Static threshold variability in the peripheral visual field in normal subjects

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

Purpose

The VisuALL S is an automated, static threshold, virtual reality-based perimeter for mobile evaluation of the visual field. We examined same-day and 3-month repeatability.

Methods

Adult participants with a diagnosis of glaucoma or ocular hypertension underwent two VisuALL 24-2 Normal T- Full threshold strategy tests at baseline and one additional exam at 3 months for each eligible eye. Spearman, intraclass correlation coefficients (ICCs), and Bland-Altman plots were used to assess the correlation of individual point sensitivities and mean deviation (MD) among three tests.

Results

Eighty-eight eyes (44 participants) were included. Average age was 68.1 ± 14.3 years, and 60.7% were male. VisuALL MD was highly correlated between tests (intravisit: r = 0.89, intervisit: r = 0.82; P < 0.001 for both). Bland-Altman analysis showed an average difference in intravisit MD of -0.67 dB (95% confidence interval [CI], -6.04 to 4.71 dB) and -0.15 dB (95% CI, -8.04 to 7.73 dB) for intervisit exams. Eight-five percent of pointwise intravisit ICCs were above 0.75 (range, 0.63 to 0.93), and 65% of pointwise intervisit ICCs were above 0.75 (range, 0.55 to 0.91).

Conclusions

VisuALL demonstrated high correlation of MD between tests and good repeatability for individual point sensitivities among three tests in 3 months, except at the points around the blind spot and superiorly.

Translational Relevance

The preliminary reproducibility results for VisuALL are encouraging. Its portable design makes it a potentially useful tool for patients with glaucoma, enabling more frequent assessments both at home and in clinical settings.

Predicting 60-4 visual field tests using 3D facial reconstruction

BACKGROUND

Despite, the potential clinical utility of 60-4 visual fields, they are not frequently used in clinical practice partly, due to the purported impact of facial contour on field defects. The purpose of this study was to design and test an artificial intelligence-driven platform to predict facial structure-dependent visual field defects on 60-4 visual field tests.

METHODS

Subjects with no ocular pathology were included. Participants were subject to optical coherence tomography, 60-4 Swedish interactive thresholding algorithm visual field tests and photography. The predicted visual field was compared with observed 60-4 visual field results in subjects. Average and point-specific sensitivity, specificity, precision, negative predictive value, accuracy, and F1-scores were primary outcome measures.

RESULTS

30 healthy were enrolled. Three-dimensional facial reconstruction using a convolution neural network (CNN) was able to predict facial contour-dependent 60-4 visual field defects in 30 subjects without ocular pathology. Overall model accuracy was 97%±3% and 96%±3% and the F1-score, dependent on precision and sensitivity, was 58%±19% and 55%±15% for the right eye and left eye, respectively. Spatial-dependent model performance was observed with increased sensitivity and precision within the far inferior nasal field reflected by an average F1-score of 76%±20% and 70%±29% for the right eye and left eye, respectively.

CONCLUSIONS

This pilot study reports the development of a CNN-enhanced platform capable of predicting 60-4 visual field defects in healthy controls based on facial contour. Further study with this platform may enhance understanding of the influence of facial contour on 60-4 visual field testing.

Predicting Global Test-Retest Variability of Visual Fields in Glaucoma

PURPOSE

To model the global test-retest variability of visual fields (VFs) in glaucoma.

DESIGN

Retrospective cohort study.

PARTICIPANTS

Test-retest VFs from 4044 eyes of 4044 participants.

METHODS

We selected 2 reliable VFs per eye measured with the Humphrey Field Analyzer (Swedish interactive threshold algorithm 24-2) within 30 days of each other. Each VF had fixation losses (FLs) of 33% or less, false-negative results (FNRs) of 20% or less, and false-positive results (FPRs) of 20% or less. Stepwise linear regression was applied to select the model best predicting the global test-retest variability from 3 categories of features of the first VF: (1) base parameters (age, mean deviation, pattern standard deviation, glaucoma hemifield test results, FPR, FNR, and FL); (2) total deviation (TD) at each location; and (3) computationally derived archetype VF loss patterns. The global test-retest variability was defined as root mean square deviation (RMSD) of TD values at all 52 VF locations.

MAIN OUTCOME MEASURES

Archetype models to predict the global test-retest variability.

RESULTS

The mean ± standard deviation of the root mean square deviation was 4.39 ± 2.55 dB. Between the 2 VF tests, TD values were correlated more strongly in central than in peripheral VF locations (intraclass coefficient, 0.66-0.89; P < 0.001). Compared with the model using base parameters alone (adjusted R2 = 0.45), adding TD values improved prediction accuracy of the global variability (adjusted R2 = 0.53; P < 0.001; Bayesian information criterion [BIC] decrease of 527; change of >6 represents strong improvement). Lower TD sensitivity in the outermost peripheral VF locations was predictive of higher global variability. Adding archetypes to the base model improved model performance with an adjusted R2 of 0.53 (P < 0.001) and lowering of BIC by 583. Greater variability was associated with concentric peripheral defect, temporal hemianopia, inferotemporal defect, near total loss, superior peripheral defect, and central scotoma (listed in order of decreasing statistical significance), and less normal VF results and superior paracentral defect.

CONCLUSIONS

Inclusion of archetype VF loss patterns and TD values based on first VF improved the prediction of the global test-retest variability than using traditional global VF indices alone.

The Relationship between Pupillometric Values and Visual Evoked Potential Test Results in Patients with Early Glaucoma

SIGNIFICANCE

Measuring pupil diameter may provide an additional objective method to detect and monitor glaucoma.

PURPOSE

The purposes of this study were to evaluate whether pupillometry can be used in the assessment of glaucomatous damage and to determine whether pupillometer can be used in glaucoma screening.

METHODS

In this retrospective study, patients with early stages of glaucomatous optic neuropathy were tested using visual evoked potential (VEP), standard automated perimetry, and pupillometer. The VEP record was made using two consecutive check sizes (1° and 15') at 1-Hz frequency. Patients with a mean deviation of <-2 and >-6 dB were included in the study. Pupil size measurements were performed under photopic conditions at 60-, 100-, and 130-cd/m luminance levels with the OPD Scan (Nidek, Gamagori, Japan) device.

RESULTS

In all, 24 eyes of 24 patients (14 women and 10 men) with newly diagnosed open-angle glaucoma were included, and 30 eyes of 30 healthy subjects (15 women, 15 men) were used as controls. There was no significant difference between sexes in photopic pupil diameters in either group. Comparing the pupil diameters in different luminance levels, the diameters were significantly larger in the patient group. When age-corrected values in the glaucoma group were compared with an age-matched control group, the differences in P100 latency and amplitudes were statistically significant. There were significant correlations between photopic pupil diameters and timing of VEP waveforms.

CONCLUSIONS

There is a relationship between pupil diameters and VEP results in eyes with early glaucoma.

Association between Combined Structure Function Index and Glaucoma Severity

The aim of this study was to investigate the relationship between combined structure function index (CSFI) and standard automated perimetry (SAP) parameters such as mean deviation (MD) and visual field index (VFI) in open-angle glaucoma (OAG). We retrospectively reviewed medical records from September 2009 to July 2015, which included 195 eyes of 195 patients with OAG or normal-tension glaucoma who underwent SAP and optical coherence tomography on the same day (male: female, 128 : 67; mean age, 61.4 ± 11.3 years; mean spherical equivalent, −2.39 ± 2.3 D). We divided participants into three stages based on MD value: early, MD > −6 dB; middle, −6 dB ≥ MD ≥ −12 dB; and advanced, MD < 12 dB. We then evaluated correlations between CSFI and SAP parameters in each stage using Pearson's correlation coefficient. Mean CSFI (%), mean MD (dB), and VFI (%) in each stage were early (22.4, −2.13, and 94.0); middle (47.9, −8.78, and 75.4); and advanced (68.3, −17.32, and 49.0), respectively. Correlations between CSFI and whole, early, middle, and advanced MD were −0.88 (p < 0.001), −0.68, −0.24, and −0.76, respectively. Correlations between CSFI and whole, early, middle, and advanced VFI were −0.86 (p < 0.001), −0.59, −0.20, and −0.83, respectively. Consistency between CSFI and SAP indices in middle-stage glaucoma was low.

The peripheral and Central Humphrey visual field - morphological changes during aging

Background

To define age-related changes in the visual field by comparing ‘standard’ central and unique peripheral visual field measurements in healthy volunteers.

Methods

In a single center, retrospective, Cross-sectional, observational study, 20 volunteers with no retinal diseases or risk factors, ranging in age between 30 and 94 years (four age groups: 30’s, 50’s, 70’s, 90’s) were measured in one eye (preferentially the right one) using a Humphrey visual field 24–2 and 60–4.

Results

While the central visual field remained relatively well preserved during aging showing only a mild reduction in sensitivity, a profound loss of the peripheral visual field was observed beginning in the fifth decade of life and decreasing continuously up to the 90ies.

Conclusions

The peripheral visual field declined substantially from the 4th decade onward while the central visual field remained quite stable.

Electronic supplementary material

The online version of this article (doi:10.1186/s12886-017-0522-3) contains supplementary material, which is available to authorized users.

Evaluation of Central and Peripheral Visual Field Concordance in Glaucoma

Purpose

The purpose of this study was to characterize the extent to which central visual field (VF) loss reflects peripheral VF loss in patients with varying degrees of glaucoma severity.

Methods

A total of 232 patients with glaucoma or suspect glaucoma completed static central VF testing using the 24-2 pattern and peripheral VF testing using the suprathreshold 30-60 pattern. Points from 24-2 tests were reclassified as normal/abnormal based on pattern deviation values.

Results

Strong positive correlations (r ≥ 0.7) were observed between the proportion of abnormal central and peripheral points for the full VF, superior hemifield, and inferior hemifield, although the percentage of total central and peripheral abnormal points differed by ≥10% in 45% of eyes. In eyes with an average of 10%–40% abnormal points in the central and peripheral VFs, 12.0% more abnormal peripheral points were noted compared with the percentage of abnormal central points (P < 0.001; SD, 16.7%; range, 61% more to 37% less). In eyes with an average of 60%–90% abnormal points in the central and peripheral VFs, 16.4% fewer abnormal peripheral points were noted compared with the percentage of abnormal central points (P = 0.04; SD, 20.9%; range, 19% more to 49% less).

Conclusions

Central 24-2 testing generally reflects the extent of damage to the more peripheral VF in glaucoma, although significant disagreement exists for individual eyes. Further work is needed to determine whether integration of peripheral test points can improve detection of true VF loss in early glaucoma or be useful in monitoring progressive glaucomatous damage to areas of preserved VF in advanced glaucoma.

New approach for the glaucoma detection with pupil perimetry

OBJECTIVE

To calculate the pattern deviation for identifying abnormal points of pupil perimetry, and also to evaluate the grayscale display for distinguishing glaucomatous pupil field loss (abnormal test points) from normal pupil field (normal test points).

METHODS

Fourteen patients ranging in age from 51 to 80 years, who had normal-tension glaucoma (6 eyes) and primary open-angle glaucoma (8 eyes) were tested. Pupil perimetry (Kowa & Hamamatsu, Japan) was used to objectively measure the visual field. Also, to obtain a subjective visual field, the analysis was performed with a Humphrey Field Analyzer (30-2, Full threshold program, Carl Zeiss Meditec, Dublin). Of the 76 test points, the 22 surrounding points and the 3 points corresponding to the blind spot are excluded; and among the remaining 51 points, the 85th percentile value of pupil perimetry was calculated. The abnormal and normal test points were recorded, and the amount of positive or negative deviation of each test point from the normal median value for the corresponding test points was determined. We also used this technique to identify the value for distinguishing glaucomatous pupil field loss from the normal pupil field.

RESULTS

This study could be improved by calculating the sensitivity and specificity of a certain cut-off value between the normative data and the glaucoma patients. The value for identifying both abnormal and normal test points was a negative deviation of -4. Based on these results, pupil perimetry gray scales were determined: white (< -3), 25% gray (from -4 to -8), 50% gray (from -9 to -13), 75% gray (from -14 to -18) and black (> -19). Glaucomatous pupil field losses were generally distinguished from the normal pupil field by use of a gray scale.

CONCLUSION

Our studies demonstrated that, when a deviation of > -4 was regarded as an abnormal value, the detection of pupil perimetry exhibited improvement in glaucoma patients.

Learning effect, short-term fluctuation, and long-term fluctuation in frequency doubling technique

PURPOSE

To evaluate short-term and long-term fluctuations and learning effects in healthy subjects tested with the frequency doubling technique, which is based on a low spatial frequency and a high temporal frequency stimulus.

METHODS

Twenty-three healthy adult subjects were consecutively recruited from volunteers, and 20 subjects finished the study. All the visual fields were assessed by the frequency doubling technique, program C-20, full threshold. The frequency doubling technique presents stimuli on a black-and-white video monitor with specialized control circuitry interfaced to a microprocessor. During program C-20, full threshold, 17 points are tested, one round point centrally and 16 square ones in the periphery up to 20 degrees of eccentricity. Each stimulus consists of a 0.25-cycle/degree sinusoidal grating undergoing a 25-Hz counterphase flicker. One eye of each patient was chosen at random. Each subject was tested once in the first session, three times in the second session, and once in the third and fourth sessions. Both short-term and long-term fluctuation were studied either as the average fluctuation value of all the points tested or as a point-to-point fluctuation. To study the learning effect, the results of the first session were compared with those of the second, the third, and the fourth sessions.

RESULTS

The average mean sensitivity of the three examinations of the second session was 30.4 +/- 1.24 dB, and the average short-term fluctuation of all the subjects was 2.16 +/- 0.5 dB. The short-term fluctuation of each point tested ranged from 1.4 to 3.4 dB. The average mean sensitivity for all the sessions was 32.4 +/- 1.14 dB, with an average long-term fluctuation of 3.23 +/- 0.5 dB, and the long-term fluctuation of each tested point ranged from 2.5 to 4.4 dB. A mild learning effect was found between the first section and the others.

CONCLUSION

Short-term and long-term fluctuations were similar to those known to occur with the conventional threshold perimetry when they were compared with the literature data. A learning effect was also observed and should be taken into account for the clinical use of this test.

Normal values for fundus perimetry with the scanning laser ophthalmoscope

PURPOSE

To evaluate the normal light sensitivity values for fundus perimetry and their short time fluctuation (reliability) in normal volunteers of different ages. After the development of full-threshold static fundus perimetry, age-corrected sensitivity values for normal subjects are required to interpret results and to compare them with conventional computerized perimetry.

METHOD

Full-threshold fundus perimetry of the central field (33 x 21 degrees) by means of the scanning laser ophthalmoscope was performed on 152 eyes of 99 healthy persons aged 16 to 77 years with normal vision and no eye disease. Fixation was simultaneously documented. Light sensitivity values were evaluated according to each subject's age and test point location.

RESULTS

Linear regression analysis disclosed a significant (P < .0001) decrease of the mean sensitivity of 0.275 dB per decade of increasing age, starting with 16.6 dB at age 10 years. Standard deviation around the center of fixation was 0.287 degrees in the first decade, and it increased by 2.82 minutes of arc per decade (P < .0001). Variation in triple examinations of subjects did not differ from short time fluctuation.

CONCLUSION

Visual fields examined with fundus perimetry show reliable measurements in a range comparable to conventional computerized perimetry. There is a significant correlation between increase of age and decrease of light sensitivity in fundus perimetry. Visual fields obtained with fundus perimetry seem to correlate well with known data from computerized static threshold perimetry. It should be recognized that even in normal subjects, the stability of fixation decreases with increasing age.

Threshold variation in automated perimetry

A physiologic fluctuation in threshold levels exists in automated perimetry, which is greater in glaucoma and ocular hypertensive patients than in normal subjects. Fluctuation increases with greater eccentricity from fixation and in areas of reduced retinal sensitivity. Other factors related to automated perimetry testing potentially may influence threshold fluctuation including: a learning effect, reliability, pupil size, age, and the mode of stimulus presentation. Statistical software may aid in analyzing both the single field and the changes between successive fields. However, statistical programs cannot replace physician judgment, and all factors that may influence threshold levels should be considered when interpreting automated visual fields.

Temporal visual field in glaucoma: a re-evaluation in the automated perimetry era

We prospectively studied 152 glaucoma patients (192 eyes) and 31 normal subjects (31 eyes) tested with the 30-2 program and a customized temporal periphery program on the Humphrey Field Analyzer to determine the usefulness of routine testing temporal to the blind spot. We found that in 53 glaucomatous and each of 31 control eyes the central 30 degrees and temporal peripheral field were normal. In eyes with glaucomatous defects, testing temporal to the blind spot provided information equivalent to the central Bjerrum area in 66 eyes, less in 62 eyes, and more in 11 eyes. Temporal field testing was most useful in eyes with a diffusely depressed Bjerrum area (mean defect less than -8.30 dB). This study suggests that automated static perimetry commonly reveals glaucomatous defects temporal to the blind spot, but usually adds significant information over central testing only in patients with late visual field changes.

Static versus kinetic testing in the nasal peripheral field in patients with glaucoma

One-hundred and seventy-seven subjects (207 eyes) were tested on the Humphrey Field Analyzer to evaluate the usefulness of static and kinetic peripheral nasal visual field testing in identifying glaucomatous defects. In 20 of the 187 glaucomatous or ocular hypertensive eyes glaucomatous defects were found in the peripheral nasal field while the central 30 degrees remained normal or showed non-specific diffuse depression. Kinetic peripheral nasal field testing identified 17 of these eyes while the static testing identified eleven. This difference was not statistically significant (P greater than 0.05, Stuart-Maxwell test). Twenty control eyes showed one glaucomatous peripheral nasal defect on static testing, and none with kinetic testing. These results differed statistically from the diagnoses in the diseased population (P less than 0.005, chi 2-test). This study suggests the potential value of nasal peripheral field testing in selected glaucoma patients for which static testing has no apparent diagnostic advantage over kinetic techniques.

The peripheral visual field in glaucoma: reevaluation in the age of automated perimetry

With the advent of automated static perimetry has come the common practice of measuring only the central 30 degrees of vision in the diagnosis and management of glaucoma. While most glaucomatous field defects appear first in this portion of the visual field, the question remains as to how much useful information is being missed by ignoring the peripheral field, i.e., outside the central 30 degrees. Studies with both static and kinetic automated perimetry have revealed the same peripheral glaucomatous field defects previously recognized with manual perimetry, including generalized contraction, nasal steps, temporal sector defects, and hemianopic offsets. Of these, however, only measurement of the nasal periphery may add sufficient information to that obtained with static testing in the central 30 degrees to justify the added examination time; however, there are special situations in which peripheral field testing in other or all quadrants may be useful. Further study is required to establish optimum techniques for automated measurement of the peripheral visual field and to determine the significance of the results in the management of glaucoma.