliation glaucoma patients in clinical practice indicated a significant inverse association between the level of medication adherence and rate of visual field progression.Purpose:The aim was to quantify the effect of nonadherence to topical hypotensive medication on glaucomatous visual field progression in clinical practice.Methods:Retrospective analysis of combined visual field and pharmacy data from Kaiser Permanente Southern California’s HealthConnect electronic health record database. Patients with a diagnosis of primary open-angle glaucoma or pseudoexfoliation glaucoma (2001 to 2011) and ≥3 subsequent visual field tests of the same Swedish Interactive Threshold Algorithm type were followed up from first medication fill to final visual field test. Medication adherence (proportion of days covered) was estimated from pharmacy refill data. A conditional growth model was used to estimate the effect of adherence level in modifying the progression of mean deviation over time after adjusting for potential confounders, including age, sex, race/ethnicity, baseline glaucoma severity, and comorbidity.Results:In total, 6343 eligible patients were included in the study and followed for (mean) 5.8 years; average treatment adherence during follow-up was 73%. After controlling for confounders and the interaction between time and baseline disease severity, the model indicated that mean deviation progression was significantly (P=0.006) reduced by 0.006 dB per year for each 10% (absolute) increase in adherence. Model estimates of time to glaucoma progression (mean deviation change −3 dB from baseline) were 8.3 and 9.3 years for patients with adherence levels of 20% and 80%, respectively.Conclusions:Improving patient adherence to topical glaucoma medication may result in slower deterioration in visual function over time.

Comparison of clinical usefulness of central 30-2 and 24-2 threshold tests using SITA strategy.

To compare the clinical utilities of the SITA-based central 24-2 and 30-2 threshold tests. Three hundred sixty-five (365) eyes of 183 glaucoma and glaucoma suspect patients who had undergone both central 30-2 and 24-2 threshold testing using the Swedish interactive threshold algorithm (SITA) standard strategy were retrospectively reviewed. The tests were performed in patients with a minimum visual acuity of LogMAR best-corrected visual acuity (BCVA) 0.3. We compared test time, fixation loss (%), false-positive error rate (%), and false-negative error rate (%), all of which are indices of reliability. We additionally compared the mean deviation (MD), pattern standard deviation (PSD), and visual field index (VFI), all of which are indices of the visual field test. The mean age was 54.67 ± 14.95. MD, VFI, and fixation loss showed no significant difference between the 30-2 and 24-2 tests. As expected, 24-2 was shorter in duration: 5.64 ± 1.09min versus 7.51 ± 1.38min (p < .001), a 24.51 ± 9.45% difference. The false-positive error rate was significantly higher, but the false-negative error rate was lower, with the 24-2 threshold test (p = .009, p < .001). The PSD also was lower with 24-2 than with 30-2 (p < .001). The two tests' VFI and MD are comparable. The 24-2 test may be a more efficient examination for most patients in terms of test time. In the other relevant aspects, the two tests are not identical. Therefore, it would be advisable to tailor visual field testing to the individual patient.

Evaluation of Macular and Retinal Ganglion Cell Count Estimates for Detecting and Staging Glaucoma.

Purpose: To investigate the clinical significance of macular estimated retinal ganglion cell (mRGC) and estimated retinal ganglion cell (eRGC) in the diagnosis and staging of glaucoma.Methods: This is a cross-section study. All enrolled subjects underwent standard automated perimetry (SAP) and optical coherence tomography (OCT) examination. Swedish Interactive Threshold Algorithm (SITA)-FAST detection strategy and 24-2, 10-2 detection programs were employed in SAP assessment. The visual-field parameters and OCT parameters were calculated according to three formulas to obtain the eRGC and mRGC1 or mRGC2. The efficiency of eRGC, mRGC1, and mRGC2 estimates for the staging of glaucoma was compared. The sensitivity and specificity of each parameter for diagnosis of glaucoma were analyzed using the receiver operating characteristic (ROC) curve.Results: A total of 119 eyes were included in the analysis. Compared with the healthy controls, eRGC, mRGC1, and mRGC2 estimates were significantly decreased in patients with glaucoma. As glaucoma progressed, eRGC, mRGC1, and mRGC2 estimates were gradually reduced. In preperimetric glaucoma, mRGC1, mRGC2, and eRGC were reduced by 13.2, 14.5, and 18%, respectively. In the mild stage of glaucoma, mRGC1, mRGC2, and eRGC were reduced by 28, 34, and 38%, respectively. In the advanced stage of glaucoma, mRGC1, mRGC2, and eRGC were reduced by 81, 85, and 92% respectively. The proportion of retinal ganglion cell (RGC) loss in the macula was close to that outside the macula. The specificity at 95% gave a sensitivity of 95.51, 86.52, and 87.64% for eRGC, mRGC1, and mRGC2, respectively. The sensitivity of structural parameters macular ganglion cell complex thickness and retinal nerve fiber layer (RNFL) were 98.88 and 95.51%, respectively. The sensitivity of functional parameters mean deviation (24-2) and visual field index (VFI) were 80.90 and 73.03%, respectively. The area under ROC curve of mRGC1, mRGC2, and eRGC were 0.982, 0.972, and 0.995 (P < 0.0001), respectively.Conclusion: Estimated retinal ganglion cell, mRGC1, and mRGC2 provide value to the staging of glaucoma and better diagnostic performance. Macular RGC estimatesthat integration of both structural and functional damages in macular may serve as a sensitive indicator for assessing macular damage in glaucoma and are of importance for the diagnosis and progression management of glaucoma.

Central macular OCTA parameters in glaucoma

Background/aimsTo investigate the relationship between the foveal avascular zone (FAZ) parameters assessed by optical coherence tomography angiography (OCTA) and central visual field parameters in glaucoma and healthy subjects.MethodsOne hundred and...

Comparison of the SITA Faster-a new visual field strategy with SITA Fast strategy.

To compare visual field defects using the Swedish Interactive Thresholding Algorithm (SITA) Fast strategy with SITA Faster strategy, a newly developed time-saving threshold visual field strategy. Ninety-three participants (60 glaucoma patients and 33 normal controls) were enrolled. One eye from each participant was selected randomly for the study. SITA Fast and SITA Faster were performed using the 24-2 default mode for each test. The differences of visual field defects between the two strategies were compared using the test duration, false-positive response errors, mean deviation (MD), visual field index (VFI) and the numbers of depressed test points at the significant levels of P<5%, <2%, <1%, and <0.5% in probability plots. The correlation between strategies was analyzed. The agreement between strategies was acquired by Bland-Altman analysis. Mean test durations were 246.0±60.9s for SITA Fast, and 156.3±46.3s for SITA Faster (P<0.001). The test duration of SITA Faster was 36.5% shorter than SITA Fast. The MD, VFI and numbers of depressed points at P<5%, <2%, <1%, and <0.5% in probability plots showed no statistically significant difference between two strategies (P>0.05). Correlation analysis showed a high correlation for MD (r=0.986, P<0.001) and VFI (r=0.986, P<0.001) between the two strategies. Bland-Altman analysis showed great agreement between the two strategies. SITA Faster, which saves considerable test time, has a great test quality comparing to SITA Fast, but may be not directly interchangeable.

Multicenter Comparison of the Toronto Portable Perimeter with the Humphrey Field Analyzer: A Pilot Study

To evaluate the agreement between glaucomatous 24-2 visual field (VF) testing performed with the Toronto Portable Perimeter (TPP; VEM Medical Technologies) and the Humphrey Field Analyzer (HFA; Carl Zeiss Meditec). Multicenter prospective cohort analysis. Patients with suspected or confirmed glaucoma treated at Prism Eye Institute (Oakville, Canada), York Finch Eye Associates (North York, Canada), or the Ontario Mobile Medical Eye Care Unit (Cochrane, Canada) between March 2019 and March 2020. Patients underwent consecutive VF tests on the same eye using the HFA Swedish Interactive Threshold Algorithm Standard 24-2 test and TPP Standard 24-2 test in randomized order. Bland-Altman analysis and paired t tests were used to compare VF results obtained by the TPP and the HFA. Participants completed a 5-question validated questionnaire after completing both testing methods. Mean difference and degree of agreement in mean deviation (MD), pattern standard deviation (PSD), visual field index (VFI), and test duration between VF modalities. One hundred fifty eyes from 91 patients were included in analysis. Average MD of the overall cohort using HFA and TPP VF testing was -4.32 ± 5.47 dB and -4.53 ± 5.22 dB, respectively (P= 0.74). Bland-Altman analysis showed good agreement between HFA and TPP tests. The mean differences (95% limits of agreement) between HFA and TPP for MD, PSD, VFI, and test duration were 0.21 dB (-4.25 to 4.67 dB), -0.13 dB (-3.72 to 3.47 dB), 0.66% (-10.94% to 12.26%), and 0.65 seconds (-97.51 to 98.81 seconds), respectively. No statistically significant mean difference was found between HFA and TPP tests for MD, PSD, VFI, or test duration. Mean deviation (R2= 0.830) and VFI (R2= 0.866) were correlated strongly with both modalities. Questionnaire results demonstrated that patients significantly preferred the TPP over the HFA for VF testing (P < 0.001). Mean deviation, PSD, and VFI outcomes measured by the TPP were statistically similar to corresponding parameters obtained with the HFA. Test time duration did not differ significantly between the TPP and HFA, and patients significantly preferred the TPP to the HFA examination experience. These pilot results suggest that the TPP may offer an accessible alternative to HFA VF testing.

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.