Early Choriocapillaris Dysfunction in Fellow Eyes of Patients with Unilateral Neovascular Age-Related Macular Degeneration.

PURPOSE: To investigate early changes in AMD by evaluating and comparing choriocapillaris (CC) flow in fellow eyes of patients with unilateral neovascular age-related macular degeneration (nAMD) and in healthy controls using swept-source optical coherence tomography angiography (SS-OCTA). METHODS: Patients with unilateral nAMD and no/early/intermediate AMD (no/e/iAMD) in their fellow eye and normal controls who underwent SS-OCT and OCTA where included. CC perfusion was assessed on MATLAB as percentage of flow deficits (FD%) in the central 4.5 × 4.5 mm macular region, after removing artifacts. RESULTS: 81 eyes/patients (22 eyes with noAMD, 30 with eAMD, 29 with iAMD) with unilateral nAMD and 24 controls were analyzed. Median FD% was 8.97 (IQR 8.58-9.53) in AMD group, 8.92 (IQR 8.64-9.27) in noAMD group, 8.96 (IQR 8.46-9.38) in eAMD group, 9.05 (IQR 8.58-9.8) in iAMD group, and 8.22 (IQR 7.78-8.55) in controls. A statistically significant difference in FD% was observed between controls and AMD group (p < 0.001), as well as between each AMD subgroup and controls (noAMD vs controls p = 0.0037; eAMD vs control p = 0.0012; iAMD vs controls p = 0.0002). CONCLUSION: This study suggests that CC dysfunction may occur in fellow eyes of patients with unilateral nAMD before visible AMD signs, potentially preceding RPE changes. Further longitudinal studies are needed to confirm these findings and explore the correlation with AMD development/progression.

Vascular changes in optical coherence tomography angiography unveiling the depths of dry age-related macular degeneration: a review.

INTRODUCTION: Recent advancements in imaging techniques, particularly optical coherence tomography angiography (OCTA), have transformed our understanding of retinal microvascular changes in various ocular diseases, including dry age-related macular degeneration (AMD). Our literature review summarizes key findings on retinal vascular alterations in dry AMD as observed with OCTA, highlighting their implications for disease progression and management. AREAS COVERED: Studies reveal significant changes in dry AMD patients, affecting the superficial and deep capillary plexuses as well as the choroid. These alterations include decreased vascular and flow density, variations in the foveal avascular zone, reduced choriocapillaris perfusion, and alterations in choroidal vascularity and thickness. Such changes reflect the complex vascular pathology of dry AMD and serve as potential biomarkers for monitoring disease progression. Variability in study results underscores the importance of considering AMD stage, sample size, follow-up duration, imaging protocols, and standardization. EXPERT OPINION: OCTA in dry AMD is primarily research-focused due to technical and methodological challenges. Its adoption in clinical practice requires standardized protocols and improved software. With future advancements and a better understanding of disease pathology, OCTA could become a routine part of dry AMD management, especially as new therapies emerge that utilize OCTA for assessing dry AMD progression.

Ghost vessels in the eye: Cell free choriocapillaris domains in atrophic age-related macular degeneration.

The choriocapillaris is a dense vascular bed in the inner choroid that supplies the photoreceptor cells and retinal pigment epithelium (RPE). While loss of choriocapillaris density has been described in association with age-related macular degeneration (AMD), whether these changes are primary or secondary to RPE degenerative changes in AMD has been debated. In this study we characterized choriocapillaris loss by quantifying "ghost" vessels in a series of 99 human donor maculae labeled with the UEA-I lectin, and found significant increases in early-intermediate AMD and a greater difference in geographic atrophy in areas with intact RPE. Eyes were genotyped at the CFH Tyr402His locus, and those homozygous for the His allele showed significantly more ghost vessels than those with other genotypes. When only non-AMD eyes were evaluated, His homozygotes had increased ghost vessel density but this trend did not reach statistical significance. These results support the notion that choriocapillaris death often precedes RPE degeneration in AMD and that this loss is an important therapeutic consideration for AMD.

Dynamic changes of choroidal vasculature and its association with myopia control efficacy in children during 1-year orthokeratology treatment.

PURPOSE: To investigate the dynamic changes of choroidal vasculature and its association in mediating ocular elongation over 1 year of orthokeratology (ortho-k) treatment. METHODS: This observational study included 8-14 year old myopic children who were willing to receive ortho-k treatment or wear single vision spectacle lenses (SVL). Axial length (AL) and choroidal characteristics, including submacular luminal area (LA), stromal area (SA), total choroidal area (TCA), choroidal vascularity index (CVI), subfoveal choroidal thickness (SFCT) and choriocapillaris flow deficits (CcFD) from OCT/OCTA images, were evaluated at baseline, 3, 6 and 12 months. RESULTS: After 1 year, AL elongation was significantly less in 25 children treated with ortho-k than in 29 children wearing SVL (0.17 ± 0.14 v.s. 0.28 ± 0.16 mm, P<0.01). In the ortho-k group, LA, SA, TCA and SFCT were significantly increased by 0.033 ± 0.059 mm2, 0.024 ± 0.035 mm2, 0.058 ± 0.087 mm2, 8.9 ± 17.4 µm, respectively, at 3 months (all P<0.05). These parameters returned to near baseline levels over the following 9 months. Meanwhile, CcFD decreased by 0.83 ± 1.09 % over 12 months, but CVI remained steady during this period. No significant changes in these choroidal parameters (except for CcFD, decreased by -0.56 ± 1.23 %) were observed in the SVL group over 12 months. Increases in SFCT, LA, SA and TCA over 12 months were significantly greater in the ortho-k group than in the SVL group. Mediation analyses showed that 44.8 % of effect on inhibiting AL elongation through ortho-k was mediated via TCA (in particular LA). CONCLUSIONS: The decelerated ocular elongation during ortho-k treatment is accompanied by increases in content of choroidal vascular lumen and stromal component. Dynamic changes of choroidal vasculature provide a possible mechanism underlying myopia control efficacy via ortho-k.

Comparing Optical Coherence Tomography Angiography Metrics in Healthy Chinese and Caucasian Adults.

BACKGROUND: The goal of the present study was to identify differences in retinal microvasculature between healthy Caucasians and healthy Asians in order to provide a better understanding of the variability between different ethnic groups. METHODS: In this cross-sectional study, 191 healthy Chinese and Caucasian participants were enrolled. They underwent optical coherence tomography angiography (OCTA) scans with Zeiss Cirrus HD-5000 Spectral-Domain with AngioPlex. Linear regression models were used to investigate the association of OCTA metrics with potential risk factors. RESULTS: Whereas participants in both groups are comparable in age and sex, Chinese participants had a longer axial length, higher spherical equivalent, higher intraocular pressure (p < 0.001), and a significantly higher perfusion density of large vessels in the superficial capillary plexus (p < 0.001). Regarding the foveolar avascular area (FAZ), Chinese participants had a larger superficial FAZ, a wider superficial FAZ perimeter, and a more circular deep FAZ shape (p < 0.001). CONCLUSIONS: There are significant differences in the retinal vasculature between Caucasian and Asian eyes as measured using OCTA. This needs to be considered when developing normative databases. Whether such findings relate to inter-racial differences in the incidence of retinal vascular disease remains to be shown.

Effect of Buerger's disease on ocular microvascular structure.

CLINICAL RELEVANCE: Buerger's disease, being a systemic inflammatory vasculopathy, may present with ocular findings. BACKGROUND: This study aims to understand the potential role of optical coherence tomography and angiography findings in evaluating the course of Buerger's disease. METHODS: This was a prospective, cross-sectional study that included 25 patients with Buerger's disease (Group 1) and 51 healthy control participants, of whom 27 were smokers (Group 2) and 24 were non-smokers (Group 3). Following a detailed ophthalmic examination, optical coherence tomography and angiography measurements were conducted on participants. The values of macular superficial and deep capillary plexus, peripapillary capillary plexus vessel density measurements were taken into account from optical coherence tomography angiography measurements. Furthermore, measurements were taken for the parameters of the foveal avascular zone, including its area, perimeter and acircularity index. Additionally, the choriocapillaris flow area was assessed between radii of 1 mm, 2 mm, and 3 mm. RESULTS: In patients with Buerger's disease, the area and perimeter of the foveal avascular zone were higher than in both smoker and non-smoker healthy groups (p < 0.001 for all). The vessel densities in superficial capillary plexus were found to be lower in patients with Buerger's disease compared to both smokers and non-smokers in all regions except the parafovea (p < 0.05 for all). The radial peripapillary capillary plexus vessel densities in the whole retina and peripapillary region were lower than those in the non-smoker group (p < 0.001 and p = 0.008). The choriocapillaris flow areas in all three radius were lower in the smoker group than in the non-smoker group (1 mm, p = 0.01; 2 mm, p = 0.005; 3 mm, p = 0.011). CONCLUSIONS: Buerger's disease extends beyond the extremities, affecting vascular density and tissue perfusion in the optic disc and macula, making it a systemic condition. This disease can have ocular involvement without causing serious ocular findings.

Choriocapillaris in Age-Related Macular Degeneration.

Age-related macular degeneration (AMD) is a multifactorial disease characterized by progressive alterations of different retinal structures ultimately leading to vision loss. Among these, the choriocapillaris (CC) has been found to be affected in different stages of AMD. In this review we provide a discussion on the different stages of AMD, focusing particularly on the alterations involving the CC. This has been possible thanks to the introduction of optical coherence tomography-angiography, a recently developed imaging technique which allows the detection of blood flow in choroidal vessels. Therefore, the aim of this review is to provide a description of the various alterations involving the CC in the different stages of AMD.

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

PURPOSE: To quantitatively analyze choroidal and retinal vascular changes in HLA-B27-associated anterior uveitis. STUDY DESIGN: A retrospective study. METHODS: 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. RESULTS: 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. CONCLUSION: 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.

OCT Angiography of the Retina and the Choroid in the Macula in Patients with Normal Tension Glaucoma and Primary Open Angle Glaucoma.

The aim of this study was to compare vessel density (VD) in the retina and choroid in eyes with primary open angle glaucoma (POAG), normal tension glaucoma (NTG) and controls. Patients with POAG, NTG and controls underwent OCT scanning of the macula and the disc followed by 6 × 6 mm macula OCT angiography (OCTA) imaging. Global and hemifield VD were recorded for the superficial (SVP) and deep (DVP) vascular plexus and the choriocapillaris (CC). The OCT thickness of the nerve fiber layer (NFL) and ganglion cell layer (GCC) was also measured. Data from 65 POAG, 33 NTG and 40 control eyes matched for age were analyzed. Mean SVP VD was lower in NTG and POAG eyes compared to controls (38.8 ± 5.3, 40.7 ± 6.8 and 48.5 ± 4.0%, p < 0.001). Mean DVP VD was lower in NTG and POAG eyes compared to controls (43.1 ± 6.1, 44.5 ± 7.6 and 48.6 ± 5.8%, p = 0.002). There was no difference in SVP VD or DVP VD between the glaucoma groups (p > 0.050). No difference was noted in CC VD between the groups (68.3 ± 2.3, 67.6 ± 3.7 and 68.5 ± 2.6%, p = 0.287). Lower SVP and DVP VD was seen in eyes with glaucoma compared to normal eyes. NTG and POAG eyes had similar VD loss. Eyes with glaucoma manifested similar CC VD compared to controls.

Function and Circulation of the Retina and Choroid in Case of Indolent Nonprogressive Multifocal Choroidal Lesions.

Indolent nonprogressive multifocal choroidal lesions have been reported to be benign choroidal lymphatic lesions that do not affect the visual function. However, as best known, there are no reports on whether these lesions affect the circulation and function of the retina and choroid. We report a case of indolent nonprogressive multifocal choroidal lesions in which retinal images were available to assess the retinal and choroidal circulation and whether it impacted the retinal function. The patient was a 45-year-old man. Swept-source optical coherence tomography (OCT) showed multiple well-defined, uniform, hyporeflective cavernous lesions in the choroidal layer. Then a diagnosis of indolent nonprogressive multifocal choroidal lesions was made based on the similarity of the features with those reported. OCT angiography showed no blood flow signals in the lesions and reduced blood flow signals in the choroid and choriocapillaris directly above the lesions. Fundus autofluorescence showed retinal pigment epithelial damages that were colocalized with the choroidal lesions. We then performed static visual field testing and multifocal electroretinography (mfERG). The static visual field test showed no decrease in sensitivity in the entire visual field, and mfERG showed no decrease in the amplitudes or implicit times indicating normal retinal function. In indolent nonprogressive multifocal choroidal lesions, the photoreceptor function is preserved but a mild retinal pigment epithelium disorder is present. Thus, the follow-up examinations of indolent nonprogressive multifocal choroidal lesions should include retinal function tests.

Impact of preocular and ocular circulatory dynamics on the vascular density of retinal capillary plexuses and choriocapillaris.

PURPOSE: To highlight the influence of preocular and ocular vascular circulatory dynamics on the vascular density (VD) of retinal capillary plexuses (RCPs) and choriocapillaris (CC) in patients with and without cardiovascular risk (CVR) factors. METHODS: A retrospective observational study in patients with and without CVR factors (type 1 and 2 diabetes, arterial hypertension, and hypercholesterolemia). Fluorescein (FA) and indocyanine (ICGA) angiography circulatory times were arterial time (FAAT), start (FAstartLF) and end (FAendLF) of laminar flow, and arterial time (ICGAAT), respectively. OCT angiography VDs were superficial (VDSCP) and deep (VDDCP) RCPs and CC (VDCC) VDs. Correlation and regression analysis were performed after adjusting for confounding factors. RESULTS: 177 eyes of 177 patients (mean age: 65.2 ± 15.9 years, n = 92 with and 85 without CVR) were included. VDSCP and VDDCP were significantly inversely correlated with FAAT, FAstartLF and FAendLF likewise VDCC with ICGAAT. Correlations were stronger in patients without CVR than with CVR. CVR, FAAT, FAstartLF and FAendLF were more strongly correlated with VDDCP than VDSCP. FAAT, FAstartLF and FAendLF significantly impacted VDSCP and VDDCP, likewise ICGAAT impacted VDDCP. VDDCP was most strongly impacted by FAAT and FAstartLF. CONCLUSION: Ocular and pre-ocular circulatory dynamics significantly impacted RCPs and CC VDs, especially deep RCP.

Normative data and correlation parameters for vessel density measured by 6 × 6-mm optical coherence tomography angiography in a large chinese urban healthy elderly population: date from the Beichen eye study.

BACKGROUND: To establish a normative database for macular vessel density (VD) measured by optical coherence tomography angiography (OCTA) and explore the parameters related to the VD. METHODS: An observational study in epidemiology. 5840 healthy elderly participants in Beichen district, Tianjin, China underwent detailed ophthalmic and systemic examinations. OCTA was performed in all subjects using a 6 × 6-mm line scan mode centered on the macula and the built-in software was used to quantify VD and stratify the retina. RESULTS: One thousand four hundred sixty-one healthy elderly citizens (30.4% men) were included, with a median age of 60.0 years (8.0 years) and an age range of 50 to 87 years.VDs in the different plexuses: superficial capillary plexus (SCP) 43.9% (3.2%), deep capillary plexus (DCP) 44.3% (2.8%), outer capillary plexus (OCP) 21.9% (5.9%), choriocapillaris (CC) 52.1% (1.4%). 90% medical reference range of the VDs at different plexuses was reported. Age was correlated with the VDs of each capillary plexus. Sex was correlated with the VDs of DCP and OCP, and the VDs of DCP (p < 0.001) and OCP (p = 0.015) in women were higher than that in men. After age and sex adjustment, choroid average thickness was positively correlated with VDs of SCP (R = 0.067, p = 0.010) and DCP (R = 0.108, p < 0.001), ganglion cell layer (GCL) average thickness (R = 0.072, p = 0.006) was positively correlated with the VD of OCP, best-corrected visual acuity (BCVA) (R = 0.082, p = 0.002) was positively correlated with the VD of CC. CONCLUSIONS: In this study, the normative VD database of the Chinese urban healthy elderly population measured by the OCTA was established, and parameters related to the VD of each capillary plexus were analyzed, providing new ideas for the future study of the relationship between macular VD and disease. TRIAL REGISTRATION: The Beichen Eye Study had been registered on the Chinese Clinical Trial Registry website (registry number: ChiCTR2000032280) on April 25, 2020.

Decreased Macular Choriocapillaris Perfusion Correlates with Contrast Sensitivity Function in Dry Age-Related Macular Degeneration.

PURPOSE: To investigate the relationships between contrast sensitivity (CS), choriocapillaris perfusion, and other structural OCT biomarkers in dry age-related macular degeneration (AMD). DESIGN: Cross-sectional, observational study. PARTICIPANTS: One hundred AMD eyes (22 early, 52 intermediate, and 26 late) from 74 patients and 45 control eyes from 37 age-similar subjects. METHODS: All participants had visual acuity (VA) assessment, quantitative CS function (qCSF) testing, macular OCT, and 6 × 6-mm swept-source OCT angiography scans on the same day. OCT volumes were analyzed for subretinal drusenoid deposits and hyporeflective drusen cores, and to measure thickness of the outer nuclear layer. OCT angiography scans were utilized to calculate drusen volume and inner choroid flow deficit percentage (IC-FD%), and to measure the area of choroidal hypertransmission defects (HTDs). Inner choroid flow deficit percentage was measured from a 16-µm thick choriocapillaris slab after compensation and binarization with Phansalkar's method. Generalized linear mixed-effects models were used to evaluate the associations between functional and structural variables. MAIN OUTCOME MEASURES: To explore the associations between qCSF-measured CS, IC-FD%, and various AMD imaging biomarkers. RESULTS: Age-related macular degeneration exhibited significantly reduced qCSF metrics eyes across all stages compared with controls. Univariate analysis revealed significant associations between various imaging biomarkers, reduced qCSF metrics, and VA in both groups. Multivariate analysis confirmed that higher IC-FD% in the central 5 mm was significantly associated with decreases in all qCSF metrics in AMD eyes (ß = -0.74 to -0.25, all P < 0.05), but not with VA (P > 0.05). Outer nuclear layer thickness in the central 3 mm correlated with both VA (ß = 2.85, P < 0.001) and several qCSF metrics (ß = 0.01-0.90, all P < 0.05), especially in AMD eyes. Further, larger HTD areas were associated with decreased VA (ß = -0.89, P < 0.001) and reduced CS at low-intermediate frequencies across AMD stages (ß = -0.30 to -0.29, P < 0.001). CONCLUSIONS: The significant association between IC-FD% in the central 5 mm and qCSF-measured CS reinforces the hypothesis that decreased macular choriocapillaris perfusion contributes to visual function changes in AMD, which are more pronounced in CS than in VA. FINANCIAL DISCLOSURE(S): Proprietary or commercial disclosure may be found in the Footnotes and Disclosures at the end of this article.

Microvascular Density Analysis of Patients with Inactive Systemic Lupus Erythematosus-A Two-Year Follow-Up Optical Coherence Tomography Angiography Study.

Background/Objectives: This study aims to investigate the long-term effect of inactive systemic lupus erythematosus (SLE) on the retinal microcirculation measured via optical coherence tomography angiography (OCT-A). Methods: Twenty-four eyes of 24 patients with inactive SLE under hydroxychloroquine (HCQ) therapy were included. The OCT-A data (mainly vessel density (VD) and foveal avascular zone (FAZ) data of the superficial and of the deep capillary plexus (SCP, DCP) and the choriocapillaris (CC)) were analyzed and compared between the baseline examination (t0) and 2 years later (t1). Results: At t1, VD in the whole en face SCP and in the CC was notably reduced compared to t0 (SCP: p = 0.001, CC: p = 0.013). VD in the DCP, CRT and FAZ area showed no difference at t1 compared to t0 (DCP: p = 0.128, FAZ: p = 0.332, CRT fovea: p = 0.296). Correlation analysis between the increase in cumulative doses of HCQ between t0 and t1 and the VD of the whole en face SCP did not show any correlation (Spearman r = 0.062 (95% CI -0.367; 0.477). Conclusions: SLE patients demonstrated a decrease in the retinal VD of the SCP and CC over a 2-year period. There was no correlation with the change in cumulative doses of HCQ. These results suggest an ongoing effect of the disease on the retinal and choriocapillary microcirculation.

Corrigendum: Comparison of indocyanine green angiography and swept-source wide-field optical coherence tomography angiography in posterior uveitis.

[This corrects the article DOI: 10.3389/fmed.2022.853315.].

Subclinical choroidal involvement in Systemic Lupus Erythematosus.

PURPOSE: To assess the choroidal status of Systemic Lupus Erythematosus (SLE) patients using Optical Coherence Tomography (OCT) and OCT-Angiography. METHODS: SLE patients with disease duration < 10 years, no disease activity and no ocular involvement were recruited and cross-sectionally evaluated. A demographically similar cohort of healthy subjects was used for comparison. The main outcome is choroidal vascularity index (CVI). As secondary outcomes, choriocapillaris parameters and choroidal thickness (CT) were evaluated. RESULTS: Forty eyes of 40 subjects (20 SLE patients and 20 healthy subjects) were studied with a mean ± SD age of 36.7 ± 9.9 years. In the SLE group, the mean ± SD duration of disease was 7.35 ± 2.21 years. Increased CVI was found in the SLE group (p = 0.022). Considering the choriocapillaris, SLE patients presented a lower number (p = 0.037) and a smaller total area (p = 0.041) of signal voids. No differences between groups were found in CT. For SLE patients, CT at subfoveal, temporal and inferior locations presented a negative moderate correlation with disease duration. A strong correlation between choriocapillaris parameters and age was demonstrated for both groups. CONCLUSIONS: This study provides evidence of subclinical choroidal changes in adult SLE patients with inactive disease and no overt ocular manifestation. Increased CVI and fewer and smaller flow voids in choriocapillaris with normal CT suggest increased choroidal vascularity in SLE.

Choriocapillaris reduction accurately discriminates against early-onset Alzheimer's disease.

INTRODUCTION: This study addresses the urgent need for non-invasive early-onset Alzheimer's disease (EOAD) prediction. Using optical coherence tomography angiography (OCTA), we present a choriocapillaris model sensitive to EOAD, correlating with serum biomarkers. METHODS: Eighty-four EOAD patients and 73 controls were assigned to swept-source OCTA (SS-OCTA) or the spectral domain OCTA (SD-OCTA) cohorts. Our hypothesis on choriocapillaris predictive potential in EOAD was tested and validated in these two cohorts. RESULTS: Both cohorts revealed diminished choriocapillaris signals, demonstrating the highest discriminatory capability (area under the receiver operating characteristic curve: SS-OCTA 0.913, SD-OCTA 0.991; P < 0.001). A sparser SS-OCTA choriocapillaris correlated with increased serum amyloid beta (Aß)42, Aß42/40, and phosphorylated tau (p-tau)181 levels (all P < 0.05). Apolipoprotein E status did not affect choriocapillaris measurement. DISCUSSION: The choriocapillaris, observed in both cohorts, proves sensitive to EOAD diagnosis, and correlates with serum Aß and p-tau181 levels, suggesting its potential as a diagnostic tool for identifying and tracking microvascular changes in EOAD. HIGHLIGHTS: Optical coherence tomography angiography may be applied for non-invasive screening of Alzheimer's disease (AD). Choriocapillaris demonstrates high sensitivity and specificity for early-onset AD diagnosis. Microvascular dynamics abnormalities are associated with AD.

Evaluation of choroid vascular layer thickness in wet age-related macular degeneration using artificial intelligence.

PURPOSE: To facilitate the assessment of choroid vascular layer thickness in patients with wet age-related macular degeneration (AMD) using artificial intelligence (AI). METHODS: We included 194 patients with wet AMD and 225 healthy participants. Choroid images were obtained using swept-source optical coherence tomography. The average Sattler layer-choriocapillaris complex thickness (SLCCT), Haller layer thickness (HLT), and choroidal thickness (CT) were auto-measured at 7 regions centered around the foveola using AI and subsequently compared between the 2 groups. RESULTS: The SLCCT was lower in the AMD group than in the control group (P < 0.05). The HLT was significantly higher in the AMD group than in the control group at the Tparafovea and T-perifovea in the total population (P < 0.05) and in the ≤70-year subgroup (P < 0.05). The CT was higher in the AMD group than in the control group, particularly at the N-perifovea, T-perifovea, and T-parafovea in the ≤70-year subgroup; Interestingly, it was lower in the AMD group than in the control group at the Nparafovea, N-fovea, foveola, and T-fovea in the >70-year subgroup (P < 0.05). CONCLUSION: This novel AI-based auto-measurement was more accurate, efficient, and detailed than manual measurements. SLCCT thinning was observed in wet AMD; however, CT changes depended on the interaction between HLT compensatory thickening and SLCCT thinning.

[Effects of Susac syndrome on the central vascular structure of the retina-An optical coherence tomography angiography study]. / Auswirkungen des Susac-Syndroms auf die zentrale Gefäßstruktur der Netzhaut ­ eine optische Kohärenztomographie-Angiographie-Studie.

BACKGROUND: Susac syndrome (SS) describes an endotheliopathy of vessels in the central nervous system. Retinal involvement plays a central role in the manifestation of the disease. OBJECTIVE: This case-control study investigated the macular microvasculature in patients with chronic SS compared to controls using optical coherence tomography angiography (OCTA). MATERIAL AND METHODS: 12 eyes of 12 patients with SS were compared with age-matched healthy control subjects with regard to their OCT angiographic parameters. The flow density (FD) of different macular layers, foveal avascular zone (FAZ) parameters and central retinal thickness and volume values were compared between the two groups. RESULTS: The FD of the choriocapillaris was reduced in Susac patients compared to healthy controls. The FD values of the superficial and deep capillary plexus of the inner retina, parameters of the FAZ as well as central retinal thickness and volume showed no significant differences between the two groups. DISCUSSION: Treated chronic SS does not appear to significantly affect the vascular and structural composition of the central inner retina; however, differences in the choriocapillaris indicate changes in deeper, highly vascularized capillary layers.

Choriocapillaris Perfusion after 8 Weeks of High-Speed Circuit Training in Older Healthy Adults.

PURPOSE: The aim of this study was to examine the impact of an 8-week high-speed circuit resistance training program (HSCT) on choriocapillaris density (CCD) in healthy older adults. METHODS: Eighteen cognitively normal older adults were enrolled and randomly assigned to either the HSCT or the control group (CON). The HSCT group was comprised of 11 participants who trained three times a week for eight weeks, while the CON group consisted of 7 participants who did not engage in formal training. Optical coherence tomography angiography (OCTA) was employed to image both eyes of each subject at baseline and at the 8-week follow-up. The choriocapillaris density (CCD) of 2.5 mm in diameter centered on the fovea was measured. RESULTS: The average age of the HSCT group was 70.3 ± 5.7 years, which was not different from the CON group (average age: 71.6 ± 5.2 years, p = 0.62). There were no significant changes in CCD between baseline and the 8-week follow-up in either the HSCT or the CON group-specifically, the baseline CCD in the HSCT group was 63.3% ± 5% (Mean ± SD), which did not differ significantly from the 8-week follow-up after HSCT training (64.7% ± 4%, p = 0.19). Likewise, there was no significant difference in CCD between baseline and the 8-week follow-up in the CON group (63.3% ± 3% and 62.7% ± 5%, respectively, p = 0.66). CONCLUSION: CCD appeared to remain stable after 8 weeks of HSCT in healthy older individuals, possibly due to autoregulation. Further research with extended training may be necessary to verify these findings.