Choroidal Parameters Research Articles

Does the Presence of the Cilioretinal Artery Affect the Incidence, Clinical Picture and Progression of Age-Related Macular Degeneration?

The aims of this study were to analyze the relationship between the presence of the cilioretinal artery (CRA) and the incidence, severity and progression of age-related macular degeneration (AMD) and to estimate the influence of the CRA on choroidal and retinal parameters. A total of 287 patients with AMD and 110 healthy controls were enrolled in the study. CRA occurrence was determined using color fundus images. AMD progression was assessed after 3 years. There was no difference in the incidence of CRA between the AMD and control groups (23.34% vs. 24.55%; p = 0.8). Lower-stage AMD was more frequently observed in eyes with the CRA than in eyes without the artery (p = 0.016). The CRA did not influence disease progression (p = 0.79). The CRA did not influence retinal and choroidal thickness and volume parameters or the retinal vessel caliber and functionality in either the AMD or control groups. There was no relationship between CRA presence and CFH Y402H and ARMS2 A69S risk variants. The results did not show a protective effect of the CRA on the incidence and progression of AMD. The CRA may affect the severity of AMD; however, the mechanism of this phenomenon is unclear.

Distribution and determinants of choroidal vascularity index in healthy eyes from deep-learning choroidal analysis: a population-based SS-OCT study

AimsTo quantify the profiles of choroidal vascularity index (CVI) using fully artificial intelligence (AI)-based algorithm applied to swept-source optical coherence tomography (SS-OCT) images and evaluate the determinants of CVI in...

Effects of COVID-19 on Retinal and Choroidal Thickness by Optical Coherence Tomography.

The aim of our study was to evaluate the subclinical changes in the macula, retinal nerve fiber layer (RNFL), and choroidal thickness after coronavirus disease 2019 (COVID-19) infection using spectral domain optical coherence tomography. Our study was prospectively designed and involved 170 eyes of 85 patients. Patients with polymerase chain reaction (PCR)-positive COVID-19 infection were examined in the ophthalmology clinic before and after infection were included. All included patients had mild COVID-19 with no hospitalization and no need for intubation. Control ophthalmic examination was repeated at least 6 months after PCR positivity. Macular and choroidal thickness and RNFL parameters were compared before and at least 6 months after PCR-positive COVID-19 infection using optical coherence tomography. When the mean macular thickness data were evaluated, a significant decrease was detected in the inner (mean difference, -3.37 µm; 95% CI: -6.09 to -0.65, P = 0.021) and outer (mean difference, -6.56 µm; 95% CI: -9.26 to -3.86, P < 0.001) temporal segments and the inner (mean difference, -3.39 µm; 95% CI: -5.46 to -1.32, P = 0.002) and outer (mean difference, -2.01 µm; 95% CI, -3.70 to -0.31, P = 0.018) su p erior segments in the post-COVID-19 measurements compared with pre-COVID-19 measurements. Similarly, on RNFL evaluation, some thinning was evident in the temporal superior (mean = 1.14 µm, P = 0.004) and temporal inferior (mean = 1.30 µm, P = 0.032) regions. All choroidal regions, including central, nasal 500 µm and 1500 µm and temporal 500 µm and 1500 µm, exhibited significant thinning ( P < 0.001). At least 6 months after mild COVID-19 infection, significant thinning was seen in the temporal and superior quadrants of the macula, the temporal superior and temporal inferior regions of the RNFL, and all measured areas of choroidal regions.

Evaluation of the choroidal vascular index and choroidal changes in migraine subgroups

PurposeTo investigate binarized choroidal structural parameters, retinal nerve fiber layer (RNFL) thickness, and retina changes duringattack-free periods in patients with migraine using enhanced depth imaging optic coherence tomography (EDI-OCT), and compare patients with migraine with aura and without aura (MwA and MoA, respectively) and aura subgroups (visual aura, non-visual aura), with age and sex-matched healthy subjects. MethodThis observational, prospective study included 102 patients with migraine and 36 healthy controls. Central macular thickness (CMT), retinal nerve fiber layer (RNFL), ganglion cell layer (GCL), and choroidal thickness (CT) were measured using a Spectralis OCT device. The choroid vascularity index (CVI) was evaluated using the Image-J software. CVI was calculated as the proportion of the luminal area (LA) to the total choroidal area (TCA). RNFL, CMT, CT, and CVI measurements were compared statistically. ResultsChoroidal thickness at 1500 µm temporal of the fovea was found to be statistically significantly thinner in the MwA and MoA groups compared with the control group (p ≤ 0.01). There was a significant difference in the subfoveal CT values of the MwA and control groups (p < 0.05). The mean RNFL thickness of patients with migraine with visual aura was found to be statistically significantly thinner than in the migraine group with non-visual aura (98.73 ± 8.4 and 109.4 ± 16.8) (p < 0.05). There were no statistically significant differences between the RNFL CMT, GCC, and CVI values in the MwA, MoA, and control groups (p > 0.05). ConclusionWe found that the choroidal thickness was significantly decreased in patients with migraine, especially in the MwA group. In the visual aura subgroup, the mean RNFL thickness was significantly decreased compared with the non-visual aura subgroup.

Investigation of changes in retinal vascular parameters and choroidal vascular index values during the early recovery period of COVID-19: The COVID-OCTA study

BackgroundCOVID-19 effects microvasculature in many tissues. This study investigated whether the choroidal structure is also affected. MethodsThis cross-sectional study included 80 patients with COVID-19 and the same number of age- and gender-matched healthy individuals. All participants' right eye measurements were examined. Optical coherence tomography angiography (OCTA) was used for imaging. Otherwise, two independent researchers used the Choroidal vascular index (CVI) for choroidal parameters calculation. ResultsSuperior and deep flow values were lower in the COVID-19 group than in the control group, and vascular density (VD) values were lower in all regions in this group. Except for the superior mean VD, there was no statistically significant difference (p = 0.003). However, the COVID-19 group had significantly lower subfoveal choroidal thickness (SFChT) measurements than the control group (p = 0.001). In addition, no significant difference was observed between the groups in evaluating mean CVI values (p>0.05). ConclusionNoninvasive diagnostic tools such as OCTA and EDI-OCT can be used to monitor early changes in diseases affecting microvessels, such as from COVID-19.

Acute hyperglycemia compromises the responses of choroidal vessels using swept-source optical coherence tomography during dark and light adaptations.

To clarify the effects of acute hyperglycemia on the responses of choroidal structural components and vascularity index during light modulation in healthy participants using techniques including image binarization and artificial intelligence (AI) segmentation based on swept-source optical coherence tomography (SS-OCT). Twenty-four eyes of 24 healthy participants were imaged at different stages after ambient light, 40 min of dark adaptation, and 5 min of light adaptation in two imaging sessions: control and after receiving 75 g of oral glucose solution. The choroidal structural parameters, including luminal volume (LV), stromal volume (SV), total choroidal volume (TCV), and choroidal vascularity index (CVI) within a 6 mm area were determined using a custom algorithm based on image binarization and AI segmentation of SS-OCT. These measurements were compared among the conditions after adjusting for axial length, age to identify the differences. In the dark, CVI decreased (-0.36 ± 0.09%) significantly in acute hyperglycemia compared to the control condition. During the transition to ambient light, there was an increasing trend in the choroidal parameters compared with the control experiment. However, only TCV (0.38 ± 0.17 mm3) and LV (0.27 ± 0.10 mm3) showed a significant increase at the time point of 5 min after ambient light. Analysis of choroidal structural parameters and CVI based on SS-OCT images is a potentially powerful method to objectively reflect subtle changes in neurovascular coupling between the choroid and photoreceptor during dark adaptation.

Choroidal thickness and vascular microstructure parameters in Chinese school-age children with high hyperopia using optical coherence tomography.

The current study was to evaluate the choroidal thickness (CT) and vascular microstructure parameters in Chinese children with high hyperopia through enhanced depth imaging optical coherence tomography (EDI-OCT). Cross-sectional study. A total of 23 children with high hyperopia and 29 children with normal refractive status were retrospectively enrolled in the study. The measurement of the macular CT, 7 points: the sub-foveal area point, the temporal and nasal points at a radius of 0.5-mm, 1.5-mm, and 3-mm were measured. After binarization of the OCT images, the total choroidal area (TCA), stromal area (SA) as well as the luminal area (LA) were identified and measured. The choroidal vascularity index (CVI) was defined as the ratio of LA to TCA. The independent t-test for normal distributions and Kruskal-Wallis tests for non-normal distributions were used to compare other parameters between groups. The Tamhane's T2 test was performed to adjust for multiple comparisons between groups within each analysis. The subfoveal CT (SFCT) in the high hypermetropic group was significantly thicker than that in normal controls (309.22 ± 53.14 μm vs. 291.27 ± 38.27 μm; P = 0.019). At 0.5 mm, 1.5 mm, and 3.0 mm in diameter, the nasal choroidal sectors of the high hyperopia eyes were significantly thicker than that of the control (P < 0.05). There was significant difference in the choroidal vascular parameters. TCA and LA in the high hyperopia eyes was significantly larger than that of the normal control eyes (3078129.54 ± 448271.18 μm2 vs. 2765218.17 ± 317827.19 μm2, 1926819.54 ± 229817.56 μm2 vs. 1748817.18 ± 191827.98 μm2; P = 0.009, P = 0.011; Table 2). SA values were 1086287.55 ± 212712.11 um2 in the high hyperopia eyes and 999712.71 ± 209838.12 μm2 in the control eyes. The CVI and LA/SA ratio values were differed significantly in the two groups (P = 0.019, P = 0.030, respectively). AL was significantly correlated with SFCT (r = -0.325, P = 0.047), but not significantly correlated with other parameters. Spherical equivalent (SE) was significantly correlated with AL and SFCT (r = -0.711, r = 0.311; P = 0.001, P = 0.016), whereas no significant association between sphere and other parameters. The choroidal structure of the high hyperopia eyes was different from the normal control eyes. The thicker SFCT, higher LA, and TCA were characteristic of high hyperopia eyes. Choroidal blood flow may be decreased in amblyopic eyes. SFCT of high hyperopia children abnormally increased and correlated with shorter AL and higher SE. AL and SE affect choroidal structure and vascular density.

Comparison of the fluorescein angiography-guided and indocyanine green angiography-guided photodynamic therapy in the treatment of non-resolving central serous chorioretinopathy

To compare the functional and anatomical outcome of fluorescein angiography (FA) versus indocyanine green angiography (ICGA) guided photodynamic therapy (PDT) in the treatment of non-resolving central serous chorioretinopathy (CSCR). In this prospective interventional case series, all patients with non-resolving CSCR, defined as persistent SRF involving subfoveal area for at least three months, were nonrandomly assigned to receive either FA or ICGA-guided half dose PDT. Baseline and 4 months post-treatment data including best corrected visual acuity (BCVA), the status of foveal subretinal fluid, subfoveal choroidal thickness, choroidal vascularity index, pigment epithelial detachment area, treatment and PDT spot numbers were collected. Thirty-six eyes were included; 24 received ICGA-guided and 12 received FA-guided PDT. Overall, improvement in BCVA and choroidal parameters were observed in all patients. There was no significant difference in baseline parameters as well as follow-up measurements between groups. However, the mean total energy dose and spot number in the IGCA-guided PDT were significantly higher than the FA-guided PDT group (P = 0.001). Both FA-guided and ICGA-guided half-dose PDT were effective in the treatment of non-resolving CSCR, with favorable functional and anatomical outcome. In FA group, PDT with smaller spot sizes and fewer numbers of spots were applied.

Choroidal morphologic and vascular features in patients with unilateral idiopathic epiretinal membranes: An optical coherence tomography analysis integrated with assessment of retinal layers.

Integrated analysis of retinal and choroidal morphologic and vascular features is urgently needed to examine whether and how these two elements interact with each other, thus contributing to visual impairment in patients with idiopathic epiretinal membranes (iERMs). An observational retrospective study consisting of 181 patients diagnosed with unilateral iERM between August 2019 and July 2022 was carried out at Peking University Third Hospital. All patients underwent a standardized set of ophthalmologic examinations, including EDI-OCT and OCTA scanning, and were subsequently categorized into four stages according to current classification schemes based on their OCT findings. Altogether, 15 qualitative and quantitative parameters of both the retina (full-layer, inner and outer layers) and choroid were identified. The results revealed variations in the choroidal vascularity index (CVI) among different stages of iERMs (p < 0.001) for the first time. Distributions of retinal parameters across four stages of iERMs were validated. Correlation analysis between choroidal and retinal parameters showed that the CVI was associated with both inner and outer retinal morphologic biomarkers. Functional damage to retinal integrity was determined to be a strong contributor to visual acuity reduction in iERMs. This study complemented our present understanding of posterior segment structural and vascular alterations in iERMs.

Evaluation of Choroidal Vascularity Index in Keratoconus Patients: Does Choroidal Vascularity Change in Keratoconus?

To investigate the choroidal structure in keratoconic patients with different severity using the choroidal vascularity index (CVI) derived from image binarization on enhanced depth imaging optical coherence tomography scans (EDI-OCT). Sixty-eight eyes from 34 keratoconus (KCN) patients and 72 eyes from 36 healthy subjects were recruited in this prospective, noninterventional, comparative cross-sectional study. EDI-OCT was employed to measure choroidal parameters, including choroidal thickness (CT), total choroidal area (TCA), luminal area, stromal area, and CVI. Subfoveal CT was 354.6 ± 66.8 μm in the control group and 371 ± 64.5 μm in the KCN group (P = 0.86). There was no significant difference between control and KCN groups in terms of TCA (0.66 ± 0.14 mm2 vs. 0.7 ± 0.12 mm2; P = 0.70), luminal area (0.49 ± 0.10 mm2 vs. 0.53 ± 0.08 mm2; P = 0.67), and stromal area (0.16 ± 0.05 mm2 vs. 0.17 ± 0.05 mm2; P = 0.84). CVI was also comparable in the control group (75.4% ±3.4%) and the KCN group (75.6% ±4.5%; P = 0.43). There was also no significant correlation between other choroidal parameters and KCN severity indices. It seems that CVI as well as other choroidal biomarkers were not significantly different between patients with KCN and healthy subjects.

Within-day changes in luminal, stromal choroidal thickness, and choroidal vascularity index in healthy adults.

To investigate topographical and within-day changes in the choroidal vascularity index and its association with choroidal thickness parameters (total, luminal, and stromal thickness) among young adults. : Choroidal thickness and vascularity index were measured in 28 healthy young adults (age mean ± standard deviation [SD]: 25 ± 3.0) using spectral-domain optical coherence tomography. Participants were divided into three refractive groups: emmetropes, myopes, and high myopes. Choroidal parameters were evaluated in the macular and peripheral regions in the superior and inferior regions at two time points during the day; in the morning (at 7 am) and in the afternoon (at 1 pm). : All investigated choroidal thickness parameters showed a significant topographical variation across the vertical meridian, between the foveal (270 ± 89 μm, 170 ± 45 μm, and 111 ± 47 μm, respectively) and peripheral (246 ± 68 μm, 160 ± 39 μm, 86 ± 36 μm, respectively). The superior choroid was thicker in all thickness parameters compared to the inferior choroid. A significant increase in the vascularity percentage was seen from the fovea (61.8 ± 7%) toward the periphery (66.4 ± 7%). Thinner choroidal parameters were associated with high myopia, whereas an increase in the vascularity index was observed in high myopes. Significant within-day changes were observed in all choroidal thickness parameters, which were slightly reduced in the afternoon. The choroidal vascularity index (CVI) increased from 61.3 ± 5.3% in the morning and 63.2 ± 5.8% in the afternoon. High myopes exhibited reduced within-day amplitude in stromal thickness. : All parameters showed significant regional variations. Myopia is associated with greater thinning in stromal thickness rather than vascular thickness. Only high myopes experienced reduced within-day change amplitudes in stromal choroidal thickness that was more predominant in the foveal and parafoveal regions.

Pigment epithelium and choroid changes in pachychoroid pigment epitheliopathy: A descriptive study

AbstractPurpose: To describe characteristic elementary lesions of retinal pigment epithelium and choroidal vascular parameters determined by swept source optical coherence tomography (SS‐OCT) and OCT‐angiography (OCT‐A) in eyes with pachychoroid pigment epitheliopathy.Methods: Twenty‐seven patients with retinal pigment epithelium (RPE) abnormalities associated to pachychoroid features, with no history or findings indicative of subretinal fluid or soft drusen were evaluated. All eyes underwent comprehensive ophthalmic examination, fundus photography, SS‐OCT and OCT‐A. After binarization of B‐scan images with ImageJ Software, the choroidal vascularity index (CVI), the choroidal vascularity proportion (CVP) and flow voids area were calculated.Results: A total of 27 eyes of 23 patients, 19 of whom were male (70.37%), with a mean age of 59.11 ± 12.76 years were enrolled in this study. We detected six different types of RPE lesions: focal disruption in ellipsoid and interdigitation zones in 18 eyes (66.66%), RPE elevation with microbreak appearance in 12 eyes (44.44%), RPE thickening in 10 eyes (37.03%), small pigment epithelium detachment in seven eyes (25.92%), RPE spike in five eyes (18.51%) and outer nuclear layer thinning in five eyes (18.51%). The subfoveal choroidal thickness (SFCT) was 399, 78 ± 88, 13 μm. The mean inner choroidal thickness was 87.18 ± 36.67 μm. The CVI was 65.28 ± 3.35%. The CVP was 59.10 ± 0.58% in the choriocapillaris and 59.69 ± 1.42% in the Haller layer. The total choriocapillaris flow void area was 39.87 ± 1.21%.Conclusions: SS‐OCT and OCT‐A are valuable diagnostic tools to characterize pigment epithelium and choroidal changes in PPE eyes.

Are choroidal vascularity parameters influenced by age, hypertension and visual acuity in pachychoroid spectrum diseases?

AbstractPurpose: To identify correlations of subfoveal choroidal thickness (SFCT) and choroidal vascularity index (CVI) with age and best corrected visual acuity in eyes with pachychoroid spectrum diseases (PSD) and their association to systemic hypertension using a retrospective study design.Methods: Our study included 82 eyes of 45 patients with PSD: 15 eyes had uncomplicated pachychoroid (UCP), 27 had pachychoroid pigment epitheliopathy (PPE), 32 had central serous chorioretinopathy (CSC) and 8 had pachychoroid neovasculopathy (PNV). All patients underwent DRI TRITON Swept‐Source Optical Coherence Tomography (SS‐OCT). A 1500 mm width subfoveal choroidal area was defined in SS‐OCT B‐scans and divided into luminal area (LA) and stromal area (SA) by the imageJ binarization technique. CVI was defined as the ratio of LA to the total subfoveal choroidal area (TCA).Results: The mean SFCT was 393, 23 ± 95, 65 μm and it was correlated negatively with age (p = 0.003, R = −0.326). We found a negative correlation of TCA and LA with age (p = 0.043, r = −0.227, p = 0.04, r = −0.230). Mean choroidal vascularity index was 64.45 ± 2, 74% with no correlation with age (p = 0.169, R = −0.155). No parameter among SFCT, CVI, TCA, LA and SA had a significant correlation with BCVA or spherical equivalent. Patients with essential hypertension were found to have significantly thinner SFCT when compared with healthy controls (374, 49 ± 83 141 μm vs. 423, 98 ± 130 466 μm, p = 0.046). CVI was not affected by a history of systemic hypertension (64.05 ± 1.97 vs. 64.83 ± 3.3, p = 0.207). The total choroidal area, luminal area, and stromal area, as well as the CVI correlated with SFCT (p &lt; 0.001, r = 0.817, p &lt; 0.001, r = 0.821, p &lt; 0.001, r = 0.750 and p &lt; 0.001, r = 0.371 respectively).Conclusions: SFCT and CVI are dynamic parameters that are affected in patients with pachychoroid diseases. Unlike CVI, SFCT is also affected by age, ocular and systemic factors like hypertension. CVI may be a more specific biomarker for PSD.

Insights into the underlying choroid in different stages of idiopathic epiretinal membranes after Viteromacular surgery.

The purpose of the study was to longitudinally investigate the correlation between choroidal morphologic and vascular parameters and postoperative visual outcome in different stages of idiopathic epiretinal membranes (iERMs). A prospective, observational, institutional case series of 102 consecutive patients diagnosed with unilateral iERMs were recruited at Peking University Third Hospital and were followed up for 12 months after surgical treatment with vitrectomy. Participants were classified into four stages according to current staging scheme. All eligible subjects underwent standardized imaging evaluation of choroidal parameters including subfoveal choroidal thickness (SFCT), choroidal vascularity index (CVI), and choroidal capillary perfusion (CCP) at baseline and each follow-up by enhanced depth optical coherence tomography (EDI-OCT) and OCT angiography (OCTA). Longitudinal follow-up of choroidal parameters over 12 months was analysed, and their correlations with best-corrected visual acuity (BCVA) were also assessed for predictive prognostic value. CVI and CCP were significantly correlated with BCVA at each follow-up examination (all p < 0.05). However, SFCT exhibited no variation among different stages of iERMs at baseline (p=0.981) or during follow-up (p=0.520). The preoperative CVI correlated with 12-month postoperative BCVA (p < 0.001) and its predictive prognostic effect on BCVA was validated in multiple regression analysis (p=0.006). CVI varied among different stages of iERM and was significantly correlated with visual outcomes after the surgery. CVI could serve as a predictive prognostic marker in iERMs, which further indicates the underlying choroid should be taken into consideration in clinical evaluation of iERMs.

Vascular Changes of the Choroid and Their Correlations With Visual Acuity in Pathological Myopia.

Photoreceptor loss plays a role in visual impairment in pathological myopia. As the nutrition and oxygen demands of photoreceptors are mainly supported by the choroidal vessels, we aimed to investigate changes in the choroidal vasculature and their correlations with visual acuity in pathological myopia. The cohort was composed of 136 eyes from 80 participants, including 42 eyes from 21 participants with emmetropia/low myopia, 48 eyes from 26 participants with simple high myopia, and 46 eyes from 33 participants with pathological myopia. Swept-source optical coherence tomography (OCT) was used to image the eyes with a 12-mm radial line scan protocol. The parameters for 6-mm diameters of macula area centered on the fovea were analyzed. A custom deep learning algorithm based on a modified residual U-Net architecture was used to segment the choroidal boundaries. Then, the distance between the two boundaries was determined and choroidal thickness (CT), luminal area (LA), and stromal area (SA) were demarcated based on Niblack's auto-local threshold algorithm after binarization of the OCT images. Finally, the ratio of LA and total choroidal area was defined as the choroidal vascularity index (CVI). The choroidal parameters in three groups were compared, and correlations of the choroidal parameters with age, gender, axial length, and best-corrected visual acuity (BCVA) were analyzed. The CVI, CT, LA, and SA values were lower in pathological myopia than in emmetropia/low myopia and simple high myopia (P < 0.05). The CT, LA, and SA values were lower in simple high myopia than in emmetropia/low myopia (P < 0.05), whereas there was no difference between the CVIs in the emmetropia/low myopia and high myopia groups (P > 0.05). The CVI was nonlinear with increases in axial length (AL), and there was a critical AL flexion point, approximately 27.26 mm; however, the CT, LA, and SA were negatively correlated with AL. Further analysis showed that only younger subjects (40 years old or less) showed significant AL flexion points. Simple and multiple regression models showed that the CVI was correlated with BCVA (P < 0.05). Choroidal vascular alterations, especially decreased CVI, occurred in patients with pathological myopia. The CVI decreased with axial elongation beyond the flexion point and was correlated with visual impairment, indicating that the CVI might be a reliable imaging biomarker to monitor the progression of pathological myopia.

Impact of Reticular Pseudodrusen on Choriocapillaris Flow Deficits and Choroidal Structure on Optical Coherence Tomography Angiography

To examine the impact of reticular pseudodrusen (RPD) on choriocapillaris blood flow and choroidal structure in individuals with intermediate age-related macular degeneration (AMD). Individuals with bilateral large drusen underwent optical coherence tomography (OCT), color fundus photography, near-infrared reflectance, and fundus autofluorescence imaging to determine the presence of RPD. These participants also underwent swept-source OCT angiography (SS-OCTA) imaging to determine (1) choriocapillaris flow deficit (FD) parameters, including the percentage, mean size, and number of FDs present; and (2) choroidal structural parameters, including mean choroidal thickness and choroidal vascularity index. Differences in these parameters between eyes with and without coexistent RPD were examined with and without adjustment for potential key confounders such as drusen volume from the SS-OCTA scans and age. This study included 102 eyes from 51 individuals with bilateral large drusen, and the analyses showed that there were no significant differences in the choriocapillaris FD parameters (P ≥ 0.062 for all) and choroidal structural parameters (P ≥ 0.059 for all), with or without adjustment for potential confounders in this cohort. However, the percentage of FDs and the mean FD size were both significantly greater with increasing drusen volume (P ≤ 0.038 for both). The coexistence of RPD in eyes of individuals with intermediate AMD was not associated with significant impairments in choriocapillaris blood flow and choroidal vascular structural changes, with or without adjustment for key confounders. These findings suggest that macular changes in these vascular parameters may not be associated with the presence of RPD.

Immediate Effect in the Retina and Choroid after 650 nm Low-Level Red Light Therapy in Children

Introduction: The objective of this study was to investigate the changes in the retina and choroid of children after 650 nm low-level red light therapy (LLRLT). Methods: In this prospective study, 25 subjects in the Shanghai Eye and ENT Hospital of Fudan University were included from August 2021 to September 2021. One eye was randomly selected to receive LLRLT for 3 min. Swept-source optical coherence tomography (OCT) and OCT angiography were used to measure retinal fovea perfusion density (RFPD), retinal fovea thickness (RFT), choroidal fovea blood flow (CFBF), and choroidal fovea thickness (CFT) before LLRLT, 5 min and 1 h after LLRLT. Baseline characteristics between LLRLT and non-LLRLT eyes were compared. Changes in the retinal and choroidal parameters were analyzed by ANCOVA models. SAS software was used for data analysis. The difference was considered statistically significant if p < 0.05. Results: There was no difference in baseline characteristics between LLRLT eyes and non-LLRLT eyes. The RFPD in LLRLT eyes significantly increased 5 min after LLRLT, and the increment was 1.70 ± 0.83% (p = 0.0389). The RFPD significantly decreased from 5 min to 1 h after LLRLT with a mean of −2.62 ± 0.86% decrement (p = 0.0031). The RFPD levels returned to baseline at 1 h after LLRLT (p = 0.8646). However, compared with insignificant RFPD changes in non-LLRLT eyes, there was no significant difference in RFPD changes at any sampling point. No significant changes in RFT, CFBF, and CFT were found in LLRLT eyes at each sampling point. Conclusion: Although 3 min of LLRLT has no effect on the choroid, it may cause a short-term transient increase in RFPD. It will provide theoretical support for the role of LLRLT in myopia control.

Short-term effect of orthokeratology lens wear on choroidal blood flow in children with low and moderate myopia

We investigated changes in choroidal vascularity and choriocapillaris blood perfusion during orthokeratology (Ortho-K) lens wear. Sixty-two children with low to moderate myopia were enrolled. The Ortho-K group (n = 42) continuously wore Ortho-K lenses for 3 months, and the controls (n = 20) wore single-vision distance spectacles. All of the patients were instructed to return for follow-up visits after 1 day, 1 week and 1 month and 3 months of treatment. The subfoveal choroidal thickness (SFChT), choroidal vascularity [including the total choroidal area, luminal area, stromal area, and choroidal vascularity index (CVI)] and percentage of choriocapillaris flow voids (FV%) were determined with a Cirrus HD-OCT instrument. Additionally, ocular parameters were measured. In the Ortho-K group, the SFChT significantly increased by 12.61 ± 5.90 μm, the CVI was significantly increased by 2.99 ± 2.07% and 3.01 ± 2.32% on the horizontal and vertical scans respectively, and the FV% was significantly decreased by 0.89 ± 0.34% from baseline at the 1-week visit (all p < 0.001). The choroidal parameters remained unchanged at the 1-month and 3-month follow-ups with respect to the 1-week follow-up. In the control group, the choroidal parameters did not change significantly at 1 month (all p > 0.05). At the 3-month visit, the changes in the axial length (AL) and vitreous chamber depth (VCD) were significantly greater in the control group than in the Ortho-K group (0.14 ± 0.23 and 0.03 ± 0.05 mm in AL, 0.15 ± 0.23 and 0.06 ± 0.03 mm in VCD respectively). Our longitudinal study showed several choroidal parameter changes in the early stage in Ortho-K lens wearers with low to moderate myopia, and these changes persisted over 3 months. We speculate that Ortho-K lenses regulate choroidal thickness and blood perfusion, affecting myopia development.

Association between central serous chorioretinopathy susceptibility genes and choroidal parameters.

To evaluate the association between central serous chorioretinopathy (CSC) susceptibility genes and choroidal parameters in a large Japanese cohort. Retrospective cohort study. Of the 9850 individuals in the Nagahama study whose second visit was between 2013 and 2016, those with optical coherence tomography (OCT) images with enhanced depth imaging (EDI), axial length, and genome-wide single nucleotide polymorphism (SNP) genotyping data were included. We calculated subfoveal choroidal thickness (SFCT), choroidal vascularity index (CVI), normalized choroidal intensity (NCI), and vertical asymmetry of choroidal thickness. Genome-wide quantitative trait locus (QTL) analyses were performed for each parameter. We screened for four CSC susceptibility SNPs: CFH rs800292, TNFRSF10A rs13278062, GATA5 rs6061548, and VIPR2 rs3793217. Whenever an SNP was not included in the genotyping data after quality control, its proxy SNP was selected. In total, 4586 participants were evaluated. CFH rs800292 was significantly associated with SFCT (P < 0.001) and CVI (P < 0.001). VIPR2 rs3793217 was significantly associated with SFCT (P < 0.001) but not with CVI. Whereas, TNFRSF10A rs13254617 and GATA5 rs6061548 were not significantly associated with SFCT or CVI. None of these SNPs was associated with NCIEDI and asymmetry of choroidal thickness. CFH, VIPR2, TNFRSF10A, and GATA5 showed different association patterns with choroidal parameters. Although the mechanism of CSC pathogenesis by choroidal changes is not fully understood, this finding suggests that each gene may be involved in different mechanisms of CSC development. Our genetic study provides a basis for understanding the role of CSC susceptibility genes.

IMPACT OF PENETRATION AND IMAGE ANALYSIS IN OPTICAL COHERENCE TOMOGRAPHY ON THE MEASUREMENT OF CHOROIDAL VASCULARITY PARAMETERS.

To investigate the impact of penetration and image analysis in different optical coherence tomography (OCT) instruments on the measurement of choroidal vascularity parameters. Twenty-three healthy volunteers were imaged using two swept-source OCTs and one spectral-domain OCT. A fully automatic segmentation method based on ResNet-UNet and Niblack local threshold binarization was performed to quantify the relevant choroidal vascular parameters, including choroidal vascularity index, total choroidal volume, and luminal volume. The intraclass correlation coefficient (ICC) and coefficient of repeatability (COR) were used to analyze the repeatability and consistency of automatic and manual segmentation, respectively. Both swept-source OCT devices showed good consistency of luminal volume and total choroidal volume measurements (all ICC value >0.98 with COR% < 8.53%) based on manual segmentation, whereas the consistency of the spectral-domain OCT was lower (ICC value <0.60 with COR% > 40%), which was greatly improved after using the automatic algorithm (ICC value >0.99 with COR% < 4%). The repeatability of choroidal vascularity index obtained from different OCT images using manual or automatic segmentation showed good agreement (all ICC values >0.85), whereas the choroidal vascularity index measurement from the spectral-domain OCT was larger than the other two swept-source OCT devices (ICC value <0.65). For healthy youngsters, the penetration of OCT plays a role in the measurement precision for choroidal vascularity parameters, and automatic segmentation can improve the ability of choroidal boundary identification with deficient penetration, suggesting these factors need to be considered in clinical work.