5-year disease progression of patients across the glaucoma spectrum assessed by structural and functional tools

Association of Optic Nerve Head and Macular Optical Coherence Tomography Measures With Glaucoma-Related Disability

PRCIS

Optical coherence tomography (OCT) estimated retinal nerve fiber layer (RNFL) thickness associated with glaucoma-related disability independent of the visual field (VF) damage and thus may provide additional patient-relevant disability information beyond what is captured by standard VF testing.

PURPOSE

To examine whether OCT metrics [peripapillary RNFL thickness and macular ganglion cell/inner plexiform layer (GCIPL) thickness] are associated with quality of life (QoL) measures and additional disability metrics, and whether these associations are independent of VF damage.

METHODS

In this cross-sectional study, 156 patients with glaucoma or suspected glaucoma received VF testing and OCT scans to measure RNFL and GCIPL thickness. QoL was assessed using the Glaucoma Quality-of-Life 15 and additional disability measures including fear of falling, reading speed, and steps per day were assessed. Multivariable regression models adjusting for relevant covariates tested whether RNFL or GCIPL thickness from the less-impaired eye were associated with disability measures and whether associations were independent of VF damage.

RESULTS

Greater VF damage is associated with worse QoL (95% CI=0.4-1.4; P <0.001) and slower reading speed (CI=-0.06 to -0.02; P <0.001). Lower RNFL and GCIPL thicknesses were associated with lower QoL scores, but not with QoL scores or other disability metrics after correcting for VF damage. However, post hoc analyses in patients with better eye thicknesses between 55 and 75 µm demonstrated associations between lower RNFL thickness and worse QoL (CI=-2.2 to -0.1; P =0.04) and greater fear of falling (CI=-6.1 to -0.4; P =0.03) even after accounting for VF damage. No such associations were observed for GCIPL thickness.

CONCLUSIONS

OCT RNFL, but not GCIPL, thickness is associated with multiple disability measures independent of VF damage severity.

Glaucoma progression. Clinical practice guide

OBJECTIVE

To provide general recommendations that serve as a guide for the evaluation and management of glaucomatous progression in daily clinical practice based on the existing quality of clinical evidence.

METHODS

After defining the objectives and scope of the guide, the working group was formed and structured clinical questions were formulated following the PICO (Patient, Intervention, Comparison, Outcomes) format. Once all the existing clinical evidence had been independently evaluated with the AMSTAR 2 (Assessment of Multiple Systematic Reviews) and Cochrane "Risk of bias" tools by at least two reviewers, recommendations were formulated following the Scottish Intercollegiate Guideline network (SIGN) methodology.

RESULTS

Recommendations with their corresponding levels of evidence that may be useful in the interpretation and decision-making related to the different methods for the detection of glaucomatous progression are presented.

CONCLUSIONS

Despite the fact that for many of the questions the level of scientific evidence available is not very high, this clinical practice guideline offers an updated review of the different existing aspects related to the evaluation and management of glaucomatous progression.

Association of High Polygenic Risk With Visual Field Worsening Despite Treatment in Early Primary Open-Angle Glaucoma

Importance

Irreversible vision loss from primary open-angle glaucoma (POAG) can be prevented through timely diagnosis and treatment, although definitive diagnosis can be difficult in early-stage disease. As a consequence, large numbers of individuals with suspected glaucoma require regular monitoring, even though many of these may never develop disease and other high-risk individuals with suspected glaucoma may have delayed or inadequate treatment. POAG is one of the most heritable common diseases, and this provides an opportunity to use genetic instruments in risk-stratified screening, diagnosis, and treatment of early glaucoma.

Objective

To assess the association of glaucoma polygenic risk with glaucoma progression in early-stage disease.

Design, Setting, and Participants

This cohort study used clinical and genetic data obtained from a longitudinal cohort study, Progression Risk of Glaucoma: Relevant SNPs With Significant Association (PROGRESSA). Participants of European ancestry with characteristic optic nerve head changes suggestive of glaucoma were included. Data were collected between February 2012 and June 2020. Analysis took place between July 2020 and April 2022.

Main Outcomes and Measures

The association of a glaucoma polygenic risk score (PRS) (2673 uncorrelated variants) with rate of peripapillary retinal nerve fiber layer thinning on optical coherence tomography and progression of visual field loss on 24-2 Humphrey visual fields.

Results

A total of 1777 eyes from 896 individuals had sufficient data for structural progression analyses and 1563 eyes from 808 individuals for functional progression analyses. The mean (SD) age was 62.1 (9.9) years, 488 (44%) were male, and 1087 of 1103 individuals (98.5%) had European ancestry. An ancestrally matched normative population cohort (n = 17 642) was used for PRS reference. Individuals in the top 5% PRS risk group were at a higher risk of visual field progression compared with the remaining 95% after 5 years (hazard ratio, 1.5; 95% CI, 1.13-1.97; P = .005). Conversely, those in the bottom 20% PRS risk group were at a lower risk of visual field progression compared with an intermediate risk group over 3 years (hazard ratio, 0.52; 95% CI, 0.28-0.96; P = .04).

Conclusions and Relevance

In this study, high polygenic risk was associated with more rapid structural and functional progression in early POAG, despite more intensive treatment. A PRS may serve as a valuable adjunct to identify individuals who stand to benefit the most from more frequent surveillance and earlier or more intensive treatment.

Baseline Vessel Density Parameters for Predicting Visual Field Progression in Open-Angle Glaucoma Eyes With Central Visual Field Damage

PURPOSE

To identify the baseline vessel density (VD) parameters that predict visual field (VF) progression in patients with open-angle glaucoma (OAG) with central visual field (CVF) damage.

DESIGN

Retrospective cohort study.

METHODS

This study enrolled 208 eyes from 208 consecutive patients with OAG with CVF damage at baseline and with a minimum 2 years of follow-up. Optical coherence tomography (OCT) angiography was used to measure circumpapillary and macular VDs in the retina and parapapillary VD in the choroid (pCVD) at the baseline. The circumpapillary retinal nerve fiber layer (cpRNFL) and macular ganglion cell-inner plexiform layer (mGCIPL) thicknesses were also measured as reference standards. Cox proportional hazard analysis was performed to identify the baseline clinical factors associated with VF progression according to the glaucoma stage. The relationships between the CVF mean sensitivity reduction rate during follow-up and the baseline clinical factors were evaluated.

RESULTS

VF progression was detected in 54 eyes (26.0%) during 2.78 years of mean follow-up. A lower pCVD (hazard ratio = 0.916, P = .014) at baseline in early-stage OAG eyes and a reduced baseline average mGCIPL thickness (hazard ratio = 0.896, P = .001) in eyes with moderate to advanced glaucoma were independent predictors of VF progression. The baseline pCVD (β = 0.018, P = .028) in eyes with early-stage glaucoma and the baseline average mGCIPL thickness (β = 0.035, P = .013) in eyes with moderate to advanced glaucoma were significantly correlated with the rate (dB/y) of CVF mean sensitivity reduction.

CONCLUSION

In eyes with OAG with CVF damage, a lower baseline pCVD in early-stage glaucoma and a reduced mGCIPL thickness at baseline in moderate to advanced glaucoma are significantly associated with subsequent VF progression.

Non-invasive electrophysiology in glaucoma, structure and function-a review

Glaucoma, its early diagnosis, and monitoring of interventions remain an ongoing challenge. We here review developments in functional assessment and its relation to morphology, evaluating recent insights in electrophysiology in glaucoma and highlighting how glaucoma research and diagnostics benefit from combined approaches of OCT and electrophysiological investigations. After concise overviews of OCT and non-invasive electrophysiology in glaucoma, we evaluate commonalities and complementarities of OCT and electrophysiology for our understanding of glaucoma. As a specific topic, the dynamic range (floor effects) of the various techniques is discussed.

Association Between Progressive Retinal Capillary Density Loss and Visual Field Progression in Open-Angle Glaucoma Patients According to Disease Stage

PURPOSE

To investigate the longitudinal changes in circumpapillary capillary density (cpCD) and retinal nerve fiber layer thickness (cpRNFLT) and their association with visual field (VF) progression in open-angle glaucoma (OAG) eyes at different stages of glaucoma.

DESIGN

Retrospective, observational case series METHODS: This study enrolled 158 eyes of 158 OAG patients classified into early (89 eyes) and moderate-to-advanced (69 eyes) stage based on VF mean deviation (MD; -6 dB). Serial cpCD and cpRNFLT measurements were performed using optical coherence tomography (OCT) angiography and OCT during a mean follow-up of 2.66 years. The reference standard of glaucoma progression was determined by VF progression. The rates of longitudinal change in cpCD and cpRNFLT were evaluated using linear mixed effects models and compared between progressors and nonprogressors. The factors associated with VF progression, including the rates of longitudinal change in cpCD and cpRNFLT, were assessed using logistic regression analyses.

RESULTS

The rate of longitudinal change in cpCD was significantly faster in progressors (-1.25% ± 1.15% per year for early stage and -1.61% ± 1.04% per year for moderate-to-advanced stage) than in nonprogressors (0.04% ± 1.12% per year for early stage and -0.34% ± 0.97% per year for moderate-to-advanced stage) regardless of glaucoma stage (all, P < .05). The rates of longitudinal change in cpRNFLT (-0.85 ± 1.20 µm/y vs -0.70 ± 1.02 µm/y, P = .396) did not differ between progressors and nonprogressors in eyes with moderate-to-advanced glaucoma. In multivariable logistic regression analyses, a faster rate of cpCD loss (odds ratio [OR] 0.244, P = .009) had a significant association with VF progression in eyes with moderate-to-advanced glaucoma, whereas faster rates of both cpCD (OR 0.340, P = .012) and cpRNFLT (OR 0.155, P = .031) loss were significantly associated with VF progression in eyes with early-stage glaucoma.

CONCLUSIONS

In OAG eyes, the rate of longitudinal cpCD loss was significantly associated with VF progression regardless of glaucoma stage.

Effect of baseline test selection on glaucoma progression detection by optical coherence tomography-guided progression analysis

PURPOSE

To evaluate the effect of baseline test selection on progression detection of circumpapillary retinal nerve fibre layer (RNFL) and macular ganglion cell-inner plexiform layer (GCIPL) in glaucomatous eyes by optical coherence tomography (OCT)-guided progression analysis (GPA).

METHODS

A total of 53 eyes with either RNFL or GCIPL progression determined using OCT-GPA were included. Three different baseline conditions were created by dividing eight serial OCT tests from each eye into three sets. Specifically, these sets presented baseline tests at exams 1-2 (1st set), 2-3 (2nd set) and 3-4 (3rd set), respectively. Agreement on progression detection was defined as the presence of 'Possible Loss' or 'Likely Loss' in the 2nd or 3rd sets at the same location in the 1st set.

RESULTS

The proportion of eyes with agreement on progression detection was 47.1%, 20.0% and 31.0% for RNFL 'thickness map progression', 'thickness profiles progression' and 'average thickness progression', respectively. In GCIPL 'thickness map progression' and 'average thickness progression', 53.8% and 62.8% of eyes showed agreement, respectively. Eyes with disagreement showed a greater change in thickness (slope of change in the 3rd set-1st set) compared to the eyes with agreement (p<0.05), with the exception of RNFL 'thickness profiles progression' (p=0.064).

CONCLUSION

Glaucoma progression detection by OCT-GPA was affected by baseline test selection, especially in eyes with a greater reduction in progression. GCIPL thickness was less influenced by baseline test selection compared to RNFL thickness.

Review of Longitudinal Glaucoma Progression: 5 Years after the Shaffer Lecture

In 2013, the senior author delivered the American Academy of Ophthalmology Robert N. Shaffer Lecture entitled "Glaucoma Changes-Reality Bites." This talk focused on describing the longitudinal structure-function relationships in glaucoma progression. The study was based on a 10-year longitudinal dataset created by calibrated measurements across multiple OCT generations with corresponding visual fields (VFs). The prior held observation was that functional damage follows structural damage. The lecture posited that structure and function change at similar times, but that current measurement technology limits our ability to detect functional abnormalities and change early in glaucoma, as well as to measure structural change late in the disease. The Shaffer lecture provided evidence that structure and function change concordantly and that any apparent discordance in the relationship was due to technologic limitations to measure glaucomatous change. Furthermore, we observed 5 longitudinal relationships of concordance and discordance that can exist with structure-function interactions. Concordance: (1) structure-structure progression, (2) structure-function tipping point, (3) structural floor tipping point. Discordance: (4) functional progression in a "stable" VF with structure-function correlation, (5) functional progression with "normal" structure. In this review article, we will review longitudinal glaucoma progression studies with long-term follow-up and discuss the clinical relevance of relationships of concordance and discordance that can exist with structure-function interactions.

Progression patterns of normal-tension glaucoma groups classified by hierarchical cluster analysis

OBJECTIVES

To investigate differences in progression patterns of normal-tension glaucoma (NTG) patients in three clusters classified by hierarchical cluster analysis (HCA).

MATERIALS AND METHODS

In a retrospective study, 200 eyes of NTG patients classified by HCA in 2015 who were followed up to the current date were evaluated. Peripapillary retinal nerve fibre layer (RNFL) thicknesses were measured by Cirrus HD-OCT and progression rate was calculated by trend analysis (Guided Progression Analysis [GPA]). VF progression rate was evaluated by linear regression analysis of mean deviation (MD). Progression patterns of three clusters were compared by histograms.

RESULTS

In total, 153 eyes of 153 patients were followed up. Mean observation period was 5 years. RNFL reduction rate was -0.83 μm/year in cluster 1, which showed early glaucomatous damage in previous reports; -0.45 μm/year in cluster 2, which showed moderate glaucomatous damage; and -0.36 μm/year in cluster 3, which showed young and myopic glaucomatous damage. The progression pattern of cluster 3 showed a double-peak distribution; RNFL reduction rate was 0.11 μm/year in the non-progressive group and -1.07 μm/year in the progressive group.

CONCLUSION

The progression patterns were different among three NTG groups that were divided by HCA. In particular, the group of young and myopic eyes showed a mixture of two different patterns.

[Structural endpoints for glaucoma studies]

BACKGROUND

Structural endpoints have been discussed as surrogate endpoints for the approval of neuroprotective drugs in glaucoma.

OBJECTIVE

Is the evidence strong enough to establish structural endpoints as surrogate endpoints?

MATERIAL AND METHODS

Review of current understanding between structure and function in glaucoma.

RESULTS

The introduction of optical coherence tomography has revolutionized imaging in glaucoma patients. Clinically either the nerve fiber layer thickness can be measured along a circle centered in the optic nerve head or the ganglion cell layer thickness can be assessed in the macular region, the latter being quantified in combination with other inner retinal layers. On a microscopic level there is a strong correlation between structural and functional loss but this relation can only partially be described with currently available clinical methods. This is particularly true for longitudinal course of the disease in glaucoma patients. Novel imaging techniques that are not yet used clinically may have the potential to increase our understanding between structure and function in glaucoma but further research in this field is required.

CONCLUSION

The current evidence does not allow the establishment of structural endpoints as surrogate endpoints for phase 3 studies in glaucoma. Neuroprotective drugs have to be approved on the basis of visual field data because this is the patient-relevant endpoint. Structural endpoints can, however, play an important role in phase 2 and proof of concept studies.