Membrane frizzled-related protein: a comprehensive analysis of genetic characteristics, phenotypic manifestations and impact on retinal microvasculature

Objective: The foveal avascular zone (FAZ) is the round capillary-free zone within the macula and is supplied only by a single-layered parafoveal capillary arcade. This study aimed to evaluate the quantitative FAZ and retino-choroidal vessel density (VD) using optical coherence tomography angiography (OCTA) in a healthy Indian population.Methods: This was a cross-sectional observational study that was conducted for evaluating the quantitative FAZ and retino-choroidal VD of 200 eyes of 100 healthy Indian subjects, including 62 males and 38 females (age range 17-50 years) having the best-corrected visual acuity (BCVA) of logMAR 0 (20/20; 6/6) and spherical equivalent refractive error of not more than 1 D. The subjects were examined using OCTA automated software on spectral-domain OCT (SD-OCT; Nidek RS 3000 Advance 2; Nidek, Inc., Fremont, CA) on a 3 x 3 mm OCTA macular scan centred on the fovea. The FAZ size, perimeter and circularity index, VD in superficial, deep, and outer retina (OR), outer retinal chorio-capillaries (ORCC), chorio-capillaries (CC) and choroid (C) were analysed in the circular and quadrant-segmented zones. A correlation was found between the FAZ size, perimeter and circularity, and VD in retino-choroidal layers, and between BCVA, age, central foveal thickness (CFT) and sub-foveal choroidal thickness (SFCT), and OCTA parameters.Results: The FAZ and surrounding vascular arcades were intact in all eyes, showing either a vertical or horizontal oval-shaped symmetrical formation without gaps, holes or interruption of the capillary network. The mean value of CFT was 237.5±26.0 microns and SFCT was 269.6±53.0 microns. The mean FAZ area was 0.42±0.23 mm2, FAZ perimeter was 3.3±1.0 mm and FAZ circularity index was 0.46±0.1. The mean VD in superficial capillary plexus (SCP) was 23.87±10.66, in deep capillary plexus (DCP) was 16.03±9.90, in OR was 13.22± 12.27, in ORCC was 39.74±14.32, in CC was 37.02±16.43 and in choroid was 37.43±16.76. The increasing order of VD in different retino-choroidal layers was OR<DCP<SCP<CC<C<ORCC. The FAZ area and perimeter had a statistically significant (SS) negative correlation with the VD in SCP, DCP and OR, while the FAZ perimeter additionally had a SS negative correlation with the VD in the choroid. The FAZ circularity had a SS positive correlation with VD in SCP, DCP and OR. There was no SS correlation between the age of subjects and OCTA parameters. The BCVA had a SS correlation with only one parameter, i.e. ORCC foveal (r=-0.15; p=0.03). There was a SS negative correlation between CFT and FAZ area and perimeter, and a SS positive correlation between the CFT and VD in SCP, DCP and OR. There was a SS positive correlation between the SFCT and VD in different layers including SCP, DCP, ORCC, CC and choroid.Conclusions: VD is the highest in the ORCC and lowest in the OR segment. A better VD in SCP, DCP and OR is associated with a reduced FAZ area/FAZ perimeter and an increased FAZ circularity index. A lower VD in the ORCC is associated with worse BCVA. In a healthy subject, a relatively thicker foveal region is likely to have better vascularity of SCP, DCP and OR and a smaller FAZ area/FAZ perimeter. In the absence of diseases, relatively thicker sub-foveal choroid is expected to have better vascularity of SCP, DCP, ORCC, CC and choroid.

AimsTo investigate the structural changes of the superficial capillary plexuses (SCP) and deep capillary plexuses (DCP) using optical coherence tomography (OCT) angiography (OCTA) in patients with idiopathic macular hole (MH)...

Objective To analyze the correlation between foveal avascular zone (FAZ) size and foveal morphology in patients with idiopathic macular epiretinal membrane (IMEM) using OCT angiography (OCTA). Methods A retrospective case series study contained of 54 eyes of 54 patients affected with IMEM (IEM group) and 50 eyes of 50 normal persons as the control group. The BCVA was measured using the international standard visual acuity chart, and the results were converted to the logMAR visual acuity. The FAZ areas were evaluated with OCTA in both the superficial and deep capillary plexus layers by using 3 mm×3 mm images of the macular. The central macular thickness (CMT), inner retinal layer thickness (IRT), outer retinal layer thickness (ORT), subfoveal choroidal thickness (SFCT), and the status of ellipsoid zone (EZ) were assessed with spectral-domain optical coherence tomography. The differences of FAZ areas between the two groups were analyzed. The correlative analysis was performed to investigate the relationship between areas and foveal morphology. Results Compared with control group, the FAZ area in superficial and deep capillary plexus in the IMEM group were significantly smaller (t=−29.095, −28.743; P<0.001, <0.001); the mean CMT, IRT, ORT and SFCT were significantly thickening in the IMEM group (Z=−8.784, −8.524, −7.709, −7.535; P<0.001,<0.001, <0.001, <0.001). In the IMEM group, the FAZ area in superficial capillary plexus correlated inversely with the CMT, IRT, and the integrity of EZ (r=−0.464, −0.536, −0.293; P<0.001, <0.001, 0.039), no significant correlation of superficial plexus FAZ areas with ORT and SFCT (r=−0.218, −0.165; P=0.172, 0.157). The FAZ area in deep capillary plexus correlated inversely with the CMT, IRT, and the integrity of EZ (r=−0.306, −0.694, −0.468; P=0.037, <0.001, <0.001), no significant correlation with ORT and SFCT (r=−0.242, −0.227; P=0.079, 0.094). Conclusions The FAZ areas is significantly decreased in IMEM eyes compared with normal eyes. Both superficial and deep FAZ area are correlated with the CMT, IRT, and the integrity of EZ. Key words: Macula lutea; Membranes; Tomography, optical coherence; Foveal avascular zone

Objective To observe the changes of foveal avascular zone (FAZ) size before and after surgery in idiopathic macular epiretinal membrane (IMEM) eyes and analyze the correlation of FAZ with metamorphopsia. Methods A retrospective case series study. From August 2016 to October 2017, 42 eyes of 38 patients affected with IMEM diagnosed in Central Theater Command General Hospital of Chinese People's Liberation Army were enrolled in this study. All the patients underwent a 25G pars plana vitrectomy (PPV) with IMEM removal and ininternal limiting membrane (ILM) peeling. The BCVA was measured using the international standard visual acuity chart, and the results were converted to the logMAR visual acuity. The severity of metamorphopsia was measured using M-charts. The FAZ areas were evaluated with OCT angiography in both the superficial and deep capillary plexus layers. The central macular thickness (CMT) were assessed with spectral-domain OCT before and after surgery. The logMAR BCVA was 0.61±0.21. The M-score was 0.66±0.38. The CMT of fovea was 337.71±57.63 μm. The FAZ areas in superficial and deep capillary plexus were 0.113±0.037 mm2 and 0.202±0.03 mm2, respectively. The differences in BCVA, M-score and FAZ area before and 1, 3, 6, 12 months after surgery were analyzed by ANOVA. The Spearman rank correlation analysis was performed to investigate the relationship between FAZ areas, visual acuity and metamorphopsia. Results At 12 month after surgery, the FAZ areas in superficial and deep capillary plexus were 0.146±0.021 mm2 and 0.240±0.019 mm2, respectively. Compared with baseline, the the FAZ areas in superficial and deep capillary plexus after surgery significantly increased (F=8.484, 14.346; P<0.001,<0.001). The postoperative logMAR BCVA 0.47±0.19, M-score 0.12±0.22 and CMT 270.60±33.27 μm were significantly improved compared with baseline (F=5.044, 17.763, 13.545; P=0.001, <0.001, <0.001). The preoperative FAZ area in superficial capillary plexus correlated negatively with preoperative M-score (r=-0.816, P<0.001); the preoperative FAZ area in deep capillary plexus correlated negatively with preoperative BCVA and M-score (r=-0.422, -0.882; P=0.005,<0.001). The postoperative FAZ area in superficial capillary plexus correlated negatively with preoperative and postoperative M-score (r=-0.791,-0.716; P<0.001,<0.001). The postoperative FAZ area in deep capillary plexus correlated negatively with BCVA and preoperative and postoperative M-score (r=-0.343, -0.330, -0.732, -0.694; P=0.026, 0.033,<0.001,<0.001). Conclusions PPV with ILM peeling can effectively restore the FAZ areas in superficial and deep capillary plexus, improve the visual acuity and metamorphopsia in patients with IMEM. Both superficial and deep plexus FAZ areas correlated negatively with metamorphopsia, and deep plexus FAZ area also correlated negatively with BCVA. Key words: Macula lutea; Membranes; Vitrectomy; Tomographyoptical coherence; Foveal avascular zone; Metamorphopsia

To investigate microvascular changes in the superficial capillary plexus (SCP) and deep capillary plexus (DCP) in eyes with resolved branch retinal vein occlusion (BRVO) and their association with best-corrected visual acuity (BCVA). Eighty-five eyes (82 consecutive patients) with BRVO after resolution of the macular edema were retrospectively evaluated. All patients underwent optical coherence tomography angiography (OCTA) for assessment of microvascular changes, including capillary telangiectasia, microaneurysm, and disruption of the foveal avascular zone (FAZ). The areas of vascular perfusion and FAZ in the SCP and DCP were quantitatively evaluated. Best-corrected visual acuity was measured on the same day as OCTA examination. The correlation between BCVA and OCTA findings was assessed. In eyes with resolved BRVO, the mean vascular perfusion areas in the SCP and DCP within a 3 × 3-mm area were 3.75 ± 0.49 and 3.80 ± 0.55 mm2, respectively. The mean FAZ areas of the SCP and DCP were 0.57 ± 0.36 and 0.76 ± 0.38 mm2, respectively. Better BCVA was significantly associated with a larger vascular perfusion area in the SCP (P < 0.001) and DCP (P < 0.001), and a smaller FAZ area in the SCP (P = 0.025) and DCP (P = 0.017). Stepwise multiple regression analysis revealed that the vascular perfusion area in the DCP was the most important parameter significantly correlated with BCVA (R2 = 0.33, P < 0.001). Preservation of the deep retinal vasculature is crucial for better visual function in BRVO.

Introduction: The aim of this study was to investigate the correlation between ischemic index (ISI) measured on ultra-widefield (UWF) fluorescein angiography (FA) images and macular parameters obtained by optical coherence tomography angiography (OCT-A) in eyes affected by central retinal vein occlusion (CRVO). Methods: Retrospective study of data from 12 eyes affected by treatment-naïve CRVO. All patients underwent a comprehensive ocular examination including structural OCT, OCT-A, and UWF FA. Variables analyzed included best corrected visual acuity (BCVA) measured with the ETDRS chart; foveal avascular zone (FAZ) area at full-thickness OCT-A angiogram; perfusion density (PD) in the superficial (SCP) and deep capillary plexus (DCP); ISI; and central macular thickness (CMT). Results: ISI showed a significant positive correlation with FAZ area (r = 0.63, p = 0.019) and a significant negative correlation with PD in the SCP (r = −0.62, p = 0.022), PD in the DCP (r = −0.66, p = 0.011), and BCVA (r = −0.75, p = 0.002). FAZ area also negatively correlated to PD in the SCP (r = −0.75, p = 0.002) and DCP (r = −0.64, p = 0.016). BCVA positively correlated to PD in the SCP (r = 0.67, p = 0.009) and DCP (r = 0.68, p = 0.008), while a negative correlation was found with FAZ area (r = −0.65, p = 0.013) and CMT (r = −0.70, p = 0.006). Discussion/Conclusion: OCT-A macular parameters (namely, FAZ area and PD of SCP and DCP) significantly correlated with ISI, a quantitative way to assess peripheral retinal nonperfusion on UWF FA. Macular OCT-A analysis may help in assessing the need for additional UWF FA testing in eyes affected by CRVO.

Background. Diabetic macular edema (DME) is one of the main complications of diabetic retinopathy, which occurs in almost 12 % of patients and causes more than 10,000 new cases of blindness per year. About 5 % of patients with type 2 diabetes already have DME at the time of diagnosis. Thanks to the ra­pid development of research methods such as optical coherence tomography (OCT) and OCT-angiography, the possibilities of measuring retinal layer thickness, visualizing retinal and choroidal vessels have significantly expanded. The purpose of the study is to investigate the features of moderate diabetic macular edema (DME 2) in patients with type 2 diabetes. Materials and methods. Six hundred and eighty patients (1296 eyes) of the Ukrainian popu­lation with nonproliferative diabetic retinopathy and type 2 diabetes were under observation. In them, the nature and frequency of DME development were studied. Two hundred and three patients (360 eyes) with DME refused treatment, and eyes with DME 2 were selected from this group, and these patients were the target of our study. All of them were examined for uncorrected visual acuity, best corrected visual acuity, OCT and OCT-angiography indicators at presentation and after 3 months. Results. Moderate diabetic macular edema was detected in 56 eyes (15.56 %). Uncorrected visual acuity in these patients averaged 0.310 ± 0.004. Best corrected visual acuity was 0.4 ± 0.0 on average. According to OCT data, the average area thickness in quadrant 6 × 6 was 321.80 ± 1.40 μm, the minimum thickness of the retina in the fovea was 213.41 ± 2.30 μm, the average thickness of the retina in the central sector of the macula — 245.57 ± 2.50 μm, the average retinal volume in quadrant 6 × 6 — 9.23 ± 0.03 mm³, nerve fiber layer (NFL) + ganglion cell layer (GCL) + inner plexiform layer (IPL) average — 127.73 ± 0.10 μm, NFL + GCL + IPL min — 117.8 ± 0.1 μm, average thickness of GCL — 91.54 ± 0.20 μm, of NFL — 38.84 ± 0.10 μm. During OCT angiography, the surface area of the superficial foveal avascular zone (FAZ) was on average 0.51 ± 0.01 mm², the surface area of the deep FAZ was 0.59 ± 0.01 mm². The average density of the superficial capillary plexus was 47.75 ± 0.40 %. The average density of the deep capillary plexus was 48.52 ± 0.30 %. After 3 months, according to OCT, area thickness was 321.45 ± 1.34 μm, min in fovea — 213.41 ± 2.32 μm, central sector — 246.0 ± 2.4 μm, volume — 9.23 ± 0.03 mm³, NFL + GCL + IPL average — 127.52 ± 0.10 μm, NFL + GCL + IPL min — 117.59 ± 0.20 μm, GCL — 91.21 ± 0.20 μm, NFL — 38.84 ± 0.10 μm. According to OCT-angiography, superficial FAZ averaged 0.53 ± 0.01 mm², deep FAZ — 0.61 ± 0.01 mm². The ave­rage density of the superficial capillary plexus was 47.7 ± 0.4 %. The average density of the deep capillary plexus was 48.46 ± 0.40 %. Conclusions. The average frequency of DME 2 in patients with type 2 diabetes was 15.56 %. Uncorrected visual acuity appeared to have a statistically significant dependence on the area thickness (p &lt; 0.01), min in fovea (p &lt; 0.01), central sector (p &lt; 0.01), NFL + GCL + IPL average (p &lt; 0.01), NFL + GCL + IPL min (p &lt; 0.01), GCL (p &lt; 0.01), NFL (p &lt; 0.05) according to OCT data, as well as on the average area of foveal avascular zone in the superficial and deep capillary plexus (p &lt; 0.05), the density of the superficial and deep capillary plexus (p &lt; 0.01) according to OCT angiography.

Purpose: To provide clinical evidence of the associations between retinal neuronal degeneration and microvasculopathy in diabetic retinopathy (DR).Methods: This case-control study included 76 patients (76 eyes) with type 2 diabetes mellitus (DM), and refraction error between −3.0 and +3.0 D. The eyes were assigned into DM (without DR), non-proliferative DR (NPDR), and proliferative DR (PDR) groups. Age-, sex-, and refractive error-matched normal subjects were enrolled as controls. The mean retinal thickness (mRT), the relative mean thickness of the retinal nerve fiber layer (rmtRNFL, mtRNFL/mRT), ganglion cell layer (rmtGCL), ganglion cell complex (rmtGCC) layer, foveal avascular zone area (FAZa), FAZ perimeter (FAZp), FAZ circularity index (FAZ-CI), and vessel density (VD) in superficial capillary plexus (SCP) and deep capillary plexus (DCP) were assessed by swept-source optical coherence tomography (OCT) and OCT angiography (OCTA). Group comparison and Spearman's partial correlation coefficient analysis were applied to evaluate the correlation between these morphological parameters.Results: rmtRNFL, FAZa, and FAZp in SCP and DCP increased with the DR severity (prmtRNFL < 0.001; pFAZa, SCP = 0.001; pFAZa, DCP = 0.005; pFAZp, SCP < 0.001; pFAZp, DCP < 0.001). The rmtGCL, FAZ-CI in SCP and DCP, and VD in DCP decreased with the DR severity (prmtGCL = 0.002, pFAZ−CI, SCP = 0.002; pFAZ−CI, DCP < 0.001, pVD, DCP < 0.001). After controlling age, sex, duration of diabetes, and hypertension, the rmtRNFL, FAZa in SCP and DCP, and FAZp in SCP and DCP were correlated with the severity of DR (p < 0.05), while VD in SCP and DCP, FAZ-CI, and rmtGCL were negatively correlated with the severity of DR (p < 0.05). The rmtGCL was negatively correlated with the FAZa in SCP (r = −0.34, p = 0.002) and DCP (r = −0.23, p = 0.033), and FAZp in SCP (r = −0.37, p = 0.001) and DCP (r = −0.32, p = 0.003), but positively correlated with VD in SCP (r = 0.26, p = 0.016), VD in DCP (r = 0.28, p = 0.012), and FAZ-CI in DCP (r = 0.31, p = 0.006).Conclusions: rmtRNFL, FAZ-CI in SCP and DCP, and FAZp in SCP are strong predictors of the severity of DR. The ganglion cell body loss is highly correlated with increased FAZp and FAZa, decreased FAZ-CI, and reduced VD with the severity of DR.

To evaluate pre- and postoperative microvasculature features in eyes with different idiopathic macular epiretinal membrane (iERM) classifications using optical coherence tomography angiography (OCTA). In this retrospective study, 100 eyes with iERM were enrolled; 62 eyes underwent pars plana vitrectomy (PPV). All iERM eyes were evaluated and graded using optical coherence tomography (OCT). According to the thickness of the fovea relative to the surrounding macula from OCT radial line scans, we classified iERM into three grades. Optical coherence tomography angiography (OCTA) was used to measure the foveal avascular zone (FAZ)-related parameters and the superficial and deep capillary plexus layers using 3×3mm scans. Measurements were taken at baseline and 3months postoperatively. Best corrected visual acuity (BCVA), vessel density (VD), FAZ area, FAZ perimeter (PERIM), acircularity index (AI), and foveal vessel density (FD) were evaluated. Idiopathic macular epiretinal membrane (iERM) eyes with a higher grade had a lower FAZ area and perimeter (p<0.0001), higher foveal vessel density (FVD) both in the superficial capillary plexus (SCP) (p<0.0001) and in the deep capillary plexus (DCP) (p<0.05), and a lower parafoveal vessel density (PRVD) in the DCP (p<0.0001). The macular vessel density ratio (MVR=FVD/PRVD) increased with an increase in grade both in the SCP and in the DCP (p<0.0001). For grade 1 iERM eyes, only PRVD in the DCP significantly changed before versus after the operation (p<0.05). For grade 2 iERM eyes, the FAZ area and perimeter became larger after the operation (p<0.05). The MVR of grade 2 iERM eyes decreased postoperatively both in the SCP (p<0.05) and in the DCP (p<0.001). For grade 1 and grade 2 iERM eyes, preoperative LogMAR BCVA was negatively correlated with the FAZ area (p<0.01) and perimeter (p<0.01), and was positively correlated with the MVR in the SCP (p<0.05). Postoperative LogMAR BCVA was positively correlated with the FVD in the DCP (p<0.05). Idiopathic macular epiretinal membrane (iERM) eyes of different grades have significant differences in microvasculature features. According to OCTA, eyes with higher grades have more serious microvascular changes. Grading plays a part in predicting postoperative microvascular characteristics, and grade 1 iERM eyes have a better visual outcome compared with grade 2 iERM eyes.

Objectives: To evaluate the long-term effects of coronavirus disease (COVID-19) on optic disc and macular microvasculature. Methods: 40 post-COVID-19 and 40 healthy subjects were included. Optical coherence tomography angiography (OCTA) was performed for all subjects at the first visit and repeated in the fourth and twelfth months. Radial peripapillary capillary (RPC) vessel density (VD), retinal nerve fiber layer (RNFL) thickness, foveal avascular zone (FAZ) area, FAZ perimeter, VDs of the fovea, parafovea, and perifovea at superficial capillary plexus (SCP) and deep capillary plexus (DCP), and central macular thickness (CMT) were evaluated. The OCTA measurements of the COVID-19 group were compared with the control group. Results: The COVID-19 group showed lower VD values than the control group in the nasal parafoveal quadrant of the SCP at all visits (p = 0.009, p = 0.47, p = 0.042) and in the superior perifoveal quadrant of the DCP in the twelfth-month visit (p = 0.014). At all visits, FAZ area and FAZ perimeter were higher (p = 0.02, p = 0.02, p = 0.002; p = 0.002, p = 0.003, p = 0.005), foveal VD values of both SCP and DCP were lower (p < 0.001, p < 0.001, p < 0.001; p = 0.005, p = 0.001, p = 0.001), and CMT was lower (p < 0.001, p = 0.001, p = 0.001) in the COVID-19 group. The COVID-19 group had higher temporal quadrant RPC at all visits (p = 0.003, p = 0.003, p < 0.001) and higher average, superior and inferior RNFL at first and fourth-month visits (p = 0.014, p = 0.020; p = 0.001, p = 0.003; p = 0.021, p = 0.024). Conclusions: There are long-term changes that mainly point to the ischemia in the COVID-19 patients. We emphasize the need for long-term ophthalmologic and systemic follow-up of COVID-19 patients regarding potential complications.

To characterize changes in the retinal microvasculature in eyes with birdshot chorioretinopathy (BCR) using OCT angiography (OCTA). Retrospective, observational, single center. Twenty-eight patients (53 eyes) with BCR and 59 age-matched controls (110 eyes). En face OCTA images of the superficial capillary plexus (SCP) and deep capillary plexus (DCP) of each eye were assessed for the presence of microvascular abnormalities and used to measure the vessel and foveal avascular zone (FAZ) areas. A longitudinal analysis was performed with a representative cohort of 23 BCR eyes (16 patients) at baseline and at a 2-year time point. Whole-image vessel density (VD, %), extrafoveal avascular zone (extra-FAZ) VD (%), and FAZ area (%) were calculated and compared between control and BCR eyes. The frequency of microvascular abnormalities in BCR eyes was recorded. In the SCP, increased intercapillary space and capillary loops were common features present on OCTA images. Whole-image and extra-FAZ VD were lower in the BCR group compared with controls (P < 0.0001 [SCP and DCP]). Foveal avascular zone area was enlarged in BCR eyes (P= 0.0008 [DCP]). Worsening best-corrected visual acuity was associated with a decrease in whole-image and extra-FAZ VD in the SCP (P<0.0001 for both) and the DCP (P < 0.005 for both). Multivariable analysis, with vessel analysis parameters as outcomes, demonstrated that increasing age, increasing disease duration, lower central subfield thickness, and treatment-naive eyes (compared with those on only biologics) were associated with a significant decrease in both DCP whole-image and extra-FAZ VD. Increasing disease duration was associated with a significant decrease in both SCP whole-image and extra-FAZ VD. Longitudinal analysis demonstrated no significant difference in any vessel analysis parameters except for an increase in DCP FAZ area. Our results demonstrate a significant a decrease in VD in BCR eyes and an association on multivariable analysis with disease duration. Quantifying VD in the retinal microvasculature may be a useful biomarker for monitoring disease severity and progression in patients with BCR. Further studies with extended longitudinal follow-up are needed to characterize its utility in monitoring disease progression and treatment response. Proprietary or commercial disclosure may be found in the Footnotes and Disclosures at the end of this article.

Background and objective Vascular endothelial growth factor-A (VEGF-A) plays an important role in the development of diabetic macular edema (DME). In this study, we aimed to correlate optical coherence tomography angiography (OCTA) parameters with serum VEGF-A levels in DME. Methodology We conducted a prospective study, which examined 44 eyes of 32 DME patients (mean age: 56.0 ±9.1 years) for visual acuity (VA), defective colour vision (CV), and contrast sensitivity (CS). The OCT was done for central foveal thickness (CFT), sub-foveal choroidal thickness (SFCT), neurosensory detachment (NSD), epiretinal membrane (ERM), and disorganized retinal inner layers (DRIL). The OCTA was used to study the foveal avascular zone (FAZ) in superficial capillary plexus (SCP) and vessel density (VD) in six retino-choroidal layers, including SCP, deep capillary plexus (DCP), outer retina (OR), outer retinal chorio-capillaries (ORCC), chorio-capillaries (CC), and choroid. The serum VEGF-A levels were measured using an enzyme-linked immunosorbent assay (ELISA) kit. The eyes were treated with a single intravitreal injection of 0.3 mg/0.05 ml ranibizumab biosimilar (RbB). The subjects were re-examined after a short period of one month for visual, OCT, and OCTA parameters and serum VEGF-A levels. A correlation between OCTA parameters and serum VEGF-A was done on both occasions. Results At baseline, the logarithm of the minimum angle of resolution(logMAR) best-corrected visual acuity (BCVA) was 0.82 ±0.13, CFT 464.60 ±173.06 microns, SFCT 238.02 ±42.88 microns, and the serum VEGF-A level was 487.94 [interquartile range (IQR): 305 to 775.52] pg/ml. There was a positive correlation of serum VEGF-A level with LogMAR BCVA (r=0.15), CFT (Rho=0.02) and SFCT (Rho=0.14), while there was a negative correlation with FAZ area (Rho=-0.20), perimeter (Rho=-0.19) and VD of SCP (Rho=-0.22), DCP (Rho=-0.02), OR (Rho=-0.10), ORCC (Rho=-0.12), CC (Rho=-0.10) and choroid (Rho=-0.17). After a short follow-up of one month following intravitreal injection, LogMAR BCVA was 0.53 ±0.22, CFT 350.07 ±153.02 microns, SFCT 232.40 ±44.30 microns, and the serum VEGF-A level measured 404.02 (IQR 204.61 to 750.87) pg/ml. There was a positive correlation of serum VEGF-A level with LogMAR BCVA (r=0.48), CFT (Rho=0.19), and SFCT (Rho=0.11), while there was a negative correlation of serum VEGF-A levels with FAZ area (Rho=-0.01), perimeter (Rho=-0.06), and VD of SCP (Rho=-0.22), DCP (Rho=-0.13), OR (Rho=-0.10), ORCC (Rho=-0.25), CC (Rho=-0.18), and choroid (Rho=-0.29). The correlation coefficient values indicated that all observed correlations were weak. Conclusion In our study, the BCVA decreased while CFT and SFCT increased, along with an increase in serum VEGF-A levels. The higher serum VEGF-A was related to smaller FAZ and lower retino-choroidal VD. The observed weak correlation of ocular, OCT, and OCTA features with serum VEGF-A levels may limit the predictive value and clinical utility of these biomarkers in the management of DME.

Objective: To observe changes in foveal avascular zone(FAZ) and capillary plexus in idiopathic macular epiretinal membrane (IMEM) in optical coherence tomography angiography (OCTA) and analyze their correlation with the visual acuity. Methods: Cross-sectional study. 42 patients (15 Males and 27 females, age 64.8) from the Eye Hospital of Wenzhou Medical University were included with 51 eyes diagnosed as IMEM (IMEM group), and 23 normal eyes (9 Males and 14 females, control group). All patients received the examination of fissure lamp combined with fundus pre-set lens, best corrected visual acuity (BCVA), OCT angiography (OCTA) and fundus photo. OCTA was performed on 3 mm× 3 mm sections centred on the fovea. The software automatically measured the superficial capillary plexus (SCP) and deep capillary plexus (DCP) vessel density(VD) and retinal thickness(RT) and FAZ area. The IMEM eyes were compared with the normal eyes and correlation between the parameters of OCTA and BCVA was analyzed in IMEM. Independent-sample t test and MannWhitney test were used for comparison between groups, and Spearman test was used for correlation analysis. Results: LogMAR BCVA in the IMEM group was 0.40(0.15, 0.70), in the control group was 0.10(0.05, 0.22). FAZ area of IMEM group was (0.09±0.05) mm(2), while that of control group was (0.34±0.13)mm(2).Compared with the control group, in IMEM group, the BCVA was worse (Z=-4.443, P<0.001), FAZ area was smaller (t=-9.198, P<0.001), RT was increased (P<0.001), The foveal DCP and SCP vessel density was increased (t=4.280, 9.079, P<0.01), The parafoveal DCP vessel density was decreased (P<0.05), The parafoveal SCP vessel density was decreased in superior, inferior and nasal side (t=-2.759, Z=-3.998, Z=-2.108; P<0.05). The BCVA was negatively correlated with FAZ area (r=-0.337, P=0.017), positively correlated with center macular thickness (r=0.324, P=0.020). The BCVA was no correlated with foveal VD and parafoveal DCP vessel density (P>0.05), but correlated with SCP vessel density(P<0.05). Conclusions: In the IMEM eyes the BCVA was worse, FAZ area was smaller, foveal vessel density was increased and the parafoveal vessel density was decreased compared with the normal eyes. The smaller the FAZ area, the smaller foveal SCP vessel density, the poorer BCVA. There was no correlation between BCVA and DCP vessel density. Changes in VD in IMEM eyes may lead to changes in vision. (Chin J Ophthalmol, 2019, 55:757-762).

To analyze the correlation of superficial and deep capillary plexuses using optical coherence tomography (OCT) angiography with visual acuity in eyes with retinal vein occlusion (RVO). We retrospectively reviewed the medical records of 33 patients with retinal vein occlusion (RVO; branch retinal vein occlusion in 21 patients, central retinal vein occlusion in 12 patients) and included 33 healthy subjects as a control group, who were evaluated by OCT angiography. The OCT angiography was performed on a 3 mm × 3-mm region centered on the fovea and parafoveal area. The foveal avascular zone (FAZ), and foveal and parafoveal vascular density (VD) in superficial and deep vascular plexuses were analyzed using OCT angiography. The area of superficial and deep FAZ in eyes with RVO were larger than those in fellow eyes and control eyes (P = 0.034, P = 0.018). The superficial and deep parafoveal VDs in eyes with RVO were significantly lower than those in fellow eyes and control eyes (P = 0.001, P< 0.001). The area of superficial FAZ was negatively correlated with best-corrected visual acuity, and the superficial and deep parafoveal VDs were positively correlated with best-corrected visual acuity. Eighteen of the total 21 eyes with branch retinal vein occlusion (85.7%) showed a high concordance rate with respect to the location of branch retinal vein occlusion and the lowest parafoveal VD area. The multivariate analysis showed that the deep parafoveal VD was associated with best-corrected visual acuity. The OCT angiography allows to detect FAZ enlargement, increased parafoveal capillary nonperfusion, and decreased parafoveal VD in eyes with RVO. The area of superficial FAZ and the parafoveal VD are correlated with best-corrected visual acuity in eyes with RVO.

Purpose: The purpose of this paper is to evaluate macular microvascular changes and their correlation with visual outcomes after idiopathic epiretinal membrane (iERM) surgery. Methods: Forty-seven eyes operated for iERM were included in this retrospective case series. The foveal avascular zone (FAZ) area, and the vessel density (VD) in the superficial and the deep capillary plexus (SCP and DCP) were evaluated using optical coherence tomography angiography (OCTA). The association between the OCTA parameters and best-corrected visual acuity (BCVA) was examined preoperatively and postoperatively. Regression analyses were conducted to determine the potential predictive factors for visual recovery. Results: At baseline, the FAZ area in iERM eyes was significantly smaller than that in the control eyes (p < 0.001). iERM eyes also had a lower macular VD in both the SCP and the DCP (p < 0.001). Preoperative BCVA was negatively correlated with the FAZ area (r = -0.499, p < 0.001) and macular VD in the DCP (r = -0.422, p = 0.003). A negative correlation was also found between postoperative BCVA and macular VD in both the SCP (r = -0.394, p = 0.006) and the DCP (r = -0.569, p < 0.001). In the bivariate analyses, age, preoperative BCVA, iERM stage, and baseline macular VD in the SCP were significantly associated with BCVA at 6 months post-surgery. Multivariate regression analysis revealed that the preoperative BCVA was the only predictor of visual outcomes in iERM eyes (p < 0.001). Conclusions: Idiopathic epiretinal membrane (iERM) causes microvascular changes, including foveal avascular zone (FAZ) contraction and decreased macular vessel density (VD) in both the superficial capillary plexus (SCP) and the deep capillary plexus (DCP). These changes were significantly correlated with pre- and/or postoperative best-corrected visual acuity (BCVA). However, none of these alterations appeared to have prognostic value for visual outcomes in patients with iERM.