Choroidal Vascularity and Axial Length Elongation in Highly Myopic Children: A 2-Year Longitudinal Investigation.

Purpose: To examine the influence of subfoveal choroidal thickness (SFCT) and choroidal vascularity index (CVI) on axial length (AL) elongation over a 2-year period in highly myopic children. Methods: In this is prospective, longitudinal, observational study, 163 participants (74%), who were 8 to 18 years of age with bilateral high myopia (sphere ≤ -6.0 D) and without pathologic myopia, completed follow-up visits over 2 years. All participants underwent baseline and follow-up ocular examinations, including swept-source optical coherence tomography (SS-OCT) and AL measurements. SFCT and CVI were derived from SS-OCT scans using a deep-learning-based program for choroidal structure assessment. Results: The mean age of the participants at baseline was 15.0 years (±2.3), with males constituting 47% of the cohort. An inverse relationship was observed between AL elongation and increases in baseline age, baseline SFCT, and CVI, as well as a decrease in baseline AL. Adjusting for other factors, every 10-µm increase in SFCT and each 1% increase in CVI were associated with decreases in AL elongation of 0.007 mm (95% confidence interval [CI], -0.013 to -0.002; P = 0.011) and 0.010 mm (95% CI, -0.019 to 0.000; P = 0.050), respectively. The incorporation of SFCT or CVI into predictive models improved discrimination over models using only age, gender, and baseline AL (both P < 0.05, likelihood ratio test). Conclusions: Our findings suggest a possible association between a thinner choroid and increased AL elongation over 2 years in children with high myopia, after adjusting for potential baseline risk factors such as age, gender, and initial AL.

Association of choroidal thickness and blood flow features with asymmetric axial lengths in children with unilateral myopic anisometropia.

BACKGROUND: Considering that changes in the choroidal thickness are closely related to ocular growth, we studied the choroidal thickness (CT) and the blood flow features in children with unilateral myopic anisometropia (UMA) as well as investigating the relationship between choroidal changes and myopia. METHODS: Subjective refractive, axial length (AL), and biometric parameters were measured in 98 UMA children (age: 8-15 years). CT and choroidal blood-flow features, including the choroidal vessel volume (CVV), choroidal vascularity index (CVI), and choriocapillaris perfusion area (CCPA), were measured through swept-source optical coherence tomography angiography. The macular region was categorized into four concentric circles of diameters 0-1 mm (central fovea), 1-3 mm (parafovea), 3-6 mm (perifovea), and 6-9 mm (extended), and further categorized into superior (S), inferior (I), temporal (T), and nasal (N) quadrants. RESULTS: The aforementioned four regions of myopic eyes displayed significantly lower CT, CVV, and CVI than those of non-myopic eyes. CCPA changes differed across different regions of both the eyes (parts of N and T quadrants). There was an inverse association between CT and the interocular AL difference (central and other regions S, T quadrant). No correlation was noted between CVV and CVI with interocular AL difference. CT and CVV were positively correlated in the 0-6-mm macular region of myopic eyes (Spearman correlation coefficient = 0.763, P < 0.001). CONCLUSIONS: In UMA children, CCT and blood flow may be related to myopia progression. A robust correlation between CT and CVV in the 0-6-mm macular region and reduced CT and diminished blood flow indicated an association with myopia.

Influence of Carotid Artery Stenting on the Retina and Choroid.

Purpose: The effect of carotid artery stenting in patients with unilateral carotid artery stenosis on the retina and choroid was evaluated using swept-source optical coherence tomography angiography (SS-OCTA). Methods: SS-OCTA examination was conducted before stenting and 4 days and 3 months after stenting. The retinal nerve fiber layer, ganglion cell-inner plexiform layer (GCIPL), inner nuclear layer, superficial vascular complex (SVC), deep vascular complex (DVC), choroidal vascular volume (CVV), and choroidal vascular index were measured. Repeated-measures analysis of variance was performed to assess the impact of carotid artery stenting on optical coherence tomography angiography (OCTA) metrics. Results: At baseline, 303 eyes from 160 patients (61.82 ± 9.98 years; 85.29% males) were enrolled. SVC and DVC densities and CVV were lower in ipsilateral eyes (stenosed side) compared to contralateral eyes (all P < 0.05). Four days after stenting, a significant increase was seen in SVC density in ipsilateral eyes (P < 0.05) while a significant increase was seen in CVV in ipsilateral eyes and contralateral eyes (both P < 0.05). Three months after stenting (63 patients with 114 eyes), a significant decrease was seen in the GCIPL thickness of ipsilateral and contralateral eyes (all P < 0.001). Conclusions: Short term after carotid artery stenting, ipsilateral eyes showed a rapid and significant increase in SVC density and CVV. Translational Relevance: Optical coherence tomography (OCT)/OCTA measurements may have the potential to detect retinal and choroidal changes after stenting. Future research on the long-term effect of stenting on the retina and choroid will be guided by these findings.

The effect of long-term hemodialysis on diabetic retinopathy observed by swept-source optical coherence tomography angiography.

BACKGROUND: Diabetes can cause chronic microvascular complications such as diabetic retinopathy (DR) and diabetic nephropathy (DN). DR and DN can lead to or exacerbate diabetic macular edema (DME). Hemodialysis (HD) is the main treatment method for patients with end-stage kidney disease (ESKD) secondary to DN. PURPOSE: The aim of this prospective cohort study was to determine the immediate effect of single HD session on retinal and choroidal thickness in DR patients with ESKD and the features of DR and the prevalence of DME in these patients who have received long-term HD. METHODS: Eighty-five eyes of 44 DR patients with ESKD who underwent long-term HD were examined by swept-source optical coherence tomography angiography (SS-OCTA). Based on OCTA images, the characteristics of DR and the prevalence of DME in these patients were analyzed. Changes in central retinal thickness (CRT), central retinal volume (CRV), subfoveal choroidal thickness (SFCT) and subfoveal choroidal volume (SFCV) within 30 min before and after single HD session were compared. CRT, CRV, SFCT and SFCV were compared before single HD session and before the next single HD session. RESULTS: There was no significant difference in the average CRT (251.69 ± 39.21 µm vs. 251.46 ± 39.38 µm, P = 0.286) or CRV (0.15 ± 0.62 µm vs. 0.15 ± 0.63 µm, P = 0.324) between before and after single HD session. After single HD session, SFCT (243.11 ± 77.15 µm vs. 219.20 ± 72.84 µm, P < 0.001) and SFCV (0.15 ± 0.10 µm vs. 0.13 ± 0.90 µm, P < 0.001) significantly decreased. There was no statistically significant difference in CRT (251.69 ± 39.21 µm vs. 251.11 ± 38.47 µm, P = 0.206), CRV (0.15 ± 0.62 µm vs. 0.15 ± 0.61 µm, P = 0.154), SFCT (243.11 ± 77.15 µm vs. 245.41 ± 76.23 µm, P = 0.108), or SFCV (0.15 ± 0.10 µm vs. 0.16 ± 0.10 µm, P = 0.174) before HD and before the next single HD session. On en face OCTA images, eighty-five eyes (100%) had retinal nonperfusion areas, foveal avascular zone (FAZ) enlargement, and abnormal retinal microvasculature. Based on cross-sectional OCTA images, retinal neovascularization (RNV) was confirmed in 42 eyes (49.41%), and intraretinal microvascular abnormalities (IRMAs) were detected in 85 eyes (100%). Seventeen eyes (20%) still had DME, all of which were cystoid macular edema (CME). Among eyes with DME, the epiretinal membrane (ERM) was present in 7 eyes (8.24%). CONCLUSIONS: For DR patients with ESKD who have undergone long-term HD, the choroidal thickness still changes significantly before and after single HD session, which may be related to short-term effects such as reduced blood volume and plasma osmotic pressure caused by single HD session. Although macular features seem to have stabilized in DR patients undergoing long-term dialysis, the DR of patients with ESKD should still be given attention.

Early and Late Treatment Influence on Chorioretinal Microvasculature in Vogt-Koyanagi-Harada Patients Using Optical Coherence Tomography Angiography.

Purpose: To study the impact of early and late treatment on chorioretinal microvasculature in Vogt-Koyanagi-Harada (VKH) disease using optical coherence tomography angiography (OCTA). Methods: A total of 103 patients with VKH disease were divided into early (group 1, starting treatment within 2 months after disease onset) and late (group 2, starting treatment 2 months after disease onset) treatment groups. Flow area (FA) and vessel density (VD) of the retinal superficial vascular complex (SVC) and deep vascular complex (DVC), FA of the choriocapillaris, three-dimensional choroidal vascular volume (CVV), and choroidal vascularity index (CVI) were analyzed and compared to 103 healthy individuals. The relationship between the final best-corrected visual acuity (BCVA) and the aforementioned parameters was also analyzed. Results: FA of the SVC (all P < 0.05, except 0-1 mm P = 0.087), DVC (all P < 0.05), choriocapillaris (1-2.5 mm P = 0.033), and CVV (all P < 0.05) were lower in group 2 as compared to group 1. Compared to healthy controls, FA of the SVC (all P < 0.001, except 0-1 mm P = 0.104) and DVC (all P < 0.05), VD of the SVC (1-2.5 mm P = 0.001) and DVC (1-5 mm P = 0.003, 2.5-5 mm P < 0.001), FA of the choriocapillaris (all P < 0.05), and CVV (total area P = 0.049, 1-5 mm P = 0.045, 2.5-5 mm P = 0.041) were lower in group 2, while FA (all P < 0.05, except 0-1 mm P = 0.925) and VD (1-5 mm P = 0.003, 2.5-5 mm P = 0.004) of the DVC and FA of the choriocapillaris (total area P = 0.007, 0-1 mm P < 0.001, 1-2.5 mm P = 0.007) were lower in group 1. There was no significant difference concerning CVI among groups (all P > 0.05). FA of the SVC, DVC, and choriocapillaris and VD of DVC and CVI were negatively associated with the final logarithm of the minimum angle of resolution BCVA. Conclusions: Patients with VKH disease who are treated within 2 months of disease onset showed a better chorioretinal microvascular outcome as defined by OCTA compared to those treated late. Translational Relevance: Our study employs OCTA to design three-dimensional metrics for the retina and choroid, bridging the gap between traditional two-dimensional OCTA findings and enhanced clinical outcomes for patients with VKH disease.

Changes in the outer nuclear layer and choroidal vascularity during the manifest and quiescent phases of acute central serous chorioretinopathy.

To investigate alteration of outer nuclear layer (ONL) and choroidal vascularity index (CVI) in different status of central serous chorioretinopathy (CSC). A retrospective review of 65 CSC eyes with subretinal fluid (manifest CSC) and 40 control eyes was conducted in a single tertiary university hospital. Differences in best-corrected visual acuity (BCVA), ONL, and CVI were compared. CVI was assessed both in the entire choroid (CVI-EC) and around the 1500 µm leakage area (CVI-1500). Measurements were repeated after the subretinal fluid resorption (quiescent CSC), and compared. CSC eyes showed worse BCVA, thinner ONL and greater CVI than controls. Quiescent CSC showed a recovery of ONL compared to the manifest CSC, along with the BCVA improvement. The resolution of the CSC revealed a decrease across all three choroidal areas (total, stromal and luminal), with a more pronounced reduction in the stromal than in the luminal choroidal area, leading to an increase in the CVI. This phenomenon was shown in both CVI-EC and CVI-1500. Conclusively, ONL thickness can be used as a quantitative biomarker for photoreceptor function in CSC. Increased CVI may reflect a disease activity. The stromal choroidal area is particularly sensitive in illustrating leakage from the choroidal vasculature.

Correlation in retinal thickness and macular retina plus choroidal microcirculation in pediatric myopia.

To analyze the relationship in retinal thickness, macula retina and choroidal microcirculation in pediatric patients with myopia. Pediatric patients with high myopia (high myopia group, n = 30, 60 eyes) and pediatric patients with low to moderate myopia (low myopia group, n = 30, 60 eyes) admitted to our hospital from January 2021 to January 2022 were randomly selected as the study subjects. Retinal thickness, the blood density of retina, and the blood density of the choroid were collected in each area of the macula by taking optical coherence tomography (OCT) and OCT angiography (OCTA). Pearson correlation analysis was conducted to compare the results from the 2 groups. Outer retinal thickness showed a weak positive correlation with Superficial vascular complex flow density (SVD) and deep vascular complex flow density (DVD) (P < .05), but no significant correlation with choroidal capillary density (P > .05); inner retinal thickness showed a weak positive correlation with SVD and DVD (P < .05), but no significant correlation with choroidal capillary density (P > .05). In pediatric patients with myopia, there is a positive correlation between the blood flow density of macular retina and retinal thickness, and the retinal thickness will become thinner with increasing myopia.

Optical coherence tomography angiography in thyroid associated ophthalmopathy: a systematic review.

PURPOSE: To evaluate the evidence for alterations of blood flow, vascular and perfusion densities in the choroid, macula, peripapillary region, and the area surrounding the optic nerve head (ONH) in patients with thyroid-associated ophthalmopathy (TAO) based on changes of OCTA parameters. METHODS: A systematic review of Pubmed, Google Scholar, Scopus, WOS, Cochrane, and Embase databases, including quality assessment of published studies, investigating the alterations of OCTA parameters in TAO patients was conducted. The outcomes of interest comprised changes of perfusion and vascular densities in radial peripapillary capillary (RPC), ONH, superficial and deep retinal layers (SRL and DRL), choriocapillaris (CC) flow, and the extent of the foveal avascular zone (FAZ). RESULTS: From the total of 1253 articles obtained from the databases, the pool of papers was narrowed down to studies published until March 20th, 2024. Lastly, 42 studies were taken into consideration which contained the data regarding the alterations of OCTA parameters including choriocapillary vascular flow, vascular and perfusion densities of retinal microvasculature, SRL, and DRL, changes in macular all grid sessions, changes of foveal, perifoveal and parafoveal densities, macular whole image vessel density (m-wiVD) and FAZ, in addition to alterations of ONH and RPC whole image vessel densities (onh-wiVD and rpc-wiVD) among TAO patients. The correlation of these parameters with visual field-associated parameters, such as Best-corrected visual acuity (BCVA), Visual field mean defect (VF-MD), axial length (AL), P100 amplitude, and latency, was also evaluated among TAO patients. CONCLUSION: The application of OCTA has proven helpful in distinguishing active and inactive TAO patients, as well as differentiation of patients with or without DON, indicating the potential promising role of some OCTA measures for early detection of TAO with high sensitivity and specificity in addition to preventing the irreversible outcomes of TAO. OCTA assessments have also been applied to evaluate the effectiveness of TAO treatment approaches, including systemic corticosteroid therapy and surgical decompression.

Choroidal vascularity features of fundus tessellation in adults with high myopia.

BACKGROUND: To investigate alterations in choroidal vascularity index among highly myopic adults with fundus tessellation, utilizing optical coherence tomography. METHODS: Total of 143 highly myopic adults (234 eyes) with fundus tessellation were collected in this cross-sectional study, which was stratified into different lesion groups based on the novel tessellated fundus classification. Subfoveal choroidal thickness (SFCT), choroidal luminal area (LA), stromal area (SA), total choroidal area (TCA), and choroidal vascularity index (CVI) were analyzed utilizing optical coherence tomography (OCT) with enhanced depth imaging (EDI) mode, enabling precise quantification of these parameters. RESULTS: Comparison analysis demonstrated notable distinctions in spherical equivalent (SE), axial length (AL), and SFCT across the four tessellation grades (p < 0.001). Analysis of the choroidal vascularity parameters, including LA, TCA, and CVI, demonstrated notable disparities across the four groups (p < 0.001), while no significant variations were observed in SA when comparing Grade 1 versus Grade 2, as well as Grade 2 versus Grade 3 (p > 0.05). Logistic regression analyses illustrated that the higher grade of tessellated exhibited a positive association with AL (OR = 1.701, p = 0.027), while negatively associated with SFCT (OR = 0.416, p = 0.007), LA (OR = 0.438, p = 0.010) and CVI (OR = 0.529, p = 0.004). Multiple regression analyses demonstrated a significant negative association between CVI and both SE and AL after adjusting for age, while positively associated with SFCT (p < 0.05). CONCLUSION: Subtle choroidal vascularity changes may have a meaningful contribution to the development and progression of fundus tessellation. CVI and LA dramatically decreased during the early stages of tessellation development and maintained a relatively stable status when in the severe tessellated grades.

Choriocapillaris Impairment, Visual Function, and Distance to Fovea in Aging and Age-Related Macular Degeneration: ALSTAR2 Baseline.

Purpose: In aging and early-intermediate age-related macular degeneration (AMD), rod-mediated dark adaptation (RMDA) slows more at 5° superior than at 12°. Using optical coherence tomography angiography (OCTA), we asked whether choriocapillaris flow deficits are related to distance from the fovea. Methods: Persons ≥60 years stratified for AMD via the Age-Related Eye Disease Study's nine-step system underwent RMDA testing. Two adjacent 4.4° × 4.4° choriocapillaris OCTA slabs were centered on the fovea and 12° superior. Flow signal deficits (FD%) in concentric arcs (outer radii in mm, 0.5, 1.5, 2.2, 4.0, and 5.0 superior) were correlated with rod intercept time (RIT) and best-corrected visual acuity (BCVA). Results: In 366 eyes (170 normal, 111 early AMD, 85 intermediate AMD), FD% was significantly worse with greater AMD severity in all regions (overall P < 0.05) and poorest under the fovea (P < 0.0001). In pairwise comparisons, FD% worsened with greater AMD severity (P < 0.05) at distances <2.2 mm. At greater distances, eyes with intermediate, but not early AMD differed from normal eyes. Foveal FD% was more strongly associated with longer RIT at 5° (r = 0.52) than RIT at 12° (r = 0.39) and BCVA (r = 0.21; all P < 0.0001). Choroidal thickness was weakly associated with longer RIT at 5° and 12° (r = 0.10-0.20, P < 0.05) and not associated with AMD severity. Conclusions: Reduced transport across the choriocapillaris-Bruch's membrane-retinal pigment epithelium complex, which contributes to drusen formation under the macula lutea (and fovea), may also reduce retinoid resupply to rods encircling the high-risk area. FD% has potential as a functionally validated imaging biomarker for AMD emergence.

Progressive Choriocapillaris Changes on Optical Coherence Tomography Angiography Correlate With Stage Progression in AMD.

Purpose: We investigated the association between inner choroid flow deficit percentage (IC-FD%) using swept-source optical coherence tomography angiography (SS-OCTA) and progression of AMD. Methods: Retrospective, observational study including 64 eyes (42 participants) with early or intermediate AMD at baseline. Participants had two or more consecutive swept-source optical coherence tomography angiography covering a period of at least 18 months. Demographics, visual acuity, and AMD staging based on Beckman classification were reviewed. OCT was analyzed for hyperreflective foci, subretinal drusenoid deposits, hyporeflective drusen cores, and subfoveal choroidal thickness. IC-FD% was measured within the central 3- and 6-mm using a 16-µm slab, after compensation and binarization (Phansalkar method). Mixed-effects Cox regression models assessed the association between imaging biomarkers and AMD progression. Results: During follow-up (37 ± 9 months), 4 eyes with early AMD (31%) progressed to intermediate AMD and 30 (59%) eyes with intermediate AMD developed late AMD (19 geographic atrophy; 11 wet AMD). Baseline hyporeflective drusen core was associated with geographic atrophy development (P < 0.01), whereas greater IC-FD% (3-mm) was associated with wet AMD (P = 0.03). Time-varying analysis showed that faster subfoveal choroidal thickness reduction and IC-FD% (6-mm) increase were associated with geographic atrophy onset (P < 0.05), whereas IC-FD% (3-mm) increase was associated with wet AMD (P = 0.03). Notably, greater IC-FD% increases in the 3 mm (area under the curve = 0.72) and 6 mm (area under the curve = 0.89) were better predictive of wet AMD and geographic atrophy development, respectively. Conclusions: Our longitudinal IC-FD% assessment emphasizes the role of progressive choriocapillaris changes as a biomarker for AMD progression. Our findings support that widespread choriocapillaris alterations (6 mm) may precede progression to geographic atrophy, whereas more central choriocapillaris loss (3 mm) may provide an ischemic stimulus for wet AMD.

Exploratory analysis of choriocapillaris vasculature as a biomarker of idiopathic epiretinal membrane.

PURPOSE: To investigate the preoperative choriocapillaris perfusion (CCP) as a biomarker in patients with idiopathic epiretinal membrane (iERM). MATERIALS AND METHODS: 28 patients (28 eyes) with unilateral iERM who received pars plana vitrectomy (PPV) with internal limiting membrane (ILM) peeling were included for retrospective observational study. Optical coherence tomography (OCT) and angiography (OCTA) was performed before and after PPV. Area, perimeter, and circularity of superficial foveal avascular zone (FAZ) were analyzed preoperatively in both eyes using OCTA. Preoperative CCP was also analyzed with binarized en-face OCTA images. Measurements of best-corrected visual acuity (BCVA) and central foveal thickness (CFT) by OCT were conducted at the baseline and 6 months following the surgery. The correlations of preoperative OCT parameters with postoperative BCVA and CFT reduction were analyzed. RESULTS: CCP was significantly lower (p < 0.001) and FAZ had shrunk (p < 0.001) in eyes with iERM compared to unaffected fellow eyes before surgery. BCVA and CFT became significantly improved after surgery (p = 0.001, p < 0.001). Multiple regression analysis revealed that preoperative CCP was significantly related with BCVA improvement (ß = 0.185, p = 0.005), postoperative BCVA (ß = 0.108, p = 0.023) and ratio of post- to preoperative CFT (ß = 0.106, p = 0.044). CONCLUSIONS: Preoperative CCP is a biomarker for poor functional and anatomical prognosis after surgery in iERM.

Establishment of an in vitro choroid complex system for vascular response screening.

The choroid, a vascularized tissue situated between the retina and the sclera, plays a crucial role in maintaining ocular homeostasis. Despite its significance, research on choroidal abnormalities and the establishment of effective in vitro models have been limited. In this study, we developed an in vitro choroid model through the co-culture of human induced pluripotent stem cells (hiPSC)-derived endothelial cells (ECs) and mouse choroidal fibroblasts (msCFs) with hiPSC-derived retinal pigment epithelial (RPE) cells via a permeable membrane. This model, inclusive of ECs, CFs, and RPE cells, exhibited similarities with in vivo choroidal vessels, as confirmed through immunohistochemistry of extracellular matrix markers and vascular-related markers, as well as choroid angiogenesis sprouting assay analysis. The effectiveness of our in vitro model was demonstrated in assessing vascular changes induced by drugs targeting vasoregulation. Our model offers a valuable tool for gaining insights into the pathological mechanisms underlying choroid development and the progression of choroidal vascular diseases.

Pachychoroid Spectrum Disease: Comparison of Patients with Central Serous Chorioretinopathy Complicated with Pachychoroid Neovasculopathy.

PURPOSE: This study aimed to determine the incidence and visual outcomes of pachychoroid neovasculopathy (PNV) in patients initially diagnosed with central serous chorioretinopathy (CSC). METHODS: In this study, 144 patients aged 20 to 55 years with treatment-naive chronic CSC, defined as the persistence of subretinal fluid (SRF) for ≥6 months, were retrospectively enrolled. Patients with PNV at the initial evaluation were categorized as group 1, whereas those who developed new-onset PNV during follow-up were categorized as group 2. Patients without PNV until the end of the follow-up were categorized as group 3. RESULTS: Over a mean follow-up period of 49.9 ± 39.9 months, new-onset PNV was diagnosed in 11.8% of patients with CSC. The time taken to reach the initial resolution was longest in group 1 (group 1, 11.13 ± 10.70 months; group 2, 8.14 ± 7.90 months; group 3, 7.32 ± 9.55 months), although these differences were not statistically significant. The numbers of injections needed to achieve initial resolution were 3.76 ± 5.90, 1.64 ± 2.06, and 1.74 ± 4.33 in groups 1, 2, and 3, respectively, with no significant differences. SRF recurrence was recorded in seven patients (29.2%) in group 1, nine (64.3%) in group 2, and 28 (26.7%) in group 3. The recurrence rates were significantly higher in group 2 than those in group 1 or 3. At the end of the follow-up period, significant improvements in best-corrected visual acuity were achieved in groups 1 and 3, compared with baseline, but not in group 2. CONCLUSIONS: Patients with chronic CSC with new-onset PNV exhibited higher SRF recurrence and worse visual outcomes compared to those with initial PNV or those with chronic CSC without PNV. Our study emphasizes the importance of routine screening for prompt diagnoses of new-onset PNV in individuals with chronic CSC.

ASSOCIATIONS BETWEEN CHOROIDAL ALTERATIONS AND EARLY NEURODEGENERATION IN DIABETES WITHOUT DIABETIC RETINOPATHY: Insights From Ultra-Widefield Optical Coherence Tomography Angiography Imaging.

PURPOSE: To identify associations between choroidal alterations and the reduction of peripapillary retinal nerve fiber layer (pRNFL) thickness in diabetes without diabetic retinopathy (nondiabetic retinopathy, NDR). METHODS: This retrospective cross-sectional study included 143 eyes from 83 patients with NDR and 124 eyes from 82 matched healthy controls. Ultra-widefield swept-source optical coherence tomography angiography was used to automatically measure retinal and choroidal thickness (ChT), retinal vascular density, and choroidal vascular metrics. Data were analyzed using Student's t-tests, generalized estimating equations, and generalized linear mixed models. RESULTS: Patients with NDR exhibited significant reductions in perifoveal ChT (e.g., perifoveal inferior region: 253.42 ± 86.59 µm vs. 281.01 ± 80.25 µm, P = 0.026 in GEE test) compared with the controls. The NDR group showed a significant decrease in the choroidal vascular index (P = 0.012 in GEE test), and an increase in the choroidal stromal index (P = 0.012 in GEE test). The average pRNFL thickness significantly decreased in patients with NDR (114.58 ± 11.88 µm vs. 120.25 ± 16.36 µm, P = 0.005 in GEE test). The thickness of the outer nuclear layer and total retina significantly decreased in patients with NDR (P < 0.05). In multivariate models, ChT was significantly correlated with pRNFL thickness (ß = 0.041, P = 0.001), even after adjusting by confounding factors (ß = 0.056, P = 0.001). CONCLUSION: In NDR, there were decreases in ChT, choroidal vascular index, pRNFL thickness, and outer nuclear layer thickness. The reduction in ChT was independently associated with the reduction in pRNFL thickness, suggesting that ChT could serve as a predictor of retinal neurodegeneration in NDR.

Long-Term Effects of Intravitreal Ranibizumab Compared With Panretinal Photocoagulation on Optical Coherence Tomography Measured Choroidal Thickness and Vascularity.

Purpose: Compare choroidal changes in ranibizumab versus panretinal photocoagulation (PRP)-treated eyes with proliferative diabetic retinopathy (PDR). Methods: DRCR Retina Network Protocol S post hoc analysis evaluated optical coherence tomography change in choroidal thickness (subfoveal and 3mm superior and inferior to the fovea) through five years; choroidal vascularity index (CVI) was assessed at baseline and one year. Mixed linear models for choroidal change included adjustments for the baseline choroidal value and age. Results: This study included 328 eyes (158 ranibizumab and 170 PRP) from 256 participants (88 ranibizumab and 95 PRP eyes at five years). Mean change in choroidal thickness from baseline to five years at the fovea was -12 µm in ranibizumab versus -8 µm in PRP (difference [95% confidence interval]: -4 [-18 to 10], P = 0.57), superior was -14 µm versus -19 µm (difference: 5 [-8 to 17], P = 0.45) and inferior was -26 µm versus -32 µm [difference: 5 (-9 to 20), P = 0.45]; change at all three points within the ranibizumab group, and the superior and inferior points for PRP, were statistically significant (P < .05). Mean change in CVI at one year was -0.02% in ranibizumab versus -0.95% in PRP (difference: 0.93 [-0.35 to 2.21], P = 0.14). Conclusions: In patients with PDR, treatment with ranibizumab versus PRP did not result in statistically significant differences in five-year choroidal thickness or one-year CVI change. Both groups had significant decreases in choroidal thickness at five years. Translational Relevance: Ranibizumab treatment for PDR did not statistically significantly affect choroidal thickness or vascularity differently than PRP.

Quantitative optical coherence tomography angiography assessments in the fellow eyes of those with central serous chorioretinopathy.

BACKGROUND: To analyze the vessel density (VD) of the retina and choriocapillaris (CC) layer and the structure of the foveal avascular zone (FAZ) in the fellow eyes of central serous chorioretinopathy (CSC) patients by using optical coherence tomography angiography (OCTA). METHODS: This was a case-control study. Unilateral CSC patients and age-matched healthy subjects were recruited from the Affiliated Eye Hospital of Wenzhou Medical University between July 2016 and July 2021. All eyes were divided into three groups: acute CSC (aCSC), chronic CSC (cCSC), and healthy controls. Both aCSC and cCSC were again divided into two subgroups: the affected eyes and the fellow eyes. In this study, all parameters of VD and FAZ were measured by self-software of OCTA. RESULTS: A total of 231 eyes of 137 subjects were included, with 47 aCSC patients, 47 cCSC patients, and 43 healthy controls. In the fellow eyes of CSC, the retinal VD was significantly lower (all P < 0.05), and the FAZ was significantly larger (all P < 0.05) in the cCSC group than in healthy controls, while no difference was detected in the CC layer. There was no significant difference between the aCSC group and healthy controls in all OCTA parameters. In the affected eyes of CSC, the superficial retinal vessel density (SRVD) was significantly higher (all P < 0.05) in healthy controls than in the aCSC and cCSC groups, while the deep retinal vessel density (DRVD) was significantly lower (all P < 0.05) and the FAZ was larger (all P < 0.05) in the cCSC group than in the aCSC group and healthy controls. A liner regression equation was established: Y (BCVA, best corrected visual acuity) = 3.692-0.036✱X1 (DRVD-Fovea)-0.031✱X2 (FD-300, vessel density around the 300 µm width of the FAZ), R2 = 0.427. CONCLUSION: Based on OCTA measurements, this study revealed that the retinal microvascular network was impaired even in the fellow eyes of those with cCSC, which should arouse attention to the observation of unilateral CSC.

[Terminology of quantitative optical coherence tomography angiography metrics]. / Osobennosti terminologii kolichestvennykh pokazatelei opticheskoi kogerentnoi tomografii-angiografii.

This review is devoted to the English- and Russian-language terminology of quantitative metrics that are used in the evaluation of images obtained by optical coherence tomography angiography (OCT-A). The paper presents an analysis of the use of terms characterizing intraretinal blood flow (vascular density, perfusion density, skeletonized density, etc.), area and shape of the foveal avascular zone, and choriocapillaris blood flow. The factors causing the heterogeneity of OCT-A terminology are described, including the lack of a unified international nomenclature for OCT-A, features of their Russian translation, inconsistency of the parameters in optical coherence tomography systems of different manufacturers. The article also considers ways to standardize the terminology.

[A preliminary study on the characteristics of refractive parameters and retinal blood flow in dominant eyes].

Objective: To explore the characteristics of refractive parameters and retinal and choroidal blood flow in dominant and non-dominant eyes. Methods: A cross-sectional study. Students who were 18 to 32 years old and had emmetropia or myopia but no systemic diseases were recruited from universities in Wuhu, Anhui Province from April 2019 to August 2023. They were divided into 4 groups based on the difference in spherical equivalent between two eyes:<0.50 D (group A), 0.50 to 1.74 D (group B), 1.75 to 2.49 D (group C), and≥2.50 D (group D). The card hole method was used to determine the dominant eye. The refractive parameters of both eyes were recorded, including spherical equivalent, myopia degree, astigmatism degree, axial length, and corneal curvature difference (K2-K1). Optical coherence tomography angiography was performed to measure the blood flow density of the superficial retinal capillaries, deep retinal capillaries (DVC), avascular layer (AC), entire retina, choroidal capillaries, and choroidal vessels, as well as the retina and choroid as a whole. Statistical analysis was conducted using the paired sample t-test, chi square test, and variance analysis. Results: A total of 78 eligible subjects, aged (24.50±2.36) years old, 28 males and 50 females, were included. Fifty subjects had the right eye and 28 had the left eye as the dominant eye. Forty-two subjects had high myopia in the dominant eye, and 30 had high myopia in the non-dominant eye. There were statistically significant differences (all P<0.05) in the spherical equivalent [(-4.588±2.534) D vs. (-4.058±2.453) D], myopic spherical power [(-4.253±2.504) D vs. (-3.779±2.425) D], and axial length [(25.531±1.212) mm vs. (25.256±1.238) mm] between dominant and non-dominant eyes among all subjects, as well as in the astigmatism degree of groups A and C, spherical power of groups B to D, and spherical power and axial length of groups C and D. There were also statistically significant differences (all P<0.05) in the blood flow density of the DVC [(0.291±0.130) vs. (0.257±0.148)], AC [(0.347±0.118) vs. (0.326±0.126)], and overall retina and choroid [(0.385±0.102) vs. (0.349±0.084)] between dominant and non-dominant eyes among all subjects, as well as in the blood flow density of the superficial retinal capillaries, DVC, AC, choroidal capillaries, and overall retina and choroid of groups C and D, density of the choroidal vessels of group C, and density of the entire retina of group D. Conclusions: In young individuals with emmetropia or near vision, the degree of myopia in dominant eyes is higher than that in non-dominant eyes. When the difference in the spherical equivalent between two eyes is ≥1.75 D, the blood flow density of the retina and choroid in the dominant eye is greater than that in the non-dominant eye.

[Influence of implantable Collamer lens implantation on choroidal thickness and blood flow density].

Objective: To observe the impact of implantable Collamer lens (ICL) implantation surgery on choroidal thickness and blood flow density in myopic patients. Methods: This was a prospective cohort study. Patients undergoing ICL surgery at Qingdao University Affiliated Hospital between June 2021 and May 2023 were consecutively enrolled. Patients were categorized into high myopia (HM) and super high myopia (SHM) groups based on whether their spherical equivalence power exceeded 10.00 D. Comprehensive ophthalmic examinations, including optical coherence tomography, optical coherence tomography angiography, visual acuity assessment, intraocular pressure measurement, and optometry, were performed preoperatively and at 1 week, 1 month, and 3 months postoperatively. Results: A total of 42 patients (84 eyes), with an average age of (25.27±3.18) years, comprising 11 males and 31 females, were enrolled in the study. Among them, 20 patients belonged to the HM group, while 22 patients were in the SHM group. Both choroidal thickness and blood flow density exhibited significant increases at postoperative 1 week and 1 month compared to preoperative levels (P<0.05), but returned to baseline levels by postoperative 3 months. Specifically, the subfoveal choroidal thickness increased from (169.49±61.57) µm preoperatively to (180.16±66.61) µm at 1 week, (186.69±63.32) µm at 1 month, and then reverted to (169.58±60.82) µm at 3 months. The central choroidal blood flow density showed changes from 60.03%±1.60% preoperatively to 61.04%±1.17% at 1 week, 60.42%±1.81% at 1 month, and 60.22%±1.57% at 3 months. Furthermore, the HM group exhibited more pronounced changes in both choroidal thickness and blood flow density across all time points compared to the SHM group. Significant differences were observed in choroidal thickness changes at various areas at 1 month, while changes in blood flow density in specific areas were significant. However, no significant differences were noted at 3 months postoperatively. Correlation analysis revealed a negative correlation of changes in subfoveal choroidal thickness and central choroidal blood flow density postoperatively at 1 week and 3 months with preoperative choroidal blood flow density. Notably, no correlation was found between preoperative choroidal thickness and postoperative changes. Conclusions: In the early period following ICL implantation, the increase in choroidal thickness and blood flow density may be more pronounced in HM compared to SHM, but the two parameters can return to baseline levels by 3 months. ICL implantation transiently affects the fundus microenvironment in myopic patients, with implications of preoperative choroidal blood flow.