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.     

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.     

Evaluation of the effect of obstructive sleep apnea syndrome on retinal microvascularity by optical coherence tomography angiography

PurposeUsing optical coherence tomography angiography (OCTA), we sought to determine whether there are retinal microvascular changes in patients with obstructive sleep apnea syndrome (OSAS).MethodThe study included 56 patients diagnosed with OSAS by polysomnography [21 patients with mild OSAS (group 1), 14 with moderate OSAS (group 2) and 21 with severe OSAS (group 3)], and 26 healthy individuals as a control group (group 4). The vascular densities of the superficial capillary plexus and deep capillary plexus of the retinal segmentations, together with the foveal avascular zone (FAZ) width, were measured for all participants, using OCTA.ResultCompared with the control group, vascular densitiy in whole image of superficial capillary plexus were found to be significantly lower in group 2. In addition, vascular densitiy in fovea region of superficial capillary plexus was significantly lower in group 1 than the control group. In deep capillary plexus, vascular densitiy of whole image, superior hemi and nasal regions were found to be significantly lower in group 2 and group 3 compared with the control group. Parafoveal region in group 3 had significantly lower vascular densities than the controls. A significantly larger FAZ was also found in group 1 and group 3 in the deep capillary plexus, compared with the controls.ConclusionWe detected smaller vascular densities in both the superficial capillary plexus and deep capillary plexus and a larger deep capillary plexus FAZ in OSAS patients. Therefore, OCTA may be useful as a non-invasive method to understand the systemic effects of OSAS.     

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.     

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.     

The role of optical coherence tomography angiography in reticular pseudodrusen

BackgroundTo investigate the changes in retinal and choriocapillaris vessel density (VD) in patients effected by early age-related macular degeneration (AMD) and reticular pseudodrusen (RPD), using Optical Coherence Tomography Angiography (OCTA).MethodsA total of seventy-eight eyes of 78 patients (43 male, 35 female, mean age 72.61 ± 5.15) with non-neovascular AMD (38 eyes with early AMD and 40 eyes with RPD) was recruited in this observational prospective study. Forty eyes of 40 healthy subjects represented the control group. The VD was measured in superficial capillary plexus (SCP), deep capillary plexus (DCP) and choriocapillaris in different macular regions.ResultsThere were no significant differences in VD of the SCP and DCP among the controls and the two study groups (p > 0.05). The VD of the choriocapillaris revealed a statistically significant reduction in early AMD and RPD groups respect to controls (p < 0.001). Furthermore, the patients with RPD showed a significantly decreased VD respect to patients with early AMD in different macular regions (p < 0.001).ConclusionsThe quantitative analysis of retinal and choriocapillaris blood flow by OCTA provided useful information regarding the vascular changes in non-neovascular AMD patients suggesting that the choriocapillaris loss is mainly involved in the pathogenesis of RPD.     

Quantitative changes in peripapillary,macular, and choriocapillaris microvasculature of patients with non-ocular Behçet's disease and relationship with systemic vascular involvement,an optical coherence tomography angiography study

BackgroundTo evaluate the changes in the peripapillary, macular and choriocapillaris microvasculatures in the eyes of patients with Behçet's disease (BD) without ocular involvement by optical coherence tomography angiography (OCT-A) and to investigate the relationship with systemic vascular involvement (SVI).MethodsThe study included 56 eyes of 33 patients with non-ocular BD and 61 eyes of 33 healthy subjects. The macular microvascular (MMV) vessel densities (VDs), FAZ parameters, Choriocapillaris flow area (CCFA), radial peripapillary capillary (RPC) VDs and optic nerve head (ONH) analyses were performed with OCT-A. MMV, RPC, ONH, and CCFA measurements were compared between the non-ocular BD patients and healthy controls. Then, the patient group was divided into two subgroups according to the presence of SVI. MMV, RPC, and CCFA measurements of these subgroups were compared with the healthy controls.ResultsWhile deep capillary plexus VD and foveal density decreased in MMV analysis in the BD group compared to the control group, CCFA was not different. In the RPC and ONH analysis, the VDs of the inside-disc small vessels and the VDs of the inside-disc all vessels were decreased while the cup/disk area ratio and cup volume were increased in the BD group compared to the healthy controls. Furthermore, the VDs of the inside-disc vessels were reduced in patients without SVI compared to those with SVI and healthy controls.ConclusionsThe RPC network, ONH and MMV architecture analysis by OCT-A revealed changes in the MMV, RPC, and ONH structures in non-ocular BD patients. Moreover, the decrease in RPC VDs and MMV VDs in patients without SVI suggested that the patients with BD without SVI had subclinical ocular involvement even in the absence of clinical ocular findings.     

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.     

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 findings of COVID-19 patients using ocular coherence tomography angiography two to three months after infection: Ocular appearance recovered COVID-19 patient

PurposeThe aim of this study was to evaluate the ocular disorders in COVID-19 patients, two to three months after infection.MethodsIn this cross-sectional, historically controlled study, fifty-one COVID-19 patients were compared with thirty-seven age, and gender-matched healthy individuals. After complete ophthalmological examination, all participants underwent peripapillary and macular optical coherence tomography, and optical coherence tomography angiography (OCTA) measurements (OptoVue Inc, Freemont, CA, USA).ResultsThe time between the initial onset of symptoms, and ophthalmologic examination was 63.31±15.21 (40–95 days). Ophthalmic examination of all the recovered COVID-19 patients was within normal range. None of the peripapillary and macular OCTA parameters were significantly different between the two groups with pairwise comparisons, but after adjusting for age, gender, axial length, and signal strength index (SSI), recovered COVID-19 eyes showed a significant increase in peripapillary retinal nerve fiber (RNFL) thickness, superficial, and deep macular vessel densities in parafoveal and perifoveal regions compared with healthy control eyes (p<= 0.05). Inner retinal thickness overall is higher in recovered COVID-19 eyes compared to healthy eyes after adjustment.ConclusionPatients with moderate-intensity SARS-CoV-2 pneumonia had altered peripapillary and macular vessel density compared to healthy subjects. Further investigation is warranted to analyze the correlation of these changes with disease severity as well as evolution of these changes over time.     

Is it useful to do OCTA in coronary artery disease patients to improve SYNTAX-based cardiac revascularization decision?

BackgroundTo investigate retinal and optic disk microcirculation using optical coherence tomography angiography (OCTA) in order to predict related outcomes based on the SYNergy between PCI with TAXUS and Cardiac Surgery (SYNTAX) score (SS) system in coronary artery disease patients.Methods104 patients were grouped based on coronary angiography results: 32 chronic coronary syndrome (CCS) patients, 35 acute coronary syndrome (ACS) patients, and 37 healthy controls. The SS system determined atherosclerosis degree and lesion-related mortality risk, followed by scoring as SYNTAX I score (SS-I) and SYNTAX II score (SS-II). Patients were further subdivided into SS-I, SS-II percutaneous coronary intervention (PCI), and SS-II coronary artery by-pass grafting (CABG) groups. Following a thorough ophthalmological examination, an OCTA Angio Retina mode (6 × 6 mm) automatically quantified retinal and optic disk microcirculation.ResultsThe mean ages did not differ significantly among groups (p = 0.940). The outer retinal select area varied significantly among groups, with the highest values found in ACS patients (p = 0.040). Despite non-significant differences between SS-I patients and healthy controls, the former had lower capillary plexus vessel densities in all regions and in foveal vessel density 300 μm around foveal avascular zone (FD-300) (p>0.05). Vessel densities were lowest in SS-II PCI≥28.5 patients, particularly in whole (p = 0.034) and parafoveal (p = 0.009) superficial capillary plexus, and in FD-300 (p = 0.019). Vessel densities were lowest in SS-II CABG (p = 0.020), and perifoveal (p = 0.017) deep capillary plexus, and in FD-300 (p = 0.003). The outer retina flow area increased the most in SS-II CABG≥25.1 patients (p = 0.020).ConclusionsUsing OCTA, a non-invasive imaging technique, to assess retinal and optic disk microcirculation appears to have the potential to yield significant clinical results in the early diagnosis or prognosis of cardiovascular diseases.     

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.     

Associations between body mass index and choroidal thickness,superficial and deep retinal vascular indices,and foveal avascular zone measured by OCTA

AimThe present study explores the effects of Body Mass Index (BMI) on choroidal thickness, the deep and superficial retinal capillary plexuses, and the foveal avascular zone (FAZ).MethodsThe subjects in this prospective study were divided into five groups based on their calculated BMI. Choroidal thickness, superficial and deep retinal capillary plexuses, and FAZ were measured using enhance depth imaging (EDI) and optical coherence tomography angiography (OCTA). The groups were then compared and correlations with BMI were evaluated.ResultsThe study included 210 eyes of 105 subjects. The comparison of the BMI groups revealed a significant decrease in the mean choroidal thicknesses in the obese groups (p = 0.001), and a significant negative correlation between BMI and mean choroidal thickness (p = 0.02). The results of the analysis of the mean superficial and deep retinal capillary plexuses did not differ between the groups (p = 0.089, p = 0.808 respectively), while the deep FAZ measurements revealed a significant decrease in the obese groups (p = 0.003).ConclusionChoroidal thickness and deep FAZ are significantly negatively correlated with BMI, suggesting potential choroidal and retinal microvascular effects of obesity.     

Optical coherence tomography angiography findings in transfusion-dependent beta-thalassemia patients with and without splenectomy

BackgroundOcular involvement is common in transfusion-dependent beta-thalassemia (TDβ-T) patients. We aimed to investigate the effect of splenectomy on optical coherence tomography angiography (OCTA) findings in TDβ-T patients.MethodsThe study is a prospective cross-sectional study. A total of 45 eyes of 23 patients with splenectomy (34.04±8.83 years), 18 eyes of 9 patients without splenectomy (27.44±5.43 years), and 54 eyes of 27 controls (33.22±6.44 years) were included. Vessel density in superficial capillary plexus, deep capillary plexus and radial peripapillary capillary, foveal avascular zone, choriocapillaris flow area, choroidal and retinal thickness detected by OCTA were evaluated. p < 0.05 was considered significant.ResultsVessel density of superficial capillary plexus and deep capillary plexus were similar in patients with and without splenectomy, and controls. Choriocapillaris flow area was significantly decreased in patients with splenectomy than that in those without splenectomy and controls (2.02±0.12 vs. 2.17±0.1 and 2.14±0.12; p < 0.001). Choroidal thickness was significantly lower in patients without splenectomy than in patients with splenectomy and controls (260.05±61.02 vs. 305.11±42.13 and 298.89±29.14, p = 0.008). Parafoveal and perifoveal thickness of the full retina and outer retina were significantly lower in patients without splenectomy than in patients with splenectomy and controls (301.06±10.0, 279.78±10.28 vs. 311.04±14.89, 290.87±13.67 and 316.63±13.57, 289.56±9.31, p < 0.001 and p = 0.002; 174.72±7.81, 167.17±6.21 vs. 182.87±8.81, 173.60±7.09 and 185.11±9.26, 173.96±6.79, p = 0.001 and p < 0.001, respectively).ConclusionsOCTA findings can provide information about the microvascular effects of splenectomy on the retina of patients with TDβ-T.     

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.     

Association between macular and papillary vessel density by optical coherence tomography angiography in a large healthy population

PurposeTo provide a normative data set of the relationship between macular and papillary vessel density (VD) using swept-source optical coherence tomography angiography (SS-OCTA) in a large healthy population.MethodsCross-sectional study conducted on 346 right eyes of healthy subjects. Macular and papillary SS-OCTA VD measurements of the retinal superficial capillary plexus (SCP), deep capillary plexus (DCP), and choriocapillaris (CC) in the central area and the four quadrants were obtained. Correlations between macular and papillary VD among different quadrants were assessed.ResultsThe mean participant age was 37.7 ± 19.8 years (range 5–83); 59% were women. No correlation was detected neither for the global SCP (R = 0.050; P = 0.040), DCP (R = -0.056; P = 0.038) nor CC (R = 0.102; P < 0.001) between macular and papillary VD. In a subanalysis, there was also no correlation in any of the quadrants studied (R ≤ 0.180; P < 0.001). In a subgroup of 45 left eyes, there was no correlation in the different plexus and layers studied between macular and papillary vasculature. No differences in SCP, DCP and CC were found according to gender, age or axial length in the relationship between macular and papillary VD.ConclusionThere is no association between macular and papillary VD neither in the SCP, DCP or CC in any of the regions studied. Hence, macular and optic nerve head vascularization should be investigated separately to identify which structure is more relevant in each disease.     

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.     

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.     

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.