Wide-field Swept-source Optical Coherence Tomography Research Articles

Sensitive optical coherence tomography angiography parameters detecting retinal vascular changes in Behcet's uveitis

PurposeTo compare the retinal parameters in Behcet's uveitis (BU) patients with wide-field swept-source optical coherence tomography angiography (SS-OCTA) and find a sensitive OCTA parameter. MethodsFifty-two eyes from 52 quiescent BU patients and 50 healthy eyes were included. All subjects underwent SS-OCTA examinations with 12 × 12 mm region. Vessel density (VD) and flow area (FA) in nerve fiber layer (NFL), superficial vascular plexus (SVP), intermediate capillary plexus (ICP) and deep capillary plexus (DCP) were analyzed and compared in central, parafoveal, and peripheral regions with diameters of 1, 6 and 12 mm. Receiver operating characteristic curves (ROC), area under the curve (AUC), correlation analysis between OCTA metrics and best-corrected visual acuity (BCVA) were respectively evaluated. ResultsBU patients showed significantly lower peripheral VD and FA in NFL (P = 0.019 and 0.002), lower central and parafoveal VD-SVP (P = 0.006 and <0.001), and lower VD-ICP, VD-DCP, FA-SVP, FA-ICP and FA-DCP in all regions (all P < 0.05) as compared to healthy controls. The ROC analysis indicated that the parafoveal, peripheral FA-DCP-1, and a combination of the two metrics were sensitive parameters for identifying retinal vessel changes in BU (AUC=0.90, 0.90, 0.91, respectively). The parafoveal and peripheral FA-DCP were negatively associated with logMAR BCVA (r=-0.764, P < 0.0001; r=-0.641, P < 0.0001). ConclusionThe deep retinal layers were apt to be affected in BU patients. The parafoveal and peripheral FA values of DCP may be sensitive parameters for detecting retinal vasculature alterations in BU.

Contrast Sensitivity Better Reflects Wide-Field Swept-Source Optical Coherence Tomography Angiography Vascular Metrics Among Healthy Eyes Compared to Visual Acuity.

To evaluate the association between widefield swept-source optical coherence tomography angiography (WF SS-OCTA) and visual function in healthy eyes. Fifty-seven eyes of 45 patients were evaluated with visual acuity (VA), contrast sensitivity (CS), and WF SS-OCTA (3 × 3, 6 × 6, and 12 × 12 mm images) on the same day. Mixed-effects multivariable regression analyses were performed. Contrast sensitivity metrics, including CS between 6 to 18 cycles per degree (cpd) and area under the logarithm CS function, were significantly associated with vessel density (VD) and vessel skeletonized density (VSD), whereas VA was not. The largest effect size was between CS at 18 cpd and VD (β = 0.41, P = 0.007) and VSD (β = 0.42, P = 0.006) on 12 × 12 mm images. Reduced VSD and VD on WF SSOCTA was significantly associated with decreased CS, whereas VA was not. These results suggest CS could serve as a screening tool for early stage retinal and neurologic disorders. [Ophthalmic Surg Lasers Imaging Retina 2024;55:494-502.].

Peripheral Ganglion Cell Complex Thickness and Retinal Microvasculature in Myopia Using Wide-Field Swept-Source OCT.

This study aims to investigate the impact of axial elongation on ganglion cell complex thickness (GCCT) and retinal capillary density (CD) using wide-field swept-source optical coherence tomography angiography. A retrospective cross-sectional analysis was conducted involving 506 eyes. Fovea-centered scans were obtained to assess the subregional GCCT and capillary density across the whole retina, the superficial capillary plexus (SCP), and deep capillary plexus (DCP) among three groups: normal control, high myopia (HM) eyes with axial length < 28mm, and HM eyes with axial length > 28mm. Regional variations (central vs. peripheral, quadrants difference [superior, inferior, nasal, and temporal]) were analyzed. In HM eyes with axial length > 28mm, GCCT and retinal CD exhibit a general decline in most regions (P < 0.05). In HM eyes with axial length < 28mm, significant reductions were observed specifically in peripheral regions, as in the GCCT beyond the 3 × 3mm2 area and CD in the 9-12mm whole retina, 9-12mm superior SCP, and 6-12mm DCP (P < 0.05). Maximum GCCT and retinal CD reduction with axial elongation was observed in subregions beyond 6 × 6 mm2. GCCT beyond the 3 × 3 mm2 area and peripheral retinal CD beyond the 6 × 6 mm2 area were more susceptible to axial elongation and are thereby deserving of particular attention. It is necessary to evaluate different regions during the clinical assessment of the effect of myopia on the fundus and pay close attention to the peripheral retina.

Adaptive contour-tracking to aid wide-field swept-source optical coherence tomography imaging of large objects with uneven surface topology.

High-speed and wide-field optical coherence tomography (OCT) imaging is increasingly essential for clinical applications yet faces challenges due to its inherent sensitivity roll-off and limited depth of focus, particularly when imaging samples with significant variations in surface contour. Here, we propose one innovative solution of adaptive contour tracking and scanning methods to address these challenges. The strategy integrates an electrically tunable lens and adjustable optical delay line control with real-time surface contour information, enabling dynamic optimization of imaging protocols. It rapidly pre-scans the sample surface to acquire a comprehensive contour map. Using this map, it generates a tailored scanning protocol by partitioning the entire system ranging distance into depth-resolved segments determined by the optical Raleigh length of the objective lens, ensuring optimal imaging at each segment. Employing short-range imaging mode along the sample contour minimizes data storage and post-processing requirements, while adaptive adjustment of focal length and reference optical delay line maintains high imaging quality throughout. Experimental demonstrations show the effectiveness of the adaptive contour tracking OCT in maintaining high contrast and signal-to-noise ratio across the entire field of view, even in samples with significantly uneven surface curvatures. Notably, this approach achieves these results with reduced data volume compared to traditional OCT methods. This advancement holds promise for enhancing OCT imaging in clinical settings, particularly in applications requiring rapid, wide-field imaging of tissue structures and blood flow.

One-year choroidal thickness changes after photodynamic therapy for central serous chorioretinopathy evaluated by widefield optical coherence tomography.

To evaluate the changes in choroidal thickness 1 year after half-dose photodynamic therapy (PDT) for central serous chorioretinopathy (CSC) using widefield swept-source optical coherence tomography. We retrospectively reviewed 21 patients with CSC who unilaterally underwent half-dose PDT and completed a 12-month follow-up. Choroidal thickness was evaluated before and after PDT within an 18-mm circular grid centered on the fovea subdivided into nine areas in the treated and untreated fellow eyes. All 21 treated eyes showed complete resolution of subretinal fluid at 3 months after PDT, without any recurrence at 12 months. The mean choroidal thickness in all nine areas significantly decreased after PDT at 3 months (P < 0.05) and remained unchanged at 12 months (P < 0.05) compared with that at baseline. However, the subtracted choroidal thickness maps between 3 and 12 months detected significant variations among the cases, classified into an enhanced pattern in 10 eyes (47.6%), an attenuated pattern in six eyes (28.6%), and a stable pattern in five eyes (23.8%). The 21 untreated fellow eyes also showed a decrease in mean choroidal thickness in three of the nine subdivided areas at 12 months (P < 0.05), but this decrease was limited posteriorly. The reduction in mean choroidal thickness after half-dose PDT for CSC was extensively maintained for 1 year. However, subclinical hemodynamic changes in the entire choroid occurred longitudinally even in the absence of disease recurrence.

High-speed, long-range and wide-field OCT for in vivo 3D imaging of the oral cavity achieved by a 600 kHz swept source laser.

We report a high-speed, long-range, and wide-field swept-source optical coherence tomography (SS-OCT) system aimed for imaging microstructures and microcirculations in the oral cavity. This system operates at a scan speed of 600 kHz, delivering a wide imaging field of view at 42 × 42 mm2 and a ranging distance of 36 mm. To simultaneously meet the requirements of high speed and long range, it is necessary for the k-clock trigger signal to be generated at its maximum speed, which may induce non-linear phase response in electronic devices due to the excessive k-clock frequency bandwidth, leading to phase errors. To address this challenge, we introduced a concept of electrical dispersion and a global k-clock compensation approach to improve overall performance of the imaging system. Additionally, image distortion in the wide-field imaging mode is also corrected using a method based on distortion vector maps. With this system, we demonstrate comprehensive structural and blood flow imaging of the anterior oral cavity in healthy individuals. The high-speed, long-range, and wide-field SS-OCT system opens new opportunities for comprehensive oral cavity examinations and holds promise as a reliable tool for assessing oral health conditions.

Comparison of choroidal vasculature between central serous chorioretinopathy with and without thick choroid using widefield swept-source optical coherence tomography angiography

Purpose: To distinguish between central serous chorioretinopathy (CSC) with and without thick choroid, and elucidate their characteristics of choroidal vasculature. Methods: This prospective observational study enrolled 76 eyes with treatment-naive CSC and 76 normal eyes. Mean±2 times standard deviation (SD) of subfoveal choroidal thickness (SFCT) of healthy individuals was set as the upper limit of normal choroidal thickness to divide CSC patients into two groups: the thick-choroid and non-thick-choroid groups. Their choroid blood flow was compared using widefield swept-source optical coherence tomography angiography (WF SS-OCTA). Results: According to the discrimination value of SFCT as 326.8 μm, 76 eyes with CSC were divided into thick-choroid (55, 72.4%) and non-thick-choroid groups (21, 27.6%). Higher proportions of vortex vein anastomosis were found in the thick-choroid group (81.8% vs 33.3%, P&lt;0.001). Choroid thickness, three-dimensional choroidal vascularity index (3D-CVI) and mean choroidal stroma volume per 1 mm2 (mCSV) were higher in the thick-choroid group. In multivariate analysis, younger age, higher percentages of vortex vein anastomosis and double layer sign were the independent predictors of choroid thickening in CSC. Conclusion: There are discrepancies in the degree of choroidal congestion and distribution of vortex veins in the CSC with different choroidal thicknesses.

Comparative study of widefield swept-source optical coherence tomography angiography in eyes with concomitant age-related macular degeneration and diabetic retinopathy

Background/aimsWe sought to evaluate widefield swept-source optical coherence tomography angiography (WF SS-OCTA) among eyes with concomitant age-related macular degeneration (AMD) and diabetes mellitus or diabetic retinopathy (DM/DR).MethodsThis cross-sectional, comparative study...

Wide-field swept-source optical coherence tomography angiography (SS-OCTA) in the assessment of retinal vessel density and thickness in 4-to 16-year-old myopic children

PurposeTo analyze the characteristics of macular retinal vessel density and thickness in children with myopia. MethodsA cross-sectional study was conducted. A total of 228 children aged 4–16 years who visited the Ineye Hospital of Chengdu University of Traditional Chinese Medicine from September 2022 to November 2023 were included. Those with −0.5D < spherical equivalent (SE) < +2.0D were included in the non-myopia group (150 eyes), those with −3.0D < SE ≤ −0.5D were included in the low myopia group (246 eyes), and those with SE ≤ −3.0D were included in the moderate-to-high myopia group (60 eyes). All subjects underwent cycloplegic refraction, IOLmaster500, and Wide-field SS-OCTA (to exclude some peripheral retinal degeneration). Multiple linear regression analysis was used to analyze the correlation between macular ETDRS subfield of full retinal thickness (FRT), outer, inner retinal thickness (ORT, IRT), retinal vessel density (VD), deep and superficial retinal vessel density (DVD, SVD), and SE, axial length (AL). ResultsThere were statistically significant differences (P < 0.05) in FRT in the central fovea (1 mm diameter)and perifovea (Diameter 3 to 6 mm) among the non-myopia group, low myopia group, and moderate-to-high myopia group. The three groups also showed statistically significant differences (P < 0.05) in VD in the central fovea and parafovea with a diameter of 1 to 3 mm (except the lower part). In multiple linear regression analysis adjusted for gender and age, SE and AL were found to be correlated with FRT in all ETDRS regions (except the central fovea) (P < 0.01), and SE and AL were correlated with IRT in the central fovea and perifovea, respectively (β range −2.302 to 1.652; P < 0.05). SE and AL were also correlated with ORT in the parafovea and perifovea, respectively (β range −4.371 to −2.344; P < 0.05). AL was negatively correlated with VD in the central fovea and parafovea (except the inferior region) (P < 0.05), as well as with DVD in all ETDRS regions (β range −1.314 to −1.031; P < 0.05). AL was only negatively correlated with SVD in the parafoveal nasal region (β = −0.633, P < 0.05). Additionally, the correlation between AL and DVD, ORT was higher than that with SVD, IRT. ConclusionThe more severe the myopia, the longer the AL, the thinner the FRT in the perifovea, and the lower the VD in both the fovea and parafovea in children. In addition, DVD and ORT were more significantly correlated with AL, suggesting that they may be more closely related to the growth of AL.

Assessment of Retinal Volume in Individuals Without Ocular Disorders Based on Wide-Field Swept-Source OCT

PurposeTo evaluate retinal volume in eyes without retinal disease using wide-field swept-source optical coherence tomography (SS-OCT). DesignObservational, cross-sectional design ParticipantsA total of 332 eyes of 166 healthy participants. MethodsThe eyes were imaged with OCT-S1 (Canon) using a protocol centered on the fovea cube scans (20 × 23 mm) of SS-OCT images. Retinal volume (6-mm circle, 6–20-mm ring) and various parameters were evaluated in a multivariate analysis using a generalized estimating equation model. Each quadrant of the macula except for the fovea (1–6 mm in diameter) and peripheral ring (6–20 mm in diameter) was also evaluated. Main Outcome MeasureRetinal volume ResultsIn the multivariate analysis, older age and longer axial length were associated with smaller macular retinal volume, whereas older age and left eye were associated with smaller peripheral retinal volume. The temporal area was significantly smaller than all other areas in the macula (1–6 mm), whereas the inferior area was significantly smaller than all other areas in the peripheral retina (6–20 mm). ConclusionsIn wide-field SS-OCT images, age and left eye are negatively correlated with peripheral retinal volume. The thinnest part of the retinal quadrant differs between the macular and peripheral retinas.

Diurnal Variation in Choroidal Parameters Among Healthy Subjects Using Wide-Field Swept-Source Optical Coherence Tomography Angiography.

The purpose of this study was to evaluate the diurnal variation in choroidal parameters in a wide field area among healthy subjects and to identify correlations between choroidal luminal area and stromal area and various systemic factors. In this cross-sectional study, 42 eyes from 21 healthy participants (mean age = 32.4 ± 8.8 years) were examined using wide-field swept-source optical coherence tomography angiography (WF SS-OCTA, 24 mm × 20 mm). Measurements of choroidal parameters, including choroidal volume (CV), choroidal thickness (CT), choroidal vessel volume (CVV), and choroidal stromal volume (CSV), were taken at 8:00, 12:00, 18:00, and 22:00. Systemic factors, such as blood pressure and heart rate, were concurrently monitored. Our study observed significant diurnal variations in the mean total CV, CT, CVV, and CSV, with minimum measurements around 12:00 (P < 0.001) and peak values at 22:00 (P < 0.001). Furthermore, changes in CV in specific regions were more closely associated with fluctuations in CVV than CSV in the same regions. No significant diurnal variations were found in systolic (P = 0.137) or diastolic blood pressure (P = 0.236), whereas significant variations were observed in the heart rate (P = 0.001). Our study reveals diurnal variations in choroidal parameters and their associations, emphasizing that changes in choroidal volume relate more to the luminal than the stromal area in vessel-rich regions. This enhances our understanding of choroidal-related ocular diseases. Regions with higher choroidal vasculature observed greater choroidal volume changes.

Associations of quantitative contrast sensitivity with vascular metrics on widefield swept-source OCT angiography across stages of diabetic retinopathy

PurposeTo investigate structure–function associations between contrast sensitivity (CS) and widefield swept-source optical coherence tomography angiography (WF SS-OCTA) vascular metrics across stages of non-proliferative (NPDR) and proliferative diabetic retinopathy (PDR), without...

Assessment of Microvascular Changes After Rhegmatogenous Retinal Detachment Repair Using Wide-Field Swept-Source Optical Coherence Tomography Angiography.

Our objective was to evaluate retinal microvascular changes and visual outcomes following rhegmatogenous retinal detachment (RRD) repair using wide-field swept-source optical coherence tomography angiography (WF SS-OCTA). The study included 116 eyes of 111 patients with macula-off (n = 68) or macula-on (n = 48) RRD treated with a single successful procedure, 79 fellow eyes, and 183 eyes of control patients imaged with WF SS-OCTA (3 ×3, 6 ×6, and 12 ×12 mm images). Mixed-effects multiple linear regression models were used for statistical analysis. Vessel density (VD) and vessel skeletonized density (VSD) of the superficial capillary plexus (3 ×3 mm scans) and full-thickness retina (12 ×12 mm) were significantly reduced in RRD eyes compared to fellow and control eyes. Decreased VSD and VD in all layers (3 ×3 mm and 6 ×6 mm) were significantly associated with greater preoperative extent of retinal detachment (P < 0.05) and poorer postoperative best-corrected visual acuity (BCVA) in RRD eyes (P < 0.05). Macula-off status was associated with increased foveal avascular zone irregularity (12 ×12 mm, P = 0.02). Decreased VD on WF SS-OCTA is associated with poorer postoperative BCVA following RRD repair. [Ophthalmic Surg Lasers Imaging Retina 2024;55:XX-XX.].

Widefield, Swept-Source Optical Coherence Tomography Angiography Metrics as Predictors of Anti-VEGF Treatment in Retinal Vein Occlusions.

Our objective was to assess baseline widefield swept-source optical coherence tomography angiography (WF SSOCTA) microvascular metrics as predictors for the number of anti-vascular endothelial growth factor (VEGF) injections and visual acuity (VA) at 12-months follow-up in patients with retinal vein occlusion (RVO). This was a prospective study including 49 RVO eyes from 49 patients who had not received an anti-VEGF injection for at least 3 months prior to imaging. Microvascular metrics from 6×6-mm and 12×12-mm angiograms were assessed using linear regression models, adjusting for age. Reductions in the vessel density (VD) and vessel skeletonized density (VSD) vascular metrics were associated both with a higher number of anti-VEGF injections at all follow-up time points and reduced VA 12 months after imaging in all RVO eyes. WF SS-OCTA VD and VSD micro-vascular metrics at baseline can prognosticate VA and number of anti-VEGF injections required at 3, 6, and 12 months in RVO eyes. [Ophthalmic Surg Lasers Imaging Retina 2024;55:374-382.].

Pigment Epithelial Detachment and Leak Point Locations in Central Serous Chorioretinopathy

PurposeTo examine the associations between the vortex vein characteristics and locations of the pigment epithelial detachment (PED) and leak point in patients with central serous chorioretinopathy (CSC). DesignObservational case series. MethodsWe evaluated 116 eyes of 104 patients with CSC. The PED and leak point locations were superimposed over the choroidal en face images using widefield swept-source optical coherence tomography and fluorescein angiography. We defined the draining areas of the superior and inferior vortex veins and analyzed their associations with the PED and leak point locations. ResultsOne of the 116 eyes with a unique irrigation pattern dominated by the nasal vortex vein was excluded from the analysis. Sixty-nine (60%) of the remaining 115 eyes exhibited asymmetry between the superior and inferior vortex veins. PEDs and leak points were in the vortex vein draining area with greater dilation in 66 (96%) of 69 eyes with asymmetry, and none (0%) were in the opposite areas. Both the PEDs and leak points showed significant differences in their distributions (p < .001, respectively). Additionally, 74% of PEDs and 84% of leak points were located upstream of the vortex vein draining areas, whose frequency was significantly higher compared to other areas (p < .001, respectively). ConclusionPED and leak point spatial distributions corresponded with the most terminal part of the dilated vortex veins, suggesting that blood flow disturbances, such as stasis within the affected vortex veins, may be essential in the pathogenesis of CSC.

Diagnostic performance of wide-field optical coherence tomography angiography in detecting open-angle glaucoma in high myopia.

To compare the diagnostic performance of the capillary density (CD) of the central 1-6 mm and peripheral 6-12 mm annular regions in detecting open-angle glaucoma in high myopia (HM) using 15 × 12 mm wide-field swept-source optical coherence tomography angiography (WF SS-OCTA). The study enrolled 206 and 103 eyes with HM and highly myopic open-angle glaucoma (HM-OAG), respectively. WF SS-OCTA images centred on the fovea were obtained to analyse the changes in the CD in the 1-3 mm, 3-6 mm, 6-9 mm, and 9-12 mm annular regions. CD of the superficial capillary plexus (SCP) was measured with the built-in software. The area under the receiver operating characteristic curve (AUROC) of each region was compared. The diagnostic performance of the SCP CD in the central 1-6 mm annular region (AUROC = 0.849) was better than that in the peripheral 6-12 mm annular region (AUROC = 0.756, p = 0.001). The annular AUROCs of SCP CD peaked in the 3-6 mm annular region (AUROC = 0.858) and gradually decreased with increasing diameter and were lower than the corresponding AUROCs of the ganglion cell-inner plexiform layer thickness (p < 0.05 for all comparisons). SCP CD of the inferior quadrant in the 3-6 mm annular region had the best diagnostic performance (AUROC = 0.859). The SCP CD in the central 1-6 mm annular region exhibited better diagnostic performance for the detection of HM-OAG in HM. The assessment of more peripheral regions has no added value in detecting glaucoma in HM.

Widefield swept-source optical coherence tomography angiography metrics associated with neovascular glaucoma in patients with proliferative diabetic retinopathy.

To explore the association between widefield swept-source optical coherence tomography angiography (WF SS-OCTA) metrics, including nonperfusion area (NPA) and neovascularization (NV), and presence of neovascular glaucoma (NVG) in patients with proliferative diabetic retinopathy (PDR). A prospective, cross-sectional study was conducted from November 2018 to February 2020. A total of 85 eyes of 60 PDR patients without NVG and 9 eyes of 8 PDR patients with NVG were included. Retinal ischemic parameters (NPA; ischemia index [NPA/total retinal area]) and NV features (NV number; NV area; NV vessel density) were evaluated. Foveal avascular zone (FAZ), macular thickness/volume, and choroidal thickness/volume were obtained using the Zeiss ARI Network. WF SS-OCTA retinal and choroidal metrics, systemic, and ocular parameters were screened using Least Absolute Shrinkage and Selection Operator (LASSO) logistic regression for variable selection. Firth's bias-reduced logistic regression (outcome: presence of NVG) was subsequently used to identify parameters associated with NVG. After LASSO variable selection, 8 variables were significantly associated with the presence of NVG: DM duration (years), insulin (yes/no), best-corrected visual acuity (BCVA) (logMAR), IOP, ischemia index, skeletonized vessel density, macular thickness (inner inferior, outer temporal regions). Firth's bias-reduced logistic regression showed ischemia index (odds ratio [OR]=13.2, 95% confidence interval [CI]:5.3-30.7, P<0.001) and BCVA (OR=5.8, 95%CI:1.2-28.8, P<0.05) were associated with the presence of NVG. NV metrics, FAZ, and choroidal parameters were not related to NVG. Retinal ischemia but not NV was associated with the presence of NVG in patients with PDR using WF SS-OCTA. Larger, longitudinal studies are needed to validate imaging biomarkers associated with diabetic NVG.

Widefield choroidal vasculature associated with future condition of subretinal fluid in central serous chorioretinopathy

PurposeTo examine choroidal angiographic features in the posterior pole associated with resolution or persistency of subretinal fluid (SRF) in eyes with central serous chorioretinopathy (CSC). DesignObservational case series. MethodsTwenty-nine patients with treatment-naïve CSC were divided into two groups based on the presence or absence of SRF 3 months after the initial visit (month 3) without any treatment. Using enhanced depth imaging of widefield swept-source optical coherence tomography, the choroidal thickness (CT), vessel density (VD), and vessel diameter index (VDI) in the superotemporal and inferotemporal subfields on the temporal side of the 18-mm circle from the disc were measured at the initial visit. We calculated the vertical difference in CT and other choroidal angiographic parameters and evaluated their association with the SRF condition at 3 months. ResultsThe SRF-resolved and SRF-persistent groups included 10 and 19 patients, respectively. At the initial visit, sex, age, axial length, symptom duration, the logarithm of the minimum angle of resolution visual acuity, and foveal thickness were not significantly different between the two groups. The SRF status at month 3 was not associated with the vertical difference in CT and choroidal VD (P = .614, .065, respectively). However, the vertical difference in choroidal VDI was positively associated with the future presence of SRF (P = .017). ConclusionsVertically asymmetric dilation of choroidal vessels in the posterior pole may be a vasculature feature associated with SRF from CSC and may be a good predictor of future SRF status.

Defocus-induced spatial changes in choroidal thickness of chicks observed by wide-field swept-source OCT

Choroid has been claimed to be of importance during ocular development. However, how the choroid responds spatially to different visual cues has not been fully understood. The aim of this study was to investigate defocus-induced spatial changes in choroidal thickness (ChT) in chicks. Eight 10-day-old chicks were fitted monocularly with −10 D or +10 D lenses (day 0), which were removed seven days later (day 7). The ChT was measured on days 0, 7, 14, and 21 using wide-field swept-source optical coherence tomography (SS-OCT) and analyzed with custom-made software. Comparisons of the ChT in the central (1 mm), paracentral (1–3 mm), and peripheral (3–6 mm) ring areas and the ChT in the superior, inferior, nasal, and temporal regions were conducted. Axial lengths and refractions were also evaluated. In the negative lens group, the global ChT of the treated eyes was significantly less than that of the fellow eyes on day 7 (interocular difference: 179.28 ± 25.94 μm, P = 0.001), but thicker on day 21 (interocular difference: 241.80 ± 57.13 μm, P = 0.024). These changes were more pronounced in the central choroid. The superior-temporal choroid changed more during induction but less during recovery. In the positive lens group, the ChT of both eyes increased on day 7 and decreased on day 21, with most changes occurring in the central region, too. The inferior-nasal choroid of the treated eyes changed more during induction but less during recovery. These results provide evidence for regionally asymmetric characteristics of the choroidal response to visual cues and insights into the underlying mechanisms of emmetropization.

Structure-function associations between contrast sensitivity and widefield swept-source optical coherence tomography angiography in diabetic macular edema.

To evaluate the relationship between contrast sensitivity (CS) and widefield swept-source optical coherence tomography angiography (WF SS-OCTA) vascular metrics in diabetic macular edema (DME) was the purpose. This prospectively enrolled cross-sectional observational study included 61 eyes of 48 patients that were tested with the quantitative CS function (qCSF) test on the same day as imaging with WF SS-OCTA (PLEX® Elite 9000, Carl Zeiss Meditec) 3 × 3, 6 × 6, and 12 × 12mm scans. Outcomes included visual acuity (VA) and multiple qCSF metrics. Vascular metrics included vessel density (VD) and vessel skeletonized density (VSD) in the superficial (SCP) and deep capillary plexus (DCP) and whole retina (WR) and foveal avascular zone (FAZ) parameters. Mixed effects multivariable linear regression models controlling for age, lens status, and diabetic retinopathy stage were performed. Standardized beta coefficients were calculated by refitting the standardized data. SS-OCTA metrics had a significant association with CS and VA. The effect size of OCTA metrics was larger on CS compared to VA. For example, the standardized beta coefficients for VSD and CS at 3cpd (βSCP = 0.76, βDCP = 0.71, βWR = 0.72, p < 0.001) were larger than those for VA (βSCP = - 0.55, p < 0.001; βDCP = - 0.43, p = 0.004; βWR = - 0.50, p < 0.001). On 6 × 6mm images, AULCSF, CS at 3cpd, and CS at 6cpd were significantly associated with VD and VSD in all three slab types (SCP, DCP, and WR), while VA was not. Structure-function associations in patients with DME leveraging the qCSF device suggest microvascular changes on WF SS-OCTA are associated with larger changes in contrast sensitivity than VA.