OCT and OCTA evaluation of vascular and morphological structures in the retina in recovered pediatric patients with COVID-19

BackgroundUsing OCT and OCTA imaging, we aimed to determine whether COVID-19 induces pathological changes in vascular and morphological structures in the pediatric retina.MethodsThe current prospective, cross-sectional, observational clinical study included recovered pediatric patients with COVID-19 evaluated between May 2020 and June 2020. Retinal vascular (radial peripapillary, superficial, and deep capillary plexus vessel densities) and morphological (peripapillary retinal nerve fiber, ganglion cell layer, retinal, and choroidal thickness) in the optic disk and macula regions were quantitively assessed using OCT and OCTA. Data were compared between COVID-19 patients and age-matched controls.ResultsThe COVID-19 group included 32 eyes of 16 patients and the control group included 32 eyes of 16 cases. Fundus and biomicroscopic examinations revealed no signs of pathology in the COVID-19 group. Mean peripapillary retinal nerve fiber, ganglion cell layer, and choroidal thickness values were significantly greater in the COVID-19 group than in the control group (p<0.05). OCTA indicated that mean superficial and deep capillary plexus vessel densities, and choriocapillaris flow area values were significantly lower in the COVID-19 group than in the control group, whereas mean radial peripapillary capillary plexus vessel density values were significantly higher (p<0.05).ConclusionsEven if fundus examination results appear normal in pediatric patients with COVID-19, vascular and morphological changes may be observed in the retina. Further studies with larger numbers of patients are needed to elucidate the clinical significance of vascular and morphological changes in this population.     

Retinal microvascular changes in patients recovered from COVID-19 compared to healthy controls: A meta-analysis

PurposeTo investigate changes in retinal microcirculation in patients recovered from COVID-19 infection compared to healthy controls, using optical coherence tomography-angiography.MethodsMeta-analysis of eligible studies comparing retinal microcirculation between patients recovered from COVID-19 infection and healthy controls up to 7th of September 2022 was performed, according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses 2009 guidelines. The following search algorithm was used: (COVID-19 OR coronavirus) AND (retina OR optical coherence tomography OR optical coherence tomography angiography OR vessel density OR foveal avascular zone). Standardized Mean Difference (SMD) with 95% confidence interval (CI) was calculated to compare continuous variables. Revman 5.3 was used for the analysis.Results12 studies were included in our analysis. Foveal avascular zone (FAZ) area was larger in patients recovered from COVID-19 infection compared to healthy controls, while there was no statistically significant difference in FAZ perimeter between the two groups. The foveal, parafoveal and whole image vessel density in the superficial capillary plexus showed no significant difference between the two groups. The foveal, parafoveal and whole image vessel density in the deep capillary plexus was statistically lower in patients recovered from COVID-19 compared to healthy controls.ConclusionFAZ area was enlarged and foveal, parafoveal and whole image vessel density in deep capillary plexus were reduced in patients recovered from COVID-19 infection compared to healthy controls, suggesting that COVID-19 infection may induce long-term retinal microvascular changes in patients recovered from the virus infection.     

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

BackgroundTo investigate and compare the peripapillary and macular microvascular parameters between eyes with primary angle closure glaucoma (PACG) and primary open-angle glaucoma (POAG) using optical coherence tomography angiography (OCTA).MethodsSeventy-nine eyes of 43 patients with primary angle closure glaucoma (PACG), 78 eyes of 43 patients with primary open-angle glaucoma (POAG), 64 eyes of 35 patients with primary angle closure (PAC), and 73 eyes of 40 control subjects underwent imaging with OCTA. Perfusion density (PD) and vessel density (VD) for the macular area, and PD and flux index (FI) for the peripapillary area were calculated automatically. The area under receiver operator characteristic curves (AUC) were constructed to distinguish PACG and POAG eyes from healthy control eyes.ResultsThe peripapillary FI in all quadrants and PD and VD of the macular outer circle in superior and inferior quadrants were significantly lower in PACG and POAG eyes than in control eyes. The peripapillary FI in the inferior quadrant was significantly lower in the POAG group than in the PACG group (0.348 ± 0.06 vs. 0.369 ± 0.06, p = 0.04). The remaining OCTA parameters in the peripapillary and macular area did not show a significant difference between the POAG and PACG groups. Eyes with PAC presented significantly lower PD and VD than healthy control eyes at the superior and inferior quadrant of the macular outer circle, while retinal nerve fiber layer and ganglion cell inner complex thickness were not significantly different from than control eyes. The best diagnostic parameter was peripapillary FI in both PACG (AUC: 0.922) and POAG (AUC: 0.938) eyes.ConclusionsWe found significantly lower peripapillary FI in the inferior quadrant in POAG eyes compared to the PACG eyes, which may indicate the different underlying pathogenesis between POAG and PACG. The PAC eyes had lower macular PD and VD than normal eyes. This suggests that retinal vascular impairment may develop earlier than structural damage in PAC eyes.     

Choriocapillary regional characteristics in idiopathic macular holes using optical coherence tomography angiography

Purpose: To evaluate the characteristics of vascular density (VD) of the retinal capillary plexuses in idiopathic macular hole (IMH), the fellow eye, and healthy control eyes by optical coherence tomography angiography (OCTA).Methods: A retrospective cases series study involving 20 unilateral eyes (20 patients) with IMH, the unaffected fellow eyes (n = 20) and 20 health controls, with age- and sex-matched, was conducted in Shanxi Eye Hospital from January 2019 to December 2021. VD of the retinal capillary plexuses measurements were obtained by OCTA.Results: Four quadrants of superficial capillary plexuses (SCP) in IMH eyes were not significant compared with that in the unaffected fellow eyes (all P > 0.05). The four quadrants of deep capillary plexuses (DCP) in IMH eyes were lower than that in the unaffected fellow eyes (all P < 0.05). Different regions retinal thickness in the IMH eyes was higher than that in the unaffected fellow eyes (all P < 0.05). a significant negative correlation between deep vessel density and retinal thickness in different quadrants among IMH eyes (all P < 0.05). Additionally, the correlation between the vascular density of SCP and retinal thickness was significant in macular fovea area (= 0.519, P = 0.019). <0.001.Conclusions: The morphology of retina and choroid in idiopathic macular hole is different from that in fellow eye. The thickness of choroid in the fovea area of the unaffected eye also showed a decreasing trend. Taken together, the mechanism of macular hole may be further understood, that is, the decrease of choroid thickness may occur before the macular hole formation. It was verified again that the choroidal blood flow area in macular fovea of IMH patients was significantly lower than that in fellow eyes and healthy eyes.     

Evaluation of macular and optic disc radial peripapillary vessel density with optical coherence tomography angiography in iron deficiency anemia

PurposeTo investigate effect of iron deficiency anemia (IDA) on macular and radial peripapillary capillary (RPC) vascular changes by optical coherence tomography angiography (OCTA).MethodsThirty-three patients with IDA and 33 healthy controls were enrolled in the study. Foveal avascular zone (FAZ) area, macular superficial capillary plexus (SCP) and deep capillary plexus (DCP) vessel density and RPC vessel density were evaluated by the AngioVue Imaging System. Hemoglobin (Hb), hematocrit (Hct), mean corpuscular volume (MCV), mean corpuscular hemoglobin (MCH), red cell distribution width (RDW), serum iron, total iron-binding capacity (TIBC), serum ferritin and transferrin saturation values were also recorded.ResultsThere were no statistically significant differences between the two groups in terms of FAZ area and FAZ perimeter while foveal density (FD) was significantly decreased in the IDA group. Compared to control group, IDA group revealed significantly decreased macular vessel density in all macular regions except fovea in both SCP and DCP. RPC vessel density was significantly decreased in whole image, peripapillary and superior-hemifield area wihout RNFL thinning. Hemoglobin level was positively correlated with SCP whole and RPC whole vessel density and serum iron level was also positively correlated with SCP whole vessel density.ConclusionMacular and optic disc vessel density were reduced in IDA patients. OCTA may be useful in detecting retinal ischemia before clinically visible signs of retinopathy associated with IDA appear.     

Relative peripheral refraction characteristics and their relationship with retinal microvasculature in young adults: Using a novel quantitative approach

AimTo analyze relative peripheral refraction (RPR) characteristics in young adults and to investigate the relationship between RPR and retinal microvasculature using multispectral refractive tomography (MRT), a novel quantitative approach.MethodsThis cross-sectional study included 278 eyes of 139 young adults. All eyes underwent complete ophthalmic examinations, including MRT, optical coherence tomography angiography (OCTA) and other ocular examinations. Refraction difference values (RDVs) among different rings/sectors were compared using one-way ANOVA in bilateral eyes. Stepwise multiple linear regression analyses were performed between ∆RDV in different rings and ∆density/thickness value in OCTA.ResultsAmong the different rings, the 30°-45°/45°-53° RDV was significantly greater than the inner rings in both eyes. Among the different sectors, RDV in the superior sector was most significantly reduced among all sectors, and RDV in the nasal sector was significantly greater than that in the temporal sector. In the stepwise multiple linear regression analyses, ∆RDV was negatively correlated with ∆radial peripapillary capillary plexus density and ∆macular thickness.ConclusionsMRT may be a useful tool in RPR quantitative assessment. RPR and some OCTA indexes might be closely correlated. Further research should be conducted to investigate the relationships among these indexes in young adults.     

Quantitative assessment of retinal vessel density and thickness changes in internal carotid artery stenosis patients using optical coherence tomography angiography

ObjectiveTo quantitatively assess the retinal features of patients with different degrees of internal carotid artery stenosis (ICAS), particularly mild ICAS patients, utilizing optical coherence tomography angiography (OCTA).MethodsThirty-two mild ICAS patients (mild ICAS group), 34 moderate to severe ICAS patients (nonmild ICAS group), and 40 controls were enrolled in this study. Retinal vessel density was quantitatively measured by OCTA, including radial peripapillary capillary vessel density (RPC-VD), superficial and deep capillary plexus vessel density (SCP/DCP-VD). Structural parameters were collected from optical coherence tomography (OCT), including retinal thickness and subfoveal choroidal thickness (SFCT). Furthermore, LASSO-penalized logistic regression was used to construct the diagnostic model based on retinal parameters. ROC curves and nomogram plots were used to assess the diagnostic ability of this model for ICAS.ResultsThe macular SCP-VD of mild ICAS patients was significantly lower than that of controls and lower than that of nonmild ICAS patients (all p < 0.05). However, there was no difference among the three groups in terms of DCP-VD (p > 0.05). RPC-VD could effectively discriminate between the mild ICAS group and the nonmild ICAS group (p = 0.005). For structural OCT, only the SFCT decreased as the ICAS degree increased (p < 0.05). Diagnostic scores based on retinal parameters showed a strong diagnostic capability for mild ICAS (AUC = 0.8656).ConclusionMild ICAS patients exhibited distinct retinal features compared to nonmild ICAS patients and control subjects. OCTA potentially represents a promising method for the early detection of ICAS patients and the noninvasive surveillance of haemodynamic changes in those patients.     

Peripapillary retinal nerve fiber layer and ganglion cell-inner plexiform layer changes on optical coherence tomography in patients with unilateral hypertensive cytomegalovirus anterior uveitis

PurposeTo investigate whether peripapillary retinal nerve fiber layer (pRNFL) and macular ganglion cell-inner plexiform layer (GCIPL) thinning are present in patients with unilateral hypertensive Cytomegalovirus anterior uveitis (hCMV AU).MethodsWe included 19 eyes with unilateral hCMV AU and their unaffected fellow eyes as the control group in this study. Peripapillary RNFL and macular GCIPL changes were determined using spectral-domain (SD) - optical coherence tomography (OCT).ResultsThe overall calculated mean pRNFL thickness was significantly lower in the effected eyes with hCMV AU than in the uneffected fellow eyes (p = 0.012). The mean macular GCIPL thickness in the affected eyes was also significantly lower than in the normal eyes (p < 0.001).ConclusionMeasurement of pRNFL and macular GCIPL thickness with OCT may detect signs of damage before the visual field changes in patients with hypertensive CMV AU. Early aggressive treatment in these patients may prevent further glaucomatous damage.     

Effect of blunt ocular trauma on retinal microvasculature: An optical coherence tomography angiography study

BackgroundTo evaluate the retinal vascular changes and foveal avascular zone area in patients with unilateral blunt ocular trauma using optical coherence tomography angiography.MethodsThis retrospective study consisted of 50 traumatized and 50 contralateral sound eyes of the patients with blunt ocular trauma. The foveal avascular zone area, choriocapillaris flow area, foveal, parafoveal, and perifoveal vessel densities in both superficial capillary plexus and deep capillary plexus and central macular thickness were evaluated.ResultsThere were no significant differences between traumatized and sound eyes in the foveal avascular zone area (p:0.36), choriocapillaris flow area (p:0.43), central macular thickness (p:0.67), and in vessel densities of superficial capillary plexus over all regions (p > 0.05 for all). However, the vessel densities of deep capillary plexus were significantly lower in traumatized eyes (p < 0.05 for all).ConclusionOptical coherence tomography angiography demonstrated a significant decrease in retinal deep capillary plexus vessel density of the eyes effected by blunt ocular trauma, even with no evident findings on fundus examination or structural spectral domain-optical coherence tomography changes.     

The evaluation of the effect of Nd-YAG capsulotomy on posterior ocular vascular structures by Optical coherence tomography angiography

BackgroundWe aimed to examine the changes in retinal, choroidal and optic nerve head vascular structures after Nd-YAG laser application due to posterior capsule opacification after cataract surgery by Optical coherence tomography angiography (OCTA).MethodsFifteen eyes of 15 patients who have posterior capsule opasification and underwent Nd-YAG laser capsulotomy were included in the study. OCTA imagings of patients were made before and one hour, one week and one month later after the laser procedure.ResultsNo significant change was determined before and after capsulotomy in macular thickness measurements, flow areas and vessel densities (all p > 0.05). Optic nerve head vessel densities and flow areas didn't differ preoperatively and postoperatively (p > 0.05).ConclusionsNd-YAG laser capsulotomy for posterior capsule opacification has no detectable effect on macular and optic nerve flows and vessel densities.     

Change in retinal vessel diameter and choroidal thickness in patients with severe COVID-19: Change In Retinal Parameters In Patients With Severe COVID-19

Purpose: To compare the differences in retinal vascular structure and choroidal thickness between the active disease and post-recovery periods in COVID-19 patients and healthy controls.Material and Methods: This prospective, cross-sectional study included 30 eyes from 30 patients with severe COVID-19 and 30 eyes of 30 sex-matched healthy controls. Central macular thickness (CMT), subfoveal choroidal thickness (CT) and retinal vascular changes of patients were measured after positive polymerase chain reaction (PCR) (where the patient had COVID-19-related symptoms) and then three months after two negative PCRs. Laboratory parameters, including C-reactive protein and d-dimer levels, were also recorded.Results: The mean age of the patients was 47.90 ± 9.06 years in patients group, 49.07 ± 8.41 years in control goups (p = 0.467). In terms of choroidal thicknesses subfoveal, nasal and temporal region were significantly higher in the active disease period than control group (p = 0.019, p = 0.036, p = 0.003, respectively). When the after recovery period was compared with the control group in terms of choroidal thickness, although the choroidal thickness was higher in all regions, this difference was not found statistically significant. There was no statistically significant difference in CMT between groups (p = 0.506).The mean venous and arterial wall thicknesses were significantly higher in the active period than after recovery (p = 0.023, p = 0.013, respectively) but there were no differences between after recovery and control groups in the pairwise comparison (p = 0.851, p = 0.715, respectively).Conclusion: In patients with severe COVID-19, there are changes in thickness of the choroid and retinal vessel walls. While vascular wall thickness increases due to inflammation, the absence of lumen changes may be associated with hemodynamic variables.     

Ozone-induced retinal vascular reactivity as assessed by optical coherence tomography angiography

BackgroundThis study aimed to investigate the retinal vascular reactivity (RVR) of the macular and peripapillary capillary network in response to ozonated autohemotherapy (AHT) using optical coherence tomography angiography (OCTA).MethodsThis was a single-centre prospective study. All participants that were planned to have a combination of major and minor ozone AHT underwent a complete ocular examination and OCTA imaging before and after the ozone AHT. Foveal avascular zone (FAZ) metrics and vessel density (VD) of superficial (SCP), deep capillary plexus (DCP), and radial peripapillary capillary (RPC) plexus were assessed using the built-in software.ResultsA total of 40 right eyes of 40 individuals were included. No significant differences were observed for the mean values of the FAZ metrics and choriocapillaris flow area following ozone AHT compared with baseline values (p > 0.05). The mean whole VD of SCP and DCP was 47.80 ± 2.18% and 53.09 ± 3.00% before treatment, which decreased to 47.68 ± 2.7% and 52.38 ± 3.07% after treatment (p = 0.660 and p = 0.097, respectively). No significant differences were observed in the vascular densities of both SCP and DCP in any quadrant (p > 0.05). The RPC density did not show significant alterations compared with baseline values, except the inferior-hemi region. The VD in the inferior-hemi peripapillary quadrant was significantly increased after ozone AHT (p = 0.034).ConclusionThe ozone AHT did not cause evident RVR in the macular area, whereas the peripapillary area showed a partial response.     

Investigation of changes in retinal vascular parameters and choroidal vascular index values during the early recovery period of COVID-19: The COVID-OCTA study

BackgroundCOVID-19 effects microvasculature in many tissues. This study investigated whether the choroidal structure is also affected.MethodsThis cross-sectional study included 80 patients with COVID-19 and the same number of age- and gender-matched healthy individuals. All participants' right eye measurements were examined. Optical coherence tomography angiography (OCTA) was used for imaging. Otherwise, two independent researchers used the Choroidal vascular index (CVI) for choroidal parameters calculation.ResultsSuperior and deep flow values were lower in the COVID-19 group than in the control group, and vascular density (VD) values were lower in all regions in this group. Except for the superior mean VD, there was no statistically significant difference (p = 0.003). However, the COVID-19 group had significantly lower subfoveal choroidal thickness (SFChT) measurements than the control group (p = 0.001). In addition, no significant difference was observed between the groups in evaluating mean CVI values (p>0.05).ConclusionNoninvasive diagnostic tools such as OCTA and EDI-OCT can be used to monitor early changes in diseases affecting microvessels, such as from COVID-19.     

Optic nerve head vessel density in patients with pseudoexfoliation syndrome/glaucoma: A systematic review and meta-analysis

PurposeExfoliative material has been shown to accumulate in ocular and systemic tissues. We aimed to perform a systematic review and meta-analysis of the current literature evaluating optic nerve head vessel density (VD) using optical coherence tomography angiography (OCTA) in patients with XFS and XFG.MethodsStudies were retrieved from PubMed, Scopus, and Web of Science databases. Studies comparing patients with XFS and/or XFG patients to healthy controls, using the optic nerve head-centred 4.5 × 4.5 mm square OCTA scan protocol were included. Pooled results are presented as standardised mean differences with 95% confidence intervals (CI). Meta-regression analysis was performed between mean difference in circumpapillary VD between XFG and controls and mean pRNFL thickness in patients with XFG.ResultsFifteen studies with 1475 eyes were included in this review. Whole image VD and circumpapillary VD (cpVD) were significantly decreased in patients with XFS [−0.78(95% Cl: −1.08, −0.47); −0.55(95% Cl: −0.80, −0.30); respectively] and XFG [−1.85(95% CI: −2.33, −1.36); −1.84 (95% CI: −2.30, −1.39); respectively] compared to healthy controls. Furthermore, pRNFL thickness decreased in patients with XFS [−0.55(95% Cl: −0.72, −0.35)] and XFG [−1.78(95% Cl: −2.21, −1.36)] compared to healthy controls. Meta-regression showed that pRNFL thickness decreased with increasing mean cpVD difference in XFG patients compared to healthy controls.ConclusionsOCTA provides non-invasive, objective and reproducible assessment of peripapillary VD and is important for the detection of vasculopathy in patients with XFS or XFG. This study provides strong evidence for decreased cpVD in the eyes of patients with XFS and XFG.     

The association between decreased choriocapillary flow and electroretinogram impairments in patients with diabetes

PurposeTo evaluate the association between choriocapillary flow (CCF) and electroretinogram (ERG) in patients with diabetes.MethodThis was a cross-sectional study. Patients with type 2 diabetes and healthy controls who had undergone both flicker ERG and optical coherence tomography angiography (OCTA) were included, while patients with severe diabetic retinopathy (DR) and macular edema were excluded. Correlations among OCTA and ERG parameters were conducted by generalized linear mixed models (GLMM).ResultOne hundred ninety-four eyes of 102 patients with diabetes and fifty-six eyes of 28 controls were included. The implicit time of 30-Hz flicker ERG successively increased, while the amplitudes, inner-retina vessel density and CCF were decreased from the control to the nondiabetic retinopathy (NDR) to DR group. In patients with diabetes, all GLMM models of ERG parameters had statistically significance (P<0.05), and CCF was correlated with ERG parameters (coefficient index=-0.601, P< 0.001 with 16 Td-s implicit time; coefficient index=-0.687, P< 0.001 with 32 Td-s implicit time; coefficient index=0.933, P=0.035 with 32 Td-s amplitude) and the thickness of retinal pigment epithelium, while in the GLMM model of CCF, it was correlated with the thickness of retinal pigment epithelium and the level of glycosylated hemoglobin(both P= 0.001).ConclusionCCF decreased in patients with diabetes, and it was related with ERG. Choroidopathy and its functional impairment in the retina may occur very early in patients with diabetes by influencing the outer retina.     

Macular and peripapillary optical coherence tomography angiography metrics in thyroid-associated ophthalmopathy with chorioretinal folds

PurposeTo evaluate macular and radial peripapillary capillary (RPC) microvascular densities and the thickness of the retinal nerve fiber layer (RNFL) in thyroid-associated ophthalmopathy (TAO) with chorioretinal folds (CRFs) and the associations of these characteristics with visual function.MethodA cross-sectional study was performed at the Ophthalmology Department of the Sun Yat-sen Memorial Hospital from March 2018 to August 2021. All patients underwent ocular examination, ophthalmic function tests and optical coherence tomography angiography (OCTA). The microvascular densities in the macula and optic papilla in the TAO with CRFs or without CRFs. Correlation analyses were used to examine the association of microvascular density and visual function.ResultsTen TAO patients with CRFs (CRF group, 20 eyes) and 10 TAO patients without CRFs (NCRF group, 20 eyes) were recruited for the study. Visual function measurements, including best-corrected visual acuity (BCVA), were found to be worse in the CRF group (all p < 0.05). The macular whole-image vessel density in the superficial layer (SLR-mwiVD) was significantly decreased in the CRF group (p < 0.05). The RPC whole-image vessel density (RPC-wiVD) was significantly decreased in the CRF group (p < 0.05), particularly in the temporal subfields. The P100 amplitude of visual evoked potentials (VEPs) was positively associated with SLR-mwiVD and RPC-wiVD. The thickness of RNFL in the CRF group was obviously thicker than that in the NCRF group (p < 0.05).ConclusionsOur study showed decreased microvascular density of the macula and RPC and thicker RNFL in TAO patients with CRFs. CRFs with decreased microvascular density should be regard as an indicator of visually threatening conditions.     

Macular optical coherence tomography angiography analysis in diabetes mellitus patients with a history of Covid-19

PurposeThere is evidence of decreased vessel density in optical coherence tomography angiography (OCTA) after Covid-19. We aimed to investigate whether the outcome of retinal vasculopathy would be worse if patients with diabetes mellitus (DM) were infected with coronavirus using OCTA to assess retinal vessels.MethodsOne eye of each subject was included in the study. Diabetic patients without retinopathy and non-diabetic controls were divided into four groups according to their Covid-19 history: group 1=DM(-)Covid-19(-); group 2=DM(+)Covid-19(-); group 3=DM(-)Covid-19(+); and group 4=DM(+)Covid-19(+). All Covid-19 patients were not hospitalised. Macular OCTA scans were performed in a 6 × 6 mm area.ResultsDiabetes had no effect on the area of the foveal avascular zone (FAZ), but Covid-19 caused an increase in FAZ area. Diabetes and Covid-19 had an effect on both the superficial capillary plexus (SCP) and the deep capillary plexus (DCP) in the fovea. Eta squared (ƞ2) is a measure of effect size. The effect size of Covid-19 (ƞ2=0.180) was found to be greater than that of diabetes (ƞ2=0.158) on the SCP, whereas the effect size of diabetes (ƞ2=0.159) was found to be greater than that of Covid-19 (ƞ2=0.091) on the DCP.ConclusionsThe percentage of vessel density was lower in the fovea and the FAZ area was enlarged in the diabetic patients who recovered from Covid-19. In diabetic patients Covid-19 may lead to deterioration of vascular metrics.     

Normative data assessment of age-related changes in macular and optic nerve head vessel density using optical coherence tomography angiography

ObjectiveTo investigate macular and optic nerve head vessel density in healthy individuals using optical coherence tomography angiography (OCTA), and determine their relationship with age.MethodThis retrospective study included 153 eyes of 153 individuals aged between 20 and 80 years, who had no systemic diseases, optic disk, or retinal pathologies. The retinal (6 × 6 mm) and optic disk (4.5 × 4.5 mm) OCTA images were evaluated for superficial capillary plexus (SCP), deep capillary plexus (DCP) and radial peripapillary capillary plexus (RPCP) vessel density, foveal avascular zone (FAZ) area, and choriocapillaris flow area and compared among 5 age groups.ResultsThe SCP vessel density was significantly associated with age for the whole image (P = 0.001), parafovea (P = 0.038), and perifovea (P/ce:italic>= 0.001). The DCP vessel density significantly varied with age in the whole image (P = 0.004), parafovea (P = 0.001), and perifovea (P = 0.002). The SCP and DCP vessel densities were significantly lower in the older age groups, and more prominently so after 50 years of age. The FAZ area increased with age; however, this finding was not statistically significant (P = 0.660). The choriocapillaris flow area decreased with age (P = 0.002). The RPCP vessel density in the inside disk significantly decreased with age (P = 0.038).ConclusionAge should be taken into consideration when using OCTA in the diagnosis and follow-up of retinal and optic nerve diseases. It is believed that the results here in can be used as a reference baseline for future studies.     

Comparison of peripapillary and macular vascular density in primary open-angle glaucoma,pseudoexfoliation glaucoma,and normal control eyes

PurposeTo compare the optical coherence tomography angiography (OCT-A) of the macula, and optic disc in primary open-angle glaucoma (POAG), pseudoexfoliation glaucoma (PXG), and normal eyes.MethodsIn this observational, cross-sectional study, Sixty–five eyes with POAG, 61 eyes of age, and mean deviation (MD) from standard automated perimetry matched PXG patients, and 45 normal control eyes underwent OCT-A using AngioVue, and optic disc-associated vessel density (VD), macular-associated VD, Foveal avascular zone (FAZ) area, FAZ perimeter (PERIM), and vessel density within a 300 μm wide region of the FAZ (FD) were compared between groups.ResultsPeripapillary OCT-A parameters were significantly different among normal, and glaucomatous eyes with the highest values in the control eyes, but none of the peripapillary OCT-A parameters except inside disc VD was statistically significantly different between the PXG eyes, and POAG eyes. Correlation analysis revealed significant correlation between mean retinal nerve fiber layer (RNFL) and peripapillary VD in control (r = 0.427, P = 0.006), PXG (r = 0.82, P<0.001), and POAG (r = 0.79, P<0.001) eyes.PXG eyes exhibited significantly lower superficial, and deep macular vessel densities in parafoveal and perifoveal regions compared with POAG eyes after adjustment (p<= 0.05). Overall, moderate /severe PXG eyes had lower superficial, and deep vessel densities in parafoveal and perifoveal regions compared to mild PXG.ConclusionPeripapillary VD (inside disc), and macular vessel densities (parafovea and perifovea) demonstrate a significant difference in age and glaucoma severity-matched POAG and PXG eyes. Moderate/advance glaucomatous eyes, exhibit significant damage to the superficial and deep macular vascular structures.