Foveal Avascular Zone Research Articles

Clinical and imaging characteristics associated with foveal neovascularization in proliferative diabetic retinopathy.

To assess the prevalence of foveal neovascularization (FNV) and its associated clinical features in proliferative diabetic retinopathy (PDR) eyes. Cross-sectional observational study. Participants underwent ultra-widefield photography, optical coherence tomography (OCT), and swept-source OCT angiography (SS-OCTA). FNV was defined as a hyperreflective lesion breaching the internal limiting membrane and displaying flow signal on OCTA, within 1-mm of foveal avascular zone. Vascular metrics were obtained from the ARI Network portal. Ischemic index (ISI) and inner choroid flow deficit percentage were calculated using FIJI from 12 × 12 and 6 × 6-mm scans, respectively. Logistic regression models were used to compare eyes with and without FNV. We included 249 eyes of 164 patients (age: 58 [50-65] years). FNV was identified in 20 eyes (8%). Univariate logistic regression revealed significant associations between FNV and younger age (p = 0.03), higher maximal HbA1c (p = 0.04), worse visual acuity (VA) (p = 0.01), presence of disorganization of retinal inner layers (DRIL) (p = 0.01), no macular posterior vitreous detachment (PVD) (p = 0.03), neovascularization elsewhere (NVE) and at the disc (NVD) (p = 0.01 and p = 0.001), and greater ISI (p = 0.04). In multivariable analysis, a significant association remained between FNV and worse VA (p = 0.04), NVD (p < 0.001), DRIL (p < 0.001), and absence of macular PVD (p = 0.01). No associations were found with SS-OCTA vascular metrics. This study provides a comprehensive characterization of FNV in PDR. FNV was identified in 8% of our cohort, being more prevalent in younger patients with severe PDR, as evidenced by NVD and DRIL presence. The absence of macular PVD may explain its association with younger age. What is known • Neovascularization at the fovea occurs rarely in proliferative diabetic retinopathy. • OCT and OCT-angiography can be used to evaluate foveal neovascularization, which may be associated with choroidal vascular abnormalities. What is new • Foveal neovascularization was seen in 8% of eyes with proliferative diabetic retinopathy in this cohort. • Risk factors for foveal neovascularization included younger age, absence of macular posterior vitreous detachment, presence of neovascularization of the disc, and presence of disorganization of retinal inner layers. • We did not identify an association between foveal neovascularization and choroidal perfusion abnormalities in this study.

THE RELATIONSHIP BETWEEN RETINAL PERFUSION AND FUNCTIONAL RECOVERING OF FOVEA IN DIFFERENT TYPES OF SURGICAL CLOSURE OF FULL-THICKNESS MACULAR HOLES

Rationale: The effect of retinal perfusion on functional recovery of the fovea, as well as the value of quantitative perfusion parameters as predictors of functional outcome in the surgical treatment of full-thickness macular holes (FTMH) remains poorly understood.Objective: To study the relationship between changes in retinal perfusion and functional parameters of the fovea in the postoperative period at 1 and 2 types of FTMH closure.Methods: A prospective study including 93 patients (93 eyes) with idiopathic FTMH stage 2-4 according to D. Gass after surgical treatment. In subgroups with type 1 and type 2 of FTMH closure, changes in the foveal avascular zone (FAZ) area and vessel density in the superficial and deep capillary plexuses (SCP and DCP) in the fovea, changes in BCVA, retinal sensitivity (RS) at the fixation point, and P1 amplitude in the fovea were studied. Studies were performed preoperatively, 1 and 6 months after surgery. A significant correlation was found between the changes in BCVA, RS at the fixation point, P1 amplitude in the fovea, and changes in vessel density in the SCP and DCP, which was more pronounced in the period from 1 to 6 months after surgery. The correlation of the changes in the parameters is higher in type 2 of FTMH closure than in type 1 of FTMH closure.Results:. Subgroups with type 1 and type 2 FTMH closure included 67 and 26 eyes, respectively. Type 2 FTMH closure showed lower vascular density in the DCP before (p=0.02) and 6 months after surgery (p=0.03), lower BCVA before surgery (p=0.03), 1 and 6 months after surgery (p &lt;0.001), lower RS at the fixation point before and after surgery (p&lt;0.002).Conclusion. In type 2 macular hole closure, postoperative changes in retinal perfusion have a more pronounced impact on functional recovery of the fovea, especially in the late postoperative period.

Choroidal and retinal alteration after long-term use of tadalafil: a prospective non-randomized clinical trial.

The purpose of this study is to investigate choroidal and retinal vascular features in patients taking PDE5is by measuring dynamic vascular alterations and neurostructural features of the retina before and after oral tadalafil administration. The current clinical research involved 22 patients treated with tadalafil 20 mg on alternate days (OAD) after nerve-sparing robotic radical prostatectomy (NS-RARP) for prostate cancer. Patients underwent SD-OCT to assess ganglion cell complex (GCC), retinal nerve fiber layer (RNFL), and subfoveal choroidal thickness (SFCT), as well as OCTA to assess superficial capillary plexus (SCP), deep capillary plexus (DCP), choriocapillaris (CC), foveal avascular zone (FAZ), and radial peripapillary capillary thickness (RPC). All patients were evaluated at baseline (t0), and 3 (t1) and 6 (t2) months after the use of oral tadalafil. A statistically significant reduction in DCP and CC vessel density was found at t2 compared to baseline. According to the SFCT parameter, a statistically significant increase was observed from t0 to t1, and from t1 to t2. GCC parameter increased at t2 compared to baseline in a statistically significant way. No statistically significant differences were recorded between t0, t1 and t2 for the SCP, RPC, FAZ area, RNFL parameter. Retinal and optic disc toxicity may be detected using modifications of capillary vessel density. Further studies are needed to detect the possible progression or regression of ocular or systemic vascular complications in long-term follow-up.

Retinal Microvascular Changes in Association with Endothelial Glycocalyx Damage and Arterial Stiffness in Patients with Retinal Vein Occlusion: A Cross-Sectional Study

Background/Objectives: To investigate the potential association between the endothelial dysfunction and arterial stiffness with retinal changes observed through optical coherence tomography (OCT) and OCT-angiography (OCT-A) in patients with retinal vein occlusion (RVO). Methods: Participants in this cross-sectional study were 28 patients with RVO. The demographic and clinical characteristics of all participants were recorded. Comprehensive ophthalmologic examinations were performed, including fundus photography, OCT and OCT-A. Endothelial dysfunction was assessed by measuring the endothelial glycocalyx thickness via the perfused boundary region (PBR5-25). Arterial stiffness was evaluated by measuring the carotid-femoral pulse wave velocity (PWV), the central systolic and diastolic blood pressures (cSBP and cDBP) and the augmentation index (Aix). For each ophthalmological outcome, we generated a saturated linear regression model with demographic and systemic vascular parameters serving as independent variables. Regression coefficients with the corresponding 95% confidence intervals (CIs) were reported. A p value &lt; 0.05 was considered as statistically significant. Results: A 1 m/s increase in PWV was associated with a 0.6% reduction in inferior macular vessel density (VD) (p = 0.050). A 10 mmHg increase in cSBP was associated with a 0.03 mm2 increase in foveal avascular zone (FAZ) area (p = 0.033). A 1% increase in Aix was associated with a 0.005 mm2 increase in FAZ area (p = 0.008). A 1 μm increase in PBR5-25 was associated, on average, with a 4.4% decrease in superior peripapillary VD (p = 0.027). Conclusions: In patients with RVO, structural and microvascular retinal parameters were significantly associated with markers of endothelial dysfunction and arterial stiffness.

Angioarchitectural alterations in the retina and choroid in frontotemporal dementia.

Frontotemporal dementia (FTD) is a progressive neurodegenerative disorder that affects the frontal and temporal lobes of the brain, leading to cognitive decline and personality changes. The objective of this cross-sectional study was to characterize angioarchitectural changes in the retina and choroid of individuals with FTD compared to cognitively normal controls using optical coherence tomography (OCT) and OCT angiography (OCTA). Cross-sectional comparison of patients with FTD and controls with normal cognition. All participants underwent Mini-Mental State Examination (MMSE) at the time of imaging. Outcome measures included OCT parameters: retinal nerve fiber layer (RNFL) thickness, ganglion cell layer-inner plexiform layer (GC-IPL) thickness, central subfield thickness (CST), subfoveal choroidal thickness (SFCT), choroidal vascularity index (CVI); and OCTA superficial capillary plexus parameters: foveal avascular zone (FAZ) area, 3x3mm and 6x6mm macular perfusion density (PD) and vessel density (VD), 4.5x4.5mm peripapillary capillary perfusion density (CPD) and capillary flux index (CFI). Generalized estimating equation analysis was used to account for the inclusion of 2 eyes from the same participant. 29 eyes of 19 patients with FTD and 85 eyes of 48 controls were analyzed. In FTD, 3x3mm macular PD (p = 0.02) and VD (p = 0.02) and CFI (p = 0.01) were reduced compared to controls. There was no difference in average 4.5x4.5mm CPD, RNFL thickness, GC-IPL thickness, CST, SFCT, CVI, FAZ, or 6x6mm VD or PD between FTD and controls (all p > 0.05); however, there was a trend toward lower macular 6x6mm PD and VD in patients with FTD. Decline of peripapillary and macular OCT and OCTA parameters merit further investigation as potential biomarkers for FTD detection. Noninvasive retinal and choroidal imaging may hold promise for earlier detection, and future longitudinal studies will clarify their role in monitoring of FTD.

Effect of reduced saturation and elevated D-dimer and interleukin 6 levels on vessel density and foveal avascular zone in patients with COVID-19 bilateral pneumonia.

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection can affect multiple organs, including the eyes. This study aimed to identify associations between vascular density (VD) and the foveal avascular zone (FAZ), assessed using optical coherence tomography angiography (OCTA), and baseline levels of D-dimers and interleukin 6 (IL-6) in patients with bilateral COVID-19 pneumonia, depending on oxygen saturation (SpO2) on admission. The study included patients with COVID-19 bilateral pneumonia due to SARS-CoV-2 infection who were hospitalized between March and May 2021. Ophthalmological examination was performed 2 months after hospitalization. Optical coherence tomography angiography was used for the automatic assessment of the central retinal VD and the manual assessment of FAZ. A significant monotonic negative relationship was observed between SpO2 . 90% and VD in some areas of the superficial capillary plexus (SCP) (p = 0.048) and choriocapillaris (p = 0.021), and the mean VD in the deep capillary plexus (DCP) (p = 0.048). No significant monotonic negative relationship was noted between SpO2 . 90% and the FAZ in the SCP (p = 0.075). However, there was a significant monotonic positive relationship between VD in the nasal choriocapillaris and D-dimer levels in patients with SpO2 . 90% (p = 0.003, respectively). Finally, a monotonic negative relationship was identified between foveal VD in the DCP and IL-6 levels in patients with SpO2 . 90% (p = 0.027). An OCTA study conducted 2 months after hospitalization for COVID-19 bilateral pneumonia showed reduced VD in those with SpO2 . 90% and elevated levels of D-dimers and IL-6 during hospitalization. Optical coherence tomography angiography testing can provide monitoring of ocular status in patients following SARS-CoV-2 infection, especially those who report visual disturbances.

Evaluation of retinal and choroidal microvascular alteration after ICL V4c implantation based on OCTA

BackgroundTo evaluate the changes of retinal and choroidal microvascular including the superficial retinal capillary plexus (SCP), deep retinal capillary plexus (DCP), choriocapillaris (CC), and central retinal thickness (CRT) in high myopic eyes after the implantable collamer lens with a central hole (ICL V4c) implantation using optical coherence tomography angiography (OCTA).MethodsThis retrospective study included 30 eyes of 30 patients (14 males and 16 females) who underwent ICL V4c implantation in Tianjin Aier Eye Hospital from October 2022 to May 2023. Uncorrected distant visual acuity (UDVA), best corrected distance visual acuity (BDVA), intraocular pressure (IOP), spherical equivalent (SE), axial length (AL), and optical coherence tomography angiography (OCTA) were measured and assessed before surgery, and 1 week, 1 month, and 3 months after surgery. OCTA was used to image and measure several key indicators: the foveal avascular zone (FAZ), vascular density (VD) of the SCP and DCP, blood flow density (BD) of the CC, and CRT. All measurement data were obtained utilizing the instrument’s proprietary software, ensuring accuracy and consistency.ResultsUDVA were significant improvements at the 1 week, 1 month, and 3 months after ICL V4c implantation surgery. BDVA, FAZ, and CRT maintained stable, however, IOP was higher at 1 week and 3 months post-operation compared to 1-month post-operation. The statistically significant difference was identified within the S3, S7, and S9 of SCP at each time point before and after the surgery (P1 = 0.004; P2 = 0.014; P3 = 0.037). However, paired analyses showed that there was a significant decrease in VD of S3 at 1 week after ICL V4c implantation surgery (P < 0.05), which then returned to preoperative levels by 1 month (P > 0.05), and the increase in VD of the S7 region at 1 month after ICL V4c implantation, which is significant compared to 1 week post-surgery, but not compared to preoperative levels. An overall comparison of the BD of the CC (2 mm) at each time point showed a statistically significant difference (P = 0.029).ConclusionICL V4c implantation offers a safe and efficient therapy to the high myopic patients. However, the retinal and choroidal microvascular changes need to be paid attention to in post-ICL implantation patients.

Characteristics of optical coherence tomography in patients with iron deficiency anemia : a systematic review and meta-analysis.

The primary objective of this systematic review and meta-analysis was to assess the association between iron deficiency anemia (IDA) and retinal changes via optical coherence tomography (OCT). The search was conducted in MEDLINE, Scopus, Embase, Web of Science, and Google Scholar until February 1, 2024. Two independent researchers included the articles based on the inclusion and exclusion criteria. Data regarding the study design, patient characteristics, number of patients with and without IDA, mean and SD of the retinal nerve fiber layer (RNFL), C/D ratio, foveal avascular zone (FAZ) area and perimeter, foveal density and superficial and deep capillary plexus (SCP and DCP) vascular density (VD) were collected. STATA version 17.0 was used to compute pooled measures of the standardized mean difference. I2 and chi-square tests were used to assess heterogeneity between studies. We found 1378 nonduplicate studies, 35 of which were potentially relevant. 19 articles met the inclusion criteria and were included in the review. The meta-analysis confirmed that there was a statistically significant association between IDA and RNFL thickness reduction (SMD = -0.76, 95% CI: -1.09 to -0.44 ; p-value = 0.001, I2 = 86.88%), FAZ area (SMD =-0.35, 95% CI: -0.67 to -0.02; p value = 0.04, I2 = 59.76%) and SCP VD (SMD = -1.12, 95% CI: -1.85 to -0.39; p-value = 0.001, I2 = 83.15%). The associations between IDA and the C/D ratio (SMD = 0.07, 95% CI: -0.13 to 0.28; p value = 0.49, I2 = 0.0%) and DCP VD (SMD = -0.30, 95% CI: -0.89 to 0.29; ,p-value = 0.32 ,I2 = 77.20%) were not significant. There was no considerable publication bias. The results of this meta-analysis demonstrated that, compared with healthy controls, individuals with IDA presented a thinner RNFL, a smaller FAZ, and lower SCP and DCP vascular densities. However, further studies are needed to reach more conclusive results.

Analysis of retinal and choroidal microvasculature in systemic sclerosis using optical coherence tomography angiography: A systematic review and meta-analysis.

Optical coherence tomography angiography (OCTA) is an emerging technique to investigate retinal and choroidal microvascular alterations in patients with systemic sclerosis (SSc). This systematic review and meta-analysis aimed to evaluate the features of retinal and choroidal microvasculature using OCTA among SSc patients. The methodology of the study was based on PRISMA guidelines. PubMed, Scopus, Web of Science, and Embase were searched systematically on November 25, 2023, for relevant studies utilizing OCTA as the main diagnostic tool to assess the retinal and choroidal microvasculature in SSc patients versus healthy controls. Random-effect or fixed model meta-analysis was used based on the heterogeneity of studies. Eleven observational comparative studies, including 366 patients with SSc and 350 healthy controls, conducted between 2020 and 2023, were included in this review. Meta-analysis findings revealed a significant decrease in vessel densities in both the superficial and deep capillary plexuses (SCP and DCP) among SSc patients compared to controls. However, there were no significant differences observed in the foveal avascular zone (FAZ) area and choriocapillary flow area (CCFA) between SSc patients and controls. Moreover, central macular thickness (CMT) consistently exhibited a decrease in SSc patients, while retinal nerve fiber layer (RNFL) thickness showed no significant differences. Although radial peripapillary capillary (RPC) vessel density, subfoveal choroidal thickness (CMT), and cup/disc ratio yielded mixed results, with some studies indicating significant changes in the SSc group, meta-analysis could not be performed due to variations in the OCTA machines used across the included studies. This systematic review demonstrates retinal and choroidal microvascular abnormalities in SSc using OCTA. Longitudinal studies are needed to understand how these abnormalities evolve over time in patients with SSc and whether these abnormalities correlate with the clinical features of SSc.

Retinal microvascular phenotypes can track small vessel disease burden and CPAP treatment effectiveness in obstructive sleep apnoea.

Optical coherence tomography angiography (OCT-A) retinal imaging enables in vivo visualization of the retinal microvasculature that is developmentally related to the brain and can offer insight on cerebrovascular health. We investigated retinal phenotypes and neuroimaging markers of small vessel disease (SVD) in individuals with obstructive sleep apnoea (OSA). We enrolled 44 participants (mean age 50.1 ± SD 9.1 years) and performed OCT-A imaging before and after continuous positive airway pressure (CPAP) therapy. Pre-treatment analyses using a generalized estimating equations model adjusted for relevant covariates, revealed perivascular spaces (PVS) volume in basal ganglia associated with greater foveal vessel density (fVD) (p-value < 0.001), and smaller foveal avascular zone area (p-value = 0.01), whereas PVS count in centrum semiovale associated with lower retinal vessel radius (p-value = 0.02) and higher vessel tortuosity (p-value = 0.01). A reduction in retinal vessel radius was also observed with increased OSA severity (p-value = 0.05). Post-treatment analyses showed greater CPAP usage was associated with a decrease in fVD (p-value = 0.02), and increased retinal vessel radius (p-value = 0.01). The findings demonstrate for the first time the potential use of OCT-A to monitor CPAP treatment and its possible impact on both retinal and brain vascular health.

Diminished retinal microcirculation in mild preeclampsia without obvious retinopathy in high-altitude native Tibetans by OCTA

BackgroundTo investigate the retinal microcirculation in mild preeclampsia (PE) without obvious retinopathy in high-altitude native Tibetans by optical coherence tomography angiography (OCTA). MethodsThis study enrolled 64 mild preeclamptic pregnant women without retinopathy (group PPW), 63 healthy pregnant women (group HPW), and 61 healthy non-pregnant women (group HNPW). All participants were high-altitude native Tibetans who underwent OCTA, retinal thickness (RT), vascular density (VD), perfusion density (PD) and foveal avascular zone (FAZ) parameters were measured in the macula. Differences in these parameters among the groups were compared, and the correlations of these parameters with blood pressure were evaluated. ResultsIn the entire macula, VD and PD were significantly lower in group PPW than in group HPW and HNPW (p < 0.05). In the subregions, VD was significantly different in fovea, parafovea and perifovea, PD was significantly different in parafovea and perifovea among the three groups (p < 0.05), the further pairwise comparisons showed VD and PD in parafovea and perifovea were lower in group PPW than in group HPW, and VD and PD in perifovea were lower in group PPW than in group HNPW (p < 0.05). RT and FAZ parameters did not differ among the groups (P > 0.05). VD and PD exhibited negative correlations with SBP and DBP (p < 0.05). ConclusionOCTA can objectively evaluate diminished microcirculation in mild PE without obvious retinopathy among high-altitude native Tibetans, and provide a crucial time window for early screening of PE-induced retinopathy.

The effects of topical latanoprost 0.005% treatment on microvascular changes in the optic nerve head and macula.

This prospective study aimed to assess the impact of topical latanoprost 0.005% treatment on the microvasculature of the macula and optic nerve head (ONH) in primary open-angle glaucoma (POAG). Fifty-seven eyes of 31 subjects were enrolled. ONH whole-image (wiVD), peripapillary (ppVD), and macular vascular density (VD) parameters were measured using optical coherence tomography angiography before treatment, at the 1st month, and at the 3rd month of treatment. There was a significant reduction in IOP post treatment, with a decrease of 17.0 ± 2.3 mmHg in the 1st month and 16.3 ± 2.5 mmHg in the 3rd month (P < 0.001 for both). ONH wiVD and ppVD significantly increased at the post-treatment 1st month (P = 0.001 for both) but decreased by the 3rd month, returning to baseline levels (P < 0.001 for both), indicating a return to pre-treatment levels (P > 0.05 for both). Similarly, macular wiVD and perifoveolar VD (pefVD) increased significantly at the 1st month (P = 0.013 and P < 0.001, respectively) but returned to baseline by the 3rd month (P < 0.001 for both). No significant difference was observed between before-treatment and post-treatment 3rd month regarding the macular wiVD and pefVD (P > 0.05 for both). Deep capillary plexus and foveal avascular zone parameters did not change during follow-up (P > 0.05 for both). The initial increase in ONH and peripapillary VD, as well as macular VD, is attributed to the acute reduction in IOP from topical latanoprost 0.005%. However, the diminishment of sustained differences by the 3rd month indicates adaptation of the ONH and retinal microvasculature to decreased IOP through compensatory mechanisms.

Quantitative detection of macular microvascular abnormalities identified by optical coherence tomography angiography in different hematological diseases

It is now understood that hematological diseases can have detrimental effects on the retina, reducing retinal capillaries, compromising visual function, and potentially causing irreversible visual impairment. Over the years, there has been limited research on macular microvascular abnormalities, such as changes in vessel density and the foveal avascular zone (FAZ) and variations in the severity of these effects across different types of blood disorders. This study aims to quantitatively assess the impact of various hematological disorders on the retina using optical coherence tomography angiography (OCTA). Compared with healthy eyes, patients with different blood diseases exhibited reductions in linear vessel density (LVD), perfusion vessel density (PVD), FAZ area, and FAZ perimeter. Notably, patients with erythrocyte diseases showed more significant abnormalities in LVD and PVD, while patients with lymphocytic diseases demonstrated more pronounced abnormalities in the FAZ area and perimeter. OCTA imaging could potentially reflect changes of the retinal microvascular of patients with hematological diseases and may serve as a valuable tool for distinguishing abnormalities affecting different blood cell lines. This approach offers a novel avenue for assessing, treating, and monitoring blood disorders.

Impact of retinal traction induced by epiretinal membrane on aniseikonia

We investigated the effect of retinal traction caused by epiretinal membranes (ERMs) on aniseikonia and retinal microstructures in 81 unilateral ERMs. Retinal traction was quantified by measuring the maximum depth of the retinal fold (MDRF) using en face optical coherence tomography (OCT) images. Measurements included the mean inner nuclear layer (INL), outer plexiform layer (OPL), outer nuclear layer (ONL), central retinal thickness (CRT), and interocular ratios of the foveal avascular zone (FAZ) area (FAZ ratio). Significant correlations were found between the preoperative MDRF and preoperative aniseikonia (P < 0.001), INL thickness (P < 0.001), CRT (P < 0.001), and FAZ ratio (P = 0.003). Preoperative aniseikonia was significantly correlated with preoperative INL and OPL-ONL thicknesses (P < 0.001 and P = 0.020, respectively) and CRT (P = 0.003). Multiple regression analysis revealed that preoperative aniseikonia was significantly associated with preoperative MDRF, INL, and OPL-ONL thicknesses (P = 0.029, 0.006, and 0.006, respectively). Twenty-nine eyes underwent membrane peeling, resolving all retinal folds 6 months postoperatively. A significant correlation was observed between preoperative MDRF and postoperative aniseikonia (P = 0.011). Our findings suggest that retinal traction by ERM is significantly associated with aniseikonia both pre- and postoperatively, alongside other OCT parameters.

Macular Changes in Adults with History of Premature Birth.

To characterize changes in macular structure and vascularity seen in premature-birth adults. Retrospective review of adult patients seen in our clinic from July 2018 to November 2020 with history of premature birth not requiring treatment for retinopathy of prematurity (ROP), as well as healthy controls. Swept-source OCT-angiography (OCT-A) scans were analyzed for various parameters related to macular structure and vascularity. Statistical analysis was performed using univariate linear regression. Thirty-four eyes were included (17 eyes from 10 premature-birth adults, 17 eyes from 11 control patients). Prematurity was associated with vascular changes on OCT-A: decreased foveal avascular zone (FAZ) area (p=0.001), decreased FAZ circularity index (p<0.001), decreased superficial capillary plexus vessel (CPV) density (p=0.02), and decreased deep CPV density (p<0.001). Prematurity was also associated with structural changes: shallower foveal pit depth (p<0.001), decreased cube average thickness (CAT) (p=0.005), and increased central subfield thickness-to-CAT ratio (p=0.002). This is the largest published series of OCT-A data for premature-birth adults. Even without a history of ROP treatment, premature birth is associated with multiple changes to macular structure and vascularity that persist into adulthood. These include a smaller, more irregularly shaped FAZ, decreased juxtafoveal vascular density, and a shallower foveal pit.

The relationship between ON-OFF function and OCT structural and angiographic parameters in early diabetic retinal disease.

This study measured associations between ON and OFF functional indicators and structural optical coherence tomography (OCT) and OCT angiography (OCTA) markers in diabetic retinal disease. Fifty-four participants with type 1 or type 2 diabetes (mean age = 34.1 years; range 18-60) and 48 age-matched controls (mean age = 35.4 years, range 18-59) underwent visual psychophysical testing, OCT and OCTA retinal imaging. Psychophysical tasks measuring (A) contrast increment and decrement sensitivity and (B) response times to increment and decrement targets were assessed as surrogate measures of ON and OFF retinal ganglion cell function. The group with diabetes had worse foveal contrast increment and decrement thresholds (p = 0.04) and were slower to search for increment and decrement targets relative to controls (p = 0.009). Individuals with diabetes had a less circular foveal avascular zone (FAZ) (p < 0.001) but did not differ from controls in foveal vessel density and FAZ area. Functional and structural outcome measures related to the peripheral retina were also comparable between those with and without diabetes. Functional responses to increments and decrements were not significantly correlated with FAZ circularity or vessel density in individuals with diabetes. Diabetic retinal disease results in impaired performance on measures of inferred ON and OFF pathway function in addition to vascular deficits measurable with OCTA. Future longitudinal studies may determine the temporal relationship between these deficits, and whether they predict future diabetic retinopathy.

Alterations in optical coherence tomography angiography parameters after cataract surgery in patients with diabetes

This prospective study aimed to investigate microvascular changes in diabetic patients undergoing cataract surgery. Foveal avascular zone (FAZ) area, as well as vessel density (VD) in the macula and radial peripapillary capillary plexus (RPC), were compared before and after surgery. Sixty eyes (72.3%) had no diabetic retinopathy (no DR group) and 23 eyes (27.7%) had non-proliferative diabetic retinopathy (DR group). In the no DR group, the FAZ area in the superficial capillary plexus (SCP) decreased from 0.41 ± 0.13 to 0.38 ± 0.11 mm2 (P = 0.036), while no significant change was observed in the DR group (0.33 ± 0.12 to 0.30 ± 0.12 mm2, P = 0.091) at 6 months postoperatively. VD in the RPC increased from 34.4 ± 2.3% to 35.6 ± 2.3% in the no DR group (P = 0.009), but there was no significant change in the DR group (33.0 ± 3.5% vs. 34.0 ± 2.3%, P = 0.051) after 6 months. VD in the macula did not change in either group. Phacoemulsification reduced the FAZ area in the SCP and increased the VD in the RPC in diabetic patients without diabetic retinopathy at six months postoperatively.

Severity Stratification of Coronary Artery Disease Using Novel Inner Ellipse-Based Foveal Avascular Zone Biomarkers.

Given the similarities between the retinal and coronary microvasculature, the retina holds promising potential to serve as a non-invasive screening tool for coronary artery disease (CAD). We aimed to develop novel inner ellipse-based metrics and discern whether foveal avascular zone (FAZ) alterations can serve as indicators for CAD presence and severity. Patients admitted to the Department of Cardiology who underwent coronary angiography were included. This resulted in an inclusion of 212 patients, of which 73 had no CAD. During the same visit, 6 × 6-mm (nominal size) fovea-centered optical coherence tomography angiography images of both eyes were acquired. The Gensini score (GS) was utilized to quantify CAD severity. Six known FAZ shape metrics were assessed and three novel biomarkers based on the inner ellipse were defined: absolute inner ellipse difference, Hausdorff distance, and Chamfer distance. Eight out of nine metrics showed significant associations with the GS in the left eye. However, significant differences across three CAD severity groups were only demonstrated by the novel metrics. Utilizing the Chamfer distance, age, and sex, patients with and without CAD could be distinguished with an average area under the curve (AUC) of 0.89 (95% confidence interval [CI], 0.84-0.95). Moreover, three CAD severity groups could be discerned with a macro average AUC of 0.77 (95% CI, 0.72-0.84). A comprehensive assessment of FAZ shape descriptors was performed, and a strong association with CAD was found. The inner ellipse-based biomarkers especially demonstrated high predictive abilities for CAD presence and severity.

Evaluation of the early effects of the first-dose administration of the Sinovac vaccine on the retina, choroid, and optic disc using optical coherence tomography (OCT) and OCT-angiography

Aim To determine the effects of the first-dose administration of the Sinovac vaccine on the retina, choroid, and optic disc in healthy participants. Methods This prospective design study was conducted with 27 healthy healthcare workers who received the first dose of Sinovac vaccine and 25 healthy controls who were not vaccinated. In the vaccinated group, ophthalmological examinations and measurements were performed before vaccination and one week and one month after vaccination. Subfoveal, nasal, and temporal choroidal thicknesses (CTs), retinal nerve fiber layer (RNFL) thickness, and macular thickness (MT) were determined using spectral domain-optical coherence tomography at all visits. Superficial, deep, and peripapillary radial capillary plexus (superficial capillary plexus, deep capillary plexus (DCP), and radial peripapillary capillary, respectively), choriocapillaris vascular density, and foveal avascular zone parameters were measured on optical coherence tomography-angiography (OCT-A). Results No significant difference was detected between the two groups in terms of the parameters measured by OCT and OCT-A (p > 0.05 for all). The CT values measured in all quadrants were significantly higher at the first week after vaccination (p < 0.05 for all), and they returned to their pre-vaccination values at the first month post-vaccination measurement (p > 0.05 for all). Concerning the RNFL and MT values, there was no significant difference between the pre-vaccination and post-vaccination first-week measurements (p > 0.05 for all), but a statistically significant increase was detected in the post-vaccination first-month MT and RNFL measurements (p < 0.05 for all). Only the decreases in the foveal DCP and choriocapillaris vascular density values were significant at the first week after vaccination (p < 0.05 for all). Conclusion The early changes detected after vaccination in this study suggest the possibility that autoimmune, vascular, and inflammatory diseases may simultaneously emerge in the early post-vaccination period or may be triggered after vaccination, or that the vaccine may unmask these diseases.

Subtyping stage 3 epiretinal membrane: a comprehensive study of ectopic inner foveal layers architecture and its clinical implications

AimsTo evaluate the visual function and foveal architecture in patients with stage 3 idiopathic epiretinal membrane (iERM).MethodsA cross-sectional observational study included 56 eyes of 52 patients with stage 3 iERM....