Ultra-Widefield-Guided Swept-Source OCT Findings of Peripheral Vitreoretinal Abnormality in Young Myopes.

PURPOSE: To evaluate the ultra-widefield fundus photography (UWF-FP)-guided swept-source OCT (SS-OCT) images of peripheral vitreoretinal abnormality (PVRA) in young asymptomatic myopes. DESIGN: Cross-sectional, single-center study. PARTICIPANTS: A total of 1966 eyes of 983 consecutive patients aged 18 to 42 years with refractive error in the spherical equivalent of < 0 diopters (D) who visited KEYE Eye Center, Seoul, Republic of Korea, for refractive surgery. METHODS: The prevalence of PVRA and their characteristics, including shape, location, presence of pigmentation, membrane, retinal breaks, and detachment, were evaluated. A logistic regression analysis was done to evaluate the risk factors of PVRA and the risk of retinal breaks or detachment among eyes with PVRA. RESULTS: Among 1966 eyes, 317 (16.1%) had PVRA, and 182 (57.4%) and 135 (42.6%) had focal and linear lesions, respectively. The risk of PVRA was increased with axial length of the eyes (odds ratio [OR], 1.238, 95% confidence interval [CI], 1.112-1.379, P < 0.001), corneal astigmatism (OR, 1.320, 95% CI, 1.148-1.519, P < 0.001), presence of discrete margins of different retinal reflectivity (DMDRR; indicating outer retinal disruption from abnormal vitreoretinal traction) (OR, 1.751, 95% CI, 1.334-2.300, P < 0.001), and posterior vitreous detachment (PVD) at the posterior pole of the retina (OR, 1.833, 95% CI, 1.352-2.485, P < 0.001). Among eyes with PVRA, patient age (OR, 1.063, 95% CI, 1.008-1.121, P = 0.025), linear lesions (OR, 15.234, 95% CI, 7.891-29.407, P < 0.001), and multiple lesions (OR, 3.432, 95% CI, 1.780-6.620, P < 0.001) were independently associated with the presence of retinal breaks or detachment. CONCLUSIONS: The follow-up for PVRA among young myopes should be personalized on the basis of their ocular characteristics, including asymmetric ocular expansion (axial length and astigmatism) and vitreoretinal interface status. The treatment plan for PVRA eyes should emphasize the greater risk of retinal breaks and detachment with increasing age and the presence of linear and multiple lesions. FINANCIAL DISCLOSURE(S): Proprietary or commercial disclosure may be found in the Footnotes and Disclosures at the end of this article.

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

PURPOSE: 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). METHODS: 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. RESULTS: 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. CONCLUSIONS: 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.

Assessment of Schlemm's canal with swept-source optical coherence tomography in Graves' ophthalmopathy.

PURPOSE: To evaluate the Schlemm's canal (SC) parameters obtained by swept-source optical coherence tomography (OCT) different in Graves' ophthalmopathy (GO) eyes compared to healthy eyes. METHODS: This cross-sectional observational study evaluated 64 eyes of 32 GO cases and 56 eyes of 28 healthy controls. The study was conducted between October 2020 and June 2021. SC images were obtained from the temporal limbus of individuals using swept-source OCT. SC length (SCL) and SC area (SCA) were measured. The relationship between SC parameters in the patient group and intraocular pressure (IOP), retinal nerve fiber layer (RNFL) thickness, Graves' disease (GD) duration, and clinical activity score (CAS) was evaluated. RESULTS: In the GO group, 64 eyes of 32 patients were evaluated, and in the age and gender-matched healthy control group, 56 eyes of 28 individuals were assessed. SC images from 4 eyes of 4 patients in the patient group and 1 eye of 1 patient in the control group were not clear, preventing SCL and SCA measurements for these eyes. SCL and SCA measurements were found to be lower, and IOP and Hertel values were higher in the GO group compared to the healthy controls. However, no significant correlation was observed between SCL and SCA with IOP, RNFL thickness, GD duration, GO duration, or CAS in the GO group. In the GO group, the mean value of SCA was found to be higher in eyes with glaucoma or OHT compared to those without. CONCLUSION: These findings indicate that SC in GO-affected eyes is shorter and has a smaller area than in healthy individuals. Additionally, higher IOP and Hertel values were observed in the GO group compared to healthy controls. This study suggests that assessing SC using anterior segment OCT could provide valuable insights into the regulation of IOP and the development of glaucoma in GO-affected eyes.

Anterior chamber and angle characteristics in Chinese children (6-11 years old) with different refractive status using swept-source optical coherence tomography.

BACKGROUND: The anatomic structure of the anterior chamber (AC) helps to explain differences in refractive status in school-aged children and is closely associated with primary angle closure (PAC). The aim of this study was to quantify and analyze the anterior chamber and angle (ACA) characteristics in Chinese children with different refractive status by swept-source optical coherence tomography (SS-OCT). METHODS: In a cross-sectional observational study, 383 children from two primary schools in Shandong Province, China, underwent a complete ophthalmic examination. First, the anterior chamber depth (ACD), anterior chamber width (ACW), angle-opening distance (AOD), and trabecular-iris space area (TISA) were evaluated automatically using a CASIA2 imaging device. AOD and TISA were measured at 500, 750 µm nasal (N1 and N2, respectively), and temporal (T1 and T2, respectively) to the scleral spur (SS). Cycloplegic refraction and axial length (AL) were then measured. According to spherical equivalent refraction (SER), the children were assigned to hyperopic (SER > 0.50D), emmetropic (-0.50D < SER ≤ 0.50D), and myopic groups (SER ≤ -0.50D). RESULTS: Out of the 383 children, 349 healthy children (160 girls) with a mean age of 8.23 ± 1.06 years (range: 6-11 years) were included. The mean SER and AL were - 0.10 ± 1.57D and 23.44 ± 0.95 mm, respectively. The mean ACD and ACW were 3.17 ± 0.24 mm and 11.69 ± 0.43 mm. The mean AOD were 0.72 ± 0.25, 0.63 ± 0.22 mm at N1, T1, and 0.98 ± 0.30, 0.84 ± 0.27 mm at N2, T2. The mean TISA were 0.24 ± 0.09, 0.22 ± 0.09mm2 at N1, T1, and 0.46 ± 0.16, 0.40 ± 0.14mm2 at N2, T2. The myopic group had the deepest AC and the widest angle. Compared with boys, girls had shorter AL, shallower ACD, narrower ACW, and ACA (all p < 0.05). By Pearson's correlation analysis, SER was negatively associated with ACD, AOD, and TISA. AL was positively associated with ACD, ACW, AOD, and TISA. In the multiple regression analysis, AOD and TISA were associated with deeper ACD, narrower ACW, and longer AL. CONCLUSION: In primary school students, the myopic eyes have deeper AC and wider angle. ACD, ACW, AOD, and TISA all increase with axial elongation. ACA is highly correlated with deeper ACD.

Quantitative assessment of choroidal parameters and retinal thickness in central serous chorioretinopathy using ultra-widefield swept-source optical coherence tomography: a cross-sectional study.

OBJECTIVE: In this study, we used ultra-wide field swept-source optical coherence tomography angiography (UWF SS-OCTA) to assess changes in retinal thickness (RT) and choroidal parameters in individuals who had received a diagnosis of central serous chorioretinopathy (CSC). METHODS: The study encompassed the evaluation of 59 eyes from 47 patients with a diagnosis of CSC, alongside 33 fellow eyes and 31 eyes from healthy individuals (controls). The parameters assessed included RT, choroidal thickness (CT), choriocapillaris density, vascular density of the large choroidal vessel layer, three-dimensional choroidal vascularity index (3D-CVI), choroidal vessel volume per unit area (mCVV/a), and choroidal stroma volume per unit area (mCSV/a). RESULTS: Metrics including mCVV/a, mCSV/a, 3D-CVI, CT, and RT exhibited significantly elevated values in the eyes affected by CSC compared to those of the control group across nine subfields. Moreover, a substantial number of the subfields in both CSC-affected and fellow eyes exhibited increased values for mCVV/a, mCSV/a, 3D-CVI, CT, and RT when compared with the control group. Additionally, acute and chronic CSC subfields demonstrated significantly elevated values for mCVV/a, mCSV/a, 3D-CVI, CT, and RT in comparison to healthy control eyes. Notably, specific subfields associated with complex and atypical forms of CSC revealed higher metrics compared to those of the control group. CONCLUSION: In conclusion, the UWF SS-OCTA proved to be a valuable tool for exploring the anatomical etiology and clinical classification and diagnosis of CSC.

Swept-source optical coherence tomography and swept-source optical coherence tomography angiography findings in circumscribed choroidal hemangioma before and after transpupillary thermotherapy.

PURPOSE: To investigate the swept-source optical coherence tomography (SS-OCT) and SS-OCT angiography (SS-OCTA) findings in circumscribed choroidal hemangioma (CCH) before and after treatment with transpupillary thermotherapy (TTT). METHODS: The clinical records of 21 eyes having CCH imaged with SS-OCT/SS-OCTA between September 2018 and December 2022 were evaluated. RESULTS: SS-OCT examination in CCH showed dome-shaped appearance (100%), choroidal shadowing (100%), expansion of choroidal structures (100%), subretinal fluid (66.7%), intraretinal edema/schisis (33.3%), retinal pigment epithelium (RPE) atrophy (19.0%), hyperreflective dots (19.0%), and epiretinal membrane (4.8%). Internal arborizing tumor vessels showing hyperreflectivity were observed in the choriocapillaris slab on SS-OCTA in all eyes. In the deep capillary plexus (DCP), flow void changes were seen in 7 eyes with intraretinal schisis/cystoid macular edema. Four CCHs > 2 mm in thickness showed outer retinal involvement due to unmasking of flow in intratumoral vessels related to RPE atrophy. Following TTT/indocyanine green-enhanced TTT (ICG-TTT) of CCH, SS-OCT findings included total/partial resolution of subretinal fluid (57.1%), complete/partial regression of the tumor (52.4%), and RPE atrophy (33.3%). After treatment; loss of choriocapillaris, decrease in tumor vascularity together with increase in the fibrous component and flow void areas were detected on SS-OCTA. CONCLUSIONS: SS-OCT/SS-OCTA are useful non-invasive tools for imaging the structural/vascular changes in CCHs managed with TTT or ICG-TTT. On SS-OCTA, hyporeflective spaces localizing to edema/schisis in the DCP and arborizing tumor vessels within a hyporeflective stromal background in the choriocapillaris slab were observed. After TTT/ICG-TTT, a decrease in tumor vessels and an increase in the fibrous component and flow-void areas inside the CCH were detected on SS-OCTA.

Evaluation of Selected Biometric Parameters in Cataract Patients-A Comparison between Argos® and IOLMaster 700®: Two Swept-Source Optical Coherence Tomography-Based Biometers.

Background and Objectives: To compare the biometry of eyes obtained with two swept-source optical coherence tomography-based biometers-Argos (A), using an individual refractive index, and IOLMaster 700 (IM), using an equivalent refractive index-for all structures. Materials and Methods: The biometry of 105 eyes of 105 patients before cataracts were analyzed in this study. Parameters such as axial length (AL), anterior chamber depth (ACD), and lens thickness (LT) were compared from both devices. According to the axial length measurements, patients were divided into three groups, as follows: group 1-short eyes (AL < 22.5 mm), group 2-average eyes (22.5 ≤ AL ≤ 26.0 mm), and group 3-long eyes (AL > 26.0 mm). Results: The correlation coefficiency among all compared parameters varies from R = 0.92 to R = 1.00, indicating excellent reliability of IM and A. A statistical significance in axial length was indicated in the group of short eyes (n = 26)-mean AL (A) 21.90 mm (±0.59 mm) vs. AL (IM) 21.8 mm ± (0.61 mm) (p < 0.001)-and in the group of long eyes (n = 5)-mean AL (A) 27.95 mm (±2.62 mm) vs. mean AL (IM) 28.10 mm (±2.64) (p < 0.05). In the group of average eyes (n = 74), outcomes were similar-mean AL (A) 23.56 mm (±0.70 mm) vs. mean AL (IM) 23,56 mm (±0.71 mm) (p > 0.05). The anterior chamber depth measurements were higher when obtained with Argos than with IOLMaster 700-mean ACD (A) 3.06 mm (±0.48 mm) vs. mean ACD (IM) 2.92 mm (±0.46) p < 0.001. There was no statistical significance in mean LT-mean LT (A) 4.75 mm (±0.46 mm) vs. mean LT (IM) 4.72 mm (±0.44 mm) (p = 0.054). The biometry of one eye with dense cataracts could be measured only with Argos, using the Enhanced Retinal Visualization mode. Conclusions: Axial length measurements from both devices were different in the groups of short and long eyes, but were comparable in the group of average eyes. The anterior chamber depth values obtained with Argos were higher than the measurements acquired with IOLMaster 700. These differences may be particularly important when selecting IOLs for patients with extreme AL values.

Coefficient of spatial variance of choroidal thickness on swept-source optical coherence tomography in healthy eyes.

PURPOSE: This study aims to introduce the coefficient of spatial variance of choroidal thickness to describe the choroidal variation and investigate its associated factors in healthy eyes. METHODS: This retrospective cross-sectional study included 1031 eyes from 1031 subjects who received a swept-source optical coherence tomography examination. The mean choroidal thickness in the macular 6 × 6 mm region and 900 subregions of 0.2 × 0.2 mm were computed using the embedded algorithm. Before analysis, potential segmentation and magnification errors were corrected. The coefficient of spatial variance was defined as the standard deviation divided by the mean (multiplied by 100%) of the choroidal thicknesses across 900 grids. Potential factors associated with the coefficient of spatial variance were assessed using multiple linear regression. RESULTS: The mean choroidal thickness of the entire 6 × 6 mm macular region was 204.50 ± 72.88 µm. The mean coefficient of spatial variance was 26.58 ± 8.24%, ranging from 11.00 to 61.58%. Statistical analysis revealed that the means choroidal thickness (ß = - 0.08, R2 = 0.42, p < 0.001) and anterior chamber depth (ß = - 2.39, R2 = 0.05, p = 0.06) were associated with the coefficient of spatial variance. CONCLUSION: Our study first incorporated the coefficient of spatial variance to represent the spatial variation of the choroidal thickness and observed that the greater thinning of the choroid is correlated with a more pronounced spatial variation.

Association of refractive outcome with postoperative anterior chamber depth measured with 3 optical biometers.

PURPOSE: This study evaluated the relationship between refractive outcomes and postoperative anterior chamber depth (ACD, measured from corneal epithelium to lens) measured by swept-source optical coherence tomography (SS-OCT), optical low-coherence reflectometry (OLCR), and Scheimpflug devices under the undilated pupil. METHODS: Patients undergoing cataract phacoemulsification with intraocular lens (IOL) implantation in a hospital setting were enrolled. Postoperative ACD (postACD) was performed with an SS-OCT device, an OLCR device, and a Scheimpflug device at least 1 month after cataract surgery. After adjusting the mean predicted error to 0, differences in refractive outcomes were calculated with the Olsen formula using actual postACD measured from 3 devices and predicted value. RESULTS: Overall, this comparative case study included 69 eyes of 69 patients, and postACD measurements were successfully taken using all 3 devices. The postACD measured with the SS-OCT, OLCR, and Scheimpflug devices was 4.59 ± 0.30, 4.50 ± 0.30, and 4.54 ± 0.32 mm, respectively. Statistically significant differences in postACD were found among 3 devices (P < 0.001), with intraclass correlation coefficients (ICCs) and Bland-Altman showing good agreement. No significant difference in median absolute error was found with the Olsen formula using actual postACD obtained with 3 devices. Percentage prediction errors were within ± 0.50 D in 65% (OLCR), 70% (Scheimpflug), and 67% (SS-OCT) calculated by actual postACD versus 64% by predicted value. CONCLUSION: Substantial agreement was found in postACD measurements obtained from the SS-OCT, OLCR, and Scheimpflug devices, with a trend toward comparable refractive outcomes in the Olsen formula. Meanwhile, postACD measurements may be potentially superior for the additional enhancement of refractive outcomes.

Assessment of alterations in the retina and vitreous in pre- and post-COVID-19 patients using swept-source optical coherence tomography and angiography: A comparative study.

Ocular manifestations have been well recognized in coronavirus disease 2019 (COVID-19) outbreak. Several studies have detected ocular manifestations in patients after COVID-19. However, little is known about the retinal and vitreal alterations in patients before and after COVID-19 infection. This study aimed to investigate the retinal and vitreal alterations in patients before and after contracting COVID-19 infection using swept-source optical coherence tomography (SS-OCT) and angiography (SS-OCTA). A total of 38 participants (76 eyes) were enrolled and followed-up 1 month after COVID-19 infection. Then, 26 patients (52 eyes) were evaluated 3 months after COVID-19 infection. Compared with the pre-COVID-19 status, patients with 1- and 3-month post-COVID-19 statuses had significant thinning of ganglion cell and inner plexiform layer, thickening of inner nuclear layer, a decrease in the vessel density (VD) of superficial vascular complex, and an increase in the VD of deep vascular complex. Meanwhile, alteration in parameters of foveal avascular zone (all p < 0.05) and hyper-reflective dots in the vitreous of 27 patients (54 eyes) (71.1% vs. pre-COVID-19, 34.2%, p = 0.006) were observed. These findings suggest significantly retinal and vitreal alterations occurred in patients after COVID-19 infection, possibly due to direct or indirect virus-induced injuries. Further longitudinal studies are required to investigate the long-term effects of COVID-19 infection on the human eyes.

Progression of Polypoidal Lesions Associated with Exudative Recurrence in Polypoidal Choroidal Vasculopathy.

PURPOSE: To investigate the characteristics of the branching vascular network (BVN) and polypoidal lesions in polypoidal choroidal vasculopathy (PCV) to determine near-term indicators that may predict exudative recurrence. DESIGN: Retrospective cohort study. PARTICIPANTS: Patients with PCV receiving anti-vascular endothelial growth factor (VEGF) monotherapy or anti-VEGF plus photodynamic therapy were followed for at least 1 year using swept-source OCT angiography (SS-OCTA) imaging. METHODS: Patients were divided into 2 groups based on whether exudative recurrence occurred during follow-up. Multiple parameters were collected and compared between the 2 groups, such as age, gender, visual acuity, number of polypoidal lesions, lesion area at the first SS-OCTA visit, and total lesion area change from the first SS-OCTA visit to the last SS-OCTA visit. To evaluate the association between SS-OCTA imaging-based risk factors and the exudative recurrences, imaging features associated with PCV such as BVN growth and polypoidal lesion progression (enlargement, new appearance, and reappearance) at each follow-up visit were analyzed. The time intervals from the nonexudative visit with lesion progression to the corresponding exudative recurrence visit were documented to explore their association with exudative recurrences. Cox regression and logistic regression analyses were used. MAIN OUTCOME MEASURES: Association between BVN growth and polypoidal lesion progression with exudative recurrence. RESULTS: Thirty-one eyes of 31 patients (61% men) were included. Sixteen eyes had no recurrence of exudation, and 15 eyes had recurrence during follow-up. The average follow-up duration was 20.55 ± 6.86 months (range, 12-36 months). Overall, the recurrence group had worse best-corrected visual acuity (P = 0.019) and a greater increase in lesion area (P = 0.010). Logistical regression analysis showed that polypoidal lesion progression, including new appearance, enlargement, and reappearance of polypoidal lesions, was associated with exudative recurrences within 3 months (odds ratio, 26.67, 95% confidence interval, 3.77-188.54, P = 0.001). CONCLUSIONS: Growth of nonexudative BVN and progression of polypoidal lesions were found to be lesion characteristics associated with exudative recurrences, and progression of polypoidal lesions might serve as a stand-alone indicator for the near-term onset of exudation. In PCV, more frequent follow-up visits are recommended when polypoidal lesions show progression.

Lower refractive prediction accuracy of total keratometry using intraocular lens formulas loaded onto a swept-source optical biometer.

PURPOSE: To compare refractive outcomes calculated using intraocular lens (IOL) power calculation formulas loaded onto the IOLMaster 700 with the employment of anterior keratometry (K) and total keratometry (TK). METHODS: A total of 225 eyes of 225 patients underwent uneventful cataract surgery and implantation of a single model of nontoric monofocal IOL by a single surgeon. All eyes underwent preoperative ocular biometric measurements with the IOLMaster 700. Refractive outcomes, including the mean numerical prediction error (MNE); standard deviation (SD); adjusted mean absolute prediction error (MAE); adjusted median absolute prediction error (MedAE); percentages of eyes with adjusted prediction error (PE) within ± 0.25, ± 0.50, ± 0.75, and ± 1.00 diopter; and IOL Formula Performance Index (FPI), were compared between the K-based formula and the TK-based formula of Barrett Universal II (BUII), Haigis, SRK/T, Holladay 2, and Hoffer Q. Axial length (short, medium, and long) subgroup analyses and anterior and posterior keratometry (flat, medium, and steep) subgroup analyses were conducted. RESULTS: The K-based formula performed better than the TK-based formula in the accuracy of refractive prediction of each IOL calculation formula: BUII-K (FPI 0.690), BUII-TK (0.677), Haigis-K (0.617), Haigis-TK (0.584), SRK/T-K (0.608), SRK/T-TK (0.595), Holladay 2-K (0.419), Holladay 2-TK (0.406), Hoffer Q-K (0.364), and Hoffer Q-TK (0.356). The subgroup analyses of refractive prediction outcomes showed that TK influenced the refractive outcomes in eyes with relatively normal ranges of axial length and anterior keratometry. CONCLUSIONS: Using TK instead of K leads to lower refractive prediction accuracy of the IOL power calculation formulas loaded on the IOLMaster 700.

Wide-field swept-source OCT angiography (23 × 20 mm) for detecting retinal neovascularization in eyes with proliferative diabetic retinopathy.

PURPOSE: Xephilio OCT-S1 can capture single-acquisition 23 × 20-mm wide-field swept-source optical coherence tomography angiography (SS-OCTA) images and high-resolution images using artificial intelligence. We aimed to evaluate the ability of wide-field SS-OCTA in the detection of retinal neovascularizations (NVs) in eyes with proliferative diabetic retinopathy (PDR). METHODS: This retrospective study included 64 eyes of 36 patients (age, 57 ± 10 years; 10 female, 26 male) with PDR. All patients underwent a comprehensive ophthalmological examination, including fluorescein angiography (FA), as well as fovea- and disc-centered 23 × 20-mm OCTA imaging (A-scan/B-scan, 928/807). We compared and examined the number of NV sites identified using conventional methods (merging the findings from biomicroscopy/color fundus photography, FA) and the number of NV sites identified using vitreoretinal interface and superficial retinal slabs of wide-field SS-OCTA images, including the position of NVs (nasal upper, nasal lower, temporal upper, temporal lower, or disc). RESULTS: We identified 168 NVs (32/40/45/35/16, in the abovementioned order) using the conventional method. Fovea-centered 23 × 20-mm OCTA images revealed 162 (96%) NVs (27/39/45/35/16). This method tended to miss nasal NV. In contrast, disc-centered 23 × 20-mm OCTA images identified nearly all NVs, detecting 166 (99%) NVs (32/40/44/34/16) in total. All NVs could be visualized using two wide-field OCTA images: fovea- and disc-centered. CONCLUSION: Wide-field (23 × 20 mm) SS-OCTA-especially disc-centered-using Xephilio OCT-S1 identified nearly all NVs in eyes with PDR, with a single acquisition, thereby demonstrating its potential clinical application.

Comparison of 2 modern swept-source optical biometers-IOLMaster 700 and Anterion.

PURPOSE: To compare biometric measures from 2 modern swept-source OCT biometers (IOLMaster700 (Z, Carl-Zeiss-Meditec) and Anterion (H, Heidelberg Engineering)) and evaluate the effect of measurement differences on the resulting lens power (IOLP). METHODS: Biometric measurements were made on a large study population with both instruments. We compared axial length (AL), central corneal thickness (CCT), anterior chamber depth (ACD), lens thickness (LT) and corneal front and back surface curvature measurements. Corneal curvature was converted to power vectors and total power derived using the Gullstrand formula. A paraxial lens power calculation formula and a prediction for the IOL axial position according to the Castrop formula were used to estimate differences in IOLP targeting for emmetropia. RESULTS: There were no systematic differences between measurements of AL (- 0.0146 ± 0.0286 mm) and LT (0.0383 ± 0.0595 mm), whereas CCT yielded lower (7.8 ± 6.6 µm) and ACD higher (0.1200 ± 0.0531 mm) values with H. With H, CCT was lower for thicker corneas. The mean corneal front surface radius did not differ (- 0.4 ± 41.6 µm), but the corneal back surface yielded a steeper radius (- 397.0 ± 74.6 µm) with H, giving lower mean total power (- 0.3469 ± 0.2689 dpt). The astigmatic vector components in 0°/90° and 45°/135° were the same between both instruments for the front/back surface or total power. CONCLUSION: The biometric measures used in standard formulae (AL, corneal front surface curvature/power) are consistent between instruments. However, modern formulae involving ACD, CCT or corneal back surface curvature may yield differences in IOLP, and therefore, formula constant optimisation customised to the biometer type is required.

A normative database of wide-field swept-source optical coherence tomography angiography quantitative metrics in a large cohort of healthy adults.

PURPOSE: Data from healthy eyes is needed to interpret optical coherence tomography angiography (OCTA) findings. However, very little normative data is available for wide-field swept-source OCTA (WF SS-OCTA), particularly 12 × 12-mm and disc-centered angiograms. Therefore, we aim to report quantitative metrics in a large sample of control eyes. METHODS: In this cross-sectional observational study, 482 eyes of 375 healthy adults were imaged on the 100 kHz Zeiss PLEX® Elite 9000 using protocols centered on the fovea (3 × 3, 6 × 6, and 12 × 12-mm) and optic disc (6 × 6 and 12 × 12-mm) between December 2018 and January 2022. The ARI Network (Zeiss Portal v5.4) was used to calculate vessel density (VD) and vessel skeletonized density (VSD) in the superficial capillary plexus, deep capillary plexus, and whole retina, as well as foveal avascular zone (FAZ) parameters. Mixed-effect multiple linear regression models were used for statistical analysis. RESULTS: The subjects' median age was 55 (38-63) years, and 201 (53.6%) were female. Greater age and worse best-corrected visual acuity (BCVA) were associated with significantly lower VD and VSD (p < 0.05). VD and VSD differed based on race and cataract status, but not sex, on some scan protocols (p < 0.05). FAZ circularity decreased with age, and FAZ dimensions differed based on race and ethnicity in certain scan protocols. CONCLUSIONS: We report a large database of parafoveal and peripapillary vascular metrics in several angiogram sizes. In referencing these values, researchers must consider characteristics such as age, race, and BCVA, but will have a valuable point of comparison for OCTA measurements in pathologic settings.

Quantitative evaluation of retinal and choroidal vascularity in systemic lupus erythematosus by SS-OCT/OCTA.

PURPOSE: To evaluate changes in retinal and choroidal vascularity using swept-source optical coherence tomography (SS-OCT) and optical coherence tomography angiography (OCTA) in patients with systemic lupus erythematosus (SLE). METHODS: In this prospective, cross-sectional study, 48 SLE patients and 40 healthy control (group HC) participants were included. The SLE patients were divided into two subgroups: patients with SLE with no ocular disease (group I) and patients with SLE with signs of retinopathy (group II). The superficial vessel density (SVD), deep vessel density (DVD), peripapillary retinal vessel densities (pRVD), choroidal thickness (ChT), and choroidal vascularity including total choroidal area (TCA), luminal area (LA), stromal area (SA), and choroidal vascularity index (CVI) were measured using SS-OCT/OCTA. Physical and ophthalmic examinations as well as the assessments of immunological markers were performed. The results of SS-OCT/OCTA were compared between group I, group II, and group HC, while the correlations among the parameters were analyzed. RESULTS: The SVD, DVD, and pRVD were found to be significantly lower in SLE patients than group HC, especially in SLE patients with signs of retinopathy. ChT were found to be significantly higher in group II. CVI was positively correlated with SVD and DVD in the fovea, as well as the foveal and parafoveal thickness. A significant decrease in SVD and DVD in the fovea among subjects positive for anti-dsDNA antibodies was noted. CONCLUSIONS: The application of OCTA in the evaluation of microvasculature may be useful in subclinical changes. Retinal microvascular density decreased in patients with SLE with greater severity of SLE. Disturbed retinal circulation was related to SLE disease activity, disease duration, CVI, and being positive for anti-dsDNA antibodies. The study results also suggest that SLE with signs of retinopathy may affect the choroid with increases in LA, SA, TCA, and ChT.

Prevalence of venous loops and association with retinal ischemia in diabetic retinopathy using widefield swept-source OCT angiography.

PURPOSE: To investigate the prevalence and clinical characteristics of diabetic patients with retinal venous loops (RVLs) and to assess the association with retinal ischemia using widefield swept-source optical coherence tomography angiography (WF SS-OCTA). METHODS: In this retrospective, cross-sectional study, a total of 195 eyes of 132 diabetic patients (31 eyes with no diabetic retinopathy (DR), 76 eyes with nonproliferative DR (NPDR), and 88 eyes with proliferative DR (PDR)) were imaged with WF SS-OCTA using Angio 6 × 6 mm and Montage 15 × 15 mm scans. Quantitative ischemia-related parameters, including ischemia index (ratio of nonperfusion area to total retinal area), foveal avascular zone (FAZ), and neovascularization features, were evaluated. RVLs were classified as type I or type II according to the branching level of the feeder vessel. A multivariate generalized estimating equations (GEE) logistic regression model was used to analyze the association of systemic parameters and ischemia-related metrics with RVLs in PDR eyes. RESULTS: Forty-eight RVLs were identified in 22 eyes (11.28%). The prevalence of RVLs was higher in PDR compared to NPDR eyes (21.59% vs. 3.95%, P < 0.05). Type II RVLs accounted for a higher proportion than type I (89.58% vs. 10.42%, P < 0.001). RVLs were more likely to originate from superior (vs. inferior) and temporal (vs. nasal) veins (P < 0.05). The GEE model showed that neovascularization (NV) flow area and diastolic blood pressure were associated with RVLs in the PDR group (P < 0.05). CONCLUSION: WF SS-OCTA is useful for the identification of RVLs in patients with DR. NV flow area and diastolic blood pressure were associated with the presence of RVLs in eyes with PDR. Ischemia index, FAZ, and other WF SS-OCTA parameters were not associated with RVLs. Further longitudinal studies are needed to identify the role of RVLs in DR progression.

Fractal analysis of the macular region in healthy eyes using swept-source optical coherence tomography angiography.

PURPOSE: This cross-sectional observational study evaluated the relationship between retinal vascular fractal dimension (FD) and age, as well as other vascular parameters in healthy eyes using swept-source optical coherence tomography angiography (SS-OCTA). METHODS: The study cohort consisted of 222 eyes of 116 healthy participants with no ocular or systemic disease. SS-OCTA images were captured and analyzed using the Plex Elite 9000 and software tools available in the advanced retinal imaging (ARI) network hub. The retinal vascular layers were defined by the instrument's automatic retinal layer segmentation. The fractal analysis was performed on the superficial capillary plexus (SCP), deep capillary plexus (DCP), and the whole retina. Grayscale OCTA images were standardized and binarized using ImageJ and fractal box-counting analyses were performed using Fractalyse software. Pearson's correlation was used to analyze the correlation between FD and retinal vascular parameters. RESULTS: The results showed that FD values were significantly higher in the 6 mm ring and the whole 6 × 6 scan region when compared to the 1 mm ETDRS central subfield. The correlation between age and FD was weak with a significant positive correlation between age and FD of the SCP in the 6 mm ring and between age and FD of the DCP in the 1 mm ring. Overall, differences in FD values in these healthy eyes were extremely small regardless of age or macular location. CONCLUSION: FD values in normal eyes show little variation with age and are relatively stable across the macula. This suggests that FD values may not need adjustment for age or location when evaluated in the context of retinal disease.

Evaluation and comparison of ocular biometric parameters obtained with Tomey OA-2000 in silicone oil-filled aphakic eyes.

PURPOSE: To evaluate a new non-contact instrument (OA-2000) measuring the ocular biometry parameters of silicone oil (SO)-filled aphakic eyes, as compared with IOLMaster 700. METHODS: Forty SO-filled aphakic eyes of 40 patients were enrolled in this cross-sectional clinical trial. The axial length (AL), central corneal thickness (CCT), keratometry ((flattest keratometry) Kf and (steep keratometry, 90° apart from Kf) Ks), and axis of the Kf (Ax1) were measured with OA-2000 and IOLMaster 700. The coefficient of variation (CoV) was calculated to assess the repeatability. The correlation was evaluated by the Pearson coefficient. Bland-Altman analysis and paired t test were used to analyze the agreements and differences of parameters measured by the two devices, respectively. RESULTS: The mean AL obtained with the OA-2000 was 23.57 ± 0.93 mm (range: 21.50 to 25.68 mm), and that obtained with the IOLMaster 700 was 23.69 ± 0.94 mm (range: 21.85 to 25.86 mm), resulting in a mean offset of 0.124 ± 0.125 mm (p < 0.001). The mean offset of CCT measured by OA-2000 and IOLMaster 700 was 14.6 ± 7.5 µm (p < 0.001). However, the Kf, Ks and Ax1 values from the two devices were comparable (p > 0.05). All the measured parameters of the two devices showed strong linear correlations (all r ≥ 0.966). The Bland-Altman analysis showed a narrow 95% limits of agreement (LoA) of Kf, Ks and AL, but 95%LoA of CCT and Ax1 was wide, which were - 29.3 ~ 0.1 µm and-25.9 ~ 30.7°respectively. The CoVs of the biometric parameters obtained with OA-2000 were lower than 1%. CONCLUSION: In SO-filled aphakic eyes, the ocular parameters (including AL, Kf, Ks, Ax1, and CCT) measured by the OA-2000 and IOLMaster 700 had a good correlation. Two devices had an excellent agreement on ocular biometric measurements of Kf, Ks and AL. The OA-2000 provided excellent repeatability of ocular parameters in SO-filled aphakic eyes.

Efficacy and safety of laser peripheral iridoplasty with different energy levels and locations in the treatment of primary angle closure disease assessed by swept-source anterior segment optical coherence tomography.

BACKGROUND: To explore the efficacy and safety of laser peripheral iridoplasty (LPIp) with different energy levels and locations in the treatment of primary angle closure disease (PACD) assessed by swept-source anterior segment optical coherence tomography (AS-OCT). METHODS: We enrolled patients with PACD following best-corrected visual acuity (BCVA), intraocular pressure (IOP), anterior chamber gonioscopy, ultrasound biomicroscopy(UBM), optic disc OCT, and visual field examinations. After Pentacam and AS-OCT measurements, the patients were randomly divided into four treatment groups for LPIp with two different energy levels (high vs. low energy) and two locations (far from the periphery vs. near the periphery) and combined with laser peripheral iridotomy. BCVA, IOP, pupil diameter, central anterior chamber depth, anterior chamber volume, anterior opening distance (AOD)500, AOD750, trabecular iris angle (TIA)500, and TIA750 in four quadrants before and after laser treatment were compared. RESULTS: We followed up 32 patients (64 eyes; average age, 61.80 ± 9.79 years; 8 patients/16 eyes per group) for up to 2 years. The IOP of all enrolled patients was decreased after surgery compared to that before (t = 3.297, P = 0.002), the volume of the anterior chamber was increased (t=-2.047, P = 0.047), and AOD500, AOD750, TIA500, and TIA750 were increased (all P < 0.05). Within-group comparisons showed that BCVA in the low-energy/far-periphery group was improved after surgery (P < 0.05). After surgery, the IOP was decreased in the two high-energy groups, whereas the volume of the anterior chamber, AOD500, AOD750, TIA500, and TIA750 were increased in all groups (all P < 0.05). However, when comparing every two groups, the high-energy/far-periphery group showed a stronger effect on pupil dilation than the low-energy/near-periphery group (P = 0.045). The anterior chamber volume in the high-energy/near-periphery group was larger than that in the high-energy/far-periphery group (P = 0.038). The change in TIA500 was for 6 points smaller in the low-energy/near-periphery group than in the low-energy/far-periphery group (P = 0.038). Other parameters showed no significant group differences. CONCLUSION: LPIp combined with iridotomy can effectively reduce IOP, increase anterior chamber volume, increase chamber angle opening distance, and widen the trabecular iris angle. Intraoperatively, high-energy laser spots positioned one spot diameter from the scleral spur can obtain the best effect and safety. Swept-source AS-OCT can safely and effectively quantify the anterior chamber angle.