Formulas for conversion between Octopus and Humphrey threshold values and indices

Teleglaucoma Using a New Smartphone-Based Tool for Visual Field Assessment

PRCIS

COVID-19 underlines the importance of telemedical diagnostics. The smartphone-based campimetry (Sb-C) is a newly developed digital application allowing visual field testing using a head-mounted device and a smartphone. It enables visual field screening remotely from a clinic.

BACKGROUND

Sb-C is a newly developed tool for functional ophthalmic diagnosis. This study aimed to examine the comparability of the Sb-C and Octopus 900 to ensure ophthalmological care in times of social distancing.

METHODS

Total 93 eyes were included in the study. After an ophthalmological examination, the visual field was tested by the Octopus program G1 and by the smartphone-based campimeter. The Sb-C was performed using VR glasses and an iPhone 6. The software Sb-C was downloaded and installed as SmartCampiTracker app and is examining the 30-degree visual field with 59 test positions corresponding to the G pattern of Octopus G1. Sensitivities were recorded and saved on the app. In addition, test-retest reliability was tested on 6 ophthalmologically healthy participants.

RESULTS

The group comprised 48 women and 45 men (mean age: 62.52±12.2 y) including 19 controls, 17 patients with ocular hypertension, 11 preperimetric glaucomas, and 46 perimetric glaucomas. The mean sensitivity (MS) of all points of G1 perimetry was 23.13 dB (95% CI, 22.08-24.18). The MS of the Sb-C was 21.23 dB (95% CI, 20.37-22.08). The correlation between the mean MS measured by G1 perimetry and the Sb-C was strong ( r =0.815, P <0.05). The test-retest reliability showed a correlation of r =0.591 ( P <0.05) .

CONCLUSIONS

With some technical adjustments, the Sb-C shows promise for screening glaucoma and monitoring disease progression remotely from an ophthalmologic clinic.

The Effects of Visual Field Loss from Optic Disc Drusen on Performance in a Driving Simulator

The purpose of this study was to compare the driving simulator performance of participants with visual field loss (VFL) from optic disc drusen (ODD) with a normally sighted control group and a group of individuals with glaucoma. Data on performance and safety from a traffic simulator test for five participants with VFL from ODD were retrospectively compared with data from 49 male individuals without visual deficits in a cross-sectional study. VFL of the ODD group was also compared with a group of 20 male glaucoma participants who had failed the same simulator test. Four individuals with ODD regained their driving licences after a successful simulator test and were then followed in a national accident database. All participants with ODD passed the test. No significant differences in safety or performance measures were detected between the normally sighted participants and the ODD group despite severe concentric visual field constrictions. Compared with failed glaucoma male participants, the ODD group had even lower mean sensitivity in the peripheral and peripheral inferior field of vision. None of the four participants with a regained licence were involved in a motor vehicle accident during a 3-year follow-up period after the simulator test. Despite having severe VFL, participants with ODD had no worse performance or safety than controls. As even individuals with severe VFL might drive safely, there is a need for individual practical assessments on licencing issues.

The effects of visual field loss from glaucoma on performance in a driving simulator

BACKGROUND

To examine the effects of different stages of visual field loss (VFL) from advanced glaucoma on performance in a driving simulator.

METHODS

Data on performance and safety from a traffic simulator test for 104 participants with withdrawn driver's licences due to visual field loss from advanced glaucoma were compared with data from 83 individuals without visual deficits in a cross-sectional study. Individuals with glaucoma that regained their driving licences after a successful simulator test were then followed in a national accident database.

RESULTS

Glaucoma participants passed the test in 71% (95% confidence interval 61-79%) of the cases. Younger participants were more successful than older. No significant differences on safety or performance measures were detected between glaucoma- and normally sighted participants. Compared with passed glaucoma participants, failed glaucoma participants had more collisions, more critical failed to give way events, longer time headways, and longer reaction times. This group had also a higher extent of central visual field loss. None of the participants with a regained licence were involved in a motor vehicle accident during the 2 to 4 year follow-up after the simulator test.

CONCLUSION

Severity of glaucoma predicts driver safety on a group level. However, even individuals with severe visual field loss from glaucoma might drive safely, which highlights the need for individual assessments for licencing purposes.

Validation and reproducibility of the Heidelberg Edge Perimeter in the detection of glaucomatous visual field defects

AIM

To validate the ability of the Heidelberg Edge Perimeter (HEP) in detecting glaucomatous visual field (VF) defects compared to the Octopus Visual Field (OVF) Analyzer and to determine the test-retest repeatability of both modalities.

METHODS

This prospective, cross-sectional study was conducted at Wills Eye Hospital, Philadelphia, PA. Glaucoma subjects and unaffected controls underwent VF testing using HEP standard automated perimetry (SAP) III 30-2 Adaptive Staircase Thresholding Algorithm (ASTA) FAST protocol and OVF G-TOP white-on-white strategy. Testing order was randomized. Pearson's correlation coefficient was calculated for both mean deviation (MD) and pattern standard deviation/square root of loss of variance (PSD/sLV). Receiver operating characteristic (ROC) curves were used to determine the diagnostic abilities of both modalities. Glaucoma subjects returned for repeat testing and intraclass correlation coefficients (ICCs) were calculated to assess test-retest repeatability.

RESULTS

Seventy-nine subjects with glaucoma and 36 unaffected controls were enrolled. HEP and OVF were significantly correlated for both MD (r=-0.84; P<0.01) and PSD/sLV (r=0.79; P<0.01). Areas under the ROC curves (AUCs) were also comparable between HEP and OVF for both MD (0.74 and 0.79, respectively; P=0.26) and PSD/sLV (0.74 and 0.82; P=0.08). ICC was high for both HEP (0.96 for MD, 0.95 for PSD/sLV) and OVF (0.82 and 0.88, respectively). Mean test duration (min) was significantly shorter for OVF (2.63) compared to HEP (5.15; P<0.01).

CONCLUSION

HEP and OVF show strong correlation for both MD and PSD/sLV, and have similar validity for detecting glaucoma. The test-retest repeatability is high for both HEP and OVF, however the average testing duration of HEP is significantly longer than that of OVF.

Evaluation of the Brusini Glaucoma Staging System for Follow-Up in Glaucoma

Background

Brusini developed a new interpretation system for Octopus and Humphrey automated perimeters that is based on mean defect (MD) and corrected loss variance (CLV) or corrected pattern standard deviation (CPSD). This study tested the performance of Brusini's glaucoma staging system (GSS) in staging and follow-up.

Methods

Retrospectively, 610 visual fields of 64 eyes of open-angle glaucoma patients were analyzed with Brusini GSS and compared with Aulhorn-Karmeyer stages and by PeriData 7.0 trend analysis.

Results

Follow-up was comparable to PeriData 7.0 trend analysis in 97%. Change was observed in 41% of eyes, i.e., initial improvement (19% eyes), deterioration (16%), and after an initial improvement, either deterioration (11%) or a stable period (5%). No change was seen in 59% of the eyes, of which 30% showed small and 19% high long-term fluctuation (LF) due to fatigue effect, poor cooperation of patient, impaired reliability, or short-term fluctuation (SF) greater than 1.7 dB. However, for 8% of the eyes there was no apparent reason for high LF.

Conclusions

Brusini GSS is useful for staging and recommended for follow-up evaluation of visual fields in glaucoma.

MR Imaging of the Anterior Visual Pathway in Primary Open-Angle Glaucoma: Correlation with Octopus 101 Perimetry and Spectralis Optical Coherence Tomography Findings

PURPOSE

To investigate structural changes in the visual pathway measured by magnetic resonance imaging (MRI) and its relationship with the clinical severity of glaucoma in primary open-angle glaucoma (POAG) patients.

MATERIALS AND METHODS

The study included 28 patients with POAG and 26 age- and sex-matched healthy volunteers. All the subjects underwent spectral domain optical coherence tomography (OCT) of the peripapillary retina nerve fiber layer (RNFL). The optic nerve diameter (OND), chiasma height (Ch), and lateral geniculate nucleus height (LGNh) were measured bilaterally using a 1.5-Tesla MRI system.

RESULTS

The mean values of the OND and LGNh were significantly lower in the POAG group (OND: right p = 0.043 and left p = 0.048; LGNh: right p = 0.008 and left p = 0.025). The OND was not correlated with the clinical stage of glaucoma, but it was correlated with the ipsilateral RNFL thickness. The Ch was correlated with the ipsilateral clinical stage (right r = -0.536, p = 0.004; left r = -0.537, p = 0.004) and average RNFL thickness (RNFLav) (right r = 0.655, p < 0.001; left r = 0.626, p < 0.001). The sum of bilateral clinical stages and left clinical stages showed significant correlations with the right and left LGNh and the sum of both the right and left LGNh. The left RNFLav and the sum of the right-left RNFLav were significantly correlated with all LGNh measurements.

CONCLUSIONS

1.5-Tesla MRI can detect structural changes in the visual pathway early in the course of glaucoma. Thin optic nerve can be a risk factor for glaucoma. The Ch and LGNh seem to be correlated with the clinical stage of glaucoma and RNFL thickness. In particular, LGN can be a target of glaucomatous damage.

The factors influencing peripapillary choroidal thickness in primary open-angle glaucoma

PURPOSE

To investigate whether there is a difference between primary open-angle glaucoma (POAG) patients and control group with regard to choroidal thickness (CT) and the factors influencing CT.

METHODS

Ninety eyes of 90 patients who were being followed up with POAG and 72 eyes of 72 healthy subjects matched for age and gender were included. Peripapillary retinal nerve fiber layer thickness (RNFLT), peripapillary CT, lamina cribrosa thickness (LCT), and prelaminar tissue thickness (PTT) were measured with spectral-domain optical coherence tomography (SD-OCT) enhanced depth imaging (EDI) in all patients.

RESULTS

According to multi-variable linear regression analysis results, the factors influencing CT were found as axial length (AL) (B = -22.78, p = 0.002), intraocular pressure (IOP) (B = -7.95, p = 0.001), age (B  = -1.77, p = 0.009), and radial pulse rate (B  = 1.42, p = 0.015). A statistically significant relationship was not detected between CT and central corneal thickness, mean deviation value of visual field, cup/disk ratio, RNFLT, LCT, PTT. CT was found significantly thinner in glaucoma group (147.5 ± 61.2 μm) compared to control group (167.1 ± 37.3 μm). However, IOP was found significantly higher (p < 0.001) and pulse rate was found significantly lower (p = 0.021) in POAG group. IOP and pulse rate were considered to have affected CT difference between the groups. In advanced and worser stage patients, there were significant positive correlations between CT and RNFLT in inferior and superior quadrants.

CONCLUSIONS

In addition to previous studies, IOP and pulse rate were detected to be effective on CT. Further studies are required for determining the whole factors effective on CT and better understanding CT and glaucoma relationship.

Predictive value of heidelberg retina tomograph parameters for the development of glaucoma in the European glaucoma prevention study

PURPOSE

To determine whether baseline Heidelberg Retina Tomograph (HRT) measurements of the optic disc are associated with the development of open-angle glaucoma (OAG) in individuals with ocular hypertension in the European Glaucoma Prevention Study (EGPS).

DESIGN

Retrospective analysis of a prospective, randomized, multicenter, double-masked, controlled clinical trial.

METHODS

There were 489 participants in the HRT Ancillary Study to the EGPS. Each baseline HRT parameter was assessed in univariate and multivariate proportional hazards models to determine its association with the development of OAG. Proportional hazards models were used to identify HRT variables that predicted which participants in the EGPS had developed OAG. Development of OAG was based on visual field and/or optic disc changes.

RESULTS

At a median follow-up time of about 5 years, 61 participants developed OAG. In multivariate analyses, adjusting for randomization arm, age, baseline IOP, central corneal thickness, pattern standard deviation, and HRT disc area, the following HRT parameters were associated with the development of OAG: the "outside normal limits" classification of the Frederick Mikelberg (FSM) discriminant function (hazard ratio [HR] 2.51, 95% confidence interval [CI]: 1.45-4.35), larger mean cup depth (HR 1.64, 95% CI: 1.21-2.23), cup-to-disc area ratio (HR 1.43, 95% CI: 1.14-1.80), linear cup-to-disc ratio (HR 1.43, 95% CI: 1.13-1.80), cup area (HR 1.33, 95% CI: 1.08-1.64), smaller rim area (HR 1.33, 95% CI: 1.07-1.64), larger cup volume (HR 1.30, 95% CI: 1.05-1.61), smaller rim volume (HR 1.25, 95% CI: 1.01-1.54), larger maximum cup depth (HR 1.18, 95% CI: 1.01-1.36), and cup shape measure (HR 1.18, 95% CI: 1.01-1.36).

CONCLUSIONS

Several baseline HRT parameters, alone or in combination with baseline clinical and demographic factors, were significantly associated with the development of OAG among the EGPS participants.

What do patients with glaucoma see? Visual symptoms reported by patients with glaucoma

Background:

Vision loss from glaucoma has traditionally been described as loss of “peripheral vision.” In this prospective study, we aimed to improve our clinical understanding of the visual symptoms caused by glaucoma by asking patients specific detailed questions about how they see.

Methods:

Patients who were clinically diagnosed with various types and stages of glaucoma were included. All had a comprehensive ocular examination, including Octopus visual field testing. Patients were excluded if they had other ocular conditions that affected their vision, including cornea, lens or retina pathologies. Patients responded to an oral questionnaire about their visual symptoms. We investigated the visual symptoms described by patients with glaucoma and correlated the severity of visual field loss with visual symptoms reported.

Results:

Ninety-nine patients completed the questionnaire. Most patients (76%) were diagnosed with primary open-angle glaucoma. The most common symptoms reported by all patients, including patients with early or moderate glaucoma, were needing more light and blurry vision. Patients with a greater amount of field loss (Octopus mean defect >+9.4 dB) were more likely to report difficulty seeing objects to one or both sides, as if looking through dirty glasses and trouble differentiating boundaries and colors.

Conclusions:

Vision loss in patients with glaucoma is not as simple as the traditional view of loss of peripheral vision. Needing more light and blurry vision were the most common symptoms reported by patients with glaucoma.

The Heidelberg retina tomograph ancillary study to the European glaucoma prevention study: study design and baseline factors

PURPOSE

To describe the study design and baseline factors of the Heidelberg Retina Tomograph ancillary study within the EGPS. Furthermore, to examine the relationship between HRT optic disc topographic measurements and baseline demographic and ocular factors.

METHODS

Four hundred and eighty-nine ocular hypertensive participants were included. Each participant completed HRT imaging at least annually. The associations between HRT measurements and IOP, central corneal thickness (CCT), baseline photographic estimates of vertical CDR ratio (CDR), asymmetry between the two eyes in CDR ratio and baseline visual field indices were assessed using regression analysis.

RESULTS

Associations between HRT measurements and vertical CDR by photographs were found for almost all stereometric optic disc parameters in both univariate and multivariate analysis. The strongest association was found between vertical CDR measurements and disc, cup and rim area; cup and rim volume, CDR area, linear CDR, mean and maximum cup depth and cup shape measure (all p < 0.0001). In multivariate analysis, pattern standard deviation (PSD) and HRT disc area had significant associations with several HRT optic disc measurements. Furthermore, CCT was significantly associated with reference height and the glaucoma probability score (GPS, outside normal limits).

CONCLUSIONS

The EGPS is the first multicentre, placebo-controlled randomized clinical trial to use HRT for monitoring optic disc changes in participants with ocular hypertension. We found strong associations between stereophotographic vertical CDR estimates, HRT disc area, PSD and several HRT parameters. We found, furthermore, that the parameters reference height and GPS were significantly related to central corneal thickness.

Comparison of global indices and test duration between two visual field analyzers: Octopus 300 and Topcon SBP-3000

PURPOSE

To compare the global indices and test duration as measured by Octopus 300 and Topcon SBP-3000 perimeters. To our knowledge, this is the first study performed in this way.

METHODS

Eighty eyes of 40 glaucomatous and ocular hypertensive patients with previous perimetric experience had visual field tests with Octopus 300 (TOP strategy) and TOPCON SBP-3000. All pairs of tests were performed randomly on separate days, but within 1 month of each other. Taking into account reliability factors of both perimetric examinations, 54 eyes of thirty patients were eligible. Only one eye from each patient was considered. Mean sensitivity (MS), mean defect (MD), loss of variance (sLV-Octopus- and LV -Topcon-) and test duration times were considered.

RESULTS

A significant difference was found between the global indices and duration times of the Octopus and the Topcon perimeters (p < 0.05; Wilcoxon test). Moderate degrees of correlation were obtained for MS (Spearman's rho = 0.635; p < 0.001) and MD (Spearman's rho = 0.592; p = 0.001) measurements. There was no correlation between sLV and LV (Spearman's rho = 0.181; p = 0.337). Agreements between pairs of global indices were low as measured by concordance correlation coefficient.

CONCLUSION

Global indices measured by the Octopus and Topcon perimeters are significantly different, so direct comparison of the measured values is not reliable. Because of the poor association and agreement between values obtained by these two perimeters, indirect comparison is also inadvisable.

Specificity of the program threshold noiseless trend for perimetric progression analysis

PURPOSE

To evaluate the specificity of the Threshold Noiseless Trend program (TNT), designed to measure progression in visual fields, using four procedures.

MATERIALS AND METHODS

A. In 63 eyes with ocular hypertension, whose last examination showed no perimetric or morphological defects, we performed a mean of 7.70 +/- 1.71 follow-up examinations during 2.2 +/- 0.6 years. B. In 81 glaucomatous eyes examined twice with a bracketing strategy (Octopus 1-2-3 perimeter), we calculated mean threshold value and long-term fluctuation. We simulated 12 different visual fields, adding a random component to simulate an equivalent fluctuation of amplitude. C. Seventy-two glaucomatous eyes, with and without progression, were examined 7.76 +/- 1.25 times during 4.88 +/- 1.39 years using the Humphrey-Sita Standard strategy. Visual field tests were randomly disordered and analyzed using TNT. D. 1221 eyes were examined 7.19 +/- 3.5 times during 3.50 +/- 1.45 years (10,407 visual fields) using TOP-G1 program. We detected progression in 204 eyes using TNT. They were re-evaluated after random disordering of visual field tests.

RESULTS

The four procedures indicated specificity > or = 95% as from the seventh examination; this reduced to 90% in experiment C with six examinations, and in experiments A and C with five examinations.

CONCLUSIONS

The specificity of TNT may be considered to be over 95% with a large number of examinations, and 90-100% with fewer examinations. At least five examinations are required for a basic interpretation of progression, and preferably more than six to guarantee the specificity of the result.

Predictive Factors for Open-Angle Glaucoma among Patients with Ocular Hypertension in the European Glaucoma Prevention Study

OBJECTIVE

To evaluate the predictive factors of open-angle glaucoma (OAG) in patients affected by ocular hypertension enrolled in the European Glaucoma Prevention Study (EGPS).

DESIGN

Randomized, double-masked, controlled clinical trial.

PARTICIPANTS

One thousand seventy-seven patients, > or =30 years old, were enrolled at 18 European centers. The patients met inclusion criteria: intraocular pressure, 22 to 29 mmHg; 2 normal and reliable visual fields (VFs) (on the basis of mean deviation and corrected pattern standard deviation [PSD]); and a normal optic disc, as determined by an optic disc reading center.

INTERVENTION

Treatment with dorzolamide or a placebo (the vehicle of dorzolamide) in one or both eyes.

MAIN OUTCOME MEASURES

Efficacy end points were VF and/or optic disc changes. Baseline demographic and clinical data were collected before randomization, except for corneal thickness measurements, which were determined during follow-up. Proportional hazards models were used to identify factors that predicted which participants in the EGPS had developed OAG.

RESULTS

In multivariate analyses, factors that predicted the development of OAG included older age (hazard ratio [HR], 1.32; 95% confidence interval [CI], 1.04-1.69), larger vertical cup-to-disc (C/D) ratio (HR, 1.34; 95% CI, 1.14-1.58), larger vertical C/D ratio asymmetry (HR, 1.46; 95% CI, 1.11-1.93), higher PSD (HR, 1.66; 95% CI, 1.15-2.38), and lesser central corneal thickness (HR, 1.32; 95% CI, 1.05-1.67).

CONCLUSIONS

Baseline age, vertical C/D ratio, vertical C/D ratio asymmetry, and PSD were good predictors of the onset of OAG in the EGPS. Central corneal thickness was found to be a powerful predictor of the development of OAG. The EGPS results agree with the findings of the Ocular Hypertension Treatment Study and support the need for a thorough evaluation of patients with ocular hypertension.

Categorizing the stage of glaucoma from pre-diagnosis to end-stage disease

PURPOSE

To provide a reliable, comprehensive staging system to assess glaucoma stage in the absence of an universally accepted glaucoma staging system (GSS) on the basis of visual field results.

DESIGN

Literature review and GSS adaptation.

METHODS

After a review of published GSSs was conducted, the Bascom Palmer (Hodapp-Anderson-Parrish) GSS was selected as an appropriate platform for a retrospective GSS on the basis of visual fields. The system was modified by a panel of glaucoma specialists, and additional modifications were made after pilot testing to cover the full range of disease progression, from preglaucoma diagnosis to complete blindness; the ordered stages reflect the typical progression of glaucoma.

RESULTS

The GSS is comprised of six ordered stages and is on the basis of the Humphrey visual field. The completed GSS was validated by reviewing patient charts from 12 US glaucoma centers.

CONCLUSIONS

The GSS allows accurate staging of 100% of glaucoma on the basis of visual fields and other data, enabling evaluation of disease progression and resource utilization at various glaucoma stages. Additionally, treatment costs may be assigned to determine cost-effectiveness of treatment. Research utilizing the GSS has found that cost of care increases with increasing disease severity. The GSS may be used as the basis for creating treatment guidelines, which have the potential to delay glaucoma progression and lower treatment costs.

Increasing peripapillary atrophy is associated with progressive glaucoma

OBJECTIVE

This study aimed to determine the incidence and degree of progression of peripapillary atrophy in progressive and nonprogressive glaucoma.

STUDY DESIGN

A retrospective cohort study.

PARTICIPANTS

A total of 75 eyes of 75 patients were examined.

MAIN OUTCOME MEASURES

Qualitative assessment of optic disc, peripapillary atrophy,and visual field change was performed by three experienced, masked, independent observers.

METHODS

Rim-disc area ratio and peripapillary atrophy-disc area ratio were measured at baseline and follow-up with computer-aided planimetry.

RESULTS

Among 75 eyes studied with an average duration of follow-up of 8 years (range, 4-19 years), 33 (44%) showed progressive optic disc damage. Twenty-one (64%) of 33 eyes with progressive disc damage showed peripapillary atrophy progression, and 7 (17%) of 42 eyes without progressive disc damage showed peripapillary atrophy progression; this difference was significant (P < 0.01). In groups with and without peripapillary atrophy, no statistically significant differences were found for mean intraocular pressure, baseline rim-disc area ratio, or baseline peripapillary atrophy-disc area ratio. However, optic disc progression and visual field progression were statistically more frequent in the group with peripapillary atrophy progression (75% and 54%, respectively) than in the group without peripapillary atrophy progression (26% and 11%, respectively) (P < 0.01). There was a statistically significant correlation between measurements of peripapillary atrophy area increase and disc rim loss over time (r = -0.35, P = 0.002).

CONCLUSION

Progression of peripapillary atrophy is associated with progressive optic disc damage and progressive visual field loss in glaucoma and may be used as a marker for progressive glaucomatous damage.

Acquired pit of the optic nerve: a risk factor for progression of glaucoma

PURPOSE

To examine acquired pit of the optic nerve as a risk factor for progression of glaucoma.

METHODS

In a retrospective longitudinal study, 25 open-angle glaucoma patients with acquired pit of the optic nerve were compared with a group of 24 open-angle glaucoma patients without acquired pit of the optic nerve. The patients were matched for age, mean intraocular pressure, baseline ratio of neuroretinal rim area to disk area, visual field damage, and duration of follow-up. Serial optic disk photographs and visual fields of both groups were evaluated by three independent observers for glaucomatous progression.

RESULTS

Of 46 acquired pits of the optic nerve in 37 eyes of 25 patients, 36 pits were located inferiorly (76%) and 11 superiorly (24%; P < .001). Progression of optic disk damage occurred in 16 patients (64%) in the group with acquired pit and in three patients (12.5%) in the group without acquired pit (P < .001). Progression of visual field loss occurred in 14 patients (56%) in the group with acquired pit and in six (25%) in the group without pit (P=.04). Bilateral acquired pit of the optic nerve was present in 12 patients (48%). Disk hemorrhages were observed more frequently in the group with acquired pit (10 eyes, 40%) compared with the group without pit (two eyes, 8%; P=.02).

CONCLUSION

Among patients with glaucoma, patients with acquired pit of the optic nerve represent a subgroup who are at increased risk for progressive optic disk damage and visual field loss.