Choroidal Microvascular Dropout in Primary Open-angle Glaucoma Eyes With Disc Hemorrhage

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.

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.

Choroidal Microvasculature Dropout in Glaucoma

Glaucoma is a group of diseases characterized by distinctive visual field defect and optic nerve atrophy usually associated with elevated intraocular pressure (IOP). It is one of the most serious visual disorders and the leading cause of irreversible blindness worldwide. As a multifactorial disease, the pathogenesis of glaucoma is complicated and has been far from fully understood, where vascular factors are recognized to play an important role in its development and progression of glaucoma. Empirical researches have shown that parapapillary choroidal microvasculature dropout (CMvD) is closely associated with the impairment of optic nerve head (ONH) perfusion, probably accelerating the progression of glaucoma. Accordingly, it is necessary to explore the details regarding the relationship between CMvD and glaucoma progress, hoping to enhance the understanding of pathogenesis of glaucoma. In this review, we aimed to establish comprehensive understanding of the relationship between CMvD and glaucoma with generally going through relevant up-to-date literatures. Among the events that are closely associated with CMvD, we summarized the ones specifically involved in the term of glaucomatous pathological process, including thickness of retinal nerve fiber layer (RNFL) thickness, lamina cribrosa (LC) morphology, cricumpapillary vessel density (cpVD) and visual function such as visual field (VF) defect as well as the prognosis of glaucoma. Although researchers have made great advances, there are still many issues need to be addressed particularly concerning the pathogenic role of CMvD in glaucoma development and its clinical implications with respect to glaucoma prognosis.

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.

Association between Glaucoma Progression in Macular Ganglion Cell Complex and Disc Hemorrhage: Differences between Superior and Inferior Hemiretinas

Disc hemorrhage (DH) is often associated with glaucoma progression. A vertically asymmetrical pattern is typical of glaucoma progression, but it remains unclear whether the association between DH and glaucoma progression differs between the superior and inferior hemiretinas. We compared the thickness changes of the macular ganglion cell complex (GCC) in the hemiretinas of normal-tension glaucoma patients with or without DH, as well as between hemiretinas positive and negative for DH, during five years. Both the superior and inferior hemiretinas in the DH-positive group had a more negative GCC thickness slope in association with more DH counts compared to those in the DH-negative group. Conversely, only the inferior hemiretina exhibited a significant relationship between GCC thickness slope and DH counts when hemiretinas positive and negative for DH in the DH-positive group were compared. In the superior hemifield, the slope of the total deviation changes in the DH-positive hemifield of the DH-positive group was more negative compared to that of the DH-negative group. The association between DH and glaucoma progression in the macular GCC may be stronger in the inferior hemiretina, suggesting that more attention should be paid to DH in the inferior disc area as a sign of glaucoma progression.

Lamina Cribrosa Morphology in Normal Tension Glaucoma According to the Location of Visual Field Defects

PRCIS

The morphologic alterations in lamina cribrosa (LC) may be related to the location of visual field (VF) defects.

PURPOSE

The aim of this study was to investigate morphologic differences in the LC in normal tension glaucoma (NTG) according to the location of VF defects.

DESIGN

This study was a retrospective, cross-sectional study.

METHODS

Ninety-six eyes of 96 patients with NTG were included in this study. The patients were divided into 2 groups according to the location of VF defects [parafoveal scotoma (PFS) and peripheral nasal step (PNS)]. All patients underwent an optical coherence tomography of the optic disc and macula using swept-source optical coherence tomography (DRI-OCT Triton; Topcon, Tokyo, Japan). The parameters of the optic disc, macula, LC, and connective tissues were compared between the groups. The relationships between the LC parameters and other structures were analyzed.

RESULTS

The temporal peripapillary retinal nerve fiber layer, average macular ganglion cell-inner plexiform layer, and average macular ganglion cell complex were significantly thinner in the PFS than in the PNS group ( P <0.001, P <0.001, and P =0.012, respectively). The PFS group showed a more glaucomatous LC morphology with a smaller lamina cribrosa-global shape index (LC-GSI, P =0.047), more LC defects ( P =0.034), and thinner LC ( P =0.021) than the PNS group. LC-GSI was significantly correlated with LC thickness ( P =0.011) but not with LC depth ( P =0.149).

CONCLUSIONS

In patients with NTG, those with initial PFS showed a more glaucomatous LC morphology than those with initial PNS. The morphologic differences in LC may be related to the location of the VF defects.

Microvascular Alterations of Peripapillary Choriocapillaris in Young Adult High Myopia Detected by Optical Coherence Tomography Angiography

(1) Background: The microstructural alterations of the peripapillary choriocapillaris in high myopes remain elusive. Here, we used optical coherence tomography angiography (OCTA) to explore factors involved in these alterations. (2) Methods: This cross-sectional control study included 205 young adults' eyes (95 with high myopia and 110 with mild to moderate myopia). The choroidal vascular network was imaged using OCTA, and the images underwent manual adjustments to determine the peripapillary atrophy (PPA)-β zone and microvascular dropout (MvD). The area of MvD and the PPA-β zone, spherical equivalent (SE), and axial length (AL) were collected and compared across groups. (3) Results: The MvD was identified in 195 eyes (95.1%). Highly myopic eyes exhibited a significantly greater area for the PPA-β zone (1.221 ± 0.073 vs. 0.562 ± 0.383 mm², p = 0.001) and MvD (0.248 ± 0.191 vs. 0.089 ± 0.082 mm², p < 0.001) compared with mildly to moderately myopic eyes, and a lower average density in the choriocapillaris. Linear regression analysis showed that the MvD area correlated with age, SE, AL, and the PPA-β area (all p < 0.05). (4) Conclusions: This study found that MvDs represent choroidal microvascular alterations in young-adult high myopes, which were correlated with age, SE, AL, and the PPA-β zone. In this disorder, OCTA is important for characterizing the underlying pathophysiological adaptations.

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.

Predicting Visual Field Progression by Optical Coherence Tomography Angiography and Pattern Electroretinography in Glaucoma

PRCIS

Reduced P50-N95 amplitude on pattern electroretinography (PERG) and the presence of microvasculature dropout (MvD) on optical coherence tomography angiography (OCT-A) at baseline were significant factors associated with visual field (VF) progression in predominantly normal tension glaucoma (NTG) patients.

OBJECTIVE

We investigated the baseline demographics and ocular characteristics that predict future progression in glaucoma patients, including PERG and OCT-A parameters.

METHODS

One Hundred forty eyes with open angle glaucoma that were prospectively enrolled and followed up for at least 3 years, and underwent at least 5 serial VF tests were included. Baseline PERG was performed, and N35, P50, and N95 latencies and amplitudes were obtained. Superficial vessel density at the macula and complete loss of microvasculature within the deep retinal layer of the parapapillary region (MvD) were evaluated from baseline OCT-A images. Eyes with a glaucomatous VF defect in either both hemifields within 24 points of a central 10 degrees of fixation, and with no VF abnormality in the nasal periphery outside 10 degrees of fixation, were considered to have isolated central scotoma. During follow-up, detected disc hemorrhage (DH) was recorded. Parameters associated with VF progression were determined using linear regression analysis of the mean deviation (MD) values, in combination with an event-based analysis using the Glaucoma Progression Analysis (GPA) software from the Humphrey Field Analyzer. "Likely progression" using GPA was considered to have glaucoma progression.

RESULTS

Of the 140 eyes, 107 (76.4%) were NTG and 57 (40.7%) exhibited glaucoma progression as defined by Humphrey VF GPA. The MD slopes were -0.43±1.11 dB/y in the progressors and 0.59±1.27 dB/y in the nonprogressors ( P <0.001). Glaucoma patients with progression showed frequent MvD on OCT-A, isolated central scotoma, frequent DH, and reduced baseline P50-N95 amplitude compared with patients without progression. Age at diagnosis ( P =0.038) and baseline P50-N95 amplitude ( P =0.019) showed significant associations with the MD slope. The presence of MvD on OCT-A ( P <0.001) and baseline P50-N95 amplitude ( P =0.037) were significantly associated with VF progression on GPA.

CONCLUSIONS

The presence of MvD and retinal ganglion cell dysfunction by PERG at baseline, DH or central scotoma were significant factors associated with VF progression in predominantly NTG patients. These patients should be monitored more closely.

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.

Optic Disc Hemorrhage Is Not Associated with Global Choroidal Vessel Loss, but Is Associated with Localized Choroidal Vessel Loss in Glaucoma

Purpose: To investigate the relationship between optic disc hemorrhage (ODH) and the geographic pattern (regional vs. global) of parapapillary choroidal vessel density (pCVD) loss within the β-parapapillary atrophy (β-PPA) in open-angle glaucoma (OAG) Methods: This retrospective cross-sectional study included 100 OAG eyes with visual field (VF) defects confined to a single hemifield (50 with and 50 without ODH, matched for age (≤10 years) and VF severity (≤1 decibel) at the same hemifield), as well as 50 healthy eyes. The pCVD was measured using optical coherence tomography angiography (OCTA). The relationships between pCVD and clinical factors were assessed globally and regionally. Logistic regression analyses were performed to determine the clinical factors associated with the presence of ODH. Results: The pCVD values within ODH-affected hemiretinae of ODH+ eyes were significantly lower than those in the matched hemiretinae of ODH− eyes (p = 0.001). The presence of ODH was significantly correlated with a lower pCVD within ODH-dominant inferior hemiretinae (p < 0.05). Lower pCVD values at ODH-affected hemiretinae was significantly associated with the presence of ODH (p < 0.05). Conclusions: OAG eyes with ODH demonstrate a greater severity of regional pCVD loss at the hemiretinae spatially corresponding to the ODH location compared to OAG eyes without ODH.

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.

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.

Progression of Parapapillary Choroidal Microvascular Dropout After Disc Hemorrhage in Glaucoma Patients: 2 Case Reports

PURPOSE

Microvasculature dropout (MvD) is a novel finding seen in optical coherence tomography angiography (OCTA), which is characterized by a localized dehiscence of the choriocapillaris in the parapapillary atrophy area. Disc hemorrhage (DH) is an important factor often associated with the development and especially progression of glaucoma. Here, we present 2 cases of MvD progression with DH.

METHODS AND RESULTS

Case 1: A 62-year-old female patient with normal tension glaucoma in both her eyes had recurrent DH at the inferior area of her right eye. A new DH was observed in the inferotemporal area of the right eye with MvD progression on OCTA in the same direction three months from the baseline.Case 2: A 57-year-old female patient with bilateral steroid-induced secondary glaucoma also had recurrent DH in her right eye. Four months from the baseline, DH occurred in the superotemporal and inferotemporal area of the right eye, and MvD was detected on OCTA in the superotemporal corresponding direction. After 19 months from the baseline, OCTA was repeated. The DH had resolved, but the superotemporal MvD persisted.

CONCLUSIONS

The 2 cases presented here are the first to report on the relationship between MvD progression and DH. MvD as visualized in OCTA imaging looks to be of clinical importance, and hopefully future studies will reveal the actual connection between MvD, DH, and glaucoma progression.

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.

Comparison of Peripapillary Choroidal Microvasculature Dropout in Primary Open-angle, Primary Angle-closure, and Pseudoexfoliation Glaucoma

PRECIS

The prevalence of choroidal microvascular dropout (CMvD) was significantly higher in primary open-angle glaucoma (POAG) than primary angle-closure glaucoma (PACG) or pseudoexfoliation glaucoma (PXG) in the early stage. However, in the advanced stage, it did not differ among the 3 groups.

PURPOSE

The purpose of this study was to compare the prevalence of peripapillary CMvD in POAG, PACG, and PXG.

MATERIALS AND METHODS

The presence of peripapillary CMvD was identified using optical coherence tomography angiography (AngioVue/RTVue-XR) imaging of the choroid in 186 eyes from 186 subjects [age and visual field (VF) mean deviation (MD) matched; 62 POAG, 62 PACG, and 62 PXG eyes]. Prevalence of CMvD was compared among glaucoma types in early and moderate to advanced disease, as divided by VF MD (-6 dB). The association between glaucoma type and presence of CMvD was evaluated using logistic regression analysis.

RESULTS

Prevalence of CMvD was significantly different between glaucoma types in early-stage disease (PACG 7.5%, PXG 25%, and POAG 46.3%, P<0.001), but it did not differ between glaucoma types in eyes with moderate to advanced disease (PACG 59.1%, PXG 68.2%, and POAG 81%; P=0.331). After adjusting for age, sex, the β-zone peripapillary atrophy/disc ratio, and glaucoma severity (VF MD), the CMvD odds ratio was 7.50 times greater in POAG than in PACG (P=0.001).

CONCLUSIONS

CMvD was more common in POAG relative to both PACG and PXG, especially in early-stage disease. This finding suggested a role for ischemic injury in the pathogenesis of POAG.

Longitudinal changes in superficial microvasculature in glaucomatous retinal nerve fiber layer defects after disc hemorrhage

Glaucoma is a multifactorial optic neuropathy, possibly involving vascular dysfunction, leading to the death of retinal ganglion cells and their axons. Disc hemorrhage (DH) is known to be closely associated with the widening of retinal nerve fiber layer defect (NFLD); however, it has not been well elucidated how DH affects retinal microvasculature. We aimed to investigate the association between DH history and longitudinal changes in superficial retinal microvasculature in NFLD. We enrolled 15 glaucoma patients with DH history (32 glaucomatous NFLD locations, with or without DH history). NFLD-angle, superficial retinal vessel density (VD), and decreased superficial retinal microvasculature (deMv)-angle were assessed using optical coherence tomography angiography for at least three times over time. The mean follow-up period and OCT/OCTA scan interval were 21.3 ± 5.4 months (range, 12–28) and 6.8 ± 0.4 months (range, 2–18), respectively. Linear mixed-effects models showed that the presence of DH history was significantly associated with an additional NFLD-angle widening of 2.19 degree/year (P = 0.030), VD decrease of 1.88%/year (P = 0.015), and deMv-angle widening of 3.78 degree/year (P < 0.001). These changes were significantly correlated with each other (P < 0.001). Thus, the widening of NFLD was closely associated with deMv, and DH was associated with a subsequent decrease in superficial retinal microvasculature in NFLD.

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.

Optical Coherence Tomography Angiography in Glaucoma

Optical coherence tomography angiography (OCTA) is a relatively new, noninvasive, dye-free imaging modality that provides a qualitative and quantitative assessment of the vasculature in the retina and optic nerve head. OCTA also enables visualization of the choriocapillaris, but only in areas of parapapillary atrophy. With OCTA, the movement of red blood cells is used as a contrast to delineate blood vessels from static tissues. The features seen with OCTA in eyes with glaucoma are reduction in the superficial vessel density in the peripapillary and macular areas, and complete loss of choriocapillaris in localized regions of parapapillary atrophy (called deep-layer microvascular dropout). These OCTA changes correlate well topographically with the functional changes seen on visual field examination and structural changes seen on optical coherence tomography (OCT) (ie, parapapillary retinal nerve fiber layer changes and inner retinal layer thickness changes at macula). The OCTA measurements also have acceptable test-retest variability and well differentiate glaucomatous from normal eyes. OCTA measurements can be affected by various subject-related, eye-related, and disease-related factors. Vessel density reduction on OCTA reaches a base level (floor) at a more advanced disease stage than the structural changes on OCT and therefore has the potential to monitor progression in eyes with advanced glaucomatous damage. OCTA also adds information about glaucoma patients at risk of faster progression. OCTA, therefore, complements visual field and OCT examinations to diagnose glaucoma, detect progression, and assess risk of progression.

Optic disc hemorrhage in nonglaucomatous eyes: A cross-sectional study with average 8-year follow-up

Purpose

To characterize changes in the retinal nerve fiber layer (RNFL) and peripapillary vessel density (VD) at the site of disc hemorrhage (DH) in nonglaucomatous eyes.

Materials and methods

This retrospective cross-sectional study included nonglaucomatous eyes diagnosed with unilateral DH. The change of DH was recorded using disc photography. Both anatomical data and functional visual field (VF) data were collected using optical coherence tomography angiography and Humphrey VF examination.

Results

Sixteen patients were included with average follow-up duration of 95 months. Almost half of DH episodes was initially presented at the inferotemporal area of the optic disc. Pigment formation at the previous DH site after resolution was noted in 12.5% of eyes. Sectoral radial peripapillary VD at the DH site was significantly lower in DH eyes than in the control group; however, the sectoral RNFL thickness at the DH site was not significantly decreased. Progression of the VF defect corresponding to the DH site was found in 81.3% of eyes despite regular use of antiglaucoma agents. The mean change in the VF mean deviation was –0.64 dB/year in DH eyes.

Conclusion

During long follow-up periods, decreased peripapillary VD at the DH site and progression of the VF defect corresponding to the DH site were detected in nonglaucomatous eyes. Retinal pigmentation with an RNFL defect is a clue for DH, although RNFL showed no significant change. Antiglaucoma treatment may not prevent the deterioration of visual function.

Progressive retinal nerve fibre layer thinning and choroidal microvasculature dropout at the location of disc haemorrhage in glaucoma

BACKGROUND/AIMS

To investigate whether parapapillary choroidal microvasculature dropout (MvD) is associated with progressive retinal nerve fibre layer (RNFL) thinning in eyes with primary open-angle glaucoma (POAG) and disc haemorrhage (DH).

METHODS

Parapapillary microvasculature was evaluated by swept-source optical coherence tomography (OCT) angiography (OCTA) in 50 eyes with POAG and DH, 1 year before, at the time of and 1 year after the detection of DH. MvD was defined as an area in the parapapillary deep layer of focal sectoral dropout with no visible microvascular network. Progressive changes in OCT RNFL thickness were compared in groups of eyes with and without MvD.

RESULTS

Cumulative prevalence of MvD was 76.0% (38 eyes) at 1 year after detection of DH. All MvDs were detected in the same sectoral locations as DH. In eyes with MvD, global RNFL thickness and sectoral RNFL thickness at the location of DH were significantly reduced, both from 1 year before to the time of DH detection (both p<0.001) and from DH detection to 1 year later (both p<0.001). In eyes without MvD, however, the reductions in global (p=0.011) and sectoral (p=0.007) RNFL thickness were significant only from DH detection to 1 year later.

CONCLUSION

In eyes with POAG, RNFL thinning was spatially consistent and progressive at the location of MvD accompanied by subsequent DH and continued to progress after the occurrence of DH. When DH was not accompanied by MvD, progressive RNFL thinning was more likely to occur after the detection of DH.

Rapid Central Visual Field Progression Rate in Eyes with Open-Angle Glaucoma and Choroidal Microvasculature Dropout

Central visual field (CVF) loss has been linked to poorer vision-related quality of life in eyes with open-angle glaucoma (OAG) and can occur even in early-stage OAG eyes. The present study investigated whether the detection of choroidal microvasculature dropout (CMvD) during follow-up, which may be a sign of perfusion deficiency in the optic nerve head, is associated with rapid rate of CVF loss in early-stage OAG eyes. This study included 44 Korean OAG eyes with CMvD, identified by optical coherence tomography angiography, and 44 Korean OAG eyes without CMvD matched for age and severity of visual field loss at initial presentation. The rates of mean threshold changes in global and CVF were compared in eyes with and without CMvD using a linear mixed model. Clinical variables associated with rapid rate of CVF progression were also identified using a linear mixed model. The CVF progression rate was significantly higher in eyes with CMvD than in those without CMvD (-0.584 dB/year vs. -0.190 dB/year; P < 0.001) and detection of CMvD during follow-up was an independent predictor of rapid CVF progression rate. The presence of CMvD may aid in identification of high-risk patients who may show faster CVF progression and require more aggressive treatment.