Perifoveal Vessel Density Research Articles

Optical coherence tomography angiography findings in patients with ocular and non-ocular Behcet disease.

To evaluate the optical coherence tomography angiography findings in patients with Behçet disease with and without ocular involvement. A total of 40 patients with Behçet disease and 30 healthy controls were enrolled in the study. Retinal vessel density in the superficial capillary plexus and deep capillary plexus, foveal avascular zone area and perimeter, acirculatory index, foveal density, and nonflow area in the superficial retina were automatically measured using the optical coherence tomography angiography software AngioVue and compared between the groups. The mean parafoveal and perifoveal vessel densities in the superficial capillary plexus and deep capillary plexus and foveal density were significantly lower in the eyes with Behçet uveitis compared to the eyes without Behçet uveitis and eyes of the healthy controls. In the eyes with Behçet uveitis, logMAR visual acuity showed a moderate correlation with parafoveal and perifoveal vessel densities and foveal density (r=-0.43, p=0.006; r=-0.62, p<0.001; r=-0.42, p=0.008; respectively). Behçet disease with posterior uveitis was associated with significant perifoveal and parafoveal vascular decrements in the superficial and deep retina.

Angiography with optical coherence tomography as a biomarker in multiple sclerosis

To investigate superficial retinal microvascular plexuses detected by optical coherence tomography angiography (OCT-A) in multiple sclerosis (MS) subjects and compare them with healthy controls. A total of 92 eyes from 92 patients with relapsing-remitting MS and 149 control eyes were included in this prospective observational study. OCT-A imaging was performed using Triton Swept-Source OCT (Topcon Corporation, Japan). The vessel density (VD) percentage in the superficial retinal plexus and optic disc area (6 x 6 mm grid) was measured and compared between groups. MS patients showed a significant decrease VD in the superior (p = 0.005), nasal (p = 0.029) and inferior (p = 0.040) parafoveal retina compared with healthy subjects. Patients with disease durations of more than 5 years presented lower VD in the superior (p = 0.002), nasal (p = 0.017) and inferior (p = 0.022) parafoveal areas compared with healthy subjects. Patients with past optic neuritis episodes did not show retinal microvasculature alterations, but patients with an EDSS score of less than 3 showed a significant decrease in nasal (p = 0.024) and superior (p = 0.006) perifoveal VD when compared with healthy subjects. MS produces a decrease in retinal vascularization density in the superficial plexus of the parafoveal retina. Alterations in retinal vascularization observed in MS patients are independent of the presence of optic nerve inflammation. OCT-A has the ability to detect subclinical vascular changes and is a potential biomarker for diagnosing the presence and progression of MS.

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

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). 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. 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). 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.

The effect of electronic cigarette smoking on retinal microcirculation: Enlargement of the foveal avascular zone.

To evaluate retinal microcirculation in electronic cigarette (e-cigarette) smokers using optical coherence tomography angiography (OCTA). OCTA measurements were performed on the left eyes of 21 e-cigarette smokers and 21 healthy controls. Superficial and deep foveal, perifoveal and parafoveal vessel densities, outer retina and choriocapillaris flow area, foveal avascular zone (FAZ), and central macular thickness were evaluated in both groups. The FAZ area was larger in e-cigarette smokers than the control group, and the difference was statistically significant (p = 0.003). The superficial foveal, superficial total, deep foveal and deep total vascular densities were significantly lower in the e-cigarette group compared to the control group (p = 0.011, p = 0.012, p = 0.022, and p = 0.041, respectively). Central macular thickness was lower in the e-cigarette smokers but the difference was not statistically significant (p = 0.678). E-cigarette smoking causes enlargement of the FAZ area and decreases vascular densities.

Asymmetry of Macular Vessel Density in Bilateral Early Open-angle Glaucoma With Unilateral Central 10-2 Visual Field Loss.

The purpose of this study was to investigate the characteristics, intereye and intraeye asymmetry of macular vessel density assessed by optical coherence tomography (OCT) angiography in bilateral early open-angle glaucoma with unilateral 10-2 visual field loss. Thirty-two eyes of 16 patients with bilateral early open-angle glaucoma and unilateral 10-2 visual field loss, and 13 eyes of 13 healthy participants were consecutively enrolled. All subjects underwent 30-2, 10-2 visual fields, OCT, and OCT angiography examinations. Intereye differences were compared between the perimetrically affected eye and the unaffected eye in the same patient. Intraeye differences were compared between the affected hemifields and the unaffected hemifields in the same eye with single-hemifield 10-2 visual field loss. Macular whole image vessel density of the perimetrically unaffected eyes was lower than the healthy eyes (46.6% vs. 51.1%; P<0.001). Parafoveal vessel density parameters of the perimetrically affected eyes were comparable to the unaffected eyes (all P>0.05). Although inferior perifoveal vessel density of the perimetrically affected eyes was significantly lower than the unaffected eyes (42.2% vs. 46.2%; P=0.007), similar results were found in macular ganglion cell complex. In glaucomatous eyes with single-hemifield loss, perifoveal vessel density and macular ganglion cell complex of the affected hemifields were significantly worse than the unaffected hemifields (43.6% vs. 47.0%, 78.4 μm vs. 89.0 μm; P=0.023 and 0.005; respectively). Significant macular microvascular damage was present in glaucomatous eyes without detectable 10-2 visual field damage. The damage of inferior perifoveal vessel density was more significant in early glaucoma. Macular microvascular damage spatially corresponded with functional and structural damage.

Evaluation of microvascular changes in optic disc and retina by optical coherence tomography angiography during Valsalva maneuver.

Optical coherence tomography angiography (OCTA) is an increasingly widespread imaging tool that allows the visualization of the microvascular structures of the eye. It should be kept in mind in clinical practice, Valsalva maneuver (VM) may have an effect on OCTA findings. We aimed to evaluate the effect of VM on the optic nerve and retinal blood flow parameters measured by OCTA. Sixty age- and sex-matched healthy volunteers were included into this prospective study. Optic disc status for radial peripapillary capillary (RPC) network [whole image, inside disc and peripapillary capillary densities], superficial and deep capillary plexus whole, foveal, parafoveal and perifoveal densities and foveal avascular zone (FAZ) densities of volunteers were examined by OCTA both at rest and during VM. The mean age of the subjects was 31.48 ± 7.49 (18-50) years and 51.7% were male. Superficial whole, parafoveal and perifoveal vessel densities were found to be significantly decreased during VM (p = 0.008, p= 0.015, p = 0.017, respectively). Lower levels of deep whole, parafoveal and perifoveal vessel densities were also detected while VM (p < 0.001 for all). However, there were no significant differences in terms of foveal vessel and FAZ densities. Additionally, VM significantly decreased RPC densities for whole image, inside and peripapillary capillary (p = 0.005, p < 0.001, p = 0.039, respectively). VM may cause a significant decrease in optic nerve and para-perifoveal blood flow. Therefore, patient instruction about not holding breath is required before OCTA scanning.

Assessment of macular capillary perfusion in patients with inactive Vogt-Koyanagi-Harada disease: an optical coherence tomography angiography study.

To assess macular capillary perfusion in patients with inactive Vogt-Koyanagi-Harada (VKH) disease by using optical coherence tomography angiography (OCTA). A total of 51 eyes of 51 patients with inactive VKH (group 1, n = 23) and healthy volunteers (group 2, n = 28) underwent detailed eye examination including OCTA (RTVue-XR Avanti) scanning. OCTA images (6 × 6mm) were assessed for central retinal thickness (CRT), subfoveal choroidal thickness (SFCT), vessel densities (VD) in superficial capillary plexus (SCP) and deep capillary plexus (DCP), choriocapillaris (CC) flow area and vessel flow density (VFD), foveal avascular zone (FAZ) area and acircularity index (AI). The mean ages of group 1 (13 female, 10 male) and group 2 (15 female, 13 male) were 39.9 ± 11.8 (range, 24-58) and 38.9 ± 8.5 (range, 29-51) years, respectively (p = 0.773). CRT and SFCT were 218.2 ± 39.4μm and 195.6 ± 28.6μm in group 1, while 243.5 ± 9.7μm and 316.7 ± 20.1μm in group 2, respectively (p < 0.05). VD in SCP and DCP were significantly lower in group 1 (50.6 ± 4.7% vs. 54.3 ± 3.4% and 53.9 ± 3.6% vs. 61.1 ± 2.7% respectively; p < 0.05). FAZ areas were 0.32 ± 0.11mm2 in group 1 and 0.25 ± 0.06mm2 in group 2 (p = 0.046). There was no statistically significant difference between groups regarding AI, CC flow area, and VFD (p > 0.05). There was weak negative correlation between BCVA (logMAR) and parafoveal and perifoveal VD in SCP and DCP of group 1 (p < 0.05). Macular capillary perfusion was significantly reduced both in SCP and DCP in patients with inactive VKH disease.

DIABETIC MACULAR ISCHEMIA

To examine the relationship between macular microvasculature parameters and functional changes in persons with diabetic retinopathy (DR). Cross-sectional study of 76 eyes with varying levels of DR. Optical coherence tomography angiography (OCTA) quantified superficial and deep perifoveal vessel densities and foveal avascular zone areas. Retinal sensitivity was measured using microperimetry. Optical coherence tomography angiography parameters and retinal sensitivity were correlated. Deep perifoveal vessel density decreased with increasing severity of DR (adjusted mean 51.93 vs. 49.89 vs. 47.96, P-trend = 0.005). Superficial and deep foveal avascular zone area increased with increasing DR severity (adjusted mean: 235.0 µm vs. 303.4 µm vs. 400.9 µm, P-trend = 0.003 [superficial]; 333.1 µm vs. 513.3 µm vs. 530.2 µm, P-trend = 0.001 [deep]). Retinal sensitivity decreased with increasing DR severity (adjusted mean: 25.12 dB vs. 22.34 dB vs. 20.67 dB, P-trend = 0.003). Retinal sensitivity correlated positively with deep perifoveal vessel density (Pearson's ρ = 0.276, P = 0.020) and inversely with superficial foveal avascular zone area (Pearson's ρ = -0.333, P = 0.010). Alterations in retinal microvasculature can be observed with OCTA with increasing severity of DR. These changes are correlated with reduced retinal sensitivity. Optical coherence tomography angiography is useful to detect and quantify the microvasculature properties of eyes with diabetic macular ischemia.

Comparison of vessel density and retinal nerve fiber layer thickness in patients between both eyes of subjects with clinically unilateral pseudoexfoliation syndrome using optical coherence tomography angiography

AbstractPurposeThe purpose of the study was to compare vessel density (VD) and retinal nerve fiber layer thickness (RNFLT) between eyes with pseudoexfoliation material (PE+) and fellow unaffected (PE−) eyes of patients using optical coherence tomography angiography (OCTA).MethodsA retrospective analysis of 36 eyes from 18 patients with clinically unilateral pseudoexfoliation syndrome was performed. The circumpapillary (cp) VD and RNFLT were obtained using OCTA and perifoveal, parafoveal VD and RNFLT were also calculated using OCTA. Circumpapillary parameters were obtained from octametric sections: superonasal (SN), nasalsuperior (NS), nasalinferior (NI), inferonasal (IN), inferotemporal (IT), temporalinferior (TI), temporalsuperior (TS), and superotemporal (ST) and perifoveal, parafoveal parameters were obtained in 4 different quadrants: temporal, nasal, inferior, superior.ResultsIn PE+ eyes, the cpVD was significantly lower in all eight sectors (p &lt; 0.05), while the cpRNFLT showed significant reduction in six sectors (p &lt; 0.05): NS, NI, IN, IT, ST and SN). Perifoveal VD was significantly decreased in temporal, inferior quadrant (p &lt; 0.05) and parafoveal VD was significantly lower in only temporal quadrant (p &lt; 0.05) in the PE+ group. While, significant difference was not detected in RNFLT between PE+ and PE− eyes.ConclusionsEyes with clinically unilateral pseudoexfoliation syndrome have low VD and thin RNFLT as compared to fellow unaffected eyes, but not with the all sectors. These changes appear to be associated with pseudoexfoliation material. The roles and mechanisms in pseudoexfoliative material need clarification.

Evaluation of the choroidal features in pachychoroid spectrum diseases by optical coherence tomography and optical coherence tomography angiography.

To evaluate choroidal area, stroma/lumen ratio, choriocapillaris vessel density, and choriocapillaris flow area in eyes with central serous chorioretinopathy, uncomplicated pachychoroid, and pachychoroid pigment epitheliopathy using enhanced depth imaging-optical coherence tomography and optical coherence tomography angiography. This retrospective study analyzed enhanced depth imaging-optical coherence tomography and optical coherence tomography angiography scans of 142 eyes of 92 patients with central serous chorioretinopathy, uncomplicated pachychoroid, and pachychoroid pigment epitheliopathy. The choroidal area and stroma/lumen ratio were measured by binarization of enhanced depth imaging-optical coherence tomography images. Choriocapillaris vessel density and choriocapillaris flow area were measured at the choriocapillaris level by manual segmentation of optical coherence tomography angiography scans. The mean stroma/lumen ratio results were 0.361, 0.345, and 0.354 in central serous chorioretinopathy, uncomplicated pachychoroid, and pachychoroid pigment epitheliopathy groups, respectively (p > 0.05). The mean whole image choriocapillaris vessel density in uncomplicated pachychoroid group was higher compared with central serous chorioretinopathy and pachychoroid pigment epitheliopathy groups (p < 0.0001). The mean foveal, parafoveal, and perifoveal choriocapillaris vessel densities were lower in central serous chorioretinopathy group than in uncomplicated pachychoroid group (p < 0.0001). The mean choriocapillaris flow area was lower in central serous chorioretinopathy group than in uncomplicated pachychoroid and pachychoroid pigment epitheliopathy groups (p < 0.0001 and p = 0.01, respectively). Our findings suggest that both choroidal vessels and stroma are equally involved in central serous chorioretinopathy, uncomplicated pachychoroid, and pachychoroid pigment epitheliopathy. The choriocapillaris segment seems to be more affected in central serous chorioretinopathy compared to uncomplicated pachychoroid and pachychoroid pigment epitheliopathy. However, the reduced optical coherence tomography angiography signal in central serous chorioretinopathy group could be due to shadowing artifact or choriocapillaris hypoperfusion and further studies with higher quality imaging tools are needed.

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

ABSTRACTPurpose: 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

Deep perifoveal vessel density as an indicator of capillary loss in high myopia

This study investigates the macular vasculature of both vascular layers in different degrees of myopia by optical coherence tomography angiography (OCTA). One hundred and forty-five eyes of 145 healthy subjects with spherical equivalents (SE) ranging from +0.50 to -16.50 dioptres were divided into three groups. The foveal avascular zone (FAZ) area and vessel density (VD) of OCTA images were compared. Compared with other groups, high myopia had a larger FAZ and less perifoveal VD in both layers and less deep total VD. Compared with other myopia, high myopia had less total VD in the superficial layer and parafoveal VD in the deep layer. Between emmetropia and low myopia, there was a difference only in the deep parafoveal VD. Except for the parafoveal VD in both layers and the superficial total VD, there were significant correlations of the FAZ with axial length (AL) and SE as well as VD. The deep perifoveal VD was most associated with high myopia. An increased FAZ and decreased VD in both layers were correlated with AL elongation. The decreasing deep perifoveal VD was most associated with high myopia. OCTA may provide additional information regarding the progression of pathologies in high myopia.

Foveal microvasculature, refractive errors, optical biometry and their correlations in school-aged children with retinopathy of prematurity after intravitreal antivascular endothelial growth factors or laser photocoagulation

AimsTo compare the differences and to assess the correlations regarding to foveal microvasculature, refractive errors and optical biometry in children with history of type 1 retinopathy of prematurity (ROP) treated...

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

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. Observational, cross-sectional study. A total of 509 eyes from 38 healthy participants, 63 glaucoma suspects, and 193 glaucoma patients enrolled in the Diagnostic Innovations in Glaucoma Study. 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. Estimated vessel density and tissue thickness measurement floors and corresponding dynamic ranges. 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). 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.

Early retinal neurovascular impairment in patients with diabetes without clinically detectable retinopathy

AimsTo investigate the function and the corresponding neurovascular structures in patients with diabetes without clinically detectable retinopathy.Methods Sixty-six patients with type 2 diabetes without retinopathy (NDR) and 62 healthy controls...

QUANTITATIVE ANALYSIS OF OPTICAL COHERENCE TOMOGRAPHY ANGIOGRAPHY IN ADULT-ONSET FOVEOMACULAR VITELLIFORM DYSTROPHY

To quantify the foveal avascular zone area at superficial capillary plexus (SCP) and deep capillary plexus (DCP) and the global, parafoveal, and perifoveal vessel densities at SCP, DCP, and choriocapillaris using optical coherence tomography angiography in patients affected by adult-onset foveomacular vitelliform dystrophy (AOFVD). Twenty eyes of 20 consecutive patients (10 females, 50%) with AOFVD and 20 eyes of 20 healthy controls presenting at the Department of Ophthalmology of San Raffaele Hospital, Milan, Italy were enrolled. All patients underwent a complete ophthalmic examination, including 3-mm × 3-mm optical coherence tomography angiography centered on the macula. The vessel density was calculated in the three plexuses (i.e., SCP, DCP, and choriocapillaris) by mean of image binarization, and foveal avascular zone area was manually outlined at SCP and DCP with ImageJ software. In the SCP, patients with AOFVD disclosed a significant reduction of global (P < 0.001), parafoveal (P = 0.0017), and perifoveal (P = 0.0019) vessel density. In the DCP, parafoveal vessel density was higher in patients with AOFVD (P = 0.0026), whereas no significant difference was appreciated for both the global image (P = 0.5) and the perifoveal area (P = 0.5). Patients with AOFVD showed less dense choriocapillaris (P = 0.012) and perifoveal circle (P = 0.0152), whereas no difference was observed in the perifoveal zone (P = 0.07). Foveal avascular zone area was significantly enlarged at the DCP (P = 0.0184), but not at the SCP. Patients with AOFVD have quantitative vascular alterations in all vascular layers.

Comparison of the Retinal Microvascular Density Between Open Angle Glaucoma and Nonarteritic Anterior Ischemic Optic Neuropathy.

To compare optical coherence tomography angiography (OCT-A) retinal vasculature measurements between nonarteritic anterior ischemic optic neuropathy (NAION) and open angle glaucoma (OAG) with altitudinal hemifield visual field defects. This retrospective cross-sectional study included 10 NAION eyes and 16 OAG eyes, both demonstrating hemifield visual field defects, and 27 normal eyes serving as controls. The peripapillary and macular OCT-A scans were acquired. The retinal vessel density data were compared among NAION, glaucomatous, as well as control eyes. There was statistically significant difference in peripapillary whole image vessel density (wiVD), circumpapillary vessel density (cpVD), macular wiVD, and perifoveal vessel density (pfVD) between the three groups (P < 0.05 for all). In comparison between OAG and NAION groups, the NAION group demonstrated marked decrease in average cpVD (P = 0.008) and in most sectors of cpVD except the inferior one, while the OAG group demonstrated significant decreased macular wiVD and pfVD (P = 0.03 and 0.003, respectively). Multivariate analysis indicated that average thickness of retinal nerve fiber layer was the only predictor for peripapillary wiVD and cpVD (P = 0.005 for both). By contrast, thickness of ganglion cell complex was the only predictor for macular wiVD (P = 0.007). OCT-A detected significant difference in peripapillary and macular retinal vessel densities between OAG and NAION eyes. These differences might provide comparative insight into the pathophysiology of these two diseases.

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

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). Cross-sectional study. A total of 58 eyes of 58 patients with glaucoma with VF loss confined to a single hemifield and 28 healthy eyes. 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. Total and hemispheric cpVD, pfVD, cpRNFL, mGCC, and mean sensitivity (MS). 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). 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.

Automated Quantification of Capillary Nonperfusion Using Optical Coherence Tomography Angiography in Diabetic Retinopathy.

Macular ischemia is a key feature of diabetic retinopathy (DR). Quantification of macular ischemia has potential as a biomarker for DR. To assess the feasibility of automated quantification of capillary nonperfusion as a potential sign of macular ischemia using optical coherence tomography (OCT) angiography. An observational study conducted in a tertiary, subspecialty, academic practice evaluated macular nonperfusion with 6 × 6-mm OCT angiography obtained with commercially available 70-kHz OCT and fluorescein angiography (FA). The study was conducted from January 22 to September 18, 2014. Data analysis was performed from October 1, 2014, to April 7, 2015. Participants included 12 individuals with normal vision serving as controls and 12 patients with various levels of DR. Preplanned primary measures were parafoveal and perifoveal vessel density, total avascular area, and foveal avascular zone as detected with 6 × 6-mm OCT angiography and analyzed using an automated algorithm. Secondary measures included the agreement of the avascular area between the OCT angiogram and FA. Compared with the 12 healthy controls (11 women; mean [SD] age, 54.2 [14.2] years), the 12 participants with DR (4 women; mean [SD] age, 55.1 [12.1] years) had reduced parafoveal and perifoveal vessel density by 12.6% (95% CI, 7.7%-17.5%; P < .001) and 10.4% (95% CI, 6.8%-14.1%; P < .001), respectively. Total avascular area and foveal avascular zone area were greater in eyes with DR by 0.82 mm2 (95% CI, 0.65-0.99 mm2; P = .02) and 0.16 mm2 (95% CI, 0.05-0.28 mm2; P < .001). The agreement between the vascular areas in the OCT angiogram and FA had a κ value of 0.45 (95% CI, 0.21-0.70; P < .001). Total avascular area in the central 5.5-mm-diameter area distinguished eyes with DR from control eyes with 100% sensitivity and specificity. Avascular area analysis with an automated algorithm using OCT angiography, although not equivalent to FA, detected DR reliably in this small pilot study. Further study is necessary to determine the usefulness of the automated quantification in clinical practice.

Macular Microangiopathy in Sickle Cell Disease Using Optical Coherence Tomography Angiography

To characterize the optical coherence tomography angiography (OCTA) appearance of the perifoveal macular microvasculature in visually asymptomatic patients with sickle cell disease, and to compare these findings with those of fluorescein angiography (FA). Retrospective observational case series. Eighteen eyes of 9 consecutive patients with a median age of 41 years (range: 19-54 years) with electrophoretic confirmation of sickle cell disease were included and analyzed. A complete ophthalmologic examination was performed, including fundus examination, FA, and OCTA. Nine eyes of 5 healthy subjects were also analyzed with OCTA to serve as a control group. OCTA demonstrated microvascular abnormalities in the perifoveal region of the macula in all eyes, whereas FA appeared normal in 9 of 18 eyes (50%). Most capillary abnormalities were located in the temporal juxtafoveal region and involved both the superficial and the deep capillary plexuses. The nonflow area (foveal avascular zone) was significantly larger in sickle cell disease patients than in the control group, both in the superficial and the deep capillary plexuses (P < .0001). The perifoveal vessel density was significantly lower in the sickle cell disease patients than in the control group in both the superficial (P= .0011) and the deep capillary plexuses (P= .0018). OCTA provided detailed imaging of the perifoveal microvasculature in sickle cell disease. It appeared more sensitive than FA in detecting macular microangiopathy in asymptomatic patients. Microvascular abnormalities in sickle cell disease involved both the superficial and the deep capillary plexuses.