Axial Myopia Is Associated with Visual Field Prognosis of Primary Open-Angle Glaucoma

Implications of myopia in diagnosis and screening of open angle glaucoma

PURPOSE OF REVIEW

Rapid increase in the prevalence of myopia has been documented worldwide. Myopia, especially high myopia, is not only an important risk factor for having open angle glaucoma (OAG), but also has a strong linking with the progression of OAG. Since myopic axial length (AXL) elongation is associated with nonglaucomatous optic nerve head (ONH) and visual field abnormalities, myopia poses a challenge in differential diagnosis of OAG. This review provides an overview of literature studying relationships between myopic AXL-elongation and diagnosis and prognosis of OAG, and functional and structural changes in the eye.

RECENT FINDINGS

Studies using optical coherence tomography (OCT), OCT-angiography, those using standard automated perimetry (SAP), other perimetric or electrophysiological methods showed dose-dependent effects of myopic AXL elongation on the structural changes in the ONH and parapapillary tissues, and functional abnormalities of an eye. Large cohort studies showed approximately one quarter of eyes with nonpathologic high myopia were complicated with various patterns of visual field defects including glaucoma-like ones.

SUMMARY

Findings of cross-sectional and longitudinal studies obtained using various fundus imaging devices must be integrated to perimetric results to improve differential diagnosis of OAG in myopic eyes, in which artificial intelligence technology may be useful.

Unraveling Visual Field Asymmetry: Insights Into Left-Right Differences in Glaucoma Patients

PURPOSE

Primary open-angle glaucoma (POAG) typically exhibits bilateral symmetry in visual field defects, while secondary glaucoma often manifests substantial left-right differences. This study investigates the diagnostic relevance of left-right differences in the Humphrey visual field (HVF) test and explores the factors influencing these differences.

STUDY DESIGN

This is a cross-sectional study.

METHODS

Parameters were assessed in 201 glaucoma patients, including age, sex, glaucoma disease type, central corneal thickness (CCT), corneal endothelial cell density (ECD), axial length, anterior chamber depth, refractive power, intraocular pressure (IOP), glaucoma drug score, and mean deviation (MD), pattern standard deviation (PSD), and visual field index (VFI) for both eyes in HVF. Patients were categorized into type 1 (POAG in both eyes) and type 2 (secondary glaucoma). Multivariable analysis was conducted to explore factors influencing left-right visual field test differences.

RESULTS

No significant differences were found between type 1 and type 2 in left-right MD, PSD, and VFI (p=0.13, 0.26, 0.09). Type 2 exhibited significant inter-eye differences in ECD, CCT, IOP, and glaucoma drug scores (p=0.02, <0.01, <0.001, 0.01). In the type 1 group, the left and right MD values were statistically significantly correlated (r=0.40, p<0.000001), but 24.6% of patients showed a left-right difference of 10 dB or more. Multivariable regression analysis identified anterior chamber depth as the sole significant factor influencing left-right MD differences in POAG (p=0.03).

CONCLUSION

Asymmetry in the visual field cannot distinguish between glaucoma disease types. In POAG, a shorter anterior chamber depth is associated with increased left-right MD differences, emphasizing its significance in understanding the progression of visual field defects.

Effects of Stress and Strain on the Optic Nerve Head on the Progression of Glaucoma

PRCIS

In primary open angle glaucoma, the rate of retinal nerve fiber layer thickness decrease was negatively correlated with lamina cribrosa strain, which was associated with intraocular pressure and optic nerve head geometric factors.

PURPOSE

We hypothesized that the biomechanical deformation of the optic nerve head (ONH) contributes to the progression of primary open angle glaucoma (POAG). This study investigated the biomechanical stress and strain on the ONH in patients with POAG using computer simulations based on finite element analysis and analyzed its association with disease progression.

METHODS

We conducted a retrospective analysis that included patients diagnosed with early-to-moderate stage POAG. The strains and stresses on the retinal nerve fiber layer (RNFL) surface, prelaminar region, and lamina cribrosa (LC) were calculated using computer simulations based on finite element analysis. The correlations between the rate of RNFL thickness decrease and biomechanical stress and strain were investigated in both the progression and nonprogression groups.

RESULTS

The study included 71 and 47 patients in the progression and nonprogression groups, respectively. In the progression group, the factors exhibiting negative correlations with the RNFL thickness decrease rate included the maximum and mean strain on the LC. In multivariate analysis, the mean strain on the LC was associated with optic disc radius, optic cup deepening, axial length, and mean intraocular pressure (IOP), whereas the maximum strain was only associated with mean IOP.

CONCLUSIONS

In early-to-moderate stage POAG, the rate of RNFL thickness decrease was influenced by both the mean and maximum strain on the LC. Strains on the LC were associated with mean IOP, optic disc radius, axial length, and optic cup deepening. These results suggest that not only IOP but also ONH geometric factors are important in the progression of glaucoma.

Applications of optical coherence tomography angiography in glaucoma: current status and future directions

Glaucoma is a leading cause of irreversible blindness worldwide, with its pathophysiology remaining inadequately understood. Among the various proposed theories, the vascular theory, suggesting a crucial role of retinal vasculature deterioration in glaucoma onset and progression, has gained significant attention. Traditional imaging techniques, such as fundus fluorescein angiography, are limited by their invasive nature, time consumption, and qualitative output, which restrict their efficacy in detailed retinal vessel examination. Optical coherence tomography angiography (OCTA) emerges as a revolutionary imaging modality, offering non-invasive, detailed visualization of the retinal and optic nerve head microvasculature, thereby marking a significant advancement in glaucoma diagnostics and management. Since its introduction, OCTA has been extensively utilized for retinal vasculature imaging, underscoring its potential to enhance our understanding of glaucoma's pathophysiology, improving diagnosis, and monitoring disease progression. This review aims to summarize the current knowledge regarding the role of OCTA in glaucoma, particularly its potential applications in diagnosing, monitoring, and understanding the pathophysiology of the disease. Parameters pertinent to glaucoma will be elucidated to illustrate the utility of OCTA as a tool to guide glaucoma management.

Natural History and Risk Factors for Glaucoma Progression in Chinese Patients With Normal-Tension Glaucoma

Purpose

To characterize the natural history of normal-tension glaucoma (NTG) in Chinese patients.

Methods

The prospective observational cohort study included patients with untreated NTG with a minimum follow-up of 2 years. Functional progression was defined by visual field (VF) deterioration, while structural progression was characterized by thinning of the retinal nerve fiber layer (RNFL) or ganglion cell inner plexiform layer (GCIPL).

Results

Among 84 participants (mean age, 60.5 years; mean deviation, -5.01 decibels [dB]) with newly diagnosed NTG followed for an average of 69.7 months, 63.1% progressed during the observation period. Specifically, 29.8% progressed by VF, and 48.8% progressed by either RNFL or GCIPL. In Cox proportional hazards analysis, disc hemorrhage (hazard ratio [HR], 2.82; 95% confidence interval [CI], 1.48-5.35), female gender (HR, 1.98; 95% CI, 1.08-3.62), and mean IOP during the follow-up period (HR, 1.14 per mm Hg; 95% CI, 1.00-1.31) were significant predictors of glaucomatous progression. Additionally, longer axial length (AL; HR, 0.57 per millimeter; 95% CI, 0.35-0.94) was protective against VF progression faster than -0.50 dB/y, and higher minimum diastolic blood pressure (DBP; HR, 0.96 per mm Hg; 95% CI, 0.92-1.00) was protective against structural progression.

Conclusions

Nearly two-thirds of untreated Chinese patients with NTG progressed over an average follow-up of 70 months by VF, RNFL, or GCIPL. Disc hemorrhage, female gender, higher mean IOP, shorter AL, and lower minimum DBP were significant predictors for disease progression.

Influence of Trabeculectomy with Mitomycin C on Longitudinal Changes in the Visual Field in Glaucoma Patients with High Myopia

Purpose

To evaluate the effect of trabeculectomy (Trab MMC) on visual field (VF) progression in eyes with glaucoma and high myopia.

Patients and Methods

Patients diagnosed with primary open-angle glaucoma or exfoliation glaucoma who underwent Trab MMC as the first glaucoma surgery along with ≥3 VF tests preoperatively and postoperatively were enrolled. High myopia was defined as an axial length ≥26.5 mm. Postoperative reductions in intraocular pressure (IOP) were assessed by survival analysis using IOP measurements obtained preoperatively. The longitudinal trends of the outcome measures were evaluated using linear mixed models.

Results

Thirty-five eyes of 32 patients were included in this study, including 22 eyes of 20 patients in non-highly myopic group and 13 eyes of 12 patients in highly myopic group. IOP decreased after Trab MMC, and the survival rate did not differ significantly in relation to axial length. Linear mixed-model analyses suggested that the inhibitory effects of Trab MMC on the rate of mean deviation (MD) changes were significant in the non-highly myopic group (-0.53 ± 0.15 dB/year preoperatively to -0.16 ± 0.13 dB/year postoperatively; P = 0.004), but not in the highly myopic group (-0.66 ± 0.19 dB/year preoperatively to -0.48 ± 0.18 dB/year postoperatively; P = 0.32).

Conclusion

Trab MMC reduced IOP in both highly myopic and non-highly myopic eyes, and IOP reduction was very similar in both groups. The VF deterioration rate decreased in both groups, but the change was weaker and nonsignificant in the highly myopic group.

Differences in Factors Associated With Glaucoma Progression With Lower Normal Intraocular Pressure in Superior and Inferior Halves of the Optic Nerve Head

Purpose

The purpose of this study was to investigate risk factors for progression in the superior and inferior hemi-visual fields (hemi-VFs) and the corresponding hemi-disc/retinas in eyes with normal tension glaucoma (NTG).

Methods

A 5-year prospective follow-up of 90 patients with NTG with untreated intraocular pressure (IOP) consistently ≤ 15 mm Hg was conducted. The IOP and Humphrey Perimeter measurements and disc/retina stereo-photographs were taken every 3 and 6 months, respectively. Risk factors for progression in the superior and inferior hemi-VFs and in the superior and inferior hemi-disc/retinas were investigated.

Results

The mean total deviation values decreased at -0.50 ± 0.76 and -0.13 ± 0.34 dB/year in the superior and inferior hemi-VFs, respectively (P < 0.001). In the superior hemi-VF, the risk factor for faster progression was greater long-term IOP fluctuation (P = 0.022). In the inferior hemi-VF, the risk factors were disc hemorrhage (DH), greater myopic refraction, body mass index (BMI), and vertical cup-to-disc ratio (v-C/D; P < 0.05). The progression probability was 47.7 ± 6.0 and 17.7 ± 4.7% at 5 years in the superior and inferior hemi-disc/retinas respectively (P < 0.001), and DH was a risk factor for progression in both (P = 0.001).

Conclusions

In NTG eyes, greater BMI, myopia, and v-C/D are characteristic risk factors for faster progression in the superior half of the optic nerve head (ONH), whereas long-term IOP fluctuation is the significant risk factor in the inferior half of the ONH, whereas DH is a risk factor in both.

Translational Relevance

Different risk factors were identified in superior and inferior hemifields in NTG eyes.

Relationship between Inter-Eye Asymmetries in Corneal Hysteresis and Visual Field Severity in Patients with Primary Open-Angle Glaucoma

This study investigated the influence of asymmetric corneal hysteresis (CH) on asymmetric visual field impairment between right and left eyes in patients with primary open-angle glaucoma (POAG) without a history of intraocular surgery. CH, corneal resistance factor (CRF), and corneal compensated intraocular pressure (IOPcc) were measured using the Ocular Response Analyzer. Differences between the eyes (right eye-left eye: DIF_RL) and CH-based and in target parameters (higher CH eye-lower CH eye: DIF_CH) were calculated in the same patient. In 242 phakic eyes of 121 patients, older age (p < 0.001), lower CH (p = 0.001), and lower CRF (p = 0.007) were significantly associated with worse standard automated perimetry (SAP) 24-2 mean deviation (MD). The DIFs_RL in axial length (p = 0.003), IOPcc (p = 0.028), and CH (p = 0.001) were significantly associated with the DIF_RL in SAP24-2 MD, but not in central corneal thickness (CCT), Goldmann applanation tonometry (GAT) measurement, and CRF. When dividing the patients into two groups based on the median of the CH DIFs_CH (0.46), the DIFs_CH in CRF (p < 0.001), IOPcc (p < 0.001), CCT (p = 0.004), SAP24-2 MD (p < 0.001), and SAP10-2 MD (p = 0.010) were significantly different between the groups. Large inter-eye asymmetry in CH is an important explanatory factor for disease worsening in patients with POAG.

Risk of Normal Tension Glaucoma Progression From Automated Baseline Retinal-Vessel Caliber Analysis: A Prospective Cohort Study

PURPOSE

To determine the relationship between baseline retinal-vessel calibers computed by a deep-learning system and the risk of normal tension glaucoma (NTG) progression.

DESIGN

Prospective cohort study.

METHODS

Three hundred and ninety eyes from 197 patients with NTG were followed up for at least 24 months. Retinal-vessel calibers (central retinal arteriolar equivalent [CRAE] and central retinal venular equivalent [CRVE]) were computed from fundus photographs at baseline using a previously validated deep-learning system. Retinal nerve fiber layer (RNFL) thickness and visual field (VF) were evaluated semiannually. The Cox proportional-hazards model was used to evaluate the relationship of baseline retinal-vessel calibers to the risk of glaucoma progression.

RESULTS

Over a mean follow-up period of 34.36 ± 5.88 months, 69 NTG eyes (17.69%) developed progressive RNFL thinning and 22 eyes (5.64%) developed VF deterioration. In the multivariable Cox regression analysis adjusting for age, gender, intraocular pressure, mean ocular perfusion pressure, systolic blood pressure, axial length, standard automated perimetry mean deviation, and RNFL thickness, narrower baseline CRAE (hazard ratio per SD decrease [95% confidence interval], 1.36 [1.01-1.82]) and CRVE (1.35 [1.01-1.80]) were associated with progressive RNFL thinning and narrower baseline CRAE (1.98 [1.17-3.35]) was associated with VF deterioration.

CONCLUSION

In this study, each SD decrease in the baseline CRAE or CRVE was associated with a more than 30% increase in the risk of progressive RNFL thinning and a more than 90% increase in the risk of VF deterioration during the follow-up period. Baseline attenuation of retinal vasculature in NTG eyes was associated with subsequent glaucoma progression. High-throughput deep-learning-based retinal vasculature analysis demonstrated its clinical utility for NTG risk assessment.

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.

Vessel Density in the Macular and Peripapillary Areas in Preperimetric Glaucoma to Various Stages of Primary Open-Angle Glaucoma in Taiwan

Peripapillary and macular vessel density (VD) are reduced in myopic non-glaucomatous eyes, the dynamic range of VD may be decreased by myopia, and whether VD measurement has the potential in differentiating stages of glaucoma severity in patients with myopic glaucoma remains questionable. This observational, cross-sectional study aimed to clarify the changes in peripapillary and macular VDs in preperimetric glaucoma (PPG) and primary open-angle glaucoma in the early, moderate, and late stages. A total of 1228 eyes from 661 participants (540 normal, 67 PPG, and 521 glaucomatous) were included. Participants underwent free blood tests at the internal medicine clinic to retrieve systemic data. Patients with glaucoma were grouped by disease severity, defined by glaucomatous visual field mean defect, including early-(224 eyes), moderate-(103 eyes), and late-stage glaucoma (194 eyes), and further divided into advanced (158 eyes) and terminal glaucoma (36 eyes). Macular VD, peripapillary VD, circumpapillary retinal nerve fiber layer (cpRNFL) thickness, and ganglion cell complex (GCC) thickness were evaluated and divided into superior and inferior parts. One-way analysis of variance was performed, followed by Tukey’s post-hoc test. The peripapillary VD was significantly different between the healthy and PPG groups and the early-, moderate-, and late-stage glaucoma subgroups (all p < 0.001). Peripapillary VD measurements are helpful in differentiating the various stages of glaucoma even in patients with myopic glaucoma.

Intereye comparison of ocular factors in normal tension glaucoma with asymmetric visual field loss in Korean population

PURPOSE

To identify ocular parameters corresponding to asymmetric visual field (VF) loss in normal tension glaucoma (NTG) through intereye comparisons.

PATIENTS AND METHODS

Medical records of NTG patients with asymmetric and symmetric VF losses were retrospectively reviewed. The criterion for asymmetry in VF was 6 dB difference of mean deviation. Refractive error, intraocular pressure (IOP), central corneal thickness, ovality index, and peripapillary atrophy (PPA)/disc area ratio were obtained from each patient. Intereye comparison was performed for asymmetric group, symmetric group, and myopic and nonmyopic asymmetric subgroups.

RESULTS

We included 155 patients; 110 patients in asymmetric group and 45 patients in symmetric group. In intereye comparison for total asymmetric group, refractive error (P = 0.006), initial IOP (P = 0.001), ovality index (P = 0.008), and PPA (P < 0.001) were significantly asymmetric. For myopic subgroup, refractive error (P = 0.004), ovality index (P = 0.001), and PPA (P = 0.003) were significant factors. For nonmyopic subgroup, initial IOP (P = 0.003) and PPA (P = 0.007) were significant factors. Symmetric group showed no significant difference between the eyes. Multivariate analysis demonstrated that refractive error (P = 0.002) and PPA (P = 0.028) were significant factors in myopic subgroup, and initial IOP (P = 0.022) and PPA (P = 0.002) were significant factors in nonmyopic subgroup.

CONCLUSIONS

In this intereye comparison, the more myopic eye in myopic NTG patient, and the more pressured eye in nonmyopic NTG patient demonstrated more severe VF loss. Myopic and nonmyopic patients may follow different pathophysiologic processes. Discriminative attentions should be paid to NTG patients by subtypes.

Patients with Primary Open-Angle Glaucoma May Develop Ischemic Heart Disease More Often than Those without Glaucoma: An 11-Year Population-Based Cohort Study

OBJECTIVES

To investigate whether patients with primary open angle glaucoma (POAG) have a higher proportion of ischemic heart disease (IHD) development.

DESIGN

A population-based retrospective cohort study, using the National Health Insurance Database (NHID) from 1st January, 2001, to 31st December, 2011, in Taiwan.

METHODS

3510 subjects with POAG were enrolled into the POAG group and 14040 subjects without glaucoma into the comparison group. The comparison group consisted of randomly selected individuals, matched with the POAG group based on age, gender, and index date (date of enrollment) at a ratio of 1:4. The participants of both groups should have no IHD before the index date, and they were followed until the end of 2011 to see whether they had new-onset IHD or not. Kaplan-Meier curves were used to compare the cumulative incidence of IHD between the two groups. Frailty model, a specialized form of Cox regression analysis, was used to estimate the crude and adjusted hazard ratio (HR) of IHD. Analyses were adjusted by age, gender, and systemic comorbidities (i.e. diabetes, hypertension, hyperlipidemia, atrial fibrillation and congestive heart failure).

RESULTS

The mean age of the cohort was 57.6±11.0 years. There were slightly more males than females (51.6% vs. 48.4%). A log-rank test comparing Kaplan-Meier curves of the two groups revealed a significantly higher cumulative incidence of IHD in the POAG group (p-value<0.001). In the univariate analysis by Frailty model, POAG patients had a significantly higher hazard of IHD (unadjusted HR = 2.32; 95% confidence interval 1.93 to 2.79). After adjustment, results remained significant (adjusted HR = 1.41; 95% confidence interval 1.16 to 1.72).

CONCLUSION

People with POAG may suffer from IHD more often than those without glaucoma.

Relationship between visual field progression and baseline refraction in primary open-angle glaucoma

PURPOSE

To analyze the relationship between visual field (VF) progression and baseline refraction in Japanese patients with primary open-angle glaucoma (POAG) including normal-tension glaucoma.

PATIENTS AND METHODS

In this retrospective study, the subjects were patients with POAG who had undergone VF tests at least ten times with a Humphrey Field Analyzer (Swedish interactive thresholding algorithm standard, Central 30-2 program). VF progression was defined as a significantly negative value of mean deviation (MD) slope at the final VF test. Multivariate logistic regression models were applied to detect an association between MD slope deterioration and baseline refraction.

RESULTS

A total of 156 eyes of 156 patients were included in this analysis. Significant deterioration of MD slope was observed in 70 eyes of 70 patients (44.9%), whereas no significant deterioration was evident in 86 eyes of 86 patients (55.1%). The eyes with VF progression had significantly higher baseline refraction compared to those without apparent VF progression (-1.9±3.8 diopter [D] vs -3.5±3.4 D, P=0.0048) (mean ± standard deviation). When subject eyes were classified into four groups by the level of baseline refraction applying spherical equivalent (SE): no myopia (SE > -1D), mild myopia (-1D ≥ SE > -3D), moderate myopia (-3D ≥ SE > -6D), and severe myopia (-6D ≥ SE), the Cochran-Armitage trend analysis showed a decreasing trend in the proportion of MD slope deterioration with increasing severity of myopia (P=0.0002). The multivariate analysis revealed that baseline refraction (P=0.0108, odds ratio [OR]: 1.13, 95% confidence interval [CI]: 1.03-1.25) and intraocular pressure reduction rate (P=0.0150, OR: 0.97, 95% CI: 0.94-0.99) had a significant association with MD slope deterioration.

CONCLUSION

In the current analysis of Japanese patients with POAG, baseline refraction was a factor significantly associated with MD slope deterioration as well as intraocular pressure reduction rate. When baseline refraction was classified into four groups, MD slope in myopia groups was less deteriorated as compared to those in the emmetropic/hyperopic group.