Retinal Vascular Changes Research Articles

Evaluation of Retinal and Posterior Segment Vascular Changes Due to Systemic Hypoxia Using Optical Coherence Tomography Angiography

Evaluation of Retinal and Posterior Segment Vascular Changes Due to Systemic Hypoxia Using Optical Coherence Tomography Angiography

The effectiveness of edible bird's nest in lowering VEGF, CD31, and PDGFR-β levels in diabetic retinopathy in rats with type 1 diabetes.

Diabetic eye disease, known as diabetic retinopathy (DR), is one of the problems that can arise from having high blood sugar for an extended period. This study aimed to investigate the effect of the edible bird's nest (EBN) on retinal angiogenesis in diabetic rats. The 50 rats were separated into five different groups, each containing 10 rats: control, diabetes (DM), bird's nest-fed diabetes (75 mg/kg Body weight; BW), (EBN 75), (150 mg/kg BW) (EBN 150), and glyburide (GR) for an eight-week study. H&E and Masson's trichrome staining were utilized to investigate the retinal tissue and vascular changes. The immunofluorescence study was used to detect angiogenic protein expression. The vascular corrosion cast/SEM method was also used to evaluate capillary plexus formation within the retinal layer. From histological studies, DM rats have thinning of the retinal layer. Remarkably, the retinal vessels displayed dilations resembling ruptured blood vessels. The expression of vascular endothelial growth factor (VEGF) (30.51±2.62), cluster of differentiation 31 (CD31) (28.18±0.22), and platelet-derived growth factor receptor beta (PDGFR-β) (141.67±0.97) were increased. EBN 75 exhibited some small improvements in their blood vessels and eye tissue. At a dose of 150 mg/kg BW, EBN proved to be more effective. There was a significant decrease in VEGF and CD31 expression compared with the diabetic group (p<0.001 and p<0.01, respectively). These studies have demonstrated that EBN can lower the growth levels of VEGF, CD31, and PDGFR-β, which results in a decrease in angiogenesis and a recovery from a variety of diabetic retinopathy-related diseases.

Retinal vascular changes after Silicon Oil removal in the Eye with Rhegmatogenous Retinal detachment

BackgroundThis study aims to examine vessel density changes in the optic nerve and macula following silicone oil removal (SOR) surgery in eyes with rhegmatogenous retinal detachment (RRD) at different time points by Optical Coherence Tomography Angiography (OCTA) in compared to the contralateral eye.MethodsA total of 43 eyes from 43 patients with silicone oil in their eyes for 3–9 months underwent OCT-A using AngioVue and optic disc-associated vessel density (VD) and thickness, macular-associated VD and thickness, Foveal avascular zone (FAZ) area, FAZ perimeter (PERIM), Acircularity index (AI), vessel density within a 300 μm wide region of the FAZ were compared between eyes. OCTA scans were performed one week before SOR and one month and three months after SOR.ResultsThe mean age of participants was 52.8 years (SD = 15.85) and a median visual acuity was 0.8 (range: 0.5-1.0). Notably, male participants constituted 67.4% of the sample. The preoperative mean value BCVA (logMAR) of patients was 0.73, and 3 months post-oil removal was 0.7727. Regarding optic disc parameters, RNFL thickness and vessel density (VD) measurements Peripapillary, whole disc, inside disc, and Disc Angio (superior, Nasal, inferior, temporal) did not change.In analyzing macular thickness parameters, all of them (Whole and Fovea, parafoveal, and Perifovea) remained unchanged. Examining macular vessel density parameters revealed no significant changes across superficial and deep retinal layers. Finally, the comparison of the foveal avascular zone (FAZ) area and flow density (FD) parameters demonstrated consistent measurements with non-significant alterations observed in FAZ size (p = 0.6) and FD values (p = 0.49) over the monitored duration.ConclusionThere was no change in peripapillary VD and macular vessel density of the superficial capillary plexus (SCP) and deep capillary plexus (DCP) after silicone oil removal. FAZ and full retinal thickness remained stable 3 month after SOR. Clinical trial number: Not applicable.

Vascular changes in the retinal capillary network in fellow eye of the patients with central retinal artery occlusion.

We aimed to evaluate the retinal vascular changes in the superficial and deep retinal vascular networks in the fellow eye of patients with central retinal artery occlusion (CRAO) and compare them with controls using optical coherence tomography angiography (OCT-A). In a cross-sectional study, 27 patients with CRAO and 189 normal controls were included. Ophthalmic examination and OCT-A images were performed on all participants. The total vascular density of the superficial capillary network in the 6-mm scan was significantly lower in the fellow eye of patients with CRAO than in the control group (p = 0.02). No significant difference was observed in the FAZ area of the affected eyes and their fellow eyes compared with the controls. Total vascular density at 300 microns around the fovea was lower in the fellow eye compared with the control group (p = 0.034). The retinal vascular network changes in the fellow eyes of patients with CRAO suggest that persistent microvascular changes may be present before the onset of CRAO. This finding indicates that such changes could serve as an early diagnostic window for systemic vascular changes before catastrophic vascular events occur.

Variation of retinal and choroidal microvascularization after an exercise stress test in patients with effort angina.

To describe retinal and choroidal vascular changes following an exercise stress test (ET) in patients with effort angina and to determine whether optical coherence tomography angiography (OCT-A) could play a role in the prediction of ischemic cardiac events. Prospective comparative study including patients with effort angina. All patients underwent OCT-A before and after an ET was performed. Blood flow, intercapillary spaces, and vessel density were analyzed in the superficial capillary plexus (SCP) and the deep capillary plexus (DCP). Vessel density in the choriocapillaris and the parameters of the central avascular zone (CAZ) were also analyzed. Of the 38 eyes included in the study, a decrease in blood flow was found in 39.5% in the large SCP vessels, in 50% in the capillaris of the SCP, and in 81.6% in the DCP. An increase in intercapillary spaces was observed in the SCP in 68.4% of eyes and in the DCP in 55.3% of eyes. A statistically significant decrease in the DCP density was observed after an ET (p = 0.03). There were no significant modifications in the CAZ parameters, the SCP density, nor the choriocapillaris density. Patients with a positive ET had a decreased DCP density in 83.3%. Among patients with an increased DCP density, 92.85% had a negatif ET. This pilot study suggests that DCP density significantly decreases after an ET. The DCP appears to be most affected in patients with effort angina. A larger trial is needed to further investigate these hypotheses.

Retinal Vascular and Structural Changes in the Murine Alzheimer's APPNL-F/NL-F Model from 6 to 20 Months.

Alzheimer's disease (AD) may manifest retinal changes preceding brain pathology. A transversal case-control study utilized spectral-domain OCT angiography (SD-OCTA) and Angio-Tool software 0.6a to assess retinal vascular structures and OCT for inner and outer retina thickness in the APPNL-F/NL-F AD model at 6, 9, 12, 15, 17, and 20 months old. Comparisons to age-matched wild type (WT) were performed. The analysis focused on the three vascular plexuses using AngiooTool and on retinal thickness, which was represented with the Early Treatment Diabetic Retinopathy Study (ETDRS) sectors. Compared to WT, the APPNL-F/NL-F group exhibited both vascular and structural changes as early as 6 months persisting and evolving at 15, 17, and 20 months. Significant vascular alterations, principally in the superficial vascular complex (SVC), were observed. There was a significant decrease in the vessel area and the total vessel length in SVC, intermediate, and deep capillary plexus. The inner retina in the APPNL-F/NL-F group predominantly decreased in thickness while the outer retina showed increased thickness in most analyzed time points compared to the control group. There are early vascular and structural retinal changes that precede the cognitive changes, which appear at later stages. Therefore, the natural history of the APPNL-F/NL-F model may be more similar to human AD than other transgenic models.

Choroidal and retinal vascular changes in HLA-B27-associated anterior uveitis.

To quantitatively analyze choroidal and retinal vascular changes in HLA-B27-associated anterior uveitis. A retrospective study. Medical records of 51 eyes with unilateral HLA-B27-associated anterior uveitis, their fellow eyes and 47 sex and age-matched healthy eyes were retrospectively reviewed. Their choroidal and retinal vasculature were analyzed using swept-source (SS) optical coherence tomography (OCT) and OCT angiography (OCTA) scans. Deep capillary plexus (DCP) vessel density (VD) (p < 0.001), choroidal vascularity index (CVI) (p = 0.012), and choriocapillary flow deficit (CCFD) (p < 0.001) of uveitic and fellow eye group were significantly higher than those of control group. On the contrary, superficial capillary plexus (SCP) VD (p < 0.001) of uveitic and fellow eye group were significantly lower than of control group. The vascular parameters of uveitis and fellow eye group showed no significant difference between uveitic and resolution period. Certain choroidal and retinal vascular parameters were significantly changed in both HLA-B27-associated anterior uveitis without posterior segment involvement and the quiet fellow eyes, suggesting their possible effects as a systemic inflammatory disorder.

Deep Learning‐Enabled Vasculometry Depicts Phased Lesion Patterns in High Myopia Progression

PurposeTo investigate the potential phases in myopic retinal vascular alterations for further elucidating the mechanisms underlying the progression of high myopia (HM). MethodsFor this retrospective study, participants diagnosed with high myopia at Beijing Tongren Hospital were recruited. Based on bionic mechanisms of human vision, an intelligent image processing model was developed and utilized to extract and quantify the morphological characteristics of retinal vasculatures in different regions measured by papilla-diameter (PD), including vascular caliber, arteriole-to-venule ratio (AVR), tortuosity, the angle of the vascular arch (AVA), the distance of the vascular arch (DVA), density, fractal dimension, and venular length. In addition, the optic disc and the area of peripapillary atrophy (PPA) were also quantified. The characteristics of the overall population, as well as patients aged less than 25 years old, were compared by different genders. Univariate and multiple linear regression analyses were conducted to investigate the correlation of retinal vasculature parameters with PPA width, and detailed trends of the vascular indicators were analyzed to explore the potential existence of staged morphological changes. FindingsThe study included 14,066 fundus photographs of 5775 patients (aged 41.2 ± 18.6 years), of whom 7379 (61.2 %) were female. The study included 12,067 fundus photographs of 5320 patients (aged 41.2 ± 18.6 years). Significant variations in the morphological parameters of retinal vessels were observed between males and females. After adjusting for age and sex, multiple linear regression analysis showed that an increased PPA width ratio was associated with lower AVA (1PD), DVA (1PD), vascular caliber (0.5–1.0 PD), tortuosity (0.5–1.0 PD), density and fractal dimension (all P < 0.001, Spearman’s ρ < 0). Overall, the changes in retinal vascular morphology showed two phases: tortuosity (0.5–1.0PD) and AVA (1PD) decreased rapidly in the first stage but significantly more slowly in the second stage, while vascular density and fractal dimension showed a completely opposite trend with an initial slow decline followed by a rapid decrease. ConclusionsThis study identified two distinct phases of retinal vascular morphological changes during the progression of HM. Traction lesions were predominant in the initial stage, while atrophic lesions were predominant in the later stage. These findings provide further insight into the development mechanism of HM from the perspective of retinal vasculature.

Advances in Structural and Functional Retinal Imaging and Biomarkers for Early Detection of Diabetic Retinopathy.

Diabetic retinopathy (DR), a vision-threatening microvascular complication of diabetes mellitus (DM), is a leading cause of blindness worldwide that requires early detection and intervention. However, diagnosing DR early remains challenging due to the subtle nature of initial pathological changes. This review explores developments in multimodal imaging and functional tests for early DR detection. Where conventional color fundus photography is limited in the field of view and resolution, advanced quantitative analysis of retinal vessel traits such as retinal microvascular caliber, tortuosity, and fractal dimension (FD) can provide additional prognostic value. Optical coherence tomography (OCT) has also emerged as a reliable structural imaging tool for assessing retinal and choroidal neurodegenerative changes, which show potential as early DR biomarkers. Optical coherence tomography angiography (OCTA) enables the evaluation of vascular perfusion and the contours of the foveal avascular zone (FAZ), providing valuable insights into early retinal and choroidal vascular changes. Functional tests, including multifocal electroretinography (mfERG), visual evoked potential (VEP), multifocal pupillographic objective perimetry (mfPOP), microperimetry, and contrast sensitivity (CS), offer complementary data on early functional deficits in DR. More importantly, combining structural and functional imaging data may facilitate earlier detection of DR and targeted management strategies based on disease progression. Artificial intelligence (AI) techniques show promise for automated lesion detection, risk stratification, and biomarker discovery from various imaging data. Additionally, hematological parameters, such as neutrophil-lymphocyte ratio (NLR) and neutrophil extracellular traps (NETs), may be useful in predicting DR risk and progression. Although current methods can detect early DR, there is still a need for further research and development of reliable, cost-effective methods for large-scale screening and monitoring of individuals with DM.

Defining Retinal Vasculitis

PurposeTo assess the validity of retinal vasculitis as the preferred diagnostic term for multiple conditions. DesignPerspective MethodsExpert opinion and review of literature focused on the current nosology and pathology of retinal vasculitis. Interpretation of the subset of intraocular inflammation named retinal vasculitis based on fundamental knowledge of the blood-retinal barrier, the neurovascular unit and pathological and functional responses to a variety of stimuli. Correlation with multimodal imaging and known mechanisms of immunologically mediated disease. ResultsA search of Medline in early 2024 for the phrase “retinal vasculitis” resulted in 2041 citations encompassing immunologic, genetic, neoplastic, infectious, drug- and ischemia-related disorders. Classification schemes and angiographic grading systems are descriptive and do not address pathologic mechanisms adequately, in part due to lack of histologic confirmation. Although OCT angiography holds promise for better imaging of retinal vascular changes, it does not reveal the key feature of leakage and only partially improves understanding of pathophysiology. Diagnosing catastrophic retinal vascular occlusion after intravitreal injections as a retinal vasculitis is the most recent example of speculative application of the term to complex and rare disorders. ConclusionsRetinal vasculitis is a diagnostic term that is over-used and imprecise. Revised nosology should limit the term to primary inflammation of the retinal vasculature itself that results in opening of the blood-retinal barrier with or without retinal vascular occlusions. Pending new histologic or mechanistic evidence, the provisional term of retinal vascular inflammation or retinal vasculopathy should be used for leakage or occlusion occurring in the context of intraocular inflammation.

Direct ophthalmoscopy as a screening tool to study retinal vascular changes in acute mountain sickness in response to recent ascent to high altitude: A pilot study.

Background Advanced diagnostics are not easily accessible in austere topographical locations. We documented retinal changes in patients with acute mountain sickness (AMS+) and compared these with asymptomatic individuals (AMS-) with recent induction into high altitude using direct ophthalmoscopy as a screening tool. Methods We evaluated 97 individuals (43 AMS- and 54 AMS+) who were inducted to an altitude 3800 m above sea level by direct ophthalmoscopy after pupillary dilatation, on day 2 of arrival. Results Retinal vein dilatation was seen in 36 (66.7%) AMS+ v. 14 (32.6%) AMS- (p<0.01), hyperaemia of the optic disc in 30 (55.6%) AMS+ v. 14 (32.6%) AMS- (p<0.05), hyperaemia of the optic disc along with retinal vein dilatation in 27 (50%) AMS+ v. 9 (20.9%) AMS- (p<0.01), retinal vein tortuosity in 12 (22.2%) AMS+ v. 3 (7%) AMS- (p<0.02). In AMS+ with retinal vein dilatation 17 (50%) had SpO2 >91% and 19 (79.2%) had SpO2 <91% (p<0.01). An AMS score of >5 was recorded in 25 (69.4%; p<0.001) with venular dilatation and in 19 (52.8%; p<0.001) who were AMS+ with an induction number ≥3 had retinal dilatation. Conclusion Acute hypobaric hypoxia causes retinal venous dilatation, tortuosity and hyperaemia of the optic disc in those with AMS and correlates directly with SpO2 levels. The incidence of retinal vein dilatation increases with frequent re-entry into high altitude and more severe symptoms of AMS. Hence, all those being inducted to high altitude should be screened for retinal vascular changes.

Retinal vascular changes and arterial stiffness during 8-month isolation and confinement: the SIRIUS-21 space analog mission.

Isolation and confinement are significant stressors during space travel that can impact crewmembers' physical and mental health. Space travel has been shown to accelerate vascular aging and increase the risk of cardiovascular and cerebrovascular disorders. However, the effect of prolonged isolation and confinement on microvascular function has not yet been thoroughly investigated. Retinal vascular imaging was conducted on four crewmembers during- and post-8-month SIRIUS-21 space analog mission. Central retinal arteriolar equivalent (CRAE), central retinal venular equivalent (CRVE), and arteriovenous ratio (AVR) were measured. Pulse wave velocity (PWV), an indicator of arterial stiffness, was also measured. Data from 4 participants was analyzed. These participants had a mean age of 34.75 ± 5.44years, height of 170.00 ± 2.00cm, weight of 74.50 ± 12.53kg, and average BMI of 25.47 ± 3.94kg/m2. During- and post-isolation, average CRVE showed an upward trend (Pearson's r 0.784, R-square 0.62), suggesting a dilation of retinal venules, while AVR showed a downward trend (Pearson's r -0.238, R-square 0.057), which is suggestive of a higher risk of cardiovascular and cerebrovascular dysfunctions. But neither of these trends were statistically significant. Additionally, the average PWV showed an upward trend during- and after-isolation across all crew members. Isolation and confinement appear to contribute towards retinal vascular damage and arterial stiffness. This cautiously suggests an increased risk of cardiovascular and cerebrovascular disorders due to the contribution of the isolation in space flight. Further studies are needed to confirm and expand on these results as we prepare for future manned missions to the Moon and Mars.

Longitudinal evaluation of macular vascular density alterations in unilateral amblyopic children undergoing therapy: An optical coherence tomographic angiography study

ImportanceUnderstanding the pathophysiology of the macula in amblyopic eyes is an active research area. ObjectiveTo correlate macular retinal vascular density changes with best-corrected visual acuity changes following occlusion therapy for amblyopia in children. DesignA prospective cohort study of children visiting the Pediatric Ophthalmology Division of our institution between January 2020 and January 2022 was conducted. SettingA specialist eye hospital in Saudi Arabia. ParticipantsThirty children with unilateral amblyopia. ExposureOcclusion therapy for amblyopia.Main Outcome and Measures: Best corrected visual acuity (logMAR) before and at each of the four optical coherence tomographic angiographies was compared in amblyopic and fellow eyes. The effect of pretreatment determinants on the correlation between best-corrected visual acuity and retinal vascular density changes was reviewed. ResultsIn this cohort of 30 amblyopic and 30 fellow eyes from 30 children (mean age 8.7 ± 1.4 years; male: female 18:12. The best-corrected visual acuity improved from a median of 0.6 (interquartile range 0.5; 1.1) pretreatment to a median of 0.4 (interquartile range 0.2; 0.6) posttreatment in amblyopic eyes, and from a median of 0.1 to 0.05 in the fellow eyes. The total percentage change in retinal vascular density in the amblyopic eye was significantly higher than that in the fellow eye (Z = −1.92, P = 0.05). The change in best-corrected visual acuity in the amblyopic eye after a median of 98 months (interquartile range, 69–126 months) of intervention was significantly correlated with the refraction-adjusted change in retinal vascular density (B = −0.03, 95 % confidence interval −0.04, −0.02, P < 0.001) and was influenced by strabismus (B = −0.46, 95 % confidence interval −0.59, −0.34, P < 0.001), type of amblyopia (B = 0.24, 95 % confidence interval 0.12, 0.36, P < 0.001), duration of occlusion (B = −0.43, 95 % confidence interval −0.65, −0.22, P < 0.001), and occlusion compliance (B = 0.24, 95 % confidence interval 0.11, 0.36, P < 0.001). Conclusionsand Relevance: The RVD in amblyopic eyes in the first six months of therapy was significantly lower than that in fellow eyes, but not in subsequent assessments.

Reduced Retinal Vascular Density and Skeleton Length in Amblyopia.

This study aimed to investigate the possible relationship between retinal vascular abnormalities and amblyopia by analyzing vascular structures of fundus images. In this observational study, retinal fundus images were collected from 36 patients with unilateral amblyopia, 33 patients with bilateral amblyopia, and 36 healthy control volunteers. We developed a customized training algorithm based on U-Net to digitalize the vasculature in the fundus images to quantify vascular density (area and fractal dimension), skeleton length, and number of bifurcation points. For statistical comparisons, this study divided participants into two groups. The amblyopic eyes and the fellow eyes of patients with unilateral amblyopia formed the paired group, while bilateral amblyopic patients and healthy controls formed the independent group. In the paired group, the vascular area (P = 0.007), vascular fractal dimension (P = 0.007), and vascular skeleton length (P = 0.002) of the amblyopic eyes were significantly smaller than those of the fellow eyes. In the independent group, significant decreases in the vascular fractal dimension (P = 0.006) and skeleton length (P = 0.048) were observed in bilateral amblyopia compared to control. The vascular area was also significantly correlated with best-corrected visual acuity in amblyopic eyes. This study demonstrated that retinal vascular density and skeleton length in amblyopic eyes were significantly smaller compared to control, indicating an association between the changes in retinal vascular features and the state of amblyopia. Our algorithm presents amblyopic retinal vascular changes that are more biologically interpretable for both clinicians and researchers.

Choroidal thickness and retinal vascular changes in patients with lichen planus: an inflammatory disease beyond the skin.

Lichen planus (LP) is a common inflammatory condition of unknown etiology that commonly affects the skin and mucous membranes. Optical coherence tomography angiography (OCTA) is a noninvasive technique for identifying early retinal vascular impairment in systemic disease without clinical damage by imaging deep and superficial capillary networks. To assess the impacts of LP on the choroid and assess vascular changes in retinal capillary density using OCTA. This single-center prospective case-control study included 30 therapeutic-naïve LP patients and 30 age and sex-matched healthy individuals. All study subjects underwent a complete ophthalmological examination, including best-corrected visual acuity (BCVA) measurement using a Snellen chart, slit-lamp biomicroscopy, intraocular pressure (IOP) measurement, and fundus examination. They were then examined using spectral domain OCT and choroidal thickness was measured. The vessel density of the superficial and deep capillary networks was measured and assessed using OCTA. Patients had significantly thicker choroidal and retinal thickness than controls, with subfoveal, nasal, and temporal areas showing a significant difference. A significantly higher vascular density in the superficial capillary plexus, particularly in the nasal perifoveal area, was found compared to the control group. Significantly, higher vascular density in the deep capillary plexus in the parafoveal area compared to controls was reported. Significant correlations were found between visual acuity and IOP, and age, duration of disease, and severity of disease. This study is the first to reveal that LP patients exhibit choroidal changes and retinal vascular alterations compared to healthy controls.

Optical coherence tomography angiography changes in patients with hemoglobinopathy

Aim: The aim of this study is to evaluate retinal vascular changes in patients with sickle cell disease (SCD) and beta-thalassemia with optical coherence tomography angiography (OCT-A). Methods: For this purpose, 98 patients with SCD, 75 patients with beta-thalassemia, and 100 healthy controls in Mersin University Hospital between January 1, 2020, and November 1, 2021, were included in this study. OCT-A imaging was performed with ZEISS AngioPlex OCT angiography (Carl Zeiss Meditec, Dublin, CA, USA). Results: All OCT-A parameters (FAZ area, perimeter, circularity, vessel, and perfusion density) were found to be statistically significantly different in both patients with thalassemia and patients with sickle cell disease when compared to the controls. Conclusions: In conclusion, retinopathy related to both hemoglobinopathy subgroups can be diagnosed and followed up with OCT-A. It was also found that OCT-A parameters are affected before the development of clinically detectable retinopathy.

Survey on Predicting the Risk of Heart Attack Through Retinal Eye Images Analysis

Cardiovascular diseases (CVDs) remain a leading cause of global morbidity and mortality. Early detection and intervention are crucial for improving patient outcomes and reducing the burden on healthcare systems. Recent research suggests a potential link between retinal vascular changes and cardiovascular health. Retinal images offer a non-invasive means to assess microvascular abnormalities, making them an attractive source of data for predictive modeling. This project focuses on developing a machine learning model, specifically using Recurrent Neural Networks (RNNs), to analyze retinal images and detect patterns indicative of heart diseases. RNNs are well-suited for processing sequential data, making them suitable for capturing temporal dependencies in the retinal images and improving the predictive accuracy of the model.

Evaluation of the effect of phacoemulsification surgery on retinal and choroidal microvasculature in diabetic patients using optical coherence tomography angiography

Aim To evaluate the effect of phacoemulsification surgery on retinal and choroidal microvasculature in diabetic patients using optical coherence tomography angiography (OCTA). Settings and design A prospective comparative case-control study was performed at the Ophthalmology Department of Ain Shams University hospital, between November 2020 and November 2022. Patients and material A total 50 eyes of 35 cataractous patients were included in this prospective study and divided into two groups: the control group (25 eyes of 19 patients) and the diabetic group (25 eyes of 16 patients with mild nonproliferative diabetic retinopathy). All patients underwent routine ophthalmic examination, OCT and OCTA scans of the macula before phacoemulsification surgery and 1 week, 1, 3, and 6 months after the surgery. Results The best corrected visual acuity significantly improved in both groups by ∼ 0.26 logMAR units in control and diabetic groups (P &lt;0.001 for both). The mean change in central subfoveal thickness was 23.44±43.7 versus 13.6±22 um (P=0.3) in the control group and the diabetic group, respectively but statistically insignificant. There was insignificant change in each group in all vascular parameters during the follow-up period. In addition, there was insignificant difference between the two groups at each visit in most vascular parameters of superficial vessel density, deep vessel density (DVD), and choriocapillaris vessel density (CC VD). On the other hand, the diabetic groups have significantly lower superficial vessel density of whole image and perifovea at 1 week than controls (42.92±4.54% vs. 46.16±3.98%, P=0.01 in the whole image, respectively) (44.29±4.87% vs. 47.32±3.85%, P=0.018 in perifovea, respectively). The diabetic group also showed significantly higher parafoveal deep vessel density than the control group at 1 month postoperatively: 52.67±4.00 versus 47.24±9.85% (P=0.014) that leveled up on month 3 and 6 (P=0.397, 0.538, respectively). The diabetic group showed lower CC VD of the whole image than the control group at 1 week postoperatively: 70.60±2.87 versus 72.22±1.98%, respectively (P=0.025), and also significantly lower CC VD of perifovea than the control group at 1 week: 71.19±2.82 versus 72.72±2.20% (P=0.038), 1 month: 71.08±2.87 versus 72.78±2.61% (P=0.033) and 3 months: 71.35±2.63 versus 72.83±2.52% (P=0.048). Those values leveled up at the last postoperative visit at month 6 (P=0.152). Conclusion Phacoemulsification surgery may lead to the transient and mild reduction of choroidal blood flow in diabetic eyes rather than retinal blood flow. Most of choroidal and retinal vascular changes happened in the perifoveal area within 1 week to 1 month postoperatively and rarely extended to 3 months.

Evaluation of glaucomatous macular and optic nerve vascular damage by optical coherence tomography angiography

Purpose The aim of this study was to compare the macular and optic nerve head vessel perfusion density in mild primary open-angle glaucoma (POAG) and moderate–severe POAG patients to normal eyes as a control cohort. Patients and methods This is a retrospective comparative case–control study that included 80 eyes of 46 participants. The study included 60 eyes of 36 POAG patients and 20 eyes of 10 healthy participants (control group). The patients underwent 3.0×3.0 mm optical coherence tomography angiography (OCTA) scans centered on the macula and 4.5×4.5 mm scans on the optic disc. Results The OCTA scans of the glaucomatous eyes revealed a reduction in microvasculature in the peripapillary area, which was absent in the control cohort. The whole disc vessel density (VD) was significantly less in the glaucomatous eyes (mean=38.02±8.74) compared to the control cohort (mean=50.41±2.58, P&lt;0.001). The severity of glaucoma was linked to a decrease in macular VD percentage, with a mean superficial VD of 36.09±5.67 in the glaucoma cohorts and 46.64±5.53 in the control cohort (P&lt;0.001), which was more pronounced than in the deep layer (P&lt;0.008). There was no statistically significant difference in the foveal avascular zone size between the control and glaucoma cohorts at any stage (P=0.999). Conclusion The OCTA vascular density accurately distinguished the glaucoma from healthy eyes, with superior performance in the peripapillary region. The foveal avascular zone size did not indicate glaucoma severity. The OCTA noninvasive assessment of the capillary networks showed a potential for managing the glaucoma patients by characterizing the retinal vascular changes.

Retinal Structural and Vascular Changes in Patients with Coronary Artery Disease: A Systematic Review and Meta-Analysis.

Retinal microvascular anomalies have been identified in patients with cardiovascular conditions such as arterial hypertension, diabetes mellitus, and carotid artery disease. We conducted a systematic review and meta-analysis (PROSPERO registration number CRD42024506589) to explore the potential of retinal vasculature as a biomarker for diagnosis and monitoring of patients with coronary artery disease (CAD) through optical coherence tomography (OCT) and optical coherence tomography angiography (OCTA). We systematically examined original articles in the Pubmed, Embase, and Web of Science databases from their inception up to November 2023, comparing retinal microvascular features between patients with CAD and control groups. Studies were included if they reported sample mean with standard deviation or median with range and/or interquartile range (which were computed into mean and standard deviation). Review Manager 5.4 (The Cochrane Collaboration, 2020) software was used to calculate the pooled effect size with weighted mean difference and 95% confidence intervals (CI) by random-effects inverse variance method. Eleven studies meeting the inclusion criteria were incorporated into the meta-analysis. The findings indicated a significant decrease in the retinal nerve fiber layer (WMD -3.11 [-6.06, -0.16]), subfoveal choroid (WMD -58.79 [-64.65, -52.93]), and overall retinal thickness (WMD -4.61 [-7.05, -2.17]) among patients with CAD compared to controls (p < 0.05). Furthermore, vascular macular density was notably lower in CAD patients, particularly in the superficial capillary plexus (foveal vessel density WMD -2.19 [-3.02, -1.135], p < 0.0001). Additionally, the foveal avascular zone area was statistically larger in CAD patients compared to the control group (WMD 52.73 [8.79, 96.67], p = 0.02). Heterogeneity was significant (I2 > 50%) for most features except for subfoveal choroid thickness, retina thickness, and superficial foveal vessel density. The current meta-analysis suggests that retinal vascularization could function as a noninvasive biomarker, providing additional insights beyond standard routine examinations for assessing dysfunction in coronary arteries.