Optical Coherence Tomography Angiography in Glaucoma Care

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.

Diagnostic ability of the combination of retinal microvasculature evaluation and static automated perimetry for early primary open-angle glaucoma

PURPOSE

To investigate the diagnostic ability of retinal superficial vasculature evaluation by optic coherence tomography angiography (OCTA) combined with visual field (VF) testing for early primary open-angle glaucoma (POAG).

PATIENTS AND METHODS

In this cross-sectional study, 84 participants were included, including 11 in the ocular hypertension (OHT) group, 11 in the preperimetric POAG (pre-POAG) group, 29 in the early POAG group and 33 in the control group. All participants underwent 6 × 6 mm2 scans of macula and optic nerved head by optic coherence tomography (OCT) and OCTA, along with white-on-white and blue-on-yellow VF testing by static automated perimetry. The ability of diagnosing early glaucoma by either various examinations separately or combination of examinations in both terms of function and structure was studied using the receiver operating characteristic (ROC) curve and the area under the curve (AUC).

RESULTS

The superficial retinal vessel densities (VD) in peri-nasal, para-temporal, peri-temporal and peri-inferior regions around the macula, as well as vessel area densities (VAD) in all peripapillary regions, were significantly different among the four groups, with lower VD or VAD in the early POAG patients compared to the normal individuals. The diagnostic ability of peripapillary superficial retinal VAD alone or VF testing alone was limited for early POAG only. However, the combination of these two was more effective in distinguishing normal individuals from OHT subjects or pre-POAG patients without VF defects, with better performance than the combination of peripapillary retinal nerve fiber layer (RNFL) thickness and VF indicators.

CONCLUSIONS

Peripapillary retinal vessel densities were generally lower in early POAG patients compared to normal individuals. The combination of peripapillary superficial retinal VAD by OCTA with white-on-white VF testing improved the ability to distinguish POAG patients at early stage without function impairment, which may help in providing reference and guidance for the following-up and treatment of suspected POAG patients.

Progress and challenges of in vivo flow cytometry and its applications in circulating cells of eyes

Circulating inflammatory cells in eyes have emerged as early indicators of numerous major diseases, yet the monitoring of these cells remains an underdeveloped field. In vivo flow cytometry (IVFC), a noninvasive technique, offers the promise of real-time, dynamic quantification of circulating cells. However, IVFC has not seen extensive applications in the detection of circulating cells in eyes, possibly due to the eye's unique physiological structure and fundus imaging limitations. This study reviews the current research progress in retinal flow cytometry and other fundus examination techniques, such as adaptive optics, ultra-widefield retinal imaging, multispectral imaging, and optical coherence tomography, to propose novel ideas for circulating cell monitoring.

Optical Coherence Tomography Angiography (OCTA) Differences in Vessel Perfusion Density and Flux Index of the Optic Nerve and Peri-Papillary Area in Healthy, Glaucoma Suspect and Glaucomatous Eyes

Purpose

To assess the ability of vascular perfusion parameters determined by optical coherence tomography angiography (OCTA) to detect and monitor glaucoma.

Methods

This prospective study included healthy, glaucoma suspect and glaucomatous eyes. All eyes underwent comprehensive glaucoma examination, including visual field tests and ocular imaging scans by OCTA. Parameters measured included retinal nerve fiber layer (RNFL) thickness, ganglion cell analysis (GCA), vascular perfusion density (VPD) and flux index (FI) of the optic nerve and peri-papillary area. Ocular parameters in healthy, glaucoma suspect, and glaucomatous eyes were compared by generalized estimating equations (GEE) with adjustments for age, with their relationships analyzed by Pearson's correlation coefficient. Rates of change per year were compared in glaucomatous eyes with and without glaucoma progression.

Results

This study enrolled 238 eyes, including 56 healthy, 79 glaucoma suspect, and 103 glaucomatous eyes. After adjustments for age, the average VPD (45.40 ± 0.19% vs 45.05 ± 0.22% vs 42.89 ± 0.32%, p < 0.001) and FI (0.4210 ± 0.0055 vs 0.4105 ± 0.0039 vs 0.3801 ± 0.0048, p < 0.001) in these three groups differed significantly. Average VPD in the glaucoma group was inversely associated with the severity of glaucoma, being 43.99 ± 0.32%, 42.63 ± 0.43% and 39.27 ± 0.48% in eyes with early, moderate and severe glaucoma, respectively (p < 0.001). Average VPD, as well as VPD in the superior and inferior quadrants correlated well with both OCT determined RNFL and visual field parameters. The decreases per year in both superior (-0.012 vs -0.001, p = 0.002) and inferior (-0.008 vs -0.003, p = 0.007) FI were significantly greater in glaucomatous eyes with than without glaucoma progression.

Conclusion

Both VPD and FI as measured by OCTA are promising ocular parameters that can distinguish between normal and glaucomatous eyes. VPD is sensitive in comparing eyes at different glaucoma stages, whereas FI can detect rates of glaucoma progression.

Trial Registration

Thai Clinical Trial Registry, TCTR20181031002.

Longitudinal Changes of Parafoveal Vessel Density in Diabetic Patients without Clinical Retinopathy Using Optical Coherence Tomography Angiography

PURPOSE

The purpose of this study was to identify the rate of parafoveal vessel density (VD) changes associated with the progression from non-diabetic retinopathy (NDR) to early stages of DR over a year.

METHODS

This longitudinal cohort study enrolled diabetic patients from the Guangzhou community in China. The patients with NDR at baseline were included and underwent comprehensive examinations at baseline and after 1 year. A commercial OCTA device (Triton Plus, Topcon, Tokyo, Japan) was employed to quantify the parafoveal VD in the superficial and deep capillary plexuses. The rates of change in parafoveal VD over time in the incident DR and NDR groups were compared after a year.

RESULTS

A total of 448 NDR patients were included in the study. Among them, 382 (83.2%) were stable and 66 (14.4%) developed incident DR during the 1-year follow-up. The average parafoveal VD in the superficial capillary plexus (SCP) reduced significantly more quickly in the incident DR group than in the NDR group (-1.95 ± 0.45%/year vs. -0.45 ± 0.19/year, p = 0.002). The VD reduction rate for the deep capillary plexus (DCP) was not significantly different for the groups (p = 0.156).

CONCLUSIONS

The incident DR group experienced a significantly faster reduction in parafoveal VD in the SCP compared with the stable group. Our findings further provide supporting evidence that parafoveal VD in the SCP may be used as an early indicator of the pre-clinical stages of DR.

Disagreement of Radial Peripapillary Capillary Density Among Four Optical Coherence Tomography Angiography Devices

Purpose

This prospective study evaluated the agreement among four optical coherence tomography angiography (OCTA) devices in the assessment of radial peripapillary capillary (RPC) density.

Methods

The study included 48 eyes of 48 subjects (14 healthy, 19 glaucomatous, and 15 non-glaucomatous optic neuropathy). Each participant was scanned using four OCTA devices in a random sequence: RTVue XR Avanti (RTVue), DRI OCT Triton (Triton), Revo NX 130 (Revo), and PLEX Elite 9000 (PlexE). All 6 × 6-mm grayscale OCTA images from each device were analyzed for RPC density using a customized algorithm. Agreement between each pair of devices was assessed using intraclass correlation coefficients (ICCs) and Bland-Altman plots.

Results

There was a poor correlation between devices in all comparisons (RTVue-Triton, ICC = 0.34; RTVue-Revo, ICC = 0.31; RTVue-PlexE, ICC = 0.28; Triton-Revo, ICC = 0.31; Triton-PlexE, ICC = 0.17; Revo-PlexE, ICC = 0.34). Significant proportional biases (P < 0.05) and wide limits of agreement with apparent constant biases were identified in all comparisons. The mean difference was greatest for the RTVue-Revo pair (-49.3%; 95% confidence interval [CI], -52.9 to -45.8) and smallest for the Triton-PlexE pair (-7.7%; 95% CI, -10.1 to -5.3).

Conclusions

The RPC densities obtained from each device had poor inter-device agreement and significant biases and cannot be used interchangeably.

Translational Relevance

RPC density obtained from different OCTA devices is not interchangeable; thus, the progression of optic neuropathy should be monitored using the same OCTA device.

Comparison of microvascular parameters and diagnostic ability of optical coherence tomography angiography between eyes with primary angle closure glaucoma and primary open angle glaucoma

BACKGROUND

To investigate and compare the peripapillary and macular microvascular parameters between eyes with primary angle closure glaucoma (PACG) and primary open-angle glaucoma (POAG) using optical coherence tomography angiography (OCTA).

METHODS

Seventy-nine eyes of 43 patients with primary angle closure glaucoma (PACG), 78 eyes of 43 patients with primary open-angle glaucoma (POAG), 64 eyes of 35 patients with primary angle closure (PAC), and 73 eyes of 40 control subjects underwent imaging with OCTA. Perfusion density (PD) and vessel density (VD) for the macular area, and PD and flux index (FI) for the peripapillary area were calculated automatically. The area under receiver operator characteristic curves (AUC) were constructed to distinguish PACG and POAG eyes from healthy control eyes.

RESULTS

The peripapillary FI in all quadrants and PD and VD of the macular outer circle in superior and inferior quadrants were significantly lower in PACG and POAG eyes than in control eyes. The peripapillary FI in the inferior quadrant was significantly lower in the POAG group than in the PACG group (0.348 ± 0.06 vs. 0.369 ± 0.06, p = 0.04). The remaining OCTA parameters in the peripapillary and macular area did not show a significant difference between the POAG and PACG groups. Eyes with PAC presented significantly lower PD and VD than healthy control eyes at the superior and inferior quadrant of the macular outer circle, while retinal nerve fiber layer and ganglion cell inner complex thickness were not significantly different from than control eyes. The best diagnostic parameter was peripapillary FI in both PACG (AUC: 0.922) and POAG (AUC: 0.938) eyes.

CONCLUSIONS

We found significantly lower peripapillary FI in the inferior quadrant in POAG eyes compared to the PACG eyes, which may indicate the different underlying pathogenesis between POAG and PACG. The PAC eyes had lower macular PD and VD than normal eyes. This suggests that retinal vascular impairment may develop earlier than structural damage in PAC eyes.

Spatial positional relationship between macular superficial vessel density and ganglion cell-inner plexiform layer thickness in primary angle closure glaucoma

PURPOSE

To evaluate the spatial relationship between macular superficial vessel density (SVD) and macular ganglion cell-inner plexiform layer (GCIPL) thickness in primary angle closure glaucoma (PACG), and to investigate diagnostic abilities of macular SVD and foveal avascular zone (FAZ) parameters.

METHODS

This was a cross-sectional study on 38 PACG patients (38 eyes) and 25 healthy subjects (25 eyes). Macular region was imaged using a 1050-nm-wavelength swept-source optical coherence tomography (OCT) angiography (OCTA) system (DRI OCT Triton, TOPCON). Vessel density of the macular region was quantified by ImageJ software. The peripapillary retinal nerve fiber layer (pRNFL) thicknesses and macular GCIPL thickness were obtained by swept-source OCT. Pearson correlation analysis was used to evaluate the spatial positional relationship between macular SVD and macular GCIPL thickness. At the same time, the correlation between macular SVD and pRNFL thickness was evaluated. Areas under the receiver operating characteristics curves (AUCs) of OCT, OCTA and FAZ measurement metrics were calculated to assess the diagnostic ability for glaucoma.

RESULTS

Macular GCIPL thickness had a moderate correlation with the macular SVD in the inferonasal sector (r = 0.426, P = 0.008). In addition, there was a strong correlation between inferonasal sector of macular vessel density and 5,6,7,8 clock-hour regions of the pRNFL thicknesses (all r > 0.5). Inferoinferior sector of macular SVD and 6,7 clock-hour regions of pRNFL thicknesses also had strong correlation (all r > 0.5). The AUCs of macular SVD ranged between 0.61 (superonasal sector) and 0.76 (inferoinferior sector). The FAZ circularity index showed the highest diagnostic power (AUC = 0.94;95% CI, 0.85-0.99), followed by superotemporal sector of macular GCIPL thicknesses (0.93;95% CI,0.83-0.98).

CONCLUSIONS

Sector of macular SVD not only had a spatial positional correlation with corresponding macular GCIPL thickness, but also with clock-hour regional pRNFL thicknesses in PACG eyes. FAZ circulation index might be a useful diagnostic parameter.

Optical Coherence Tomography Angiography Characteristics and Predictors of Visual Outcomes in Patients With Acute and Chronic Nonarteritic Anterior Ischemic Optic Neuropathy

BACKGROUND

To investigate the correlation between optical coherence tomography angiography (OCTA) characteristics and visual outcomes in patients with acute and chronic nonarteritic anterior ischemic optic neuropathy (NAION).

METHODS

We retrospectively reviewed clinical data and OCTA images of 26 eyes of 26 patients who had been diagnosed with unilateral NAION. OCTA images were acquired from 17 eyes at the acute stage and from 21 eyes at the chronic stage of NAION. We analyzed the peripapillary vessel density (VD) and macular VD in various layers of the retina and choroid for all images. Possible correlations between the OCTA parameters and visual outcomes were investigated.

RESULTS

Among the OCTA parameters for the acute stage of NAION, the temporal peripapillary VD was found to be positively correlated with final visual acuity and visual field with statistical significance (P = 0.039 and 0.009, respectively). In the chronic stage of NAION, both peripapillary and superficial macular VDs were positively correlated with visual outcomes. The nasal perifoveal VD in the superficial capillary plexus (SCP) also had a significant correlation with final visual acuity for both acute and chronic stages (the Spearman correlation coefficient = 0.565 and 0.685, respectively).

CONCLUSIONS

In patients with NAION, significant correlations were found between OCTA parameters and visual outcomes. The temporal peripapillary VD measured during the acute stage was a significant predictor of final visual outcomes. The decreased nasal perifoveal VD in the SCP was strongly associated with poor visual prognosis.

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.

Peripapillary vessel density measurement of quadrant and clock-hour sectors in primary angle closure glaucoma using optical coherence tomography angiography

BACKGROUND

The purpose of this study was to investigate diagnostic ability of peripapillary vessel density of primary angle closure glaucoma (PACG) eyes in quadrant and clock-hour sectors by optical coherence tomography angiography (OCTA).

METHODS

This was a cross-sectional study on forty-one PACG patients (41eyes) and twenty-seven healthy subjects (27 eyes). All subjects underwent OCTA (DRI OCT Triton; Topcon Corporation, Tokyo, Japan) and peripapillary retinal nerve fiber layer (RNFL) thickness imaging with swept-source optical coherence tomography (OCT). The peripapillary vessel density of quadrant and clock-hour sectors was quantified by imageJ software. The diagnostic capability of OCTA and OCT parameters was evaluated by the areas under the receiver operating characteristics curves (AUCs). Pearson correlation analysis or Spearman correlation test was used to evaluate the correlation between vessel density parameters and related factors.

RESULTS

Compared with the control group, the peripapillary vessel density of glaucomatous group was lower to different degrees in the four quadrants and each clock-hour sectors, and vessel density reduced most at 7 o'clock. The difference between the diagnostic ability of peripapillary vessel density and peripapillary RNFL thickness was not statistically significant, except 4 o'clock and inferior quadrant. The inferior quadrant peripapillary vessel density had the best diagnostic value (AUC0.969), followed by the 7 o'clock vessel density (AUC0.964), average vessel density (AUC0.939) and the 7 o'clock RNFL thickness (AUC0.919). The average peripapillary vessel density was correlated with average RNFL and visual field (VF) mean deviation (P < 0.001).

CONCLUSIONS

In PACG, the diagnostic ability of the peripapillary vessel density is equivalent to the peripapillary RNFL thickness. Understanding spatial characteristics of the peripapillary vessel density in PACG may be helpful for clinical diagnosis and monitoring the progress of diseases.

The occurrence of optic disc haemorrhage in primary open-angle glaucoma eyes with lower normal pressure and its relating factors

PURPOSE

To report the occurrence probability of disc haemorrhage (DH) and risk factors for it in otherwise healthy Japanese normal-tension glaucoma (NTG) patients who had lower normal intraocular pressure (IOP) and were followed without treatment for 5 years.

METHODS

A prospective observational study. Normal-tension glaucoma (NTG) patients with IOP consistently ≤15 mmHg without treatment were enrolled. The presence or absence of DH was checked semi-annually on the fundus photographs by three independent observers, while patients were followed without treatment. Cox proportional hazards model taking inter-eye correlation into consideration was adopted to identify risk factors for DH occurrence. The main outcomes were DH occurrence probability during 5-year period and its risk factors.

RESULTS

One hundred seventeen eyes of 90 patients with mean age of 54.1 years, mean deviation value of -3.6 decibels and mean IOP during follow-up of 12.4 mmHg were included. Disc haemorrhage (DH) was observed at least once in 34 eyes and more than twice in 15 eyes during the follow-up. The DH occurrence probability at 5 years was 31% (95% confidence interval: 21-40%), and lower myopic refraction (HR = 1.18; p = 0.018), higher IOP during follow-up (HR = 1.35; p = 0.047) and presence of DH at baseline (HR = 4.19; p = 0.002) were its risk factors.

CONCLUSION

Disc haemorrhage (DH) occurrence probability of Japanese healthy NTG patients with mean IOP of 12.4 mmHg and no systemic and/or topical treatment was 31% at 5 years. Lower myopic refraction, higher IOP and its existence at baseline were its risk factors.

Optical Coherence Tomography for Ophthalmology Imaging

Optical coherence tomography (OCT) is a depth-resolved imaging modality, which is able to achieve micrometer-scale resolution within biological tissue noninvasively. In the past 30 years, researchers all around the world had made several essential efforts on techniques relevant to OCT. OCT has become a routine process for eye diseases with different types. In this chapter, the three important stages in the development of OCT are briefly illustrated, including the time domain OCT (TD-OCT), the frequency domain OCT (FD-OCT) and the optical coherence tomography angiography (OCTA). Each of the technique has made great progress for use on living human eye imaging in clinical applications. TD-OCT was first proposed and commercialized, which is able to achieve acceptable 2D depth-resolved cross-sectional images of human retina in vivo. FD-OCT was the upgraded OCT technique compared with TD-OCT. By capturing the coherent signal within the Fourier space, the FD-OCT could improve the image sensitivity compared with TD-OCT, and achieve dozens of kilo hertz imaging speed. OCTA is the newest developments of OCT technique, which is able to visualize the micro vasculature networks of human retina in vivo. With OCTA technique, the newest ophthalmologic OCT system is able to achieve detailed diagnosis for both micro-structure and vasculature abnormalities for clinical applications. The further development of OCT technique on imaging speed, contrast, resolution, field of view, and so on will make OCT to be a more powerful tool for clinical usages.

Comparison of vessel density in macular and peripapillary regions between primary open-angle glaucoma and pseudoexfoliation glaucoma using OCTA

PURPOSE

The aim of our study was to compare macular and peripapillary vessel density using optical coherence tomography angiography (OCTA) between eyes with primary open-angle glaucoma (POAG) and pseudoexfoliation glaucoma (PXG).

METHODS

Thirty-six POAG and 34 PXG eyes with similar visual field defect (no statistically significant difference between average mean deviation and pattern standard deviation scores) were included. Macular superficial vessel density (msVD) in the superficial macular layer and foveal avascular zone (FAZ) parameters were assessed with (6 × 6 mm) and peripapillary vessel density (ppVD) in the radial peripapillary capillary (RPC) with (4.5 × 4.5 mm) OCTA scans. Area under the receiver operating curve was used for assessing diagnostic capability.

RESULTS

In PXG group, all msVD parameters had lesser values, and especially in parafoveal region, statistically significant decrease was shown (p = 0.008) in all subdivisions except nasal (p = 0.053). FAZ area was more larger in PXG [0.32(0.25-0.36)] than POAG [0.28(0.22-0.39)],(p = 0.944). FAZ density - 300 μm had statistically significant decrease in PXG (47.22 ± 6.92) according to POAG groups (50.63 ± 7.25) (p = 0.048). Most of RPC VD parameters had decreasing values in PXG group (p > 0.05). VDs and corresponding thicknesses had significant remarkable positive correlation in both macular and peripapillary regions. Significant remarkable negative correlations were observed between fovea VD and FAZ area, FAZ perimeter and between fovea thickness and FAZ area, FAZ perimeter.

CONCLUSION

PXG eyes were found to have lesser values in terms of VD in the macular area, especially in the parafoveal and FD-300 regions, compared to POAG eyes which had similar functional and structural glaucomatous damage. Patients whose etiology was PXG and who seemed to have the same functional damage as those with POAG were actually found to have greater macular vascular damage. In addition, it was observed that macular vascular parameters correlated with peripapillary vascular parameters.

Association Between Parapapillary Choroidal Vessel Density Measured With Optical Coherence Tomography Angiography and Future Visual Field Progression in Patients With Glaucoma

Importance

Investigating the vascular risk factors of glaucoma progression is important to individualize treatment; however, few studies have investigated these factors because the available methods have proven insufficient to evaluate the vascular features of patients with glaucoma. Recently, the advent of optical coherence tomography angiography (OCT-A) allowed both qualitative and quantitative microvascular data to be obtained, to in turn evaluate the perfusion status of different retinal layers.

Objective

To determine whether baseline parapapillary choroidal vessel density (VD) as measured by OCT-A was associated with future glaucoma progression.

Design, Setting, and Participants

A prospective, observational, comparative study was conducted at Seoul St Mary's Hospital of The Catholic University of Korea from March 1, 2016, to December 31, 2018, for 108 glaucomatous eyes in which the retinal nerve fiber layer thickness and mean deviation were measured by at least 5 serial OCT and visual field (VF) examinations. The participants underwent OCT-A at baseline. Vessel density was measured using the en face image of the choroidal map of OCT-A within the β-zone parapapillary atrophy region.

Main Outcomes and Measures

Parapapillary choroidal VD, retinal nerve fiber layer thinning rate, mean deviation rate, and progression of glaucoma as measured by OCT and VF.

Results

Among 108 patients (74 women and 34 men; mean [SD] age, 59.2 [13.1] years), 38 (35.2%) showed progression of glaucoma as measured by OCT and 34 (31.5%) showed progression of glaucoma as measured by VF at the last follow-up. The mean (SD) follow-up duration was 2.6 [2.3] years. The presence of disc hemorrhage (odds ratio, 5.57; 95% CI, 3.18-8.29; P = .001), baseline mean deviation (odds ratio, 0.83; 95% CI, 0.71-0.97; P = .02), and parapapillary choroidal VD (odds ratio, 1.18; 95% CI, 1.09-1.28; P = .01) were associated with progression of glaucoma as measured by VF, but not with progression of glaucoma as measured by OCT. Baseline parapapillary choroidal VD (β, 1.08; 95% CI, 1.02-1.13; P < .001) was associated with progression of glaucoma as measured by VF using Cox proportional hazards regression analysis.

Conclusions and Relevance

These data suggest that lower parapapillary choroidal VD within the β-zone parapapillary atrophy at baseline among individuals with glaucoma could play some role in the risk of progression of glaucoma as measured by VF. The findings suggest that patients with glaucoma with lower parapapillary choroidal VD within the β-zone parapapillary atrophy at baseline warrant careful monitoring for progression of glaucoma as measured by VF.

Quantitative Analysis of Microvasculature in Macular and Peripapillary Regions in Early Primary Open-Angle Glaucoma

Purpose: To evaluate macular and radial peripapillary capillary vessel densities (RPC VD) across normal, pre-perimetric (PPG), and early perimetric primary open-angle glaucoma (EG) using optical coherence tomography angiography (OCTA).Materials and Methods: Forty-four PPG eyes, 42 EG eyes, and 41 normal eyes were consecutively enrolled. All subjects underwent visual field, OCT, and OCTA examinations. Macular vessel densities were measured in the superficial layer. RPC VD was measured within a 750-μm-wide elliptical annulus extending outward from disc boundary. Diagnostic ability was evaluated with area under the receiver operating curve.Results: Parafoveal vessel densities (ParaVDs) in the PPG group were comparable to the normal group (p > .05), except for temporal quadrant (p = .044), while perifoveal vessel densities (PeriVD) were lower in the PPG group (p < .05). ParaVD and PeriVD were lower in the EG group compared with the normal group (p < .001). Superior-temporal and inferior-temporal retinal nerve fiber layers (RNFLs) were significantly decreased in the EG group compared with the PPG group (p < .05), while only inferior-temporal RPC VD was lower in the EG group (p < .05). RPC VD was comparable to RNFL and ganglion cell complex (GCC) in the diagnosis of PPG (p > .05). Macular whole image vessel density and PeriVD were comparable to RPC VD, RNFL, and GCC in diagnosing EG (p > .05).Conclusions: In early primary open-angle glaucoma, significant microvascular damage was present in both macular and peripapillary areas. The damage of macular microvasculature was more prominent in the peripheral area. Vessel density parameters showed promising diagnostic ability in early glaucoma.Abbreviations: POAG = primary open-angle glaucoma; RGC = retinal ganglion cell; OCTA = optical coherence tomography angiography; RNFL = retinal nerve fiber layer; PPG = pre-perimetric primary open-angle glaucoma; EG = early perimetric primary open-angle glaucoma; IOP = intraocular pressure; PSD = pattern standard deviation; MD = mean deviation; GCC = ganglion cell complex; SBP = systolic blood pressure; DBP = diastolic blood pressure; MAP = mean arterial pressure; MOPP = mean ocular perfusion pressure; wiVD = whole image vessel density; ParaVD = parafoveal vessel density; PeriVD = perifoveal vessel density; RPC VD = radial peripapillary capillary vessel density; AUC = area under the receiver operating curve.

Impact of resistance training sets performed until muscular failure with different loads on intraocular pressure and ocular perfusion pressure

PURPOSE

The aim of this article is to investigate the acute effects of bench press sets leading to muscular failure with different loads on intraocular pressure and ocular perfusion pressure.

STUDY DESIGN

A randomized experimental study.

METHODS

Seventeen physically active young men performed four resistance training sets of bench press to muscular failure against different relative loads (65% one-repetition maximum vs 75% one-repetition maximum vs 85% one-repetition maximum vs 95% one-repetition maximum). Intraocular pressure was measured before and immediately after the execution of each of the four sets, and ocular perfusion pressure was also assessed before and after physical effort.

RESULTS

We found that intraocular pressure increased after reaching muscular failure (p < 0.001, ƞ²= 0.52), being also dependent on the interaction load × point of measure (p < 0.001, ƞ²= 0.33). Our data demonstrated that higher intraocular pressure increases were found when participants performed the bench press exercise against heavier loads, showing statistical significance for the 75% one-repetition maximum (p = 0.020, d = -0.63, mean change = 0.9 mmHg), 85% one-repetition maximum (p = 0.035, d = -0.56, mean change = 1.4 mmHg), and 95% one-repetition maximum (p < 0.001, d = -1.36, mean change = 2.9 mmHg) relative loads. For its part, ocular perfusion pressure showed a reduction after exercise (p = 0.009, ƞ²= 0.35), being these changes independent on the load used.

CONCLUSION

Bench press exercise leading to muscular failure provokes an acute intraocular pressure rise, with greater changes when heavier loads are used. Ocular perfusion pressure exhibited an acute reduction after exercise; however, its clinical relevance seems to be insignificant (lower to 4%). We argue that the use of heavy loads, when training to muscular failure, should be discouraged in order to avoid acute intraocular pressure fluctuations. Future studies should corroborate the generalizability of these findings in glaucoma patients.

A Review of OCT Angiography in Glaucoma

There is growing evidence that vascular dysfunction plays a role in the pathogenesis of glaucoma. The details of this relationship have remained elusive partially due to limitations in our ability to assess blood flow in the optic nerve. Optical coherence tomography angiography (OCTA) has emerged as a promising new technology well positioned to become the first clinically suitable test of optic nerve perfusion. OCTA uses the motion of red blood cells as an intrinsic contrast agent to create reproducible images of microvascular networks rapidly and non-invasively. A significant body of research regarding the use of OCTA in glaucoma has emerged in recent years. This review aims to provide an overview of the basic principles underlying OCTA technology, summarize the current literature regarding the application of OCTA in the management of glaucoma, and address the role of OCTA in explicating the vascular pathogenesis of glaucoma.

Future clinical applicability of optical coherence tomography angiography

Optical coherence tomography angiography (OCT-A) is an emerging technology that allows for the non-invasive imaging of the ocular microvasculature. Despite the wealth of observations and numerous research studies illustrating the potential clinical uses of OCT-A, this technique is currently rarely used in routine clinical settings. In this review, technical and clinical aspects of OCT-A imaging are discussed, and the future clinical potential of OCT-A is considered. An understanding of the basic principles and limitations of OCT-A technology will better inform clinicians of its future potential in the diagnosis and management of ocular diseases.