A framework for assessing glaucoma progression using structural and functional indices jointly.

Sampson Listowell Abu,Iván Marín-Franch,Lyne Racette,Akram Belghith

doi:10.1371/journal.pone.0235255

Sampson Listowell Abu, Iván Marín-Franch + Show 2 more

Open Access

https://doi.org/10.1371/journal.pone.0235255

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Journal: PloS one	Publication Date: Jul 1, 2020
Citations: 4	License type: CC BY 4.0

Affiliation: University of Alabama at Birmingham

Abstract

PurposeWhile many tests and indices are available to identify glaucoma progression, using them in combinations may decrease overall specificity. The aim of this study was to develop a framework for assessing glaucoma progression using structural and functional indices jointly for a fixed specificity.MethodsThe study included 337 eyes of 207 patients with ocular hypertension or primary open-angle glaucoma selected from the Diagnostic Innovations in Glaucoma Study or the African Descent and Glaucoma Evaluation Study. All patients had at least 9 visits. Each visit had retinal nerve fiber layer thickness (RNFLT) and mean sensitivity from static automated perimetry (SAP MS) measured within a one-month window. Simple linear regression was applied to assess deterioration in each index for series of 5 to 9 visits. To identify progression using the two indices jointly, marginal significance levels set at a specificity of 95% were derived for two criteria: ANY (worsening on either RNFLT or SAP MS) and ALL (worsening on both RNFLT and SAP MS). Positive rate (percentage of eyes flagged as progressing) was determined individually for each index, as well as for the ANY and ALL criteria.ResultsCompared to SAP MS, RNFLT had higher positive rates (15% to 45%) for all series lengths. For the joint analyses, the positive rate was on average 12% higher for the ANY criterion compared to the ALL criterion. While RNFLT-alone had comparable positive rates and time-to-detection as the ANY criterion, each uniquely identified a subset of eyes (Kappa = 0.55 to 0.75).ConclusionsThis study provides a simple framework for assessing glaucoma progression with data from two tests jointly, without compromising specificity. This framework can be extended to include two or more parameters, can accommodate global or regional indices, and can eventually be used with novel parameters identified as predictive of glaucoma progression.

Highlights

Identifying glaucoma progression is essential to determine whether treatment should be modified to preserve vision and to define the endpoints in clinical trials [1,2,3]
While retinal nerve fiber layer thickness (RNFLT)-alone had comparable positive rates and timeto-detection as the ANY criterion, each uniquely identified a subset of eyes (Kappa = 0.55 to 0.75)
This study provides a simple framework for assessing glaucoma progression with data from two tests jointly, without compromising specificity

Summary

Introduction

Identifying glaucoma progression is essential to determine whether treatment should be modified to preserve vision and to define the endpoints in clinical trials [1,2,3]. The lack of a known ground truth for glaucoma progression [10, 11] makes it impossible to evaluate with precision the sensitivities of different clinical tests. Static automated perimetry (SAP) remains the clinical standard [2, 14], yet clinicians rely on additional tests to monitor glaucoma progression: some based on retinal imaging [2, 15, 16] and others based on alternative forms of visual function testing [14, 17, 18]. Frequency doubling technology (FDT) perimetry has been shown to identify progression earlier than SAP [22, 23]. Despite the availability of these different tests, there is no agreement in the literature as to which tests are more sensitive to identify progression

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