Progression of primary open angle glaucoma in asymmetrically myopic eyes

Assessing Glaucoma Severity and Progression in Individuals with Asymmetric Axial Length: An Intrapatient Comparative Study

PURPOSE

To investigate whether a difference exists in intereye glaucoma severity and progression in patients with asymmetric axial length.

DESIGN

Long-term observational study.

PARTICIPANTS

Patients older than 20 years with a diagnosis of glaucoma at Seoul National University Hospital, Seoul, Korea, between 2010 and 2020.

METHODS

Patients with a diagnosis of glaucoma in both eyes with an axial length difference of more than 1.0 mm were included. Each individual's eyes were classified into longer eye and shorter eye, and the baseline and follow-up clinical data were analyzed using the paired T-test and McNemar test.

MAIN OUTCOME MEASURES

Differences in clinical characteristics in patients with asymmetric axial length.

RESULTS

A total of 190 eyes of 95 patients with glaucoma with asymmetric axial length were included in the study. The patients' mean age was 51.2 ± 12.3 years, and the mean follow-up period was 10.1 ± 3.9 years. No difference was found in baseline intraocular pressure (IOP) or central corneal thickness between longer eyes and shorter eyes. Among the baseline disc parameters, ovality index, β-zone and γ-zone parapapillary atrophy (PPA) area were larger (P < 0.001) in the longer eyes. In the baseline OCT data, the retinal nerve fiber layer (RNFL) thickness (P = 0.009) and ganglion cell-inner plexiform layer (GCIPL) thickness (P < 0.001) were thinner in the longer eyes. According to a baseline visual field (VF) test, the mean deviation and VF index (VFI) values were significantly lower (P < 0.001, P = 0.034) in the longer eyes. Based on an analysis of glaucoma progression, the rate of change of superior GCIPL (longer eyes, -0.65 μm/year; shorter eyes, -0.40 μm/year), mean deviation (longer eyes, -0.40 dB/year; shorter eyes, -0.21 dB/year), and VFI (longer eyes, -0.92%/year; shorter eyes, -0.46%/year) were larger (P = 0.006, P = 0.005, P < 0.001) in the longer eyes. Additionally, the greater the difference in IOP fluctuation, the greater the difference in the rate of change between mean deviation and VFI.

CONCLUSIONS

When an axial length difference of more than 1.0 mm was present, glaucoma tended to be more severe and to progress faster in the longer eyes.

FINANCIAL DISCLOSURE(S)

The author(s) have no proprietary or commercial interest in any materials discussed in this article.

Optic neuropathy in high myopia: Glaucoma or high myopia or both?

Due to the increasing prevalence of high myopia around the world, structural and functional damages to the optic nerve in high myopia has recently attracted much attention. Evidence has shown that high myopia is related to the development of glaucomatous or glaucoma-like optic neuropathy, and that both have many common features. These similarities often pose a diagnostic challenge that will affect the future management of glaucoma suspects in high myopia. In this review, we summarize similarities and differences in optic neuropathy arising from non-pathologic high myopia and glaucoma by considering their respective structural and functional characteristics on fundus photography, optical coherence tomography scanning, and visual field tests. These features may also help to distinguish the underlying mechanisms of the optic neuropathies and to determine management strategies for patients with high myopia and glaucoma.

Influence of choroidal microvasculature dropout on progressive retinal nerve fibre layer thinning in primary open-angle glaucoma: comparison of parapapillary β-zones and γ-zones

BACKGROUND/AIMS

To compare the influence of choroidal microvasculature dropout (cMvD) on progressive retinal nerve fibre layer (RNFL) thinning in glaucomatous eyes with parapapillary β-zones and γ-zones.

METHODS

294 eyes with primary open-angle glaucoma (POAG) and parapapillary atrophy (PPA) underwent optical coherence tomography (OCT) to determine the type of PPA and OCT angiography scanning of the optic nerve head to determine the presence of cMvD. Eyes were classified based on the type of PPA (β-zones and γ-zones), and their clinical characteristics were compared. Factors associated with the rate of rapid progressive RNFL thinning were determined in each group, including the presence of cMvD as an independent variable.

RESULTS

Of the 294 eyes, 186 and 108 were classified as having β-zones and γ-zones, respectively. The rate of RNFL thinning was slower (p<0.001), axial length was longer (p<0.001) and presence of cMvD was less frequent (57.4% vs 73.1%, p=0.006) in eyes with γ-zone than those with β-zone. Multivariate analyses showed that greater lamina cribrosa curvature (p=0.047) and the presence of cMvD (p=0.010) were associated with a faster rate of RNFL thinning in eyes with β-zone, whereas larger intraocular pressure fluctuation (p<0.001), shorter axial length (p=0.042) and greater baseline RNFL thickness (p<0.001) were associated with a faster rate of RNFL thinning in eyes with γ-zone.

CONCLUSIONS

The presence of cMvD was significantly associated with a faster rate of RNFL thinning in POAG eyes with β-zone, but not γ-zone. The pathogenic consequences of cMvD in POAG eyes may depend on accompanying peripapillary structures.

Papillomacular bundle defect (PMBD) in glaucoma patients with high myopia: frequency and risk factors

Little is known about the papillomacular bundle defect (PMBD) in glaucoma. As such, we investigated the frequency of PMBD in glaucoma patients with high myopia, and its risk factors. In this retrospective, cross-sectional study, retinal nerve fiber layer (RNFL) defect was analyzed in 92 glaucomatous eyes with high myopia (axial length of 26.0 mm or more or an average spherical value of - 6.0 diopters or less). After dividing them into two groups with and without PMBD, the clinical characteristics of the groups were compared and analyzed. The mean age of the patients was 52.1 ± 10.5 years, and there were 53 males and 39 females. PMBD were observed in 55 eyes (59.8%). There was no significant intergroup difference in baseline or follow-up intraocular pressure (IOP). Parapapillary atrophy (PPA)-to-disc-area ratio (OR 3.83, CI: 1.58-10.27, p = 0.010), lamina cribrosa defect (LCD; OR 2.92, CI: 1.14-8.13, p = 0.031) and central visual field defect (CVFD; OR 3.56, CI: 1.38-9.58, p = 0.010) were significantly associated with the PMBD..

Effect of myopia on the progression of normal tension glaucoma

PURPOSE

Identify risk factors of progression in treated normal-tension glaucoma (NTG) in highly myopic and non-highly myopic eyes.

METHODS

This retrospective, observational case series study included 42 highly myopic glaucoma (HMG, <-6D) eyes and 39 non-highly myopic glaucoma (NHG,≧-6D) eyes. Glaucoma progression was determined by serial visual field data. Univariate and multivariate logistic regression method were used to detect associations between potential risk factors and glaucoma progression.

RESULTS

Among 81 eyes from 81 normal-tension glaucoma patients (mean follow-up, 3.10 years), 20 of 42 eye (45.24%) in the HMG and 14 of 39 eyes (35.90%) in the NHG showed progression. The HMG group had larger optic disc tilt ratio (p = 0.007) and thinner inferior macular thickness (P = 0.03) than the NHG group. Changes in the linear regression values for MD for each group were as follows: -0.652 dB/year for the HMG and -0.717 dB/year for the NHG (P = 0.298). Basal pattern standard deviation (PSD) (OR: 1.55, p = 0.016) and post treatment IOP (OR = 1.54, p = 0.043) were risk factors for visual field progression in normal tension glaucoma patients. In subgroup analysis of HMG patients, PSD (OR: 2.77, p = 0.017) was a risk factor for visual field progression.

CONCLUSION

Reduction IOP was postulated to be contributing in the prevention of visual field progression, especially in highly myopic NTG patients with large basal pattern standard deviation.

The Association between Myopia and Primary Open-Angle Glaucoma: A Systematic Review and Meta-Analysis

BACKGROUND

Previous studies identified myopia as a risk factor for primary open-angle glaucoma (POAG). However, recent studies have shown different results, the definitive relationship between myopia and POAG remains controversial.

OBJECTIVES

To investigate the relationship between myopia and POAG.

METHODS

Published articles were searched from PubMed, Embase, and Scopus databases between 1970 and 2020. A pooled analysis of the ORs was performed using a random-effects model.

RESULTS

Data on the association between myopia and POAG, were obtained from 16 cross sectional studies, and the pooled OR was 2.26 (95% confidence interval [CI], 1.77 - 2.89, P < 0.001) in random effects model (I2 = 86%; P < 0.01). For the relationship of myopia and POAG progression, data from seven longitudinal cohort studies were included and the pooled OR was 0.85 (95% CI, 0.73 - 0.99, P = 0.042) in the random-effects model (I2 = 88%; P < 0.01).

CONCLUSION

Our findings demonstrated that myopia may be a risk factor associated with POAG and a possible protective factor for POAG progression. It may due to myopia with the presence of a lamina cribrosa defect slow down the visual field loss also POAG progression, further research for underlying mechanisms is still needed.

Glaucoma in myopia: diagnostic dilemmas

Myopic eyes have an increased risk of glaucoma. However, glaucomatous changes in a myopic eye are often difficult to detect. Classic structural and functional investigations to diagnose glaucoma may be confounded by myopia. Here, we identify some of the common pitfalls in interpreting these structural parameters, and the possible solutions that could be taken to overcome them. For instance, in myopic eyes, we discuss the limitations and potential sources of error when using neuroretinal rim parameters, and retinal nerve fibre layer and ganglion cell-inner plexiform layer thickness measurements. In addition, we also review new developments and potential adjuncts in structural imaging such as the assessment of the retinal nerve fibre layer texture, and the examination of the microcirculation of the optic nerve head using optical coherence tomography angiography. For the functional assessment of glaucoma, we discuss perimetric strategies that may aid in detecting characteristic visual field defects in myopic glaucoma. Ultimately, the evaluation of glaucoma in myopia requires a multimodal approach, to allow correlation between structural and functional assessments. This review provides overview on how to navigate this diagnostic dilemma.

Detection of Functional Change Using Cluster Trend Analysis in Glaucoma

Purpose

Global analyses using mean deviation (MD) assess visual field progression, but can miss localized changes. Pointwise analyses are more sensitive to localized progression, but more variable so require confirmation. This study assessed whether cluster trend analysis, averaging information across subsets of locations, could improve progression detection.

Methods

A total of 133 test-retest eyes were tested 7 to 10 times. Rates of change and P values were calculated for possible re-orderings of these series to generate global analysis ("MD worsening faster than x dB/y with P < y"), pointwise and cluster analyses ("n locations [or clusters] worsening faster than x dB/y with P < y") with specificity exactly 95%. These criteria were applied to 505 eyes tested over a mean of 10.5 years, to find how soon each detected "deterioration," and compared using survival models. This was repeated including two subsequent visual fields to determine whether "deterioration" was confirmed.

Results

The best global criterion detected deterioration in 25% of eyes in 5.0 years (95% confidence interval [CI], 4.7-5.3 years), compared with 4.8 years (95% CI, 4.2-5.1) for the best cluster analysis criterion, and 4.1 years (95% CI, 4.0-4.5) for the best pointwise criterion. However, for pointwise analysis, only 38% of these changes were confirmed, compared with 61% for clusters and 76% for MD. The time until 25% of eyes showed subsequently confirmed deterioration was 6.3 years (95% CI, 6.0-7.2) for global, 6.3 years (95% CI, 6.0-7.0) for pointwise, and 6.0 years (95% CI, 5.3-6.6) for cluster analyses.

Conclusions

Although the specificity is still suboptimal, cluster trend analysis detects subsequently confirmed deterioration sooner than either global or pointwise analyses.

Detecting Change Using Standard Global Perimetric Indices in Glaucoma

PURPOSE

Various global indices are available to summarize results from standard automated perimetry. This study asks which index can detect significant deterioration earliest, for a fixed specificity.

DESIGN

Comparison of prognostic indices.

METHODS

Two cohorts were tested. A test-retest cohort contained 5 reliable visual fields, within a short interval, from 45 eyes of 23 participants with glaucoma and/or likelihood of developing glaucoma. A separate longitudinal cohort contained 508 eyes from 330 participants, tested on average 13 times. Three global indices were extracted: mean deviation (MD), pattern standard deviation (PSD), and visual field index (VFI). For each index we defined a critical P value Crit_Index, such that 5% of test-retest series showed significant deterioration with P < Crit_Index, using artificial "test dates" in random order. Therefore these criteria have 95% specificity over series of 5 tests. The times to detect significant deterioration in the longitudinal cohort were compared using a survival analysis model.

RESULTS

The median time to detect significant deterioration with MD was 7.3 years (95% confidence interval [CI] 6.8-7.9 years). For VFI, the median was 8.5 years (95% CI 7.9-9.0 years); this comparison had P = .088. For PSD, the median was 10.5 years (95% CI 9.3-11.7 years), slower than MD with P < .001. Within the first 5 years of a series, MD detected significant deterioration in 138 eyes, vs 104 for VFI (P = .0013) and 107 for PSD (P = .029).

CONCLUSIONS

MD detected significant deterioration sooner than VFI or PSD. In particular, MD detected more eyes in the first 5 years of their follow-up, which were presumably undergoing more rapid progression.