Measurement Floors and Dynamic Ranges of OCT and OCT Angiography in Glaucoma.

PURPOSE: To determine if OCT angiography (OCTA)-derived vessel density measurements can extend the available dynamic range for detecting glaucoma compared with spectral-domain (SD) OCT-derived thickness measurements. DESIGN: Observational, cross-sectional study. PARTICIPANTS: A total of 509 eyes from 38 healthy participants, 63 glaucoma suspects, and 193 glaucoma patients enrolled in the Diagnostic Innovations in Glaucoma Study. METHODS: Relative vessel density and tissue thickness measurement floors of perifoveal vessel density (pfVD), circumpapillary capillary density (cpCD), circumpapillary retinal nerve fiber (cpRNFL) thickness, ganglion cell complex (GCC) thickness, and visual field (VF) mean deviation (MD) were investigated and compared with a previously reported linear change point model (CPM) and locally weighted scatterplot smoothing curves. MAIN OUTCOME MEASURES: Estimated vessel density and tissue thickness measurement floors and corresponding dynamic ranges. RESULTS: Visual field MD ranged from -30.1 to 2.8 decibels (dB). No measurement floor was found for pfVD, which continued to decrease constantly until very advanced disease. A true floor (i.e., slope of approximately 0 after observed CPM change point) was detected for cpRNFL thickness only. The post-CPM estimated floors were 49.5±2.6 µm for cpRNFL thickness, 70.7±1.0 µm for GCC thickness, and 31.2±1.1% for cpCD. Perifoveal vessel density reached the post-CPM estimated floor later in the disease (VF MD, -25.8±3.8 dB) than cpCD (VF MD, -19.3±2.4 dB), cpRNFL thickness (VF MD, -17.5±3.3 dB), and GCC thickness (VF MD, -13.9±1.8 dB; P < 0.001). The number of available measurement steps from normal values to the CPM estimated floor was greatest for cpRNFL thickness (8.9), followed by GCC thickness (7.4), cpCD (4.5), and pfVD (3.8). CONCLUSIONS: In late-stage glaucoma, particularly when VF MD is worse than -14 dB, OCTA-measured pfVD is a promising tool for monitoring progression because it does not have a detectable measurement floor. However, the number of steps within the dynamic range of a parameter also needs to be considered. Although thickness parameters reached the floor earlier than OCTA-measured pfVD, there are more such steps with thickness than OCTA parameters.

Peripapillary and Macular Vessel Density in Patients with Primary Open-Angle Glaucoma and Unilateral Visual Field Loss.

PURPOSE: To characterize OCT angiography (OCT-A) vessel density of patients with primary open-angle glaucoma (POAG) with unilateral visual field (VF) loss. DESIGN: Cross-sectional study. PARTICIPANTS: A total of 33 patients with POAG with a VF defect in 1 eye (mean VF mean deviation [MD], -3.9±3.1 decibels [dB]) and normal VF in the other eye (mean VF MD, -0.2±0.9 dB) and 33 healthy eyes. METHODS: All subjects underwent OCT-A imaging, spectral-domain (SD)-OCT imaging, and VF testing. OCT-A retinal vascular measurements were summarized as whole image vessel density (wiVD), circumpapillary vessel density (cpVD), and parafoveal vessel density (pfVD). Inter-eye differences in vascular measures, as well as SD OCT retinal nerve fiber layer (RNFL), macular ganglion cell complex (mGCC) thickness, and rim area measurements in glaucoma and healthy eyes were compared. Areas under the receiver operating characteristic curves (AUROCs) were used to evaluate diagnostic accuracy for differentiating between unaffected eyes of patients with POAG and healthy eyes. MAIN OUTCOME MEASURES: Difference in OCT-A vessel density and SD OCT structural parameters between unaffected eyes of patients with POAG with the fellow affected eyes and healthy controls. RESULTS: Mean wiVD in unaffected eyes of patients with POAG (52.0%) was higher than in their fellow affected eyes (48.8%) but lower than in healthy eyes (55.9%; P < 0.001). Mean circumpapillary RNFL (cpRNFL) thickness, mGCC thickness, and rim area measurement in unaffected eyes of patients with POAG (87.5 µm, 87.7 µm, and 1.0 mm2) were also higher than those measurements in their fellow eyes (76.5 µm, 79.5 µm, and 0.8 mm2; P < 0.001) and lower than in healthy eyes (98.0 µm, 94.5 µm, and 1.4 mm2; P < 0.001). The AUROCs for differentiating unaffected eyes of patients with POAG from healthy eyes were highest for wiVD (0.84), followed by mGCC (0.78), cpRNFL (0.77), and pfVD (0.69). CONCLUSIONS: OCT-A measures detect changes in retinal microvasculature before VF damage is detectable in patients with POAG, and these changes may reflect damage to tissues relevant to the pathophysiology of glaucoma. Longitudinal studies are needed to determine whether OCT-A measures can improve the detection or prediction of the onset and progression of glaucoma.

Macular and Optic Nerve Head Vessel Density and Progressive Retinal Nerve Fiber Layer Loss in Glaucoma.

PURPOSE: To investigate prospectively the relationship between macular and peripapillary vessel density and progressive retinal nerve fiber layer (RNFL) loss in patients with mild to moderate primary open-angle glaucoma. DESIGN: Prospective, observational study. PARTICIPANTS: One hundred thirty-two eyes of 83 patients with glaucoma followed up for at least 2 years (average: 27.3±3.36 months). METHODS: Measurements of macular whole image vessel density (m-wiVD) and optic nerve head whole image vessel density (onh-wiVD) were acquired at baseline using OCT angiography. RNFL, minimum rim width (MRW), and ganglion cell plus inner plexiform layer (GCIPL) thickness were obtained semiannually using spectral-domain OCT. Random-effects models were used to investigate the relationship between baseline vessel density parameters and rates of RNFL loss after adjusting for the following confounding factors: baseline visual field mean deviation, MRW, GCIPL thickness, central corneal thickness (CCT), and mean intraocular pressure during follow-up and disc hemorrhage, with or without including baseline RNFL. MAIN OUTCOME MEASURES: Effects of m-wiVD and onh-wiVD on rates of RNFL loss over time. RESULTS: Average baseline RNFL thickness was 79.5±14.8 µm, which declined with a mean slope of -1.07 µm/year (95% confidence interval, -1.28 to -0.85). In the univariate model, including only a predictive factor and time and their interaction, each 1% lower m-wiVD and onh-wiVD was associated with a 0.11-µm/year (P < 0.001) and 0.06-µm/year (P = 0.031) faster rate of RNFL decline, respectively. A similar relationship between low m-wiVD and onh-wiVD and faster rates of RNFL loss was found using different multivariate models. The association between vessel density measurements and rate of RNFL loss was weak (r2 = 0.125 and r2 = 0.033 for m-wiVD and onh-wiVD, respectively). Average CCT also was a predictor for faster RNFL decline in both the univariate (0.11 µm/year; P < 0.001) and multivariate models. CONCLUSIONS: Lower baseline macular and optic nerve head (ONH) vessel density are associated with a faster rate of RNFL progression in mild to moderate glaucoma. Assessment of ONH and macular vessel density may add significant information to the evaluation of the risk of glaucoma progression and prediction of rates of disease worsening.

Rates of Local Retinal Nerve Fiber Layer Thinning before and after Disc Hemorrhage in Glaucoma.

PURPOSE: To investigate longitudinal temporal and spatial associations between disc hemorrhage (DH) and rates of local retinal nerve fiber layer (RNFL) thinning before and after DHs. DESIGN: Longitudinal, observational cohort study. PARTICIPANTS: Forty eyes of 37 participants (23 with glaucoma and 17 with suspect glaucoma at baseline) with DH episodes during follow-up from the Diagnostic Innovations in Glaucoma Study and the African Descent and Glaucoma Evaluation Study. METHODS: All subjects underwent optic disc photography annually and spectral-domain optical coherence tomography (OCT) RNFL thickness measurements every 6 months. The rates of RNFL thinning were calculated using multivariate linear mixed-effects models before and after DH. MAIN OUTCOME MEASURES: Rates of global and local RNFL thinning. RESULTS: Thirty-six eyes of 33 participants with inferior or superior DHs were analyzed. The rates of RNFL thinning were significantly faster in DH quadrants than in non-DH quadrants after DH (-2.25 and -0.69 µm/year; P < 0.001). In the 18 eyes with intensified treatment after DH, the mean rate of RNFL thinning significantly slowed after treatment compared with before treatment in the non-DH quadrants (-2.89 and -0.31 µm/year; P < 0.001), but not in the DH quadrants (-2.64 and -2.12 µm/year; P = 0.19). In 18 eyes with unchanged treatment, the rate of RNFL thinning in the DH quadrant was faster after DH than before DH (P = 0.008). Moreover, compared with eyes without a treatment change, intensification of glaucoma treatment after DH significantly reduced the global, non-DH quadrants, and DH quadrant rates of RNFL thinning after DH compared with before DH (global, P = 0.004; non-DH quadrant, P < 0.001; DH quadrant, P = 0.005). In the multiple linear regression analysis, treatment intensification (ß, 1.007; P = 0.005), visual field mean deviation (ß, 0.066; P = 0.049), and difference in intraocular pressure before and after DH (ß, -0.176; P = 0.034) were associated significantly with the difference of global RNFL slope values before and after DH. CONCLUSIONS: Although the rate of RNFL thinning worsened in a DH quadrant after DH, glaucoma treatment intensification may have a beneficial effect in reducing this rate of thinning.

Peripapillary and Macular Vessel Density in Patients with Glaucoma and Single-Hemifield Visual Field Defect.

PURPOSE: To compare hemifield differences in the vessel density of the peripapillary and macula in open-angle glaucoma eyes with visual field (VF) defect confined to one hemifield using optical coherence tomography angiography (OCT-A). DESIGN: Cross-sectional study. PARTICIPANTS: A total of 58 eyes of 58 patients with glaucoma with VF loss confined to a single hemifield and 28 healthy eyes. METHODS: Retinal vasculature information was summarized as circumpapillary vessel density (cpVD) and perifoveal vessel density (pfVD). Circumpapillary retinal nerve fiber layer (cpRNFL) and macular ganglion cell complex (mGCC) thickness were calculated using spectral domain optical coherence tomography (SD OCT). Paired and unpaired t tests were used to evaluate differences between the perimetrically affected and intact hemiretinae and healthy hemiretinae. Linear regression analyses were performed to evaluate the associations between VF measures with vascular and structural measurements. MAIN OUTCOME MEASURES: Total and hemispheric cpVD, pfVD, cpRNFL, mGCC, and mean sensitivity (MS). RESULTS: Mean cpVD and pfVD in the intact hemiretinae of glaucoma eyes (59.0% and 51.1%, respectively) were higher than in the affected hemiretinae (54.7% and 48.3%, respectively; P < 0.001) but lower than in healthy eyes (62.4% and 53.8%, respectively; P < 0.001). Similar results were noted with cpRNFL and mGCC thickness measurements (P < 0.05 for both). The strongest associations between MS in the affected hemifields were found for cpVD (r = 0.707), followed by pfVD (r = 0.615), cpRNFL (r = 0.496), and mGCC (r = 0.482) in the corresponding hemiretinae (P < 0.001 for all). Moreover, the correlations in the intact hemifields between MS with cpVD and pfVD were higher (r = 0.450 and 0.403) than the correlations between MS and cpRNFL and mGCC thickness measurements (r = 0.340 and 0.290; P values <0.05 for all). CONCLUSIONS: Reduced peripapillary and macular vessel density was detectable in the perimetrically intact hemiretinae of glaucoma eyes with a single-hemifield defect. Vessel density attenuation in both affected and intact hemiretinae was associated with the extent of VF damage in the corresponding hemifields. Optical coherence tomography angiography potentially shows promise for identifying glaucomatous damage before focal VF defects are detectable.

Deep Retinal Layer Microvasculature Dropout Detected by the Optical Coherence Tomography Angiography in Glaucoma.

PURPOSE: To investigate factors associated with dropout of the parapapillary deep retinal layer microvasculature assessed by optical coherence tomography angiography (OCTA) in glaucomatous eyes. DESIGN: Cross-sectional study. PARTICIPANTS: Seventy-one eyes from 71 primary open-angle glaucoma (POAG) patients with ß-zone parapapillary atrophy (ßPPA) enrolled in the Diagnostic Innovations in Glaucoma Study. METHODS: Parapapillary deep-layer microvasculature dropout was defined as a complete loss of the microvasculature located within the deep retinal layer of the ßPPA from OCTA-derived optic nerve head vessel density maps by standardized qualitative assessment. Circumpapillary vessel density (cpVD) within the retinal nerve fiber layer (RNFL) also was calculated using OCTA. Choroidal thickness and presence of focal lamina cribrosa (LC) defects were determined using swept-source optical coherence tomography. MAIN OUTCOME MEASURES: Presence of parapapillary deep-layer microvasculature dropout. Parameters including age, systolic and diastolic blood pressure, axial length, intraocular pressure, disc hemorrhage, cpVD, visual field (VF) mean deviation (MD), focal LC defects ßPPA area, and choroidal thickness were analyzed. RESULTS: Parapapillary deep-layer microvasculature dropout was detected in 37 POAG eyes (52.1%). Eyes with microvasculature dropout had a higher prevalence of LC defects (70.3% vs. 32.4%), lower cpVD (52.7% vs. 58.8%), worse VF MD (-9.06 dB vs. -3.83 dB), thinner total choroidal thickness (126.5 µm vs. 169.1 µm), longer axial length (24.7 mm vs. 24.0 mm), larger ßPPA (1.2 mm2 vs. 0.76 mm2), and lower diastolic blood pressure (74.7 mmHg vs. 81.7 mmHg) than those without dropout (P < 0.05, respectively). In the multivariate logistic regression analysis, higher prevalence of focal LC defects (odds ratio [OR], 6.27; P = 0.012), reduced cpVD (OR, 1.27; P = 0.002), worse VF MD (OR, 1.27; P = 0.001), thinner choroidal thickness (OR, 1.02; P = 0.014), and lower diastolic blood pressure (OR, 1.16; P = 0.003) were associated significantly with the dropout. CONCLUSIONS: Systemic and ocular factors including focal LC defects more advanced glaucoma, reduced RNFL vessel density, thinner choroidal thickness, and lower diastolic blood pressure were factors associated with the parapapillary deep-layer microvasculature dropout in glaucomatous eyes. Longitudinal studies are required to elucidate the temporal relationship between parapapillary deep-layer microvasculature dropout and systemic and ocular factors.

Relationship between Optical Coherence Tomography Angiography Vessel Density and Severity of Visual Field Loss in Glaucoma.

PURPOSE: To evaluate the association between vessel density measurements using optical coherence tomography angiography (OCT-A) and severity of visual field loss in primary open-angle glaucoma. DESIGN: Observational, cross-sectional study. PARTICIPANTS: A total of 153 eyes from 31 healthy participants, 48 glaucoma suspects, and 74 glaucoma patients enrolled in the Diagnostic Innovations in Glaucoma Study. METHODS: All eyes underwent imaging using OCT-A (Angiovue; Optovue, Fremont, CA), spectral-domain OCT (Avanti; Optovue), and standard automated perimetry (SAP). Retinal vasculature information was summarized as vessel density, the percentage of area occupied by flowing blood vessels in the selected region. Two measurements from the retinal nerve fiber layer (RNFL) were used: circumpapillary vessel density (cpVD) (750-µm-wide elliptical annulus around the optic disc) and whole-image vessel density (wiVD) (entire 4.5×4.5-mm scan field). MAIN OUTCOME MEASURES: Associations between the severity of visual field loss, reported as SAP mean deviation (MD), and OCT-A vessel density. RESULTS: Compared with glaucoma eyes, normal eyes demonstrated a denser microvascular network within the RNFL. Vessel density was higher in normal eyes followed by glaucoma suspects, mild glaucoma, and moderate to severe glaucoma eyes for wiVD (55.5%, 51.3%, 48.3%, and 41.7%, respectively) and for cpVD (62.8%, 61.0%, 57.5%, 49.6%, respectively) (P < 0.001 for both). The association between SAP MD with cpVD and wiVD was stronger (R2 = 0.54 and R2 = 0.51, respectively) than the association between SAP MD with RNFL (R2 = 0.36) and rim area (R2 = 0.19) (P < 0.05 for all). Multivariate regression analysis showed that each 1% decrease in wiVD was associated with 0.66 decibel (dB) loss in MD and each 1% decrease in cpVD was associated with 0.64 dB loss in MD. In addition, the association between vessel density and severity of visual field damage was found to be significant even after controlling for the effect of structural loss. CONCLUSIONS: Decreased vessel density was significantly associated with the severity of visual field damage independent of the structural loss. Optical coherence tomography angiography is a promising technology in glaucoma management, potentially enhancing the understanding of the role of vasculature in the pathophysiology of the disease.

Optical Coherence Tomography Angiography Vessel Density in Glaucomatous Eyes with Focal Lamina Cribrosa Defects.

PURPOSE: To investigate whether vessel density assessed by optical coherence tomography angiography (OCT-A) is reduced in glaucomatous eyes with focal lamina cribrosa (LC) defects. DESIGN: Cross-sectional, case-control study. PARTICIPANTS: A total of 82 patients with primary open-angle glaucoma (POAG) from the Diagnostic Innovations in Glaucoma Study (DIGS) with and without focal LC defects (41 eyes of 41 patients in each group) matched by severity of visual field (VF) damage. METHODS: Optical coherence tomography (OCT) angiography-derived circumpapillary vessel density (cpVD) was calculated as the percentage area occupied by vessels in the measured region extracted from the retinal nerve fiber layer (RNFL) in a 750-µm-wide elliptical annulus around the disc. Focal LC defects were detected using swept-source OCT images. MAIN OUTCOME MEASURES: Comparison of global and sectoral (eight 45-degree sectors) cpVDs and circumpapillary RNFL (cpRNFL) thicknesses in eyes with and without LC defects. RESULTS: Age, global, and sectoral cpRNFL thicknesses, VF mean deviation (MD) and pattern standard deviation, presence of optic disc hemorrhage, and mean ocular perfusion pressure did not differ between patients with and without LC defects (P > 0.05 for all comparisons). Mean cpVDs of eyes with LC defects were significantly lower than in eyes without a defect globally (52.9%±5.6% vs. 56.8%±7.7%; P = 0.013) and in the inferotemporal (IT) (49.5%±10.3% vs. 56.8%±12.2%; P = 0.004), superotemporal (ST) (54.3%±8.8% vs. 58.8%±9.6%; P = 0.030), and inferonasal (IN) (52.4%±9.0% vs. 57.6%±9.1%; P = 0.009) sectors. Eyes with LC defects in the IT sector (n = 33) had significantly lower cpVDs than eyes without a defect in the corresponding IT and IN sectors (P < 0.05 for all). Eyes with LC defects in the ST sector (n = 19) had lower cpVDs in the ST, IT, and IN sectors (P < 0.05 for all). CONCLUSIONS: In eyes with similar severity of glaucoma, OCT-A-measured vessel density was significantly lower in POAG eyes with focal LC defects than in eyes without an LC defect. Moreover, reduction of vessel density was spatially correlated with the location of the LC defect.

Agreement between Compass Fundus Perimeter New Grid and 10-2 Testing Protocols for Detecting Central Visual Field Defects.

PURPOSE: To evaluate the agreement between Compass New Grid (NG) and 10-2 test protocols for detecting early glaucomatous defects in the central 10 degrees of the visual field (CVFD). DESIGN: Cross-sectional study. PARTICIPANTS: A total of 123 eyes of 14 healthy individuals, 17 glaucoma suspects, and 32 glaucoma patients were enrolled. METHODS: Subjects performed NG and 10-2 Compass automated perimetry testing within 1 week. For both test protocols, total deviation (TD) and pattern deviation (PD) plot CVFDs were defined by 3 contiguous points with probabilities of <5%, <2%, <2% or <5%, <1%, <1%. Cohen's Kappa statistic was used to assess agreement between NG and 10-2 for identifying CVFDs. The Spectralis GMPE Hood Glaucoma Report (investigational software version) macula deviation analysis obtained within 1 year was used for calculating sensitivities and specificities of test protocols. MAIN OUTCOME MEASURES: Protocols' agreement, sensitivity, and specificity. RESULTS: Fair to moderate agreement was observed between NG and 10-2 protocols for detecting presence of superior CVFDs on TD (k = 0.57) and PD (k = 0.26) plots and for detecting inferior CVFDs on TD (0.49) and PD (0.27) plots. With the use of OCT macula deviation maps, specificity for detecting CVFD was consistently higher with NG than 10-2 tests for TD plots of the superior hemifield (0.82 and 0.65), inferior hemifield (0.92 and 0.84), and PD plots of the superior hemifield (0.81 and 0.36) and inferior hemifield (0.86 and 0.52). Sensitivity of NG was consistently lower than TD plots of the superior hemifield (0.48 and 0.72), inferior hemifield (0.28 and 0.46), and PD plots of the superior hemifield (0.48 and 0.78) and inferior hemifield (0.20 and 0.52). By using pattern standard deviation (PSD) criterion, the mean PSD values for 10-2 and NG VF tests were 1.61 (95% confidence interval [CI], 1.26-1.96) and 1.81 (95% CI, 1.45-2.17) (P < 0.001), respectively. CONCLUSIONS: Although the Compass NG detected fewer CVFDs than the 10-2 test protocol, it did detect CVFDs that were not observed in the Compass 24-2 test in patients with early glaucoma. Therefore, NG may be particularly useful in clinical situations when higher specificity is desired or PSD criterion is used.

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 Lamina Cribrosa Defects and Progressive Retinal Nerve Fiber Layer Loss in Glaucoma.

Importance: Certain features of the lamina cribrosa may be associated with increased risk of glaucoma progression. Objectives: To compare the rates of retinal nerve fiber layer (RNFL) thinning in patients with open-angle glaucoma with or without lamina cribrosa (LC) defects and to evaluate factors associated with the rate of glaucoma progression in eyes with LC defects. Design, Setting, and Participants: This longitudinal cohort study designed in September 2017 and conducted at a tertiary glaucoma center in California included 51 eyes of 43 patients with LC defects and 83 eyes of 68 patients without LC defects followed up for a mean (SD) of 3.5 (0.8) years from April 2012 to May 2017. Main Outcomes and Measures: Focal LC defects were detected using swept-source optical coherence tomographic images. All participants underwent visual field testing and spectral-domain optical coherence tomography for RNFL thickness measurements every 6 months. Univariate and multivariable random-effects models were used to compare the rate of local and global RNFL loss. Results: The mean (95% CI) age at baseline for individuals with LC defects was 69.5 (65.4 to 73.6) years, and for those without LC defects, it was 69.6 (67.2-72.0) years; 18 individuals (41%) with LC defects and 35 individuals (51%) without LC defects were men; 6 individuals (14%) with LC defects and 17 individuals (25%) without were African American. The mean (95% CI) rate of global RNFL loss in eyes with LC defects was 2-fold faster than that in eyes without LC defects (-0.91 [-1.20 to -0.62] vs -0.48 [-0.65 to -0.31] µm/y; difference, -0.43 [-0.76 to -0.09] µm/y; P = .01). The rate of RNFL thinning was faster in the LC defect sectors than that in the unaffected sectors (difference, -0.90 [95% CI, -1.68 to -0.12] µm/y, P = .02). Thinner corneal thickness was the only factor that was associated with a faster rate of RNFL loss in eyes with LC defects (ß2 = -0.09 [95% CI, -0.14 to -0.04], P = .001). No association was found between mean intraocular pressure during follow-up and the mean rate of RNFL thinning in eyes with LC defects (ß2, -0.05 [95% CI, -0.17 to 0.06], P = .36). Conclusions and Relevance: These data suggest that LC defects are an independent risk factor for RNFL thinning and that glaucoma progression may correspond topographically to the LC defect location. Thinner corneal thickness in eyes with LC defects was associated with faster further glaucoma progression. In the management of open-angle glaucoma, LC findings may inform the likelihood and rate of glaucoma progression.

Macula Vessel Density and Thickness in Early Primary Open-Angle Glaucoma.

PURPOSE: To characterize and compare the ganglion cell complex (GCC) thickness and macula vessel density in preperimetric and early primary open-angle glaucoma (POAG) eyes. DESIGN: Cross-sectional study. METHODS: Fifty-seven healthy, 68 preperimetric, and 162 early POAG eyes enrolled in the Diagnostic Innovations in Glaucoma Study. Optical coherence tomography angiography (OCT-A)-based superficial macula vessel density and OCT-based GCC thickness were evaluated simultaneously. Percent loss from normal of GCC thickness and macula vessel density was compared. Area under the receiver operating characteristic curve was used to describe the diagnostic utility. RESULTS: Both GCC thickness and vessel density were significantly lower in preperimetric and early POAG eyes compared to healthy eyes. Compared to the preperimetric POAG group, the early POAG group showed larger GCC thickness percent loss (whole image 4.72% vs 9.86%; all P < .01) but similar vessel density percent loss (whole image 4.97% vs 6.93%; all P > .05). In preperimetric POAG, GCC thickness and vessel density percent losses were similar (all P > .1). In contrast, in early POAG, GCC thickness percent loss was larger than that of vessel density (all P ≤ .001). To discriminate preperimetric or early glaucoma eyes from healthy eyes, GCC thickness and macula vessel density showed similar diagnostic accuracy (all P > .05). CONCLUSIONS: Both GCC thinning and macula vessel density dropout were detectable in preperimetric and early POAG eyes. GCC loss was greater than macula vessel density loss in early perimetric POAG. However, OCT-A and OCT measurements showed similar efficiency to detect early glaucoma.

Association of Macular and Circumpapillary Microvasculature with Visual Field Sensitivity in Advanced Glaucoma.

PURPOSE: To evaluate the association between optical coherence tomography angiography (OCTA) macular and circumpapillary vessel density and visual field mean deviation (MD) in advanced primary open angle glaucoma. DESIGN: Cross-sectional study. METHODS: Macula (superficial layer) and optic nerve head (ONH) with capillary density (CD) and without vessel density (VD) automated removal of large vessels OCTA of 34 eyes (34 patients, MD < -10 dB) were investigated as macula whole image VD (wiVD), parafoveal VD (pfVD), ONH wiVD, wiCD, circumpapillary VD, and cpCD. Spectral domain OCT circumpapillary retinal nerve fiber layer, macular ganglion cell complex, and ganglion cell inner plexiform layer were also analyzed. RESULTS: Macular and ONH VD decreased significantly with worsening MD. Each 1-dB decrease in MD was associated with a reduction of 0.43% and 0.46% for macular wiVD and pfVD with R2 of 0.28 and 0.27, respectively (all P < .01). The association between MD and VD was strongest for measures of ONH with large vessels removed, wiCD, and cpCD, followed by wiVD and circumpapillary VD with R2 of 0.26, 0.22, 0.17, 0.14, and a VD reduction of 0.43%, 0.51%, 0.33%, and 0.40%, respectively (all P < .02). There was a reduction of 1.19 µm in Avanti parafoveal ganglion cell complex, 1.13 µm in Spectralis ganglion cell inner plexiform layer, and 1.01 µm in Spectralis circumpapillary retinal nerve fiber layer, with R2 of 0.19 (P = .006), 0.23 (P = .002), and 0.24 (P = .002), respectively. CONCLUSIONS: ONH and macula OCTA VD and thickness are associated with the severity of visual field damage in advanced primary open angle glaucoma.

Association between Rates of Retinal Nerve Fiber Layer Thinning and Previous Disc Hemorrhage in Glaucoma.

PURPOSE: To investigate the relationship between previous disc hemorrhage (DH) and subsequent rates of retinal nerve fiber layer (RNFL) thinning. DESIGN: Longitudinal, observational cohort study. PARTICIPANTS: Twenty-eight patients with glaucoma and patients with suspected glaucoma who had a history of DH in 1 eye (unilateral DH), but not in the fellow eye, enrolled in the Diagnostic Innovations in Glaucoma Study and the African Descent and Glaucoma Evaluation Study were included. METHODS: All subjects underwent annual optic disc photography and semiannual spectral-domain OCT RNFL thickness measurements. Multivariable linear mixed-effects models were used to investigate the relationship between the presence of previous DH and RNFL thinning rates while adjusting for potential confounding factors, such as race, age, mean intraocular pressure (IOP), baseline disease severity, and central corneal thickness (CCT). The relationship between the timing of DH and the rates of RNFL thinning also was investigated in eyes with a history of DH. MAIN OUTCOME MEASURES: Rates of global and local RNFL thinning. RESULTS: Previous DH was significantly associated with faster RNFL thinning rates globally (-0.39 µm/year faster, P = 0.010), in DH quadrants (-0.77 µm/year faster, P = 0.012), and non-DH quadrants (-0.49 µm/year faster, P = 0.038) after adjustment for race, mean IOP, baseline age, baseline standard automated perimetry mean deviation, and CCT. Higher IOP was also significantly associated with faster thinning rates globally (-0.07 µm/year faster per 1 mmHg higher, P = 0.047) and in DH quadrants (-0.10 µm/year faster per 1 mmHg higher, P = 0.044). In eyes with a history of DH, the time elapsed from the latest DH episode to the first OCT examination was not significantly associated with the rate of RNFL thinning. CONCLUSIONS: A history of DH is an independent risk factor for faster rates of RNFL thinning in non-DH quadrants and in DH quadrants; this risk is present even in eyes that exhibited DH several years earlier.

Progression of Primary Open-Angle Glaucoma in Diabetic and Nondiabetic Patients.

PURPOSE: To compare the rates of visual field (VF) loss and retinal nerve fiber layer (RNFL) thinning in primary open-angle glaucoma (POAG) patients with or without type 2 diabetes mellitus (DM). DESIGN: Cohort study. METHODS: A total of 197 eyes (55 eyes of 32 POAG patients with DM in POAG/DM group and 142 eyes of 111 age-matched POAG patients without DM in POAG/DM- group) were included from the Diagnostic Innovations in Glaucoma Study (DIGS). Type 2 DM participants were defined by self-report of DM history and use of antidiabetic medication. The rates of VF loss and RNFL loss were compared in POAG eyes with and without DM using univariate and multivariable mixed-effects models. RESULTS: The median (interquartile range) follow-up was 5.7 years (4.0, 6.4). The mean rate of global RNFL loss in the POAG/DM group was 2-fold slower than in the POAG/DM- group overall (-0.40 µm/year vs -0.83 µm/year, respectively P = .01). Although a slower rate of VF mean deviation and pattern standard deviation loss was found in the POAG/DM group compared to the POAG/DM- group, the difference was not statistically significant. CONCLUSIONS: POAG patients with treated type 2 DM, who had no detectable diabetic retinopathy, had significantly slower rates of RNFL thinning compared to those without diagnosed DM.

Optic disc microvasculature dropout in primary open-angle glaucoma measured with optical coherence tomography angiography.

PURPOSE: To evaluate microvasculature dropout in the optic disc (Mvd-D) using optical coherence tomography angiography (OCTA) and investigate factors associated with Mvd-D in primary open-angle glaucoma (POAG) eyes. METHODS: One hundred twenty-three eyes of 123 POAG patients were included from the Diagnostic Innovations in Glaucoma Study. The 3.0×3.0-mm optic nerve head OCTA scans were acquired using a spectral-domain OCT instrument. Images with whole-signal-mode were evaluated. Eyes were classified into 3 categories (Mvd-D, pseudo-Mvd-D, and no Mvd-D). Mvd-D and pseudo-Mvd-D had complete loss of OCTA signals on the temporal side of the optic disc on the en face projection image. They were distinguished base on the visualization of the anterior lamina cribrosa in the horizontal B-scans of that area. No Mvd-D was defined when no complete signal loss of OCTA signals was observed. Covariates including focal lamina cribrosa defects assessed by swept-source OCT and microvasculature dropout in the parapapillary region (Mvd-P) were analyzed. RESULTS: Forty-two, 37, and 44 eyes were identified as having Mvd-D, pseudo-Mvd-D, and no Mvd-D, respectively. The eyes with Mvd-D showed significantly lower intraocular pressure, worse visual field mean deviation, larger cup-to-disc ratio, thinner circumpapillary retinal nerve fiber layer (cpRNFL), and lower circumpapillary vessel density within the RNFL than the eyes with pseudo-Mvd-D or the eyes without Mvd-D. Multivariable logistic regression analysis showed significant associations of Mvd-D with larger cup-to-disc ratio (OR, 1.08; P = 0.001), worse visual field mean deviation (OR, 1.09; P = 0.048), higher prevalence of focal lamina cribrosa defect (OR, 9.05; P = 0.002), and higher prevalence of Mvd-P (OR, 10.33; P <0.001). CONCLUSIONS: OCTA-derived Mvd-D was strongly associated with the presences of Mvd-P and focal lamina cribrosa defects, and these 3 findings were topographically associated with each other.

Deep-Layer Microvasculature Dropout by Optical Coherence Tomography Angiography and Microstructure of Parapapillary Atrophy.

Purpose: To investigate the association between the microstructure of ß-zone parapapillary atrophy (ßPPA) and parapapillary deep-layer microvasculature dropout assessed by optical coherence tomography angiography (OCT-A). Methods: Thirty-seven eyes with ßPPA devoid of the Bruch's membrane (BM) (γPPA) ranging between completely absent and discontinuous BM were matched by severity of the visual field (VF) damage with 37 eyes with fully intact BM (ßPPA+BM) based on the spectral-domain (SD) OCT imaging. Parapapillary deep-layer microvasculature dropout was defined as a dropout of the microvasculature within choroid or scleral flange in the ßPPA on the OCT-A. The widths of ßPPA, γPPA, and ßPPA+BM were measured on six radial SD-OCT images. Prevalence of the dropout was compared between eyes with and without γPPA. Logistic regression was performed for evaluating association of the dropout with the width of ßPPA, γPPA, and ßPPA+BM, and the γPPA presence. Results: Eyes with γPPA had significantly higher prevalence of the dropout than did those without γPPA (75.7% versus 40.8%; P = 0.004). In logistic regression, presence and longer width of the γPPA, worse VF mean deviation, and presence of focal lamina cribrosa defects were significantly associated with the dropout (P < 0.05), whereas width of the ßPPA and ßPPA+BM, axial length, and choroidal thickness were not (P > 0.10). Conclusions: Parapapillary deep-layer microvasculature dropout was associated with the presence and larger width of γPPA, but not with the ßPPA+BM width. Presence and width of the exposed scleral flange, rather than the retinal pigmented epithelium atrophy, may be associated with deep-layer microvasculature dropout.

Automated Beta Zone Parapapillary Area Measurement to Differentiate Between Healthy and Glaucoma Eyes.

PURPOSE: To evaluate whether automated assessment of beta zone parapapillary atrophy (ßPPA) area can differentiate between glaucomatous and healthy eyes of varying axial lengths (AL). DESIGN: Cross-sectional study. METHODS: ßPPA was automatically identified in glaucoma and healthy eyes with enhanced-depth imaging optical coherence tomography (OCT) optic nerve head (ONH) radial B-scans. Associations with AL and the presence of glaucoma were assessed. Manually delineated ßPPA on individual OCT ONH B-scans of 35 eyes from the Diagnostic Innovations in Glaucoma Study served to validate the automated method. RESULTS: One hundred fifty-three glaucoma eyes (mean ± standard deviation) (visual field mean deviation, -5.0 ± 6.4 dB and mean AL, 25.1 ± 1.1 mm) and 73 healthy eyes (visual field mean deviation, 0.1 ± 1.4 dB and mean AL, 24.1 ± 1.1 mm) were included. In multivariable analysis, larger ßPPA area was significantly associated with a diagnosis of glaucoma after controlling for age, central corneal thickness, and AL. Moreover, in multivariable analysis, the odds of having glaucoma were doubled for each 0.2 mm2 larger ßPPA area. The age- and AL-adjusted area under the receiver operating characteristic curve (95% confidence interval) of ßPPA area for differentiating between glaucoma and healthy eyes was 0.75 (0.68-0.81). Agreement for the location of the Bruch membrane opening and the location of retinal pigment epithelium tips was stronger between the automated technique and each individual observer than it was between the 2 observers. CONCLUSIONS: Larger ßPPA area, as determined by automated OCT assessment, is significantly associated with a diagnosis of glaucoma, even after adjusting for age and AL, and may aid in differentiating healthy from glaucomatous eyes.

Inter-eye Asymmetry of Optical Coherence Tomography Angiography Vessel Density in Bilateral Glaucoma, Glaucoma Suspect, and Healthy Eyes.

PURPOSE: To investigate inter-eye retinal vessel density asymmetry in healthy, glaucoma suspect, and mild-to-moderate glaucoma subjects, and its potential utility for early detection of glaucomatous damage. DESIGN: Cross-sectional study. METHODS: In 153 subjects including 55 healthy, 32 glaucoma suspect, and 66 glaucoma subjects enrolled in the Diagnostic Innovations in Glaucoma Study (DIGS), vessel density was obtained from optical coherence tomography angiography (OCT-A) macular and optic nerve head scans. Thickness of peripapillary retinal nerve fiber layer (RNFL) and macular ganglion cell complex (mGCC) was measured with spectral-domain optical coherence tomography (SD-OCT) scans. Inter-eye asymmetry was calculated by taking the absolute value of difference in vessel density and thickness between the right and left eyes. RESULTS: Inter-eye retinal vessel density asymmetry parameters were significantly different among the 3 groups. Glaucoma suspects had significantly higher peripapillary and macular inter-eye vessel density asymmetries compared to healthy groups in univariate (1.1% vs 2.0%, P = .014 and 1.2% vs 2.5%, P = .027, respectively) and multivariate analyses (P = .007 and P = .038, respectively). No significant differences in asymmetry of thickness parameters were found between glaucoma suspect and healthy groups (all P > .718). However, significant differences in asymmetry of thickness parameters between glaucoma suspects and glaucoma patients (P < .01) were found for all parameters. CONCLUSION: Inter-eye vessel density asymmetry can be quantified by OCT-A measurement. Glaucoma suspects have significantly greater vessel density asymmetry than healthy eyes. Longitudinal studies are needed to better characterize the relationship of vessel density asymmetry with the development and progression of glaucoma.

Progressive Macula Vessel Density Loss in Primary Open-Angle Glaucoma: A Longitudinal Study.

PURPOSE: To characterize the rate of macula vessel density loss in primary open-angle glaucoma (POAG), glaucoma-suspect, and healthy eyes. DESIGN: Longitudinal, observational cohort from the Diagnostic Innovations in Glaucoma Study. METHODS: One hundred eyes (32 POAG, 30 glaucoma-suspect, and 38 healthy) followed for at least 1 year with optical coherence tomography angiography (OCT-A) imaging on at least 2 visits were included. Vessel density was calculated in the macula superficial layer. The rate of change was compared across diagnostic groups using a multivariate linear mixed-effects model. RESULTS: Baseline macula vessel density was highest in healthy eyes, followed by glaucoma-suspect and POAG eyes (P < .01). The rate of vessel density loss was significantly different from zero in the POAG, but not in the glaucoma-suspect or healthy eyes. The mean rate of change in macula whole en face vessel density was significantly faster in glaucoma eyes (-2.23%/y) than in glaucoma-suspect (0.87%/y, P = .001) or healthy eyes (0.29%/y, P = .004). Conversely, the rate of change in ganglion cell complex (GCC) thickness was not significantly different from zero in any diagnostic group, and no significant differences in the rate of GCC change among diagnostic groups were found. CONCLUSIONS: With a mean follow-up of less than 14 months, eyes with POAG had significantly faster loss of macula vessel density than either glaucoma-suspect or healthy eyes. Serial OCT-A measurements also detected glaucomatous change in macula vessel density in eyes without evidence of change in GCC thickness.