To develop a model to simulate visual fields (VFs) in glaucoma patients, and to characterize variability of the Mean Deviation (MD) VF summary measurement using real VFs and simulations

A Heijl

A Turpin

B Bengtsson

BC Chauhan

CA Johnson

CL Tattersall

David F. Garway-Heath

David P. Crabb

DB Henson

Demetrios Vavvas

E Glass

FG Junoy Montolio

H Murata

HA Quigley

J Flammer

J Tobin

JR Piltz

K Nouri-Mahdavi

LR Shapiro

M Wall

MC Leske

NM Jansonius

P Ramulu

PG Spry

PH Artes

PJ Ernest

RA Russell

Richard A. Russell

S Kingman

SE Spenceley

SK Gardiner

PLoS ONE

PubMed

To develop a model to simulate visual fields (VFs) in glaucoma patients, and to characterize variability of the Mean Deviation (MD) VF summary measurement using real VFs and simulations.Pointwise VF variability was previously approximated using longitudinal VF data (24–2 SITA Standard, Humphrey Field Analyzer) from 2,736 patients; these data were used to build a non-parametric model to simulate VFs. One million VF simulations were generated from 1,000 VFs (1,000 simulations per ‘ground-truth’ VF), and the variability of simulated MDs was characterized as a function of ground-truth MD and Pattern Standard Deviation (PSD).The median (interquartile range, IQR) patient age and MD was 66 (56 to 75) years and −3.5 (−8.3 to −1.1) decibels, respectively. The inferred variability as a function of ground-truth MD and PSD indicated that variability, on average, increased rapidly as glaucoma worsened. However, the pattern of VF damage significantly affects the level of MD variability, with more than three-fold differences between patients with approximately the same levels of MD but different patterns of loss.A novel approach for simulating VFs is introduced. A better understanding of VF variability will help clinicians to differentiate real VF progression from measurement variability. This study highlights that, overall, MD variability increases as the level of damage increases, but variability is highly dependent on the pattern of VF damage. Future research, using VF simulations, could be employed to provide benchmarks for measuring the performance of VF progression detection algorithms and developing new strategies for measuring VF progression

Russell Richard A.

Garway-Heath David F.

Crabb David P.

Public Library of Science (PLOS)

New Insights into Measurement Variability in Glaucomatous Visual Fields from Computer Modelling

Crossref

Objective



To develop a model to simulate visual fields (VFs) in glaucoma patients, and to characterize variability of the Mean Deviation (MD) VF summary measurement using real VFs and simulations.

Methods



Pointwise VF variability was previously approximated using longitudinal VF data (24–2 SITA Standard, Humphrey Field Analyzer) from 2,736 patients; these data were used to build a non-parametric model to simulate VFs. One million VF simulations were generated from 1,000 VFs (1,000 simulations per ‘ground-truth’ VF), and the variability of simulated MDs was characterized as a function of ground-truth MD and Pattern Standard Deviation (PSD).

Results



The median (interquartile range, IQR) patient age and MD was 66 (56 to 75) years and −3.5 (−8.3 to −1.1) decibels, respectively. The inferred variability as a function of ground-truth MD and PSD indicated that variability, on average, increased rapidly as glaucoma worsened. However, the pattern of VF damage significantly affects the level of MD variability, with more than three-fold differences between patients with approximately the same levels of MD but different patterns of loss.

Conclusions



A novel approach for simulating VFs is introduced. A better understanding of VF variability will help clinicians to differentiate real VF progression from measurement variability. This study highlights that, overall, MD variability increases as the level of damage increases, but variability is highly dependent on the pattern of VF damage. Future research, using VF simulations, could be employed to provide benchmarks for measuring the performance of VF progression detection algorithms and developing new strategies for measuring VF progression

Russell, RA

Garway-Heath, DF

Crabb, DP

UCL Discovery

Russell, R. A.

Garway-Heath, D. F.

Crabb, D. P.

City Research Online

New insights into measurement variability in glaucomatous visual fields from computer modelling.

ObjectiveTo develop a model to simulate visual fields (VFs) in glaucoma patients, and to characterize variability of the Mean Deviation (MD) VF summary measurement using real VFs and simulations.MethodsPointwise VF variability was previously approximated using longitudinal VF data (24-2 SITA Standard, Humphrey Field Analyzer) from 2,736 patients; these data were used to build a non-parametric model to simulate VFs. One million VF simulations were generated from 1,000 VFs (1,000 simulations per 'ground-truth' VF), and the variability of simulated MDs was characterized as a function of ground-truth MD and Pattern Standard Deviation (PSD).ResultsThe median (interquartile range, IQR) patient age and MD was 66 (56 to 75) years and -3.5 (-8.3 to -1.1) decibels, respectively. The inferred variability as a function of ground-truth MD and PSD indicated that variability, on average, increased rapidly as glaucoma worsened. However, the pattern of VF damage significantly affects the level of MD variability, with more than three-fold differences between patients with approximately the same levels of MD but different patterns of loss.ConclusionsA novel approach for simulating VFs is introduced. A better understanding of VF variability will help clinicians to differentiate real VF progression from measurement variability. This study highlights that, overall, MD variability increases as the level of damage increases, but variability is highly dependent on the pattern of VF damage. Future research, using VF simulations, could be employed to provide benchmarks for measuring the performance of VF progression detection algorithms and developing new strategies for measuring VF progression

Richard A Russell

David F Garway-Heath

David P Crabb

Directory of Open Access Journals

Objective: To develop a model to simulate visual fields (VFs) in glaucoma patients, and to characterize variability of the Mean Deviation (MD) VF summary measurement using real VFs and simulations. Methods: Pointwise VF variability was previously approximated using longitudinal VF data (24–2 SITA Standard, Humphrey Field Analyzer) from 2,736 patients; these data were used to build a non-parametric model to simulate VFs. One million VF simulations were generated from 1,000 VFs (1,000 simulations per ‘ground-truth ’ VF), and the variability of simulated MDs was characterized as a function of ground-truth MD and Pattern Standard Deviation (PSD). Results: The median (interquartile range, IQR) patient age and MD was 66 (56 to 75) years and23.5 (28.3 to21.1) decibels, respectively. The inferred variability as a function of ground-truth MD and PSD indicated that variability, on average, increased rapidly as glaucoma worsened. However, the pattern of VF damage significantly affects the level of MD variability, with more than three-fold differences between patients with approximately the same levels of MD but different patterns of loss. Conclusions: A novel approach for simulating VFs is introduced. A better understanding of VF variability will help clinicians to differentiate real VF progression from measurement variability. This study highlights that, overall, MD variability increases as the level of damage increases, but variability is highly dependent on the pattern of VF damage. Future research, using V

David F. Garway-heath

CiteSeerX

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New insights into measurement variability in glaucomatous visual fields from computer modelling.

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Public Library of Science (PLOS)

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UCL Discovery

City Research Online

Directory of Open Access Journals

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