Parapapillary Deep-Layer Microvasculature Dropout and Visual Field Progression in Glaucoma

Comparative analysis of the optic nerve microvasculature between different optic disc phenotypes of normal-tension glaucoma patients

PURPOSE

To determine whether the optic nerve head (ONH) and parapapillary choroidal vessel density (VD), measured by optical coherence tomography angiography (OCTA), differ between two common optic disc phenotypes (ODPs) in normal-tension glaucoma (NTG).

DESIGN

A retrospective case-control study.

METHODS

This cross-sectional study analyzed 100 NTG patients with visual field (VF) loss confined to a single hemifield (50 eyes with focal ischemic [FI] ODP and 50 eyes with myopic glaucomatous [MG] ODP, matched for age [≤ 10 years] and VF severity [mean deviation ≤ 1 dB]) as well as 50 healthy eyes. Using OCTA, ONH VD (ONH-VD) was evaluated on a 4.5 × 4.5 mm ONH en-face image using the whole-signal mode. The parapapillary choroidal VD (pCVD) was measured on en-face choroidal layer image within the entire β-parapapillary atrophy (β-PPA) zone using imageJ software. The ONH-VD and pCVD were compared among the three groups. The relationships between ONH-VD and pCVD outcomes and various clinical variables were assessed using linear regression analyses.

RESULTS

The average ONH-VD and pCVD were significantly lower in eyes with MG ODPs than those with FI ODPs (56.9% vs. 60.4%, 67.1% vs. 71.8%; both P < 0.05). Multivariable linear regression analysis indicated that MG ODP, lower peripapillary retinal nerve fiber layer thickness and VD in the hemiretina, corresponding to hemifield VF loss, in addition to the presence of choroidal microvasculature dropout, were significantly associated with lower ONH-VD and pCVD (P < 0.05).

CONCLUSIONS

The OCTA-measured ONH-VD and pCVD are significantly lower in eyes with MG ODPs rather than FI ODPs. MG ODP is independently associated with lower ONH-VD and pCVD in NTG eyes.

Optical Coherence Tomography Angiography Analysis of Peripapillary Choroidal Microvascular Density in Normal Tension Glaucoma and Primary Open Angle Glaucoma

PRCIS

Glaucoma patients had a reduction in the inner annulus peripapillary choroidal microvascular density (PCMD) that became worse as the glaucoma severity progressed, which might provide new evidence supporting the vascular theory.

PURPOSE

To compare PCMD among normal tension glaucoma (NTG), primary open angle glaucoma (POAG), and healthy controls using optical coherence tomography (OCT) angiography (OCTA).

MATERIALS AND METHODS

The study included 40 POAG, 25 NTG, and 33 healthy controls. All subjects underwent OCT and OCTA testing. The inner annulus and outer annulus PCMD, as well as peripapillary vessel density (VD), were calculated. One-way analysis of variance was used to compare the vascular parameters of the 3 groups. Pearson correlation analysis or Spearman correlation test was used to evaluate the correlation between PCMD and glaucomatous severity factors. The spatial positional relationship between PCMD and corresponding peripapillary retinal nerve fiber layer (RNFL) thickness and visual field (VF) mean deviation (MD) was also assessed.

RESULTS

The average and 4 quadrants of the inner annulus PCMD and peripapillary VD in the 2 glaucomatous groups were significantly lower than in normal eyes ( P <0.05). Strong correlations were found between inner annulus PCMD and VF MD, peripapillary VD, and RNFL in POAG patients. Similarly, the inner annulus PCMD in NTG patients was strongly correlated with peripapillary VD and RNFL (all r >0.5). Strong positional correlations were found between inner superior quadrantal PCMD and RNFL thickness in both POAG and NTG patients ( r =0.566 and 0.731, respectively). Likewise, inner inferior quadrantal PCMD exhibited a strong correlation with RNFL thickness in POAG patients ( r =0.608). Strong positional correlations were also found between inner superior PCMD and VF MD in both POAG and NTG patients ( r =0.589 and 0.622, respectively). Inner inferior PCMD exhibited a moderate correlation with VF MD in both POAG and NTG patients ( r =0.487 and 0.440, respectively).

CONCLUSION

The study found that the inner annulus PCMD decreased to varying degrees in NTG and POAG patients. The inner annulus PCMD was closely related to the structural and visual function parameters of glaucoma in both NTG and POAG. Furthermore, inner PCMD demonstrated a spatial correlation with corresponding RNFL thickness and VF MD.

Baseline choroidal microvasculature dropout as a predictor of rapid global structural loss in open-angle glaucoma

This study included 102 open-angle glaucoma (OAG) eyes with or without a localized choroidal microvasculature dropout (CMvD) at the inferior hemiretina, matched for age (≤ 10 years), axial length (≤ 1 mm), and visual field severity (≤ 1dB), and with a minimum 2-year follow-up. Serial thickness [circumpapillary retinal nerve fiber layer (cpRNFLT) and macular ganglion cell-inner plexiform layer thickness (mGCIPLT)], and vessel density (VD) [circumpapillary (cpVD) and macular VD (mVD)] parameters were obtained. The rate of change in each parameter at both the superior (CMvD-unaffected) and inferior (CMvD-affected) hemiretina were compared between matched eyes with (CMvD+) and without CMvD (CMvD-). Clinical factors associated with the rate of change in each parameter both globally and at the CMvD-unaffected hemiretina were also evaluated. CMvD + eyes showed significantly faster rates of VD and thickness loss at both the CMvD-affected and -unaffected hemiretina. In addition, CMvD was significantly associated with rapid loss of both VD and thickness parameters globally and at the CMvD-unaffected superior hemiretina. In conclusion, OAG eyes with CMvD show significantly faster rates of VD and thickness loss at both the CMvD-affected and unaffected hemiretina. A localized CMvD is an independent predictor of globally rapid structural loss in OAG eyes.

Optic Disc Microvasculature Reduction and Visual Field Progression in Primary Open-Angle Glaucoma

PURPOSE

To investigate the relationship between optic disc vessel density (ODVD) reduction and visual field (VF) progression in primary open-angle glaucoma (POAG) patients.

DESIGN

Retrospective case series.

METHODS

A total of 187 POAG eyes underwent ≥5 consecutive VF, spectral-domain optical coherence tomography, and swept-source OCT angiography imaging sessions during ≥3 years of follow-up. ODVD reduction was defined as a statistically significant negative slope (P < .05) of ODVD, calculated as the ratio of pixels occupied by vessels within the temporal optic disc area for any global, superior, or inferior sectors. The association between VF progression and rate of ODVD change was assessed by logistic regression and multivariable longitudinal linear mixed-effects models vs time.

RESULTS

During 3.67 ± 0.38 years of follow-up on the 187 eyes, 90 (48.1%) and 56 (29.9%) showed ODVD reduction and VF progression, respectively. A higher proportion of eyes with ODVD reduction had VF progression than did those without ODVD reduction (51/90 eyes [56.7%] vs 5/97 eyes [5.2%]; P < .001). VF progression was associated with a faster rate of global ODVD change (odds ratio, 5.10; P = .002) as well as a faster rate of global retinal nerve fiber layer thinning (odds ratio, 39.6; P = .008) in the multivariable model.

CONCLUSIONS

Optic disc microvasculature reduction was associated with VF progression even after adjusting for possible influencing factors including retinal nerve fiber layer thinning in POAG. This suggests that deep optic nerve head circulation has a role in the pathogenesis of glaucoma.

Reduction of Optic Disc Microvasculature and Retinal Nerve Fiber Layer Thinning in Patients With Glaucoma

PURPOSE

To assess the relationship between the change of optic disc vessel density (ODVD) and retinal nerve fiber layer (RNFL) thinning in primary open-angle glaucoma (POAG) patients.

DESIGN

Retrospective case series.

METHODS

For 105 POAG patients, ≥5 consecutive optical coherence tomography (OCT) and OCT angiography images were obtained during ≥2 years of follow-up. Based on enface OCT angiography imaging, ODVD was calculated as the ratio of pixels occupied by vessels below the internal limiting membrane within the temporal area of the optic cup, and ODVD reduction was determined when there was a statistically significant negative slope (P < .05) for any of the global, superior, or inferior sectors. The association between the rates of ODVD change and RNFL thinning was assessed by a multivariable longitudinal linear mixed-effects model versus time.

RESULTS

During 2.9 ± 0.3 years of follow-up on the 105 participants with visual field mean deviation at baseline of -5.7 ± 4.8 dB, 46 (43.8%) showed ODVD reduction. Faster global RNFL thinning was associated with the smaller Bruch's membrane opening area (ß = 0.381; 95% confidence interval [CI], 0.120-0.646; P = .006), optic disc hemorrhage (ß = -0.567; 95% CI, -0.909 to -0.228; P = .002), and faster rate of global ODVD change (ß = -0.090; 95% CI, -0.139 to -0.042; P = .001).

CONCLUSIONS

Reduction of optic disc microvasculature was associated with rapid RNFL thinning in POAG. This suggests a role for deep optic nerve head circulation in the glaucoma pathogenesis.

Optic Disc Microvasculature Dropout in Preperimetric Glaucoma

PRCIS

Optic disc microvasculature dropout (MvD-D) was associated with worse disease severity in pre-perimetric glaucoma. MvD-D was not accompanied by focal lamina cribrosa defect or parapapillary deep-layer microvasculature dropout in 62.3% and 71.0% of eyes, respectively.

PURPOSE

To investigate factors associated with optic disc microvasculature dropout (MvD-D) in patients with preperimetric primary open angle glaucoma (PPG).

METHODS

One hundred thirty nine eyes of PPG patients were categorized according to the presence of MvD-D with optical coherence tomography angiography (OCTA). Factors including visual field (VF) mean deviation (MD), retinal nerve fiber layer (RNFL) thickness, focal lamina cribrosa (LC) defect, optic disc hemorrhage (DH), and parapapillary deep-layer microvasculature dropout (MvD-P) were compared between eyes with and without MvD-D.

RESULTS

MvD-D was observed in 69 PPG eyes (49.6%). Compared with eyes without MvD-D, the ones with MvD-D had a significantly thinner RNFL in all areas except the nasal sector, worse VF MD, and a focal LC defect and MvD-P ( P <0.05): male gender also was more highly prevalent. A considerable number of eyes with MvD-D lacked focal LC defect (62.3% [43/69]) or MvD-P (71.0% [49/69]), while a few eyes without MvD-D had focal LC defect (10.0% [7/70]) or MvD-P (2.9% [2/70]). In a multivariable logistic regression analysis, male gender (odds ratio [OR], 3.96; P <0.001), worse VF MD (OR, 1.44; P =0.019), thinner global RNFL (OR, 1.13; P <0.001), higher prevalence of focal LC defect (OR, 3.71; P =0.014) and MvD-P (OR, 7.85; P <0.001) were significantly associated with MvD-D.

CONCLUSIONS

MvD-D was related to worse disease severity in patients with PPG, and often was not accompanied by focal LC defect or MvD-P. This suggests that impaired optic disc circulation can be an early sign of glaucoma without noticeable changes in functional or structural features (i.e., VF, focal LC defect, MvD-P).

Variability of scan quality and perfusion density in longitudinal optical coherence tomography angiography imaging

BACKGROUND/AIMS

Optical coherence tomography angiography (OCT-A) images are subject to variability, but the extent to which learning impacts OCT-A measurements is unknown. We determined whether there is a learning effect in glaucoma patients and healthy controls imaged with OCT-A.

METHODS

Ninety-one open-angle glaucoma patients and 54 healthy controls were imaged every 4 months over a period of approximately 1 year in this longitudinal cohort study. We analysed 15°×15° scans, centred on the fovea, in one eye of each participant. Two-dimensional projection images for the superficial, intermediate and deep vascular plexuses were exported and binarised after which perfusion density was calculated. Linear mixed-effects models were used to investigate the association between perfusion density and follow-up time.

RESULTS

The mean (SD) age of glaucoma patients and healthy controls was 67.3 (8.1) years and 62.1 (9.0) years, respectively. There was a significant correlation between perfusion density and scan quality in both glaucoma patients (r=0.50 (95% CI 0.42 to 0.58); p<0.05) and healthy controls (r=0.41 (95% CI 0.29 to 0.52); p<0.05). An increase in perfusion density occurred over time and persisted, even after adjustment for scan quality (1.75% per year (95% CI 1.14 to 2.37), p<0.01).

CONCLUSIONS

Perfusion density measurements are subject to increasing experience of either the operator or participant, or a combination of both. These findings have implications for the interpretation of longitudinal measurements with OCT-A.

Clinical Significance of Recurrent Disc Hemorrhage and Choroidal Microvasculature Dropout on Optical Coherence Tomography Angiography in Glaucoma

Purpose

The purpose of this study was to investigate the clinical significance of recurrent disc hemorrhage (DH) and choroidal microvasculature dropout (MvD).

Methods

A retrospective cohort study was conducted of 181 eyes with open-angle glaucoma. The clinical characteristics of patients with nonrecurrent and recurrent DH with and without MvD were investigated.

Results

Fifty-eight patients (32.0%) had a single, nonrecurrent DH, and 63 (34.8%) had more than one DH. Sixty eyes (33.1%) with no history of DH were presented as a control group. MvD was more frequent in the recurrent DH group (44.4%) than in the nonrecurrent DH group (27.6%, P = 0.041). The recurrent DH with MvD group experienced more frequent central visual field (VF) progression (71.4%) than the recurrent DH without MvD group (17.1 %, P < 0.001). The recurrent DH without MvD group had a higher frequency of DH recurrence at different locations (42.9%) and more vascular symptoms (37.1%) than the recurrent DH with MvD group (14.3% and 7.1%, P = 0.013 and P = 0.005, respectively). Presence of DH, presence of MvD, vascular symptoms, and DH recurrence at different locations were the factors associated with central VF progression in multivariate analysis.

Conclusions

DH occurrence and the presence of MvDs constitute critical parameters associated with central VF progression. In the presence of MvD, recurrent DH was more likely to recur at the same location as the MvD, whereas recurrent DH without MvD was related to vascular symptoms and recurred at other locations. When eyes present with recurrent DH and MvD, closer follow-up and more aggressive treatment are required to prevent the progression of central VF.

Optical coherence tomography angiography in glaucoma

The use of optical coherence tomography angiography (OCTA) holds significant promise for optometrists in the diagnosis and management of glaucoma. It offers reliable differentiation of glaucomatous eyes from healthy ones and extends monitoring capabilities for advanced cases. OCTA represents a valuable addition to traditional assessment methods, particularly in complex cases. Glaucoma, a major cause of irreversible blindness, is traditionally diagnosed using structural and functional metrics. With growing interest, OCTA is being explored to diagnose, monitor, and manage glaucoma. This review focuses on the application of OCTA in glaucoma patients. A database search was carried out using Embase Elsevier (n = 664), PubMed (n = 574), and Cochrane Central Register of Controlled Trials (n = 19) on 15 August 2023. After deduplication and screening, 272 original papers were included in the narrative review. Inclusion criteria comprised English-language original studies on OCTA use in human glaucoma patients, with or without healthy controls. Exclusion criteria encompassed animal studies, in-vivo/in-vitro research, reviews, and congress abstracts. OCTA has good repeatability and reproducibility. OCTA metrics have good discriminatory power to differentiate glaucomatous eyes from healthy eyes and show strong associations with structural changes and visual field defects. OCTA can extend the monitoring of advanced glaucoma, addressing the 'floor effect' of traditional structural measurements. OCTA metrics can be affected by the choice of OCTA machine, post-image processing algorithms, systemic diseases, and ocular factors. Image artefacts can affect the accuracy of OCTA measurements, and proper scan quality evaluation is crucial to ensure reliable results. Additionally, artificial intelligence techniques offer promise for enhancing the diagnostic accuracy of OCTA by combining data from various retinal layers and regions. OCTA complements traditional methods in assessing glaucoma, especially in challenging cases, providing valuable insights for detection and management. Further research and clinical validation are needed to integrate OCTA into routine practice.

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.

Central visual field damage in glaucoma eyes with choroidal microvasculature dropout with and without high axial myopia

PURPOSE

To characterise the relationship between a deep-layer microvasculature dropout (MvD) and central visual field (VF) damage in primary open-angle glaucoma (POAG) patients with and without high axial myopia.

DESIGN

Cross-sectional study.

METHODS

Seventy-one eyes (49 patients) with high axial myopia and POAG and 125 non-highly myopic POAG eyes (97 patients) were enrolled. Presence, area and angular circumference of juxtapapillary MvD were evaluated on optical coherence tomography angiography B-scans and en-face choroidal images.

RESULTS

Juxtapapillary MvD was detected more often in the highly myopic POAG eyes (43 eyes, 86%) than in the non-highly myopic eyes (73 eyes, 61.9%; p=0.002). In eyes with MvD, MvD area and angular circumference (95% CI) were significantly larger in the highly myopic eyes compared with the non-highly myopic eyes (area: (0.69 (0.40, 0.98) mm2 vs 0.31 (0.19, 0.42) mm2, p=0.011) and (angular circumference: 84.3 (62.9, 105.8) vs 74.5 (58.3, 90.9) degrees, p<0.001), respectively. 24-2 VF mean deviation (MD) was significantly worse in eyes with MvD compared with eyes without MvD in both groups (p<0.001). After adjusting for 24-2 MD VF, central VF defects were more frequently found in eyes with MvD compared with eyes without MvD (82.7% vs 60.9%, p<0.001). In multivariable analysis, higher intraocular pressure, worse 24-2 VF MD, longer axial length and greater MvD area and angular circumference were associated with worse 10-2 VF MD.

CONCLUSIONS

MvD was more prevalent and larger in POAG eyes with high myopia than in non-highly myopic POAG eyes. In both groups, eyes with MvD showed worse glaucoma severity and more central VF defects.

Relationship of Choroidal Microvasculature Dropout and Beta Zone Parapapillary Area With Visual Field Changes in Glaucoma

PURPOSE

To evaluate the association between rates of choroidal microvasculature dropout (MvD) change, beta zone parapapillary atrophy (β-PPA) area change, and visual field (VF) changes in eyes with primary open-angle glaucoma (POAG).

DESIGN

Retrospective, observational cohort study.

METHODS

In a tertiary glaucoma clinic, we included 76 eyes from 58 patients with POAG with and without localized MvD, who had ≥2 years of follow-up with a minimum of 4 visits with optical coherence tomography angiography and optical coherence tomography scans. β-PPA area was evaluated using scanning laser ophthalmoscopy-like images and compared with the area of MvD on an en face choroidal vessel density map during the follow-up period. Joint longitudinal mixed effects models were used to estimate the rates of change in β-PPA area or MvD area and VF mean deviation (MD).

RESULTS

Mean rates of change in β-PPA and MvD area were 0.037 mm2 (95% confidence interval [CI] 0.030-0.043 mm2) per year and 0.039 mm2 (95% CI 0.029-0.048 mm2) per year, respectively, over the mean follow-up of 4.1 years. In multivariable models, MvD area enlargement was significantly associated with faster rates of VF MD loss (0.03 mm2 [95% CI 0.02-0.04 mm2] per 1-dB worse, P < .001) but not β-PPA area enlargement (0.04 mm2 [95% CI 0.03-0.05 mm2] per 1-dB worse, P = .252).

CONCLUSION

MvD area rates, but not β-PPA area rates, were associated with VF MD loss changes in eyes with POAG. Assessment of MvD is useful for the detection of patients with glaucoma who are at an increased risk of faster VF loss.

Progressive Macular Vessel Density Loss and Visual Field Progression in Open-angle Glaucoma Eyes with Central Visual Field Damage

PURPOSE

To investigate the association between the longitudinal changes in both macular vessel density (mVD) and macular ganglion cell-inner plexiform layer thickness (mGCIPLT) and visual field (VF) progression (including central VF progression) in open-angle glaucoma (OAG) patients with central visual field (CVF) damage at different glaucoma stages.

DESIGN

Retrospective longitudinal study.

PARTICIPANTS

This study enrolled 223 OAG eyes with CVF loss at baseline classified as early-to-moderate (133 eyes) or advanced (90 eyes) stage based on the VF mean deviation (MD) (-10 dB).

METHODS

Serial mVDs at parafoveal and perifoveal sectors and mGCIPLT measurements were obtained using OCT angiography and OCT during a mean follow-up of 3.5 years. Visual field progression was determined using both the event- and trend-based analyses during follow-up.

MAIN OUTCOME MEASURES

Linear mixed-effects models were used to compare the rates of change in each parameter between VF progressors and nonprogressors. Logistic regression analyses were performed to determine the risk factors for VF progression.

RESULTS

In early-to-moderate stage, progressors showed significantly faster rates of change in the mGCIPLT (-1.02 vs. -0.47 μm/year), parafoveal (-1.12 vs. -0.40%/year), and perifoveal mVDs (-0.83 vs. -0.44%/year) than nonprogressors (all P < 0.05). In advanced stage cases, only the rates of change in mVDs (parafoveal: -1.47 vs. -0.44%/year; perifoveal: -1.04 vs. -0.27%/year; all P < 0.05) showed significant differences between the groups. By multivariable logistic regression analyses, the faster rate of mVD loss was a predictor of VF progression regardless of glaucoma stage, while the rate of mGCIPLT loss was significantly associated with VF progression only in early-to-moderate stage cases.

CONCLUSIONS

Progressive mVD loss is significantly associated with VF progression (including central VF progression) in the OAG eyes with CVF loss regardless of the glaucoma stage.

FINANCIAL DISCLOSURE(S)

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

Quantitative study of spatial and temporal variation in retinal capillary network perfusion in rat eye by in vivo confocal imaging

Microvascular dysfunction is the underlying pathological process in many systemic diseases. However, investigation into its pathogenesis is impeded by the accessibility and complexity of the microvasculature within different organs, particularly for the central nervous system. The retina as an extension of the cerebrum provides a glimpse into the brain through which the microvasculature can be observed. Two major questions remain unanswered: How do the microvessels regulate spatial and temporal delivery to satisfy the varying cellular demands, and how can we quantify blood perfusion in the 3D capillary network? Here, quantitative measurements of red blood cell (RBC) speed in each vessel in the field were made in the in vivo rat retinal capillary network using an ultrafast confocal technique with fluorescently labelled RBCs. Retinal RBC speed and number were found to vary remarkably between microvessels ranging from 215 to 6641 microns per second with significant variations spatially and temporally. Overall, the RBC speed was significantly faster in the microvessels in the superficial retina than in the deep retina (estimated marginal means of 2405 ± 238.2 µm/s, 1641 ± 173.0 µm/s respectively). These observations point to a highly dynamic nature of microvasculature that is specific to its immediate cellular environment and is constantly changing.

Impact of smoking on choroidal microvasculature dropout in glaucoma: a cross-sectional study

OBJECTIVE

To investigate the effect of smoking on choroidal microvasculature dropout (MvD) in glaucoma.

DESIGN

Cross-sectional study.

SETTING

Tertiary glaucoma centre.

PARTICIPANTS

223 eyes of 163 patients with primary open-angle glaucoma who had undergone imaging with optical coherence tomography angiography and completed a questionnaire on smoking from the Diagnostic Innovations in Glaucoma Study.

PRIMARY OUTCOME MEASURES

Linear mixed-effects models were used to determine the effect of each parameter on MvD area and angular circumference. The sensitivity analysis was performed by categorising the glaucoma severity determined by visual field mean deviation (MD).

RESULTS

MvD was found in 37 (51.4%) eyes with smoking history and in 67 (44.4%) eyes with non-smokers (p=0.389). Larger MvD area and wider angular circumference were found in smokers compared with non-smokers (p=0.068 and p=0.046, respectively). In a multivariable model, smoking intensity was significantly associated with MvD area (0.30(95% CI 0.01 to 0.60) each 0.01 mm2 per 10 pack-years; p=0.044). In eyes with moderate-severe glaucoma (MD <-6), smoking intensity was associated with larger MvD area (0.47 (95% CI 0.11 to 0.83) each 0.01 mm2 per 10 pack-years; p=0.011), whereas no significant association was found in early glaucoma (MD ≥-6) (-0.08 (95% CI -0.26 to 0.11), p=0.401).

CONCLUSIONS

Smoking intensity was associated with larger choroidal MvD area in eyes with glaucoma, especially in patients with more severe disease.

TRIAL REGISTRATION NUMBER

NCT00221897.

Association Between Optic Disc Perfusion Determined by Swept-Source Optical Coherence Tomography Angiography and Visual Field Progression in Glaucoma

PRCIS

Reduced optic disc vessel density determined by swept-source optical coherence tomography angiography (SS-OCTA) was associated with visual field (VF) deterioration in glaucomatous eyes, which suggested that this parameter can be a potential biomarker that correlates well with functional deterioration.

PURPOSE

The purpose of this study was to identify the association between optic disc perfusion evaluated by SS-OCTA and VF progression in primary open angle glaucoma (POAG) eyes.

METHODS

A total of 266 POAG eyes of 266 patients (5.4 y of mean follow-up) were included. Optic nerve head SS-OCTA was performed to evaluate the optic disc vessel density (dVD), parapapillary choroidal vessel density (pcVD), choroidal microvascular dropout (cMvD), and optic disc microvascular dropout (dMvD). VF progression was defined using Early Manifest Glaucoma Trial criteria. Factors associated with VF worsening were assessed by Cox proportional hazard analysis.

RESULTS

Eighty (30.1%) out of the 266 POAG eyes showed VF progression. The progression group showed a significantly higher proportion of disc hemorrhage, cMvD, and dMvD but lower dVD and pcVD than the stable group (all P <0.05). Considering the strong association between the parameters [dMvD vs. dVD ( r = -0.757, P =0.010], cMvD vs. pcVD ( r = -0.745, P =0.012), dMvD vs. cMvD ( r = 0.802, P <0.001], dVD vs. pcVD ( r = 0.862, P <0.001), CMvD vs. dVD ( r = -0.698, P =0.031), and dMvD vs. pcVD ( r = -0.688, P =0.034)], 6 models with different combinations of covariates compensating for multicollinearity were developed. Younger age, presence of disc hemorrhage, and lower dVD were consistently associated with progression in all models that included these parameters.

CONCLUSIONS

Optic disc perfusion, represented as dVD, may be a useful biomarker that correlates well with functional deterioration in POAG eyes.

Factors associated with choroidal microvascular dropout change

BACKGROUND/AIMS

To investigate the factors associated with choroidal microvasculature drop-out (MvD) enlargement detected by optical coherence tomography angiography (OCT-A) in glaucomatous eyes.

METHODS

Ninety-one eyes of 68 primary open-angle glaucoma patients were enrolled. Only eyes with a minimum of four good quality OCT-A and OCT scans of the optic nerve head acquired at least and with a minimum of 2 years follow-up were included. Area and angular circumference of MvD were analysed on en face images. Univariable and multivariable mixed effects models were constructed to identify the factors contributing to MvD area and angular circumference change over time.

RESULTS

Peripapillary MvD was detected in 53 (58.2%) eyes at baseline and in an additional 17 (18.6%) eyes during follow-up, whereas MvD was not detected in 21 (23.0 %) eyes during the entire follow-up period. In multivariable analysis, worse baseline visual field (VF) mean deviation (MD) (ß=0.27, 95% CI 0.10 to 0.44, p=0.002), greater intraocular pressure (IOP) fluctuations (ß=0.86, 95% CI 0.24 to 1.48, p=0.007), higher peak IOP (ß=0.17, 95% CI -0.01 to 0.35, p=0.067) and greater number of IOP lowering medications (ß=1.36, 95% CI 0.67 to 2.05, p<0.001) were associated with faster MvD area enlargement. Worse baseline VF MD and greater IOP fluctuation were also associated with significantly faster MvD circumferential enlargement in multivariable models.

CONCLUSION

Greater IOP fluctuation, higher peak IOP, worse baseline VF MD and greater number of glaucoma medications were significantly associated with MvD enlargement in glaucomatous eyes. The identification of factors associated with MvD enlargement may improve our understanding of the role of choroidal vasculature in glaucoma.

Change of Choroidal Microvasculature Dropout After Trabeculectomy as Assessed by Optical Coherence Tomography Angiography

PRCIS

Reduction in the angular circumference of choroidal microvascular dropout (CMvD AC) was found in POAG patients after trabeculectomy. Greater percentage of IOP reduction was significantly associated with decreased CMvD AC.

PURPOSE

The purpose of this study was to investigate the change of choroidal microvasculature dropout (CMvD) after trabeculectomy and its associated factors in primary open angle glaucoma (POAG) eyes using optical coherence tomography angiography.

METHODS

Fifty eyes of 50 POAG participants who had preoperative CMvD and underwent trabeculectomy were prospectively enrolled. Angular circumference (AC) of CMvD was determined from choroidal layer images by optical coherence tomography angiography preoperatively and at postoperative 1 year. The cutoff for significant AC of CMvD decrease was determined by the Bland-Altman method, and accordingly, patients were divided into 2, decreased and stable/increased CMvD AC groups. Changes in intraocular pressure (IOP) and CMvD AC were compared between the groups preoperatively and at postoperative 1 year. Factors associated with CMvD AC decrease were assessed by linear regression analysis.

RESULTS

The cutoff for significant CMvD AC decrease was 3.58 degrees; accordingly, 26 eyes (52.0%) were categorized as decreased CMvD AC group. No significant intergroup differences in baseline characteristics were found. However, the decreased CMvD AC group presented significantly lower IOP (10.7±3.7 vs. 12.9±2.6 mm Hg, P =0.022), lower CMvD AC (32.03±33.95% vs. 53.44±39.33%, P =0.044), and higher parapapillary choroidal vessel density ( P =0.014) compared with the increased/stable CMvD AC group at postoperative 1 year. The greater percentage of IOP reduction was significantly associated with decreased CMvD AC ( P =0.046).

CONCLUSIONS

CMvD AC reduction associated with IOP lowering was found after trabeculectomy. The long-term clinical relevance of postoperative CMvD reduction should be further investigated.

Temporal Optic Disc Microvasculature Dropout in Glaucoma

PURPOSE

To assess the clinical characteristics of focal temporal optic disc microvasculature dropout (MvD-D) in primary open-angle glaucoma (POAG) patients.

METHODS

One hundred and eighty-seven eyes of 187 POAG patients having MvD-D on Swept-Source optical coherence tomography angiography (SS-OCTA) were enrolled. Three groups were categorized according to the presence of temporal MvD-D within the upper and lower 45° of the fovea-Bruch's membrane (BM) opening axis: focal temporal MvD-D (Group 1, isolated focal temporal MvD-D; 44 eyes), supero/inferotemporal MvD-D (Group 2, MvD-D only in superotemporal or inferotemporal sector; 78 eyes), and diffuse temporal MvD-D (Group 3, MvD-D spanning ≥ 2 consecutive sectors, at least one of which being temporal sector; 65 eyes).

RESULTS

Group 1 had a significantly longer axial length and β-zone parapapillary atrophy without BM. There also was a larger horizontal tilt angle and ovality index than the other two groups (P < 0.001). Group 1 had a significantly thinner retinal nerve fiber layer (RNFL) in the temporal sector than did Group 2 (P < 0.001), despite similar thicknesses in all other areas (P > 0.05). Group 3 had significantly worse visual field mean deviation and thinner RNFL than the other two groups in all areas other than the nasal, temporal, and superotemporal sectors (P < 0.05).

CONCLUSIONS

Focal temporal MvD-D detected by SS-OCTA was associated with a longer axial length and related subsequent morphological changes of the optic disc and parapapillary area. This suggests that stretching of the optic disc consequent on axial elongation may lead to absence of temporal optic disc microvasculature.

Optical Coherence Tomography and Optical Coherence Tomography Angiography: Essential Tools for Detecting Glaucoma and Disease Progression

Early diagnosis and detection of disease progression are critical to successful therapeutic intervention in glaucoma, the leading cause of irreversible blindness worldwide. Optical coherence tomography (OCT) is a non-invasive imaging technique that allows objective quantification in vivo of key glaucomatous structural changes in the retina and the optic nerve head (ONH). Advances in OCT technology have increased the scan speed and enhanced image quality, contributing to early glaucoma diagnosis and monitoring, as well as the visualization of critically important structures deep within the ONH, such as the lamina cribrosa. OCT angiography (OCTA) is a dye-free technique for noninvasively assessing ocular microvasculature, including capillaries within each plexus serving the macula, peripapillary retina and ONH regions, as well as the deeper vessels of the choroid. This layer-specific assessment of the microvasculature has provided evidence that retinal and choroidal vascular impairments can occur during early stages of glaucoma, suggesting that OCTA-derived measurements could be used as biomarkers for enhancing detection of glaucoma and its progression, as well as to reveal novel insights about pathophysiology. Moreover, these innovations have demonstrated that damage to the macula, a critical region for the vision-related quality of life, can be observed in the early stages of glaucomatous eyes, leading to a paradigm shift in glaucoma monitoring. Other advances in software and hardware, such as artificial intelligence-based algorithms, adaptive optics, and visible-light OCT, may further benefit clinical management of glaucoma in the future. This article reviews the utility of OCT and OCTA for glaucoma diagnosis and disease progression detection, emphasizes the importance of detecting macula damage in glaucoma, and highlights the future perspective of OCT and OCTA. We conclude that the OCT and OCTA are essential glaucoma detection and monitoring tools, leading to clinical and economic benefits for patients and society.

Relationship of macular ganglion cell complex thickness to choroidal microvasculature drop-out in primary open-angle glaucoma

BACKGROUND/AIMS

To investigate the rate of ganglion cell complex (GCC) thinning in primary open-angle glaucoma (POAG) patients with and without deep-layer microvasculature drop-out (MvD).

METHODS

POAG patients who had at least 1.5 years of follow-up and a minimum of three visits were included from the Diagnostic Innovations in Glaucoma Study. MvD was detected at baseline by optical coherence tomography angiography (OCT-A). Area and angular circumference of MvD were evaluated on en face choroidal vessel density images and horizontal B-scans. Rates of global and hemisphere GCC thinning were compared in MvD and non-MvD eyes using linear mixed-effects models.

RESULTS

Thirty-six eyes with MvD and 37 eyes without MvD of 63 patients were followed for a mean of 3.3 years. In 30 out of 36 eyes, MvD was localised in the inferotemporal region. While mean baseline visual field mean deviation was similar between the two groups (p=0.128), global GCC thinning was significantly faster in eyes with MvD than in those without MvD (mean differences: -0.50 (95% CI -0.83 to -0.17) µm/year; p=0.003)). Presence of MvD, area and angular circumference of MvD were independently associated with a faster rate of thinning (p=0.002, p=0.031 and p=0.013, respectively).

CONCLUSION

In POAG eyes, GCC thinning is faster in eyes with MvD. Detection of MvD in OCT-A images can assist clinicians to identify patients who are at higher risk for central macula thinning and glaucomatous progression and may require more intensive management.

Discrepancy between peripapillary retinal and choroidal microvasculature and the rate of localized retinal nerve fiber layer thinning in glaucoma

This observational case series study is conducted to compare the extent of microvasculature impairment in the peripapillary retina and choroid in eyes with primary open-angle glaucoma (POAG), and to investigate the association of the discrepancy between the microvasculature impairments of each layer with the rate of progressive retinal nerve fiber layer (RNFL) thinning. A total of 88 POAG eyes with a localized RNFL defect were enrolled, including 67 eyes with and 21 eyes without choroidal microvasculature dropout (CMvD). Circumferential widths of retinal microvascular impairment (RMvI) and CMvD were measured, and eyes were classified based on the relative width of CMvD to RMvI (CMvD/RMvI ratio). The rate of RNFL thinning was determined by linear regression based on ≥ 5 serial OCT examinations. Thinner global RNFL and worse visual field mean deviation at baseline were associated with a larger circumferential width of the RMvI, whereas the presence of cold extremities, lower mean arterial pressure and thinner juxtapapillary choroid were associated with a larger circumferential width of the CMvD. The rate of global RNFL thinning was faster in eyes with larger relative CMvD width than in eyes with equal CMvD and RMvI widths and in eyes without CMvD (P = 0.001). Lower mean arterial pressure (P = 0.041), larger CMvD width (P = 0.046), larger CMvD/RMvI ratio (P = 0.041), and detection of disc hemorrhage during the follow-up (P = 0.013) were significant factors associated with faster global RNFL thinning. Larger CMvD width relative to RMvI width may be indicative of an increased risk of faster RNFL thinning in POAG with localized RNFL defect. Comparing the microvasculature impairment in individual layers may help predict more rapid glaucoma progression.

Choroidal Microvasculature Dropout in the Absence of Parapapillary Atrophy in POAG

Purpose

To describe the parapapillary choroidal microvasculature dropout (CMvD) in glaucomatous eyes without β-zone parapapillary atrophy (β-PPA) and compare its characteristics with that of CMvD with β-PPA.

Methods

Peripapillary choroidal microvasculature was evaluated on en face images obtained using optical coherence tomography angiography. CMvD was defined as a focal sectoral capillary dropout with no visible microvascular network identified in the choroidal layer. Peripapillary and optic nerve head structures, including the presence of β-PPA, peripapillary choroidal thickness and lamina cribrosa curvature index were evaluated using the images obtained by enhanced depth-imaging optical coherence tomography.

Results

The study included 100 glaucomatous eyes with CMvD (25 without and 75 with β-PPA) and 97 eyes without CMvD (57 without and 40 with β-PPA). Regardless of the presence of β-PPA, eyes with CMvD tended to have a worse visual field at a given RNFL thickness than eyes without CMvD, with patients having eyes with CMvD having lower diastolic blood pressure and more frequent cold extremities than patients with eyes lacking CMvD. Peripapillary choroidal thickness was significantly smaller in eyes with than without CMvD, but was not affected by the presence of β-PPA. β-PPA without CMvD was not associated with vascular variables.

Conclusions

CMvD were found in the absence of β-PPA in glaucomatous eyes. CMvDs had similar characteristics in the presence and absence of β-PPA. Clinical and optic nerve head structural characteristics potentially relevant to compromised optic nerve head perfusion were dependent on the presence of CMvD, rather than the presence of β-PPA.

Reduced intradisc vessel density is associated with optic disc hemorrhage in eyes with primary open-angle glaucoma

We sought to investigate the association between optic nerve head (ONH)/choroidal microvasculature perfusion and optic disc hemorrhage (ODH) in eyes with primary open-angle glaucoma (POAG) using swept-source optical coherence tomography angiography (SS-OCTA). A total of 266 POAG eyes (59 with a single instance of ODH, 40 with a history of recurrent ODH, and 167 eyes without ODH) with a mean follow-up of 5.4 years were included. Intradisc vessel density (VD), parapapillary choroidal VD, optic disc microvascular dropout (MvD), and choroidal microvascular dropout (CMvD), were evaluated on a 3 × 3 mm SS-OCTA image of ONH and compared between eyes with and without ODH. Recurrent ODH was defined as occurrence 1 year after first ODH detection during the total follow-up period. Logistic regression analyses were performed to investigate factors associated with ODH. The prevalence of CMvD, optic disc MvD, and β-parapapillary atrophy were not different among the no ODH, single ODH, and recurrent ODH groups. Eyes with ODH had lower intradisc VDs than those without ODH (P = 0.021), but no difference was found in intradisc VDs between the single and recurrent ODH groups (P = 0.977). Better VF MD at baseline (odds ratio [OR], 1.150; 95% confidence interval [CI], 1.055-1.254; P = 0.002) and lower intradisc VD (OR, 0.863; 95% CI, 0.812-0.918; P < 0.001) were associated with ODH occurrence. Among POAG eyes, those with ODH had lower intradisc VDs than those without ODH. POAG eyes in an earlier disease stage or those with lower intradisc VDs should be monitored for the possibility of ODH occurrence.

Structural and vascular changes in glaucoma with single-hemifield defect: predictors of opposite hemifield visual field progression

PURPOSE

To investigate longitudinal changes in optic nerve head (ONH) superficial vessel density (VD), macular VD, circumpapillary retinal nerve fiber layer (RNFL) thickness, and macular ganglion cell-inner plexiform layer (GCIPL) thickness, and their associations with future VF defects in unaffected hemifields of primary open angle glaucoma (POAG) eyes with baseline VF defect confined to a single hemifield.

METHODS

This retrospective observational study included 61 POAG eyes with VF defect confined to a single hemifield monitored over a mean follow-up time of 2.7 years. Development of VF defect in opposite hemifield was defined based the Early Manifest Glaucoma Trail criteria. Each eye was classified into either "conversion" or "no conversion" groups according to development of VF defect in the unaffected hemifield. The rates of longitudinal changes in VD and structure parameters in each hemiretina were compared between the two groups. A Cox proportional hazard model was used to identify potential risk factors for VF conversion in the unaffected hemifield.

RESULTS

Among 61 eyes, 17 eyes (27.9%) were classified as "conversion" and 44 eyes (72.1%) were classified as "non-conversion" groups. The conversion group exhibited significantly greater rates of both VD and structural changes in both hemiretinas. In Cox proportional hazard model, greater rate of change in GCIPL thickness, ONH superficial VD, and macular VD of both hemiretinas and greater rate of change in RNFL thickness of the unaffected hemiretina were identified as risk factors for VF conversion in the unaffected hemifield.

CONCLUSIONS

Monitoring progressive changes in VD and structural parameters effectively predict future VF defect in the opposite hemifields of POAG eyes with single-hemifield defects.

Vasculature-function relationship in open-angle glaucomatous eyes with a choroidal microvasculature dropout

Identifying biomarkers associated with functional impairment is important in monitoring glaucoma patients. This retrospective cross-sectional study investigated the vasculature-function relationship in open-angle glaucoma (OAG) eyes with choroidal microvasculature dropout (CMvD) versus in OAG eyes without. Optical coherence tomography (OCT) angiography-derived circumpapillary (cpVD) and macular vessel densities (mVD) were measured in 159 early-stage OAG eyes (mean deviation >  -6 dB) in accordance with the presence or not of a CMvD. OCT-derived circumpapillary retinal nerve fibre layer thickness (cpRNFLT) and macular ganglion cell-inner plexiform layer thicknesses (mGCIPLT) were also measured as reference standards. The vasculature (cpVD and mVD)-function [24-2 visual field mean sensitivity (VFMS) and central 10° VFMS (cVFMS)] and structure (cpRNFLT and mGCIPLT)-function (24-2 VFMS and cVFMS) relationships were compared using global and sectoral maps between OAG eyes with (CMvD+) and without CMvD (CMvD-). The CMvD+ eyes showed significantly steeper cpVD-24-2 VFMS and mVD-cVFMS correlations (P < 0.05). In contrast, there were no significant differences in the cpRNFLT-24-2 VFMS and mGCIPLT-cVFMS relationships between the two groups (P > 0.05). In conclusion, OAG eyes with a CMvD have significantly stronger vasculature-function relationships than eyes without. Vessel density parameters may be useful biomarkers of disease progression in early-stage OAG patients with a CMvD.

A Prospective Longitudinal Study to Investigate Corneal Hysteresis as a Risk Factor of Central Visual Field Progression in Glaucoma

PURPOSE

To evaluate the role of corneal hysteresis (CH) as a risk factor of central visual field (VF) progression in a cohort of glaucoma suspect and glaucoma patients.

DESIGN

Prospective cohort study.

METHODS

Two hundred forty-eight eyes of 143 subjects who were followed for an average of 4.8 years with a minimum of 5 visits with 10-2 and 24-2 VF tests were included. Univariable and multivariable linear mixed-effects models were used to identify characteristics associated with the rate of change over time in 10-2 and 24-2 mean deviation (MD). Mixed-effects logistic regression was used to evaluate characteristics associated with an increased likelihood of event-based 10-2 VF progression based on the clustered pointwise linear regression criterion.

RESULTS

CH was significantly associated with 10-2 and 24-2 VF progression in the univariable trend-based analysis. In multivariable trend-based analyses, lower CH was associated with a faster rate of decline in 10-2 MD (0.07 dB/y per 1 mm Hg, P < .001) but not with 24-2 MD (P = .490). In multivariable event-based analysis, lower CH was associated with an increased likelihood of 10-2 VF progression (odds ratio = 1.35 per 1 mm Hg lower, P = .025). Similar results were found in eyes with early glaucomatous damage at the baseline (baseline: 24-2 MD ≥ -6 dB).

CONCLUSIONS

Lower CH was associated with a statistically significant, but relatively small, increased risk of central VF progression on the 10-2 test grid. Given the substantial influence of central VF impairment on the quality of life, clinicians should consider using CH to assess the risk of progression in patients with primary open-angle glaucoma including those with early disease.

The relationship between choroidal blood flow and glaucoma progression in a Japanese study population

PURPOSE

To determine whether choroidal blood flow (BF) is related to visual field (VF) defect severity and progression in eyes with open-angle glaucoma (OAG).

STUDY DESIGN

Retrospective and longitudinal.

METHODS

This study comprised 443 eyes of 285 OAG patients who underwent laser speckle flowgraphy (LSFG), optical coherence tomography, and visual-field (VF) testing at baseline. The patients were then observed for at least 2 years and at least 5 reliable VF tests were performed. In the LSFG images, we set regions of interest at the optic nerve head (ONH) and the parapapillary choroid to obtain ONH-tissue mean blur rate (MBR) and choroidal MBR, respectively. We used univariable and multivariable linear mixed-effects models to determine clinical factors associated with choroidal MBR at baseline. We also used a linear mixed-effects model to determine the contribution of ONH-tissue MBR and choroidal MBR to baseline mean deviation (MD) and to MD slope during follow-up, adjusting for potential confounding factors, including circumpapillary retinal nerve fiber layer thickness.

RESULTS

Choroidal MBR was associated with age, MD slope, and ONH-tissue MBR (β = -0.181, P = 0.001; β = 0.134, P = 0.002; β = 0.096, P = 0.049, respectively). ONH-tissue MBR was associated with both MD and MD slope (β = 0.146, P = 0.004; β = 0.152, P = 0.009, respectively), whereas choroidal MBR was associated only with MD slope (β = 0.147, P = 0.005).

CONCLUSION

LSFG-derived choroidal MBR might be a useful biomarker to predict VF defect progression in a Japanese population.

Rates of Choroidal Microvasculature Dropout and Retinal Nerve Fiber Layer Changes in Glaucoma

PURPOSE

To evaluate the association between rates of choroidal microvasculature dropout (MvD) change and rates of circumpapillary retinal nerve fiber layer (cpRNFL) loss in primary open-angle glaucoma (POAG) eyes.

DESIGN

Cohort study from clinical trial data.

METHODS

A total of 91 eyes of 68 POAG patients with and without localized MvD at baseline with at least 4 visits and 2 years of follow-up with optical coherence tomography angiography (OCT-A) and OCT scans were included. Area and angular circumference of MvD were evaluated on OCT-A en face and B-scan choroidal vessel density images during the follow-up period. Joint longitudinal mixed effects models were used to estimate the rates of change in MvD area or angular circumference and RNFL thickness. Univariable and multivariable regressions were completed to identify the factors contributing to cpRNFL thinning.

RESULTS

MvD was identified in 53 eyes (58.2%) at baseline. Seventeen eyes (18.6%) that did not show MvD at baseline developed it over the follow-up period. Over a mean follow-up of 4.0 years, the mean rates of change in MvD area and angular circumference (95% CI) were 0.05 (0.04, 0.06) mm² per year and 13.2° (10.7°, 15.8°) per year, respectively. In multivariable models, the rate of cpRNFL thinning was significantly associated with the rates of change in MvD area and angular circumference (P = .008 and P = .009, respectively).

CONCLUSIONS

Rates of MvD area and angular circumference change over time were associated with concurrent rates of cpRNFL loss in POAG eyes.

Multilayer Macula Vessel Density and Visual Field Progression in Glaucoma

PURPOSE

To evaluate the association of macular superficial vessel density (SVD) and projection-resolved deep vessel density (DVD) with past visual field (VF) progression in patients with primary open-angle glaucoma.

DESIGN

Retrospective cohort.

METHODS

In this longitudinal study, 208 eyes of 147 patients with glaucoma from the Diagnostics Innovations in Glaucoma Study were included. Eligible participants were required to have at least five 24-2 VF tests over a minimum follow-up period of 3 years before macular optical coherence tomography angiography imaging. VF progression was defined based on both event-based pointwise linear regression and trend-based methods. The association of macular SVD and DVD with the probability and rate of past VF progression was evaluated using a linear mixed effects model.

RESULTS

Fifty-two (25%) eyes had VF progression based on the pointwise linear regression based criterion at the end of a mean ± standard deviation follow-up duration of 6.9 ± 1.2 years. In the event-based multivariable analysis, a lower baseline SVD was associated with a higher likelihood of past VF progression (odds ratio per 1% lower. 1.28; 95% confidence interval, 1.02-1.59). Similarly, in the trend-based multivariable analysis, lower macular SVD was associated with a faster past rate of mean deviation decline (coefficient = -0.03 dB/year; 95% confidence interval, -0.04 to -0.01). Event-based and trend-based analyses found no significant associations for macular DVD with the likelihood/rate of past VF progression (P > .05).

CONCLUSIONS

Lower macular SVD, and not DVD, was associated with a higher probability of past VF progression. Macular optical coherence tomography angiography imaging shows promise for identifying eyes at risk of VF progression in patients with glaucoma.

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.

Attenuated Amplitude of Pattern Electroretinogram in Glaucoma Patients with Choroidal Parapapillary Microvasculature Dropout

This study aims to investigate whether parapapillary choroidal microvasculature dropout (MvD) is related to visual function measured by pattern electroretinogram (PERG) in glaucomatous eyes with β-zone parapapillary atrophy (PPA). A total of 79 patients with open angle glaucoma and preperimetric glaucoma with β-zone PPA was included in this cross-sectional study. Through the deep layer of the Swept-source optical coherence tomography angiography image, the angular width and the area of MvD were measured. Visual function was evaluated with a standard automated perimetry and PERG. N95 and P50 PERG amplitudes in eyes with MvD were noticeably decreased compared to those without MvD (p = 0.004 and p = 0.007, respectively), although the mean deviation was not significantly different (p = 0.107). The lower N95 amplitude was associated with the presence of MvD (β = −0.668, p = 0.017) and wider angular width of MvD (B = −7.612, p = 0.014). Old age (p = 0.001), average ganglion cell’s inner plexiform layer thickness (p = 0.003), and the presence of MvD (p = 0.020) were significantly related to low N95 amplitude. Association between the presence and extent of the MvD and PERG amplitudes suggests that the presence of MvD has relevance to the generalized dysfunction of retinal ganglion cells.

Optic Disc Microvasculature Dropout in Glaucoma Detected by Swept-Source Optical Coherence Tomography Angiography

PURPOSE

To assess the clinical utility of swept-source optical coherence tomography angiography (SS-OCTA) in detecting optic disc microvasculature dropout (MvD-D) in primary open-angle glaucoma (POAG) eyes.

DESIGN

Cross-sectional study.

METHODS

The study enrolled 197 eyes of 197 patients with POAG with acceptable-quality SS-OCTA (PLEX Elite 9000; Carl Zeiss Meditec) images. A whole-signal-mode 6.0- × 6.0-mm optic disc cube was obtained with projection artifact removal. Three groups were categorized: no MvD-D (group 1), MvD-D (group 2, complete loss of microvasculature within the optic disc), and indiscernible MvD-D (group 3, poor visualization of the anterior lamina cribrosa [LC]).

RESULTS

There were 82 (42.1%) and 81 (41.5%) eyes categorized as no MvD-D (group 1) and MvD-D (group 2), respectively. The remaining 32 eyes (16.4%), categorized as indiscernible MvD-D (group 3), had a significantly smaller anterior scleral canal opening (ASCO) area (P < .05). Group 2 had significantly worse visual field (VF) mean deviation (MD), thinner average retinal nerve fiber layer (RNFL), higher prevalence of focal LC defect, and parapapillary deep-layer microvasculature dropout (MvD-P) than the other 2 groups (P < .05). In the multivariable logistic regression analysis, higher prevalence of focal LC defect (odds ratio, 46.91; P < .001) and MvD-P (odds ratio, 48.94; P < .001) remained as factors associated with MvD-D.

CONCLUSIONS

The presence of MvD-D could be well determined by SS-OCTA in eyes with POAG. MvD-P and focal LC defects were strongly associated with MvD-D. This suggests that SS-OCTA can serve as a useful tool in detecting optic disc microvasculature damage.

Parapapillary deep-layer microvasculature dropout is only found near the retinal nerve fibre layer defect location in open-angle glaucoma

PURPOSE

We aimed to investigate the topographic correspondence between deep-layer microvasculature dropout (MvD) and retinal nerve fibre layer (RNFL) defects in eyes with open-angle glaucoma (OAG) using spectral-domain optical coherence tomography (SD-OCT) and optical coherence tomography angiography (OCT-A).

METHODS

Microvasculature dropout width and location were determined using OCT-A, RNFL thickness, RNFL defect width and location were revealed using SD-OCT. The association between MvD and RNFL widths and that between the location of the MvD and RNFL defects were investigated. In addition, patients with OAG were divided into two groups: the RNFL defect in one hemiretina (RNFLD-HR) group (n = 24 eyes) and the RNFL defects in both hemiretinas (RNFLD-BR) group (n = 25 eyes). The presence, width and location of MvDs were compared between the two groups.

RESULTS

Forty-nine eyes were included. In 24 RNFLD-HR eyes, all MvDs were found in the inferior area, corresponding with the location of the RNFL defect. Meanwhile, in 25 RNFLD-BR eyes, 18 MvDs (72%) were found in the inferior hemiretina, two (8%) were found in the superior hemiretina, and five (20%) were found in both hemiretinas. In RNFLD-BR eyes, the average RNFL thickness was thinner in a location with MvD than a location without MvD.

CONCLUSION

Considering that MvD is only observed at the location of the RNFL defect in RNFLD-HR eyes and is usually found in the location of more severe RNFL defects in RNFLD-BR eyes, MvD seems to be a sign that accompanies glaucomatous damage in OAG eyes.

Clinical characteristics of choroidal microvasculature dropout in normal-tension glaucoma versus nonarteritic anterior ischemic optic neuropathy: an optical coherence tomography angiography study

The present study investigated the characteristics of choroidal microvasculature dropout (CMvD) in eyes with nonarteritic anterior ischemic optic neuropathy (NAION) versus those in eyes with normal-tension glaucoma (NTG). This study included 27 NAION, 27 NTG, and 27 healthy control subjects. CMvD was observed in 15 eyes (55.6%) of the NAION group and 20 (74.1%) of the NTG group. The area and angular width of CMvD were significantly greater in eyes with NAION (0.278 ± 0.172 mm² and 86.5 ± 42.3°) than in those with NTG (0.138 ± 0.068 mm² and 35.1 ± 16.2°, p = 0.002 and p < 0.001, respectively). CMvD in eyes with NAION were distributed in 120–250° and most frequently located at the temporal region, while CMvD in eyes with NTG showed double peaks at 220–280° and 110–140° and most frequently located at the inferotemporal region. The factors associated with the discrimination of NAION from NTG were greater area of CMvD (OR, 1.181; 95% CI, 1.021–1.366; p = 0.025) and location closer to the temporal region of the CMvD (OR, 0.904; 95% CI, 0.838–0.975; p = 0.009). The clinical characteristics of CMvD differed between eyes with NAION and those with NTG. Optical coherence tomography angiography may provide an additional approach to differentiating glaucoma from NAION.

Referenced scans improve the repeatability of optical coherence tomography angiography measurements in normal and glaucoma eyes

AIM

To compare the repeatability of peripapillary perfusion density and flux index measurements on referenced and non-referenced optical microangiography (OMAG) scans in normal, glaucoma suspect and glaucoma eyes.

METHODS

In a cross-sectional study, 48 eyes (33 subjects) underwent three repeat, non-referenced peripapillary OMAG scans in the same session and 43 eyes (25 subjects) underwent three referenced peripapillary OMAG scans. In the referenced scan group, repeat scans (second and the third scan) were acquired exactly on the baseline (first) scan using the 'track to prior scan' option on the device. Repeatability estimates of the mean and four-sector (temporal, superior, nasal and inferior) OMAG measurements on the non-referenced and referenced scans were assessed using within-subject coefficient of repeatability (CR_w) and variation (CV_w).

RESULTS

CR_w (%) of peripapillary perfusion density measurements (range: 2.0-4.1) on non-referenced scans were significantly higher than that on referenced scans (range: 1.4-2.7). CV_w (%) on non-referenced and referenced scans ranged from 1.7 to 3.1 and from 1.2 to 2.1, respectively . CR_w of flux index on non-referenced and referenced scans ranged from 4.4 to 5.8 and from 3.6 to 4.8, respectively. CV_w on non-referenced and referenced scans ranged from 4.1 to 5.2 and from 3.3 to 4.5, respectively.

CONCLUSIONS

Repeatability estimates of OMAG measurements were better on referenced scans compared with non-referenced scans. Perfusion density measurements had lower variability than flux index. OCTA-measured perfusion density of referenced scans is preferable for monitoring vascular change in glaucoma.

Optical Coherence Tomography and Glaucoma

Early detection and monitoring are critical to the diagnosis and management of glaucoma, a progressive optic neuropathy that causes irreversible blindness. Optical coherence tomography (OCT) has become a commonly utilized imaging modality that aids in the detection and monitoring of structural glaucomatous damage. Since its inception in 1991, OCT has progressed through multiple iterations, from time-domain OCT, to spectral-domain OCT, to swept-source OCT, all of which have progressively improved the resolution and speed of scans. Even newer technological advancements and OCT applications, such as adaptive optics, visible-light OCT, and OCT-angiography, have enriched the use of OCT in the evaluation of glaucoma. This article reviews current commercial and state-of-the-art OCT technologies and analytic techniques in the context of their utility for glaucoma diagnosis and management, as well as promising future directions.

Optical Coherence Tomography Angiography and Visual Field Progression in Primary Angle Closure Glaucoma

PRECIS

Lower whole enface disc (coefficient: 0.02, P=0.03) and macular vessel densities (coefficient: 0.04, P=0.02) on optical coherence tomography angiography (OCTA) were significantly associated with faster rate of mean deviation (MD) decline.

PURPOSE

To evaluate the association between OCTA features and prior visual field (VF) progression in primary angle closure glaucoma (PACG).

METHODS

In a cross-sectional study, 46 eyes of 31 PACG patients with 5 reliable VF examinations performed over ≥3 years of follow-up underwent OCTA imaging. Effect of clinical (age, sex, number of antiglaucoma medications, mean, and SD of intraocular pressure during follow-up), optical coherence tomography (average retinal nerve fiber layer and ganglion cell complex thickness) and OCTA (whole enface vessel density of disc and macular scan, deep-layer microvascular dropout) parameters on the rate of MD change was evaluated using linear mixed models.

RESULTS

Average (±SD) MD of the baseline VF was -7.4±7.3 dB, and rate of MD change was -0.32±0.29 dB/y. Whole enface vessel density of disc and macular scans was 39.5%±8.1% and 38.7%±4.4%, respectively. Microvascular dropout was noted in 33.3% of the eyes. Multivariate mixed models showed that lower whole enface disc (coefficient: 0.02, P=0.03) and macular vessel densities (coefficient: 0.04, P=0.02) were significantly associated with faster rate of MD decline. Other factors significantly associated with faster progression in multivariate models were older age (coefficient: -0.02, P<0.05) and the presence of systemic hypertension (coefficient: -0.37, P=0.01) and diabetes (coefficient: -0.28, P=0.05).

CONCLUSIONS

Lower superficial vessel density measured using OCTA was significantly associated with faster VF progression in PACG. In these eyes, OCTA parameters can serve as biomarker suggestive of past VF progression.

Baseline Choroidal Microvasculature Dropout as a Predictor of Subsequent Visual Field Progression in Open-angle Glaucoma

PRECIS

Choroidal microvasculature dropout (CMvD) is an independent predictor for overall and central visual field (VF) progression in open-angle glaucoma (OAG) eyes.

PURPOSE

The purpose of this study was to investigate the impact of CMvD identified by optical coherence tomography angiography (OCT-A) at baseline on subsequent VF progression in eyes with OAG.

METHODS

This retrospective observational study included 80 OAG eyes with CMvD [CMvD(+)] and without CMvD [(CMvD(-)] at baseline [40 of each matched for both age (10 y and below) and baseline VF severity (≤1 dB)]. The patients were followed regularly at 6-month intervals. VF progression was defined according to the Early Manifest Glaucoma Trial criteria. Associations of overall VF progression with baseline clinical factors, including the presence of CMvD and other variables, were analyzed by logistic regression with a generalized estimating equation in the entire OAG cohort. Linear mixed models were used to determine the differences in visual field mean sensitivity (VFMS) between the CMvD(+) and CMvD(-) groups globally and regionally at each follow-up point.

RESULTS

During a mean follow-up of 35.91±2.51 months, a significant difference was evident in the VF progression rate between the CMvD(-) and CMvD(+) groups (22.5% vs. 70%, P<0.001). CMvD at baseline and a higher visit-to-visit intraocular pressure fluctuation were significant predictors of VF progression. The VFMS differed significantly between the 2 groups at the central and superior central VF regions after 2 years of follow-up.

CONCLUSION

The presence of CMvD at baseline is an independent predictor of subsequent VF progression. CMvD(+) eyes show a faster rate of VFMS loss at the central and superior central VF regions.

Choroidal microvasculature dropout is spatially associated with optic nerve head microvasculature loss in open-angle glaucoma

The presence of parapapillary choroidal microvasculature dropout (CMvD) may affect optic nerve head (ONH) perfusion in glaucoma patients, since parapapillary choroidal vessels provide vascular supply to the neighboring ONH. However, it remains to be determined whether the presence of parapapillary CMvD is associated with diminished perfusion in the nearby ONH. The present study investigated the spatial relationship between CMvD and ONH vessel density (ONH-VD) loss in open-angle glaucoma (OAG) eyes using optical coherence tomography angiography (OCT-A). This study included 48 OAG eyes with a single localized CMvD confined to the inferotemporal parapapillary sector and 48 OAG eyes without CMvD, matched for demographic and ocular characteristics. Global and regional ONH-VD values were compared between eyes with and without CMvD. The relationships between ONH-VD outcomes and clinical variables were assessed. ONH-VDs at the inferotemporal ONH sectors corresponding to the CMvD location were significantly lower in eyes with compared to those without CMvD. Multivariable linear regression analyses indicated that a lower inferotemporal ONH-VD was independently associated with CMvD presence and a greater CMvD angular extent (both P < 0.05). The localized presence of parapapillary CMvD in OAG eyes is significantly associated with ONH-VD loss in the neighboring ONH location, with a spatial correlation.

Juxtapapillary Deep-Layer Microvasculature Dropout and Retinal Nerve Fiber Layer Thinning in Glaucoma

PURPOSE

We sought to characterize juxtapapillary (JP) and non-JP microvasculature dropout in patients with primary open-angle glaucoma and to compare their rate of retinal nerve fiber layer (RNFL) thinning.

DESIGN

Retrospective cohort study.

METHODS

A total of 141 eyes with primary open-angle glaucoma with ≥4 serial optical coherence tomography (OCT) images after initial OCT angiography for ≥2 years were included. Based on OCT angiography imaging, the 3 groups were matched by age and visual field mean deviation: JP group (parapapillary deep-layer microvasculature dropout in contact with the optic disc boundary, n = 47), non-JP group (dropout not reaching the optic disc boundary, n = 47), and no-dropout group (lacking the dropout, n = 47). The RNFL thinning rate was compared among the 3 groups.

RESULTS

The rate of RNFL thinning tended to be fastest in the JP group followed by the non-JP group and no-dropout group in all areas except the temporal and nasal sectors. Post hoc analysis revealed that the JP group had significantly faster RNFL thinning than did the no-dropout group in the global area and the inferotemporal and inferonasal sectors (P < .05). When subgroup analysis was performed for subjects in which the main sector of dropout was the inferotemporal sector, the JP group had significantly faster RNFL thinning than the other 2 groups in the corresponding inferotemporal sector (P < .001).

CONCLUSION

Eyes with JP microvasculature dropout showed faster RNFL thinning than eyes without dropout. These findings suggest that deep-layer microvasculature dropout, especially in contact with the optic disc boundary, is associated with rapid glaucoma progression.

Superficial and Deep Macula Vessel Density in Healthy, Glaucoma Suspect, and Glaucoma Eyes

PRECIS

Macular superficial capillary plexus (SCP) vessel density is more informative than deep capillary plexus (DCP) vessel density for the detection of glaucoma.

PURPOSE

The purpose of this study was to characterize optical coherence tomography angiography macular SCP and projection-resolved DCP vessel densities and compare their diagnostic accuracies with ganglion cell complex (GCC) thickness in healthy, glaucoma suspect, and glaucoma eyes.

MATERIALS AND METHODS

Sixty-eight eyes of 44 healthy subjects, 26 eyes of 16 preperimetric glaucoma suspects, and 161 eyes of 124 glaucoma patients from the Diagnostics Innovations in Glaucoma Study with good quality high-density 6×6 mm2 macula optical coherence tomography angiography images were included. The diagnostic accuracy of SCP vessel density, projection-resolved DCP vessel density and GCC thickness were compared among groups.

RESULTS

Mean whole image vessel density (wiVD; % of area occupied by vessels containing flowing blood) in the SCP layer was highest in healthy eyes (49.7%), followed by glaucoma suspect eyes (46.0%), and glaucoma eyes (40.9%) (P<0.001). Mean wiVD in the DCP layer was similar in healthy (50.6%), glaucoma suspect (47.3%), and glaucoma eyes (45.7%) (P=0.925). Diagnostic accuracy of both GCC thickness and SCP wiVD was significantly higher than DCP wiVD for classifying healthy and glaucoma eyes [adjusted area under the receiver operating characteristic curve (95% confidence interval): GCC=0.86 (0.72, 0.94), SCP=0.80 (0.66, 0.91) and DCP=0.44 (0.30, 0.57)] (P<0.001).

CONCLUSIONS

SCP vessel densities have better diagnostic accuracy for detecting glaucoma than DCP vessel densities. Although the diagnostic accuracy of the macula SCP is relatively modest, it is more informative than the DCP.

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.

An Increased Choroidal Microvasculature Dropout Size is Associated With Progressive Visual Field Loss in Open-Angle Glaucoma

PURPOSE

To investigate whether the choroidal microvasculature dropout (CMvD) increases in size over time among open-angle glaucoma (OAG) eyes presenting with CMvD at baseline and evaluate the association between longitudinal CMvD size increases and subsequent visual field (VF) progression.

DESIGN

Retrospective cohort study.

METHODS

This study enrolled 101 eyes from 101 consecutive patients with OAG with a localized CMvD and glaucomatous VF defects at baseline and a minimum 2-year follow-up. The angular circumference (AC) of the CMvD was determined from choroidal layer images using optical coherence tomography angiography at the baseline and final follow-up. Demographic and ocular characteristics, including the rate of retinal nerve fiber layer thickness loss and amount of CMvD AC increase during follow-up, were compared between OAG eyes with and without VF progression. Cox proportional hazard analysis was performed to identify the clinical factors associated with VF progression. The relationships between CMvD angular enlargement during follow-up and clinical factors were assessed.

RESULTS

CMvD angular enlargement was found in 21.8% of patients while VF progression was observed in 26.7% of the OAG eyes with CMvD during a mean 2.52-year follow-up. OAG eyes with VF progression showed a significantly greater CMvD angular enlargement. A larger increase in the CMvD AC was an independent predictor of VF progression. CMvD AC changes were significantly correlated with the rates of VF deterioration.

CONCLUSIONS

VF progression is significantly associated with a greater longitudinal increase in the CMvD AC in OAG eyes with CMvD. CMvD AC changes have significant correlations with the rate of VF loss.

OCT Angiography for the Diagnosis of Glaucoma: A Report by the American Academy of Ophthalmology

PURPOSE

To review the current published literature on the use of OCT angiography (OCTA) to help detect changes associated with the diagnosis of primary open-angle glaucoma.

METHODS

Searches of the peer-reviewed literature were conducted in March 2018, June 2018, April 2019, December 2019, and June 2020 in the PubMed and Cochrane Library databases. Abstracts of 459 articles were examined to exclude reviews and non-English articles. After inclusion and exclusion criteria were applied, 75 articles were selected and the panel methodologist rated them for strength of evidence. Three articles were rated level I and 57 articles were rated level II. The 15 level III articles were excluded.

RESULTS

OCT angiography can detect decreased capillary vessel density within the peripapillary nerve fiber layer (level II) and macula (level I and II) in patients with suspected glaucoma, preperimetric glaucoma, and perimetric glaucoma. The degree of vessel density loss correlates significantly with glaucoma severity both overall and topographically (level II) as well as longitudinally (level I). For differentiating glaucomatous from healthy eyes, some studies found that peripapillary and macular vessel density measurements by OCTA show a diagnostic ability (area under the receiver operating characteristic curve) that is comparable with structural OCT retinal nerve fiber and ganglion cell thickness measurements, whereas other studies found that structural OCT measurements perform better. Choroidal or deep-layer microvasculature dropout as measured by OCTA is also associated with glaucoma damage (level I and II). Lower peripapillary and macular vessel density and choroidal microvasculature dropout are associated with faster rates of disease progression (level I and II).

CONCLUSIONS

Vessel density loss associated with glaucoma can be detected by OCTA. Peripapillary, macular, and choroidal vessel density parameters may complement visual field and structural OCT measurements in the diagnosis of glaucoma.

Parapapillary Intrachoroidal Cavitation in Glaucoma: Association with Choroidal Microvasculature Dropout

PURPOSE

To characterize the choroidal microvasculature in glaucomatous eyes with parapapillary intrachoroidal cavitation (PICC) using optical coherence tomography angiography (OCTA) and its association with parapapillary choroidal microvasculature dropout (MvD).

METHODS

This study included 47 glaucomatous eyes with PICC, as identified by color fundus photography and optical coherence tomography scanning of the optic nerve head area. Peripapillary choroidal microvasculature was evaluated on en-face OCTA images. Choroidal MvD was defined as a focal sectoral capillary dropout with no visible microvascular network.

RESULTS

PICC was visible as a well-demarcated area with homogeneously reduced vessel density in en-face OCTA images of the choroidal layer. MvD was detected in 42 eyes (89.4%). Although located in the juxtapapillary area adjacent to the PICC, MvD was confined to the area of parapapillary atrophy. MvD observed in OCTA en-face images was distinguished from the area of PICC by the absence of vascular signal. Of the 50 PICCs, 49 (98.0%) had hemifield visual field defects at the location corresponding to the hemispheric location of PICC.

CONCLUSIONS

PICC was found to have a characteristic microvascular feature in choroidal en-face OCTA images, and to be topographically associated with glaucomatous visual field defect. PICC was frequently accompanied by MvD and was located adjacent to the area of MvD, suggesting that PICC and MvD have similar pathogenesis.

OCT-angiography detects longitudinal microvascular changes in glaucoma: a systematic review

BACKGROUND/AIMS

Optical coherence tomography angiography (OCTA) allows the study of vessel density (VD). We intended to perform a systematic review of studies focusing on longitudinal changes in peripapillary and macular VD measurements in glaucoma.

METHODS

A search was performed across MEDLINE, Scopus, ISI Web of Science and Google Scholar, using the following query from inception until 20 September 2019: (("optical coherence tomography angiography"[tiab]) OR (optical coherence tomography angiography[MeSH]) OR ("OCTA"[tiab]) OR ("OCT-A"[tiab]) OR ("angio-OCT"[tiab]) OR ("OCT- angiography"[tiab]) OR ("OCT-angio"[tiab]) OR ("OCT-angiographie"[tiab])) AND (glaucom*[tiab] OR glaucoma[MeSH]). Prospective studies that quantitatively assessed the longitudinal changes in VD in glaucoma with at least 3 months of follow-up were included.

RESULTS

Ten out of 4516 studies were included. The rate of VD change in glaucoma varied from 0.036/year to 1.08/year and 1.3% to 3.2% per year, with significantly different rates between glaucoma and healthy controls. Five studies assessed VD change after glaucoma surgery, obtaining variable results, ranging from a temporary VD decrease to increase after 3 months. Meta-analysis was not possible due to a wide variation in methods, measurements and region of VD.

CONCLUSION

OCTA is a non-invasive technology, which shows promise in glaucoma. Measures should be taken to increase the quality and standardise the methodology of VD measures in OCTA longitudinal studies, for future meta-analyses.

Nocturnal blood pressure dip and parapapillary choroidal microvasculature dropout in normal-tension glaucoma

Choroidal microvasculature dropout (CMvD) implies compromised optic nerve head perfusion in glaucoma patients. However, there are conflicting findings whether office-hour systemic blood pressure (BP) is related to the presence of CMvD. The present study investigated which systemic BP parameters, derived from 24-h ambulatory BP monitoring (ABPM), are associated with CMvD as assessed by optical coherence tomography angiography (OCT-A) in normal-tension glaucoma (NTG). This study included 88 eyes of 88 NTG patients who underwent 24-h ABPM and OCT-A imaging. Various systemic BP parameters associated with the presence of CMvD were evaluated using logistic regression analyses. CMvD was detected in 38 NTG eyes (43.2%). NTG eyes with CMvD had nighttime diastolic BP (DBP) dip of greater magnitude and longer duration than eyes without CMvD. In multivariate logistic regression, worse VF mean deviation (MD) (odds ratio [OR] 0.786; P = 0.001), greater nighttime DBP dip “%” (OR 1.051; P = 0.034), and higher daytime peak IOP (OR 1.459; P = 0.013) were significantly associated with the presence of CMvD. Based on our findings that the eyes with CMvD are closely associated with having nighttime DBP dip, NTG patients with CMvD should be recommended to undergo 24-h ABPM.

Disc Hemorrhages Are Associated With the Presence and Progression of Glaucomatous Central Visual Field Defects

PRECIS

In this prospective cohort study, disc hemorrhages were associated with more severe central damage on 24-2 and 10-2 visual fields (VFs), and faster progression globally on 24-2 VFs and centrally on 10-2 VFs.

PURPOSE

To study the relationship between disc hemorrhage (DH) and the presence and progression of glaucomatous central VF damage.

METHODS

Cross-sectional and longitudinal analyses were performed on data from the African Descent and Glaucoma Evaluation Study (ADAGES) cohort. Two masked investigators reviewed disc photographs for the presence and location of DH. 24-2 central VF damage was based on the number of test locations within the central 10 degrees of the 24-2 field pattern deviation and their mean total deviation (MTD). 10-2 central VF damage was based on pattern deviation and MTD. Main outcome measures were the association between DH and presence of central VF damage and between DH and worsening of VF.

RESULTS

DH was detected in 21 of 335 eyes (6.2%). In the cross-sectional analysis, DH was significantly associated with more severe central damage on 24-2 [incidence rate ratio=1.47; 95% confidence interval (CI)=1.02-2.12; P=0.035] and 10-2 VFs (incidence rate ratio=1.81; 95% CI=1.26-2.60; P=0.001). In the longitudinal analysis, DH eyes progressed faster than non-DH eyes based on 24-2 global MTD rates (difference in slopes, β=-0.06; 95% CI=-0.11 to -0.01; P=0.009) and 10-2 MTD rates (β=-0.10; 95% CI=-0.14 to -0.06; P< 0.001), but not 24-2 central MTD rates (β=-0.02; 95% CI=-0.078 to 0.026; P=0.338).

CONCLUSION

DH was associated with the presence and progression of central VF defects. DH identification should prompt intensive central VF monitoring and surveillance with 10-2 fields to detect progression.