Correlation between macular perfusion status and visual acuity in retinal vein occlusion. / è§†ç½‘è†œé™è„‰é˜»å¡žåˆå¹¶é»„æ–‘çŒæ³¨çŠ¶æ€ä¸è‰¯ä¸Žè§†åŠ›çš„ç›¸å ³æ€§.

OBJECTIVES: Retinal vein occlusion (RVO) is the second most common retinal vascular disease worldwide, and the retinal perfusion status is closely related to the prognosis of the disease. Macular perfusion status is particularly correlated with visual acuity. This study aims to investigate the changes in macular perfusion indicators in RVO using optical coherence tomography angiography (OCTA) and analyze the correlation between macular perfusion status and visual acuity. METHODS: This cross-sectional study included 41 RVO patients, who were divided into 2 groups based on the occlusion site: 18 cases in the central retinal vein occlusion (CRVO) group and 23 cases in the branch retinal vein occlusion (BRVO) group. Additionally, they were categorized into ischemic RVO (23 cases) and non-ischemic RVO (16 cases) groups based on the presence of ischemia (2 eyes were excluded due to hemorrhage obscuring the peripheral retina, making it impossible to confirm the area of non-perfusion). A control group of 29 healthy individuals matched by sex and age was also recruited. Macular perfusion indicators were measured using OCTA, and the correlation between macular perfusion status and visual acuity was analyzed. RESULTS: Compared with healthy eyes, RVO eyes showed an increased foveal avascular zone (FAZ) area and significantly reduced superficial and deep vessel density (P<0.001). However, there were no significant differences in central foveal thickness (CFT) or macular perfusion indicators between the CRVO and BRVO groups (P>0.05). The best corrected visual acuity (BCVA) at the logarithm of the minimum angle of resolution (logMAR BCVA) was significantly negatively correlated with both superficial and deep retinal vessel density in RVO eyes (unstandardized coefficient B=-0.039, B=-0.042; P=0.017, P=0.040). The average BCVA in the ischemic RVO group was significantly worse than that in the non-ischemic RVO group (0.82±0.44 vs 0.45±0.29, P=0.007). The ischemic RVO group also had a larger FAZ area (P=0.003) and lower superficial and deep retinal vessel density (P<0.001, P=0.008, respectively) compared with the non-ischemic RVO group. The severity of macular ischemia did not correspond directly with the peripheral ischemia severity in RVO. CONCLUSIONS: Macular perfusion status is significantly reduced in RVO eyes compared to healthy eyes, which negatively impacts and limits visual acuity in RVO patients. Eyes with ischemic RVO have poorer visual acuity and macular perfusion status than those with non-ischemic RVO. OCTA is advantageous for observing vascular morphology and quantifying macular perfusion status, making it an effective tool for assessing disease progression.

Topographic Differences in Superficial Macular Vessel Density in Eyes with Early Primary Open-Angle Glaucoma and Normal Tension Glaucoma.

INTRODUCTION: The aim of the study was to compare macular vascular microcirculation in early primary open-angle glaucoma (POAG), normal tension glaucoma (NTG), and normal subjects. METHODS: 99 patients with early glaucoma (99 eyes: 60 POAG and 39 NTG) and 78 normal subjects were included. All subjects underwent optical coherence tomography angiography scan at 6 × 6 mm macular area. Macular vessel density (VD) and perfusion density (PD) and 9 sectors were compared between the controls, POAG, and NTG groups. Linear regression analysis was used to investigate the relationship between VD and other variables including macular PD, signal strength (SS), and mean macular ganglion cell-inner plexiform layer (mGCIPL) thickness. RESULTS: Significant losses in total area of VD and PD were detected in POAG and NTG groups compared to the controls (all p < 0.01). There were no significant differences in all inner sectors of macular VD and PD between POAG and controls (all p > 0.05). Except for outer-nasal sector, all other outer sectors of macular VD and PD were significantly lower in POAG than in the controls (all p < 0.01). The inferior-inner sector and all outer sectors of VD and PD were significantly lower in NTG than in the controls (all p < 0.01). Macular VD was significantly correlated with macular PD (r = 0.99, p < 0.001), SS (r = 0.60, p < 0.001), and mGCIPL thickness (r = 0.51, p < 0.001). CONCLUSIONS: Macular microcirculation declined significantly in early POAG and NTG patients. Macular microcirculation loss in the NTG group was more central and nasal compared with that in the POAG group. A decrease in macular VD was correlated with lower macular PD, lower SS, and thinner mGCIPL thickness.

Macular microvascular changes in children with transfusion-dependent beta-thalassemia.

BACKGROUND: To investigate the effect of iron overload on macular perfusion among transfusion-dependent thalassemia (TDT) patients using optical coherence tomography angiography (OCTA) METHODS: The study is a prospective observational case-control study. It included 27 eyes from 27 children with transfusion-dependent ß-thalassemia and 25 eyes from 25 age-matched controls. All participants were evaluated clinically and with OCTA Avanti RTVue-XR system (Optovue) to assess macular microvascular changes, by measuring vessels density (VDs) and foveal avascular zone (FAZ) area, at both superficial and deep retinal plexuses and at choriocapillaris level. RESULTS: Foveal and parafoveal zones were significantly thinner among thalassemia patients, with significantly larger FAZ area at the level of both superficial and deep retinal plexuses when compared with control group. The thalassemia group showed significant lower values compared with the controls regarding whole-image, foveal, and parafoveal deep VD. There were significant negative correlations between serum ferritin and deep (whole image and parafoveal) VD (r = - 0.429, P = 0.026, and r = - 0.452, P = 0.018, respectively). Choriocapillaris VDs (whole image and foveal) showed significant negative correlations with serum ferritin levels (r = - 0.390, P = 0.044 and r = - 0.401, P = 0.038, respectively) CONCLUSIONS: Macular microvascular changes were detected by OCTA examination in patients with TDT, mostly due to iron overload effect, as we selected patients on iron-chelating agent with the least harmful effect on the retina. The most affected layer is the DCP. Changes at the deep layer could be used as a sensitive biomarker for early macular perfusion changes in those patients. TRIAL REGISTRATION: Study registration number is UMIN000042657, date of registration: 2020/12/04 (retrospectively registered).

Ocular perfusion in patients with reduced left ventricular ejection fraction measured by optical coherence tomography angiography.

AIMS: The aim of this study is to evaluate retinal and optic nerve head (ONH) perfusion in patients with systolic chronic heart failure (CHF) compared to healthy control subjects. METHODS: Twenty-seven eyes of 27 patients with CHF (study group) and 31 eyes of 31 healthy subjects (control group) were prospectively included in this study. CHF Patients had a left ventricular ejection fraction (LVEF) < 50% and were classified by New York Heart Association (NYHA) class. OCT-A was performed using RTVue XR Avanti with AngioVue (Optovue, Inc, Fremont, CA, USA). The area of the foveal avascular zone (FAZ) and flow density (FD) data were extracted and analyzed. RESULTS: There was no significant difference in the signal strength index between the study group (group 1) and the control group (group 2) (ONH: p = 0.015; macula: p = 0.703). The difference in the area of the foveal avascular zone between the two groups was also not significant (p = 0.726). The flow density (whole en face) in the ONH (RPC) in group 1 was significantly lower compared to control (group 1 = 48.40 ± 2.48 (49.0 [46.7, 50.3]); group 2 = 50.15 ± 1.85 (50.6 [48.5, 51.70]); p = 0.008). There was a significant and strong correlation between LVEF and the macular flow density (whole en face) (superficial: rs = 0.605 deep: rs = 0.425, p < 0.01). CONCLUSIONS: Patients with CHF showed reduced flow density compared with healthy controls. The reduced FD correlated with the LVEF and the functional (NYHA) class. Retinal perfusion as measured using OCTA might provide an insight into the global microperfusion and hemodynamic state of heart failure patients.

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

PURPOSE: To assess macular capillary perfusion in patients with inactive Vogt-Koyanagi-Harada (VKH) disease by using optical coherence tomography angiography (OCTA). METHODS: 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 × 6 mm) 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). RESULTS: 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 ± 39.4 µm and 195.6 ± 28.6 µm in group 1, while 243.5 ± 9.7 µm and 316.7 ± 20.1 µm 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 ± 0.11 mm2 in group 1 and 0.25 ± 0.06 mm2 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). CONCLUSION: Macular capillary perfusion was significantly reduced both in SCP and DCP in patients with inactive VKH disease.

Evaluation of the effect of fingolimod (FTY720) on macular perfusion by swept-source optical coherence tomography angiography in patients with multiple sclerosis.

AIM: To determine changes in retinal microcirculation, caused by fingolimod (FTY720) use, via swept-source optical coherence tomography angiography (SS-OCTA) in relapsing-remitting multiple sclerosis (RR-MS) patients. MATERIALS AND METHODS: 80 patients with RR-MS, who were using fingolimod, and 50 healthy control subjects were included in the study. Group 1 consisted of 40 eyes from 40 RR-MS patients, who had been using fingolimod for less than six months, and Group 2 consisted of 40 eyes from 40 RR-MS patients, who had been using fingolimod for longer than six months. All participants underwent SS-OCTA via DRI OCT Triton (Topcon, Tokyo, Japan), analysing their central macular thickness (CMT) (µm), subfoveal choroidal thickness (SFCT) (µm), superficial (VDs) (%) and deep vascular plexuses (VDd) (%), choriocapillaris (VDcc) (%), and superficial and deep foveal avascular zones (FAZs, FAZd, respectively) (%) in mean values. RESULTS: The mean follow-up times for patients in Groups 1 and 2 were 2.9 ± 1.5 months and 22.5 ± 11.3 months, respectively. The FAZs value in Group 2 was found to be significantly higher than that in both Group 1 and the control group (p = 0.034, p = 0.042, respectively). The VDs central value in Group 2 did not differ significantly from that in Group 1 or the control group (p > 0.05), while the VDs central value was higher in Group 1 than in the control group (p = 0.008). In Group 1, the VDd central value was significantly higher than in Group 2 and the control group (p = 0.047; p = 0.020, respectively). The CMT measurement for Group 2 was significantly lower than in Group 1 and the control group (p = 0.008, p = 0.003, respectively). CONCLUSION: Fingolimod use seems to remarkably increase VDs and VDd measurements in the early period of administration and decrease CMT over a longer period of administration in patients with RR-MS.

Quantitative assessment of the effect of acute anaerobic exercise on macular perfusion via swept-source optical coherence tomography angiography in young football players.

AIM: To evaluate the effect of acute anaerobic exercise on macular perfusion measured by swept-source optical coherence tomography angiography (SS-OCTA) in young football players. MATERIALS AND METHODS: Football players with ages between 18 and 20 years were included into the study. After a detailed ophthalmological examination, physiological parameters including height (cm), body weight (kg), body fat percentage (%), systemic blood pressure (BP) (mmHg), hematocrit values (%), oxygen saturation pO2 (%) and heart rate (bpm) were recorded. Intraocular pressure (IOP) (mmHg) and SS-OCTA using DRI OCT Triton (Topcon, Tokyo, Japan) were measured immediately before and after Wingate test. RESULTS: Out of 20, 16 participants completed the study. All participants were males with a mean age of 18.12 ± .34 years. Systolic BP, hematocrit and heart rate increased, while pO2 and IOP decreased remarkably after Wingate test (p < .01). After anaerobic exercise, there was an increase in mean FAZ area in superficial capillary plexus (FAZs) which was not significant (p = .13), while decrease in FAZ area in deep capillary plexus (FAZd) (mm2) was remarkable (p = .04). No changes were observed in mean vessel density (VD) (%) in superficial capillary plexus (VDs), deep capillary plexus (VDd), choriocapillaris (VDcc), central macular thickness (CMT) (µm) and subfoveal choroidal thickness (SFCT) (µm) after Wingate test (p > .05). FAZd and some of the VD parameters showed a significant correlation with BP (p < .05). CONCLUSION: Acute anaerobic exercise seems not to alter either mean VD in retina and choroid or CMT and SFCT. Among OCTA parameters, only FAZd decreased remarkably.

Macular perfusion changes assessed with optical coherence tomography angiography after vitrectomy for rhegmatogenous retinal detachment.

PURPOSE: To explore macular perfusion changes in patients with rhegmatogenous retinal detachment (RRD) involved the macula following successful surgery and to evaluate the correlation between macular blood flow density and visual outcomes using optical coherence tomography angiography (OCTA). METHODS: This retrospective study included 14 eyes (14 patients) with macular-off RRD that underwent a standard three-port 23-gauge pars plana vitrectomy (PPV) and intraocular gas tamponade combined with phacoemulsification, aspiration, and intraocular lens implantation. OCTA was used to evaluate the macular perfusion changes throughout postoperative 12 weeks in the superficial capillary plexus (SCP), deep capillary plexus (DCP), and choriocapillary plexus (CCP). The fellow unaffected eyes were used as controls for comparison. RESULTS: A significant increase in the superficial capillary plexus flow density (SCPFD) (P = 0.000) was observed over time in RRD eyes with successful PPV, as well as the deep capillary plexus flow density (DCPFD) (P = 0.000) and the choriocapillary plexus flow density (CCPFD) (P = 0.000). Final best-corrected visual acuity (BCVA) was positively associated with CCPFD (r = - 0.577, P = 0.031) and non-correlated with SCPFD and DCPFD (P > 0.05). CONCLUSIONS: Macular perfusion gradually recovered following successful RRD repair by PPV. OCTA provided a non-invasive method to explore the underlying reason for different postoperative visual outcomes in macular-off RRD patients.

Grading of macular perfusion in retinal vein occlusion using en-face swept-source optical coherence tomography angiography: a retrospective observational case series.

BACKGROUND: To evaluate the efficacy of swept -source optical coherence tomography angiography (SS-OCTA) in grading macular perfusion in retinal vein occlusion. METHODS: Retrospective observational case series including patients with different types of retinal vein occlusion (RVO). SS-OCTA utilizes OCTARA algorithm to examine the retinal vascular plexuses for the presence of morphological signs of ischemia according to a predetermined grading scheme. The findings were compared with fundus fluorescein angiography (FFA), and swept-source optical coherence tomography (SS-OCT) features. Bivariate correlation, coefficient of determination, and crosstabs procedures were used to calculate inter-variable linear correlation, relative contribution of the tested variables, and multivariate association, respectively. RESULTS: The study included 144 eyes of 138 patients. The most common type of RVO was branch retinal vein occlusion (BRVO) (53%). The superficial capillary plexus (SCP) and the deep capillary plexus (DCP) did not correlate with each other in all parameters tested. Increased central macular thickness (CMT) and disrupted retinal outer layers (DROL) were associated with increased severity of ischemia in DCP. Disorganized retinal inner layers (DRIL) correlated significantly with the presence of perifoveal capillary ischemia in the SCP and the DCP. Macular ischemia on FFA correlated with ischemia in the SCP layer only. Increased CMT, DROL and DRIL on SS-OCT, and SCP and DCP ischemia on SS-OCTA contributed significantly to diminished best-corrected visual acuity (BCVA). CONCLUSION: SS-OCTA is more precise in defining the extent and location of maximum ischemic insult following RVO compared to FFA, hence represents a more efficient grader for ischemic damage in the posterior pole. Increased CMT, DRIL, and DROL on SS-OCT, and SCP and DCP ischemia on SS-OCTA are significant predictors of poor visual outcome.

Macular vessels density in diabetic retinopathy: quantitative assessment using optical coherence tomography angiography.

PURPOSE: The aim of this study was to evaluate macular perfusion using OCTA automated software algorithms; vessel area density (VD) and non-flow tool to measure FAZ area in treatment-naïve diabetic eyes with moderate or severe NPDR and having macular edema, and correlate these parameters with LogMAR (logarithm of the minimum angle of resolution) visual acuity. Diabetic eyes without macular edema were included, to detect and define differences within the parameters between diabetic eyes with and without macular edema. METHODS: Forty-five diabetic eyes with diabetic macular edema, forty diabetic eyes without macular edema, and forty eyes of healthy controls were examined using OCTA (RTVue-XR Avanti; Optovue, Inc, Fremont, CA). The macular vessel area density (VD) and foveal avascular zone (FAZ) area were assessed and statistically compared between the three groups and also correlated with the foveal thickness and visual acuity. Data were entered and analyzed by SPSS 19. Quantitative data were presented as mean and standard deviation, and qualitative data presented as frequency distribution; independent samples t test, Chi square test and Pearson correlation were done. RESULTS: Mean whole image VD was 44.4 ± 3.6 in diabetic eyes with DME, 45.6 ± 4.2 in diabetics without DME, and 49 ± 3.9 in control eyes (P = 0.001). Diabetic eyes with DME had significantly lower vessels density values at the level of the deep retinal plexus (in the parafoveal, superior hemi, inferior hemi, temporal, superior, and nasal areas), when compared with diabetic eyes without DME. In diabetic eyes with DME, significant fair negative correlation was found between whole image vessels density at the level of the superficial retinal plexus and LogMAR VA (r = - 0.313, P = 0.036). Also, a significant fair positive correlation was found between FAZ area (at both the superficial and deep retinal plexus) and LogMAR visual acuity, in diabetic eyes with DME, where eyes with larger FAZ area had worse vision (P = 0.005 and P = 0.016, respectively). Diabetic eyes with DME had significantly larger FAZ area at the level of the superficial capillary plexus (mean superficial FAZ ± SD 0.55 ± 0.25) than diabetic eyes without edema (mean superficial FAZ ± SD 0.41 ± 0.12) and control subjects (mean superficial FAZ ± SD 0.35 ± 0.09). CONCLUSION: Using OCTA machine with AngioAnalytics parameters (vessel area density and non-flow area) helped in objective quantification of macular perfusion and accurately measuring the FAZ area in diabetic eyes with macular edema. Both parameters were significantly correlated with visual function in treatment-naïve diabetic eyes with edema. These OCTA biomarkers could be used to predict visual function in such eyes, to monitor response to treatment.

Correlation of flow density, as measured using optical coherence tomography angiography, with structural and functional parameters in glaucoma patients.

PURPOSE: To evaluate the correlation between flow density, as measured by optical coherence tomography angiography (OCTA), and structural and functional parameters in patients with open-angle glaucoma. METHODS: Thirty-four eyes of 34 patients with open-angle glaucoma and 35 eyes of 35 healthy subjects were prospectively included in this study. OCTA was performed using RTVue XR Avanti with AngioVue. The macula was imaged with a 3 × 3 mm scan and the optic nerve head (ONH) with a 4.5 × 4.5 mm scan. Visual field parameters [mean deviation (MD), pattern standard deviation (PSD) and visual field index (VFI)], Bruch's membrane opening minimal rim width (BMO-MRW), retinal nerve fiber layer thickness (RNFLT) and the stereometric parameters rim area, cup/disc area (HRT III, Heidelberg Retina Tomograph, Heidelberg Engineering) were tested for correlation with flow density data. RESULTS: The flow density (whole en face) in the retinal OCT angiograms (superficial: p = 0.01; deep: p = 0.005), in the radial peripapillary capillary network (p < 0.001) and in the OCT angiograms of the optic nerve head (p = 0.004) were significantly lower in the glaucoma group when compared with the control group. The flow density in the RPC network correlated significantly with all functional and structural parameters tested. The strongest correlation was found between the RPC flow density (inside disc) and the BMO-MRW (Spearman's correlation coefficient = 0.912, p < 0.001). CONCLUSIONS: Glaucoma patients showed a reduced ONH and macular perfusion when compared with healthy controls. The flow density as measured by OCTA correlated with structural damage and visual field loss in glaucoma patients. Non-invasive quantitative analyses of flow density using OCTA provide a new parameter describing a different aspect of glaucoma, which could be useful in clinical practice.

Quantification of macular perfusion using optical coherence tomography angiography: repeatability and impact of an eye-tracking system.

BACKGROUND: The aim of the study was to evaluate the impact of integration of the eye-tracking system (ET) on the repeatability of flow density measurements using optical coherence tomography (OCT) angiography. METHODS: 20 healthy subjects were included in this study. OCT-angiography was performed using RTVue XR Avanti (Optovue Inc., Fremont, California, USA). The macula was imaged using a 3 × 3 mm scan twice with and twice without activation of the ET. Flow density data of the macular in the superficial and deep OCT angiograms were extracted and analyzed. RESULTS: The difference between the flow density (whole en face) in the first session and second session with and without ET was statistically non-significant (with ET: superficial retinal OCT angiogram: p = 0.50; deep retinal OCT angiogram: p = 0.89; without ET: superficial retinal OCT angiogram: p = 0.81; deep retinal OCT angiogram: p = 0.24). There was no significant difference in the coefficients of repeatability for measurements with and without ET in the superficial retinal OCT angiogram (adjusted p-value = 0.176), whereas the difference was significant for the deep retinal OCT angiogram (adjusted p-value = 0.008). CONCLUSIONS: Integration of the ET improved the repeatability of flow density measurements in the deep OCT angiogram; this needs to be considered when evaluating the long-term changes of flow density and when comparing data of different studies and different devices.

FEVR combined with macular heterotopia in children presenting as pseudo-exotropia: a case report and literature review.

Familial exudative retinopathy (FEVR) is a hereditary disease involving abnormal retinal vascular development in which macular heterotopia (MH) caused by mechanical-like pulling of the vitreous may lead to pseudo-strabismus. We describe the case of a 12-year-old male patient from China who presented to our hospital with a request for surgical correction of exotropia. Examination revealed that the strabismic appearance was due to MH, and dilated pupil examination of the peripheral fundus revealed that the blood vessels of the left eye and the macula were displaced toward the temporal retina by pulling, and further FFA examination was performed to diagnose FEVR. With good binocular vision and stereoscopic distance vision, corrective surgery for strabismus in this patient would have resulted in a hard-to-resolve diplopia. Therefore, it is important to identify FEVR combined with MH in clinical practice to avoid wrong diagnostic and treatment options.

Evaluation of the effect of ocular dominance on macular microcirculation via swept-source optical coherence tomography angiography.

PURPOSE: To determine the existence of differences in the retinal microcirculation of dominant and non-dominant eyes, as well as of interocular differences in macular microcirculation, using swept-source optical coherence tomography angiography (OCTA). METHODS: In total, 122 eyes of 61 individuals were enrolled in this cross-sectional study. Measurements were taken using the swept-source optical coherence tomography Triton device (Topcon Corp, Tokyo, Japan) coupled with non-invasive OCTA technology. Macular perfusion parameters were assessed, including superficial vascular complex, vascular density of the deep vascular complex, vascular density of the choriocapillaris vascular complex, superficial foveal avascular zone and deep foveal avascular zone. Ocular dominance was determined among individuals with healthy eyes using the hole-in-the-card test. RESULTS: Ocular dominance was found in 68.9 % of right eyes and 31.1 % of left eyes. The mean age of the subjects was 34.45 ± 16.48 years (range: 18-73 years). We found that 16 (30.76 %) males and 22 (31.42 %) females had left-eye dominance (p > 0.05). None of the OCTA parameters differed between the eyes based on dominance (p > 0.05). Central macular thickness and sub-foveal choroidal thickness did not show significant differences (p > 0.05). When comparing interocular parameters, a significant difference was observed only in the inferior sector of the superficial vascular complex (p = 0.04). CONCLUSION: There was no significant difference in OCTA parameters between dominant and non-dominant eyes. There was no predominant interocular difference in the measurements.

Evaluation of retina and choroid perfusion with optical coherence tomography angiography in patients with retinitis pigmentosa.

PURPOSE: In this study, we aimed to evaluate macular perfusion with optical coherence tomography angiography (OCTA) and to investigate the correlation between OCTA quantitative data and visual acuity (VA) in patients with retinitis pigmentosa (RP). METHODS: This retrospective single-center study was conducted on 60 eyes of 30 RP patients and 52 healthy eyes. The vessel density (VD) of the superficial capillary plexus (SCP) and deep capillary plexus (DCP) of the macula, the size of foveal avascular zone (FAZ), choriocapillary flow density (FD) were measured using OCTA. Quantitative data obtained with OCTA were compared between the two groups. In addition, the correlation between the OCTA measurements and VA was examined. RESULTS: In patients with RP, the choriocapillary FD was decreased (p = 0.001), the FAZ area was enlarged (p = 0.010), and the VDs of the SCP and DCP were decreased in all areas (p = 0.001). Correlation was found between VA and SCP VD, whole image (p = 0.011, rho = -0.327) and parafoveal (p = 0.001, rho = -0.444) areas. CONCLUSION: Quantitative data from OCTA showed reduced macular perfusion in patients with RP compared to healthy controls. There was also a correlation between the quantitative OCTA data and VA.

Evaluation of Ocular Perfusion in Patients with End-Stage Renal Disease Receiving Hemodialysis Using Optical Coherence Tomography Angiography.

Hemodialysis (HD) is known to affect ocular blood flow. This case-control study aims to evaluate macular and peripapillary vasculature in patients with end-stage renal disease (ESRD) receiving HD in comparison to matched controls. A total of 24 eyes of 24 ESRD patients receiving HD and 24 eyes of 24 healthy, age- and gender-matched control subjects were prospectively included in this study. Optical coherence tomography angiography was used to image the superficial (SCP), deep (DCP), and choriocapillary (CC) macular vascular plexus, as well as the radial peripapillary capillaries (RPC) of the optic disc. In addition, retinal thickness (RT) and retinal volume (RV) were compared between both groups. Flow density (FD) values of each retinal layer and data of parameters related to the foveal avascular zone (FAZ), as well as RT and RV, were analyzed using Mann-Whitney U tests. There was no significant difference in FAZ parameters between the two groups. Whole en face FD of the SCP and CC was noticeably reduced in the HD group in comparison to the control group. FD was negatively correlated with the duration of HD treatment. RT and RV were significantly smaller in the study group than in controls. Retinal microcirculation appears altered in patients with ESRD undergoing HD. Concurrently, the DCP appears more resilient towards hemodynamic changes in comparison to the other microvascular retinal layers. OCTA is a useful, non-invasive tool to investigate retinal microcirculation in ESRD patients.

Evaluation of macular perfusion in eyes with proliferative diabetic retinopathy using optical coherence tomography - Angiography following panretinal photocoagulation.

AIM: The aim of this study is to evaluate the effect of panretinal photocoagulation (PRP) on macular perfusion using optical coherence tomography-angiography (OCT-A) in eyes with proliferative diabetic retinopathy (PDR) by assessing the vessel density (VD) and the size of the foveal avascular zone (FAZ) of the superficial capillary plexus (SCP) and the deep capillary plexus (DCP), before and after PRP. SETTINGS AND DESIGN: Prospective interventional study. SUBJECTS AND METHODS: Twenty-nine eyes of 17 patients with PDR underwent a measurement of best-corrected visual acuity (BCVA) and were imaged using OCT and OCT-A at baseline and 6-months of follow-up. Patients received three sittings of PRP using frequency-doubled neodymium-doped yttrium aluminum garnet laser. STATISTICAL ANALYSIS USED: The OCT-A variables were analyzed using generalized estimating equations. RESULTS: BCVA was unchanged at 6-months follow-up (P = 0.09). FAZ of SCP and DCP (P = 0.28 and 0.89, respectively), VD at foveal SCP (P = 0.08), foveal DCP (P = 0.05), parafoveal SCP (P = 0.13), and parafoveal DCP (P = 0.07) showed no statistically significant difference at 6 months post PRP. CONCLUSIONS: OCT-A parameters were not significantly affected by PRP at 6-months follow-up indicating no alteration in macular perfusion. Further analyses with larger samples and longer duration are warranted to confirm our results.

Impact of Silicone Oil Removal on Macular Perfusion.

(1) Background: Silicone oil (SO) can be used as an endotamponade during vitreoretinal surgery for retinal detachment. There is emerging evidence that SO filling of the vitreous cavity and its removal may impact macular perfusion. So far, studies have not focused on choroidal sublayer perfusion, yet. (2) Methods: Optical coherence tomography angiography was applied in 19 patients with SO endotamponade before and four weeks after removal of SO. (3) Results: Perfusion of choriocapillaris increased significantly after SO removal, while perfusion of Haller's and Sattler's layer decreased significantly. (4) Conclusions: Removal of SO impacts choroidal perfusion and leads to a perfusion shift within choroidal sublayers. This study underlines that it is worth to conduct larger prospective studies that evaluate the choroidal perfusion and its functional implications in more detail.

Reproducibility of macular perfusion parameters in non-proliferative diabetic retinopathy patients by two different OCTA sweep modes.

AIM: To assess the reproducibility of macular perfusion parameters in non-proliferative diabetic retinopathy (NPDR) patients measured by different examiners and two different sweep modes of optical coherence tomography angiography (OCTA). METHODS: Ninety-eight (98 eyes) patients with NPDR were included in this study. All participates were performed three times using Cirrus OCTA with Angiography 3×3 mm2 and 6×6 mm2 sweep mode by two examiners. The macular foveal avascular zone (FAZ) and vessel density (VD) in the superficial retinal layer (SRL) were measured. The reproducibility of the measurements was evaluated with intraclass correlation coefficients (ICC) and coefficient of variation (CoV). RESULTS: The intra-mode ICCs of Angiography 3×3 mm2 and 6×6 mm2 sweep mode were 0.957 to 0.959 and 0.964 to 0.977, respectively; and the inter-mode ICCs were 0.962 to 0.970. The intra-examiner ICCs of macular perfusion parameters were >0.950; and the inter-examiner ICCs were 0.928 to 0.969. All CoVs were <1.0%. CONCLUSION: Cirrus OCTA can measure macular perfusion parameters in NPDR patients with excellent reproducibility. The measurements of FAZ and VD in the SRL determined by Angiography 3×3 mm2 and 6×6 mm2 sweep mode are highly consistent and both sweep modes are suitable for macular perfusion parameters measurement.

Retinal and choroidal vascular changes in newly diagnosed celiac disease: An optical coherence tomography angiography study.

PURPOSE: To investigate the retinal and choroidal microcirculation changes in celiac disease (CD) patients via optical coherence tomography angiography (OCT-A). METHODS: This cross-sectional study included 44 pediatric patients with newly diagnosed CD and 44 healthy pediatric subjects. The vascular densities (VD) of the superficial, deep, and choriocapillar plexuses (VDs, VDd, and VDcc, respectively) (%), the superficial and deep foveal avascular zones (FAZs and FAZd) (%), the central macular thickness (CMT) (µm), and the subfoveal choroidal thickness (SFCT) (µm) were measured with swept-source OCT-A in addition to a complete ophthalmological examination. RESULTS: Mean ages of the CD patients and the healthy participants were 12.02 ± 2.9 and 13.6 ± 2.3 years, respectively. The central sectors of the VDs and VDd measurements were found to be significantly higher in the study group compared to the control group (p = 0.006; P = 0.001, respectively), and the temporal and nasal values of the VDcc measurements were significantly lower in the study group than in the control group (p < 0.05 for both values). CMT and FAZ metrics did not differ between the groups (p > 0.05). SFCT was significantly reduced (p = 0.001), and choroidal thinning was more considerable in female CD patients (p = 0.045). CONCLUSION: CD seems to affect macular and choroidal microcirculation. The reduced choriocapillaris plexus parameters and choroidal thickness may provide disease activity information.