Swept-source Optical Coherence Tomography Research Articles

Morphologic features of iris in highly myopic eyes based on a novel swept-source optical coherence tomography.

To investigate the morphologic features of iris in the highly myopic (HM) eyes using a novel swept-source optical coherence tomography (SS-OCT). In this retrospective case-control study, 100 eyes of 100 patients scheduled to have cataract surgery were included, categorized into the control (22 mm< AL < 24.5 mm) and HM (AL ≥ 26 mm) groups. Iris volume (IV), area of anterior iris surface (IS), area of posterior IS, and average iris thickness (IT), as well as anterior chamber volume (ACV) and trabecular-iris space at 500 µm (TISA 500) were evaluated using SS-OCT. The associated factors with morphologic features of iris were also investigated. The HM group showed significantly larger IV and area of anterior and posterior IS than the control group (all P < 0.001), while no difference was identified in IT between the groups. Similar trend in IV was seen in the superior and nasal segments, and area of anterior and posterior IS showed similar trends in all segments except the temporal segment. The IV, area of anterior and posterior IS were all positively correlated with AL (all P < 0.001). Multivariate linear regression revealed that a larger IV was associated with greater ACV. Both larger areas of anterior IS and posterior IS were associated with male, longer AL, greater ACV, and smaller TISA 500. The HM eyes showed larger IV and area of IS than the control eyes, indicating a coronal expansion of the iris with AL. Iris morphology correlated with anterior chamber angle configuration.

Single-Shot Ultra-Widefield Polarization-Diversity Optical Coherence Tomography for Assessing Retinal and Choroidal Pathologies.

Background: Optical coherence tomography (OCT) is a leading ocular imaging modality, known for delivering high-resolution volumetric morphological images. However, conventional OCT systems are limited by their narrow field-of-view (FOV) and their reliance on scattering contrast, lacking molecular specificity. Methods: To address these limitations, we developed a custom-built 105∘ ultra-widefield polarization-diversity OCT (UWF PD-OCT) system for assessing various retinal and choroidal conditions, which is particularly advantageous for visualizing peripheral retinal abnormalities. Patients with peripheral lesions or pigmentary changes were imaged using the UWF PD-OCT to evaluate the system's diagnostic capabilities. Comparisons were made with conventional swept-source OCT and other standard clinical imaging modalities to highlight the benefits of depolarization contrast for identifying pathological changes. Results: The molecular-specific contrast offered by UWF PD-OCT enhanced the detection of disease-specific features, particularly in the peripheral retina, by capturing melanin distribution and pigmentary changes in a single shot. This detailed visualization allows clinicians to monitor disease progression with greater precision, offering more accurate insights into retinal and choroidal pathologies. Conclusions: Integrating UWF PD-OCT into clinical practice represents a major advancement in ocular imaging, enabling comprehensive views of retinal pathologies that are difficult to capture with current modalities. This technology holds great potential to transform the diagnosis and management of retinal and choroidal diseases by providing unique insights into peripheral retinal abnormalities and melanin-specific changes, critical for early detection and timely intervention.

Impact of quality indicators on variability of keratometry measurements using a swept-source OCT based optical biometer.

To characterize the variability of keratometry measurements on the IOLMaster 700, and relate it to device image quality indicators (QI). Two academic centers and one private practice. Multicenter, retrospective consecutive case series. Measurements from three sites, obtained between December, 2015 and July, 2023 were included. Surgery-naïve phakic eyes with same-day sequential measurements on the same eye were identified. Repeat measurement pairs were grouped by IOLMaster QIs (success vs. warning), and changes in mean standard (∆Kmean) and total (∆TKmean) keratometry as well as standard (∆Kastig) and total (∆TKastig) astigmatism vectors were calculated. Analysis was performed on 3,222 eyes of 1,890 patients. Measurement 'success' was associated with a smaller ΔKmean (0.09 ± 0.14 D) and ΔTKmean (0.11 ± 0.16 D) when compared to pairs in which both measurements had a 'warning' [0.25 ± 0.32 D and 0.14 ± 0.17 D, respectively; (p < 0.0001)]. A similarly smaller ∆Kastig (0.26 ± 0.28 D) and ∆TKastig (0.28 ± 0.30 D) was observed with measurement 'success' versus 'warning' [0.77 ± 0.79 D and 0.42 ± 0.41 D, respectively (p < 0.0001)]. Even when both measurements were successful, the proportion of measurement pairs that had a ∆Kastig > 0.50 D increased from 14% to 24% to 32% when Kmean standard deviation (SD) was ≥ 0.01, 0.05, and 0.10 D, respectively. When measurement quality is poor, total keratometry varies less than standard keratometry measurements. Clinicians may use the SD of Kmean/TKmean to estimate the repeatability of measurements and balance this against their tolerance for performing repeat measurements.

Objective quantification of posterior capsule opacification using swept-source anterior segment optical coherence tomography.

To objectively quantify posterior capsule opacification (PCO) using swept-source anterior segment optical coherence tomography (SS-ASOCT) in pseudophakic eyes. Zhongshan Ophthalmic Center, Guangzhou, China. Prospective cross-sectional study. One hundred and eighty eyes with PCO (37 multifocal intraocular lenses [MfIOLs] and 143 monofocal intraocular lenses [MoIOLs]) were enrolled. The PCO Irregular Degree (PID), defined to evaluate the surface irregularity of PCO, the average and maximum thickness of PCO (AT-PCO, MT-PCO) were applied to quantify PCO based on SS-ASOCT (CASIA2) images. Corrected distance visual acuity (CDVA), high order aberrations (HOAs), modulation transfer function (MTF) and Strehl ratio were recorded. The associations between SS-ASOCT parameters and visual function parameters were assessed by Spearman's correlation analysis. PID, AT-PCO and MT-PCO showed significant correlations with CDVA, Strehl ratio and HOAs (CDVA: r = 0.702, 0.741, 0.736; Strehl ratio: r = -0.746, -0.719, -0.740; HOAs: r = 0.762, 0.734, 0.752). The correlations of these three parameters with Strehl ratio and HOAs were significantly higher than those of clinical PCO grading with Strehl ratio and HOAs (all P < 0.05). Particularly, PID demonstrated notable correlations with Strehl ratio and HOAs. In addition, patients with MfIOLs presented worse Strehl ratio and HOAs than those with MoIOLs after matching age, PID, AT-PCO and MT-PCO. This study provides a novel method for objectively quantifying PCO using successive cross-sectional SS-ASOCT images. AT-PCO, MT-PCO and PID are presented as new indicators to document PCO severity, with PID offering a unique perspective by considering the irregularity aspect of PCO.

Severity Scale of Diabetic Macular Ischemia Based on the Distribution of Capillary Nonperfusion in OCT Angiography

To evaluate the severity scales of diabetic macular ischemia (DMI) by analyzing the quantity and distribution of capillary nonperfusion using OCT angiography (OCTA) images. A single-center, prospective case series. Three hundred one eyes from 301 patients with diabetic retinopathy. We acquired 3× 3-mm swept-source OCTA images and created en face images within a central 2.5-mm circle. The circle was divided into 15× 15-pixel squares and nonperfusion squares (NPSs) were defined as those without retinal vessels. Eyes with high-dimensional spatial data were arranged on a 2-dimensional space using the uniform manifold approximation and projection (UMAP) algorithm and classified by clustering into 5 groups: Initial, Mild, Superficial, Moderate, and Severe. Development of a severity scale for DMI. Eyes arranged on a 2-dimensional UMAP space were divided into 5 clusters, based on the similarity of nonperfusion area distribution. Nonperfusion square counts in the deep layer increased in eyes of the Initial, Mild, Moderate, and Severe groups in a stepwise manner. In contrast, there were no significant changes in superficial NPS counts between eyes of the Initial and Mild groups. In the intermediate stage, eyes of the Superficial group exhibited higher NPS counts in the central sector of the superficial layer compared with those of the Moderate group. The foveal avascular zone extended into the temporal subfield of the deep layer in eyes of the Moderate group. Eyes of the Severe group had significantly poorer visual acuity that was more frequently accompanied with proliferative diabetic retinopathy. The application of dimensionality reduction and clustering has facilitated the development of a novel severity scale for DMI based on the distribution of capillary nonperfusion in OCTA images. The authors have no proprietary or commercial interest in any materials discussed in this article.

Retinal and Choroidal Phenotypes Across Novel Subtypes of Type 2 Diabetes Mellitus

PurposeThis study aimed to investigate longitudinal changes in choroidal thickness (CT) and ganglion cell-inner plexiform layer thickness (GC-IPLT) across distinct phenotypes of type 2 diabetes mellitus (T2DM) patients. DesignProspective observational cohort study. MethodsT2DM patients were categorized into five groups (SAID, SIDD, SIRD, MOD, and MARD) using K-means clustering based on β-cell function and insulin resistance. Swept-source optical coherence tomography measured baseline and 4-year follow-up CT and GC-IPLT. Linear mixed-effects models assessed absolute and relative changes in CT and GC-IPLT across subtypes. ResultsOver a median 4.11-year follow-up, CT and GC-IPLT decreased significantly across all groups. Choroidal thinning rates were most pronounced in SIDD (-6.5±0.53 µm/year and -3.5±0.24%/year) and SAID (-6.27±0.8 µm/year and -3.19±0.37%/year), while MARD showed the slowest thinning (-3.63±0.34 µm/year and -1.98±0.25%/year). SIRD exhibited the greatest GC-IPLT loss (-0.66±0.05 µm/year and -0.91±0.07%/year), with the least in SIDD (-0.36±0.05 µm/year and -0.49±0.07%/year), all statistically significant (Ps < 0.001). Adjusted for variables, SIDD and SAID groups showed faster CT thinning than MARD [-2.57 µm/year (95% CI: -4.16 to -0.97; P=0.002) and -2.89 µm/year (95% CI: -4.12 to -1.66; P<0.001), respectively]. GC-IPLT thinning was notably accelerated in SIRD versus MARD, but slowed in SIDD relative to MARD [differences of -0.16 µm/year (95% CI: -0.3 to -0.03; P=0.015) and 0.15 µm/year (95% CI: 0.03 to 0.27; P=0.015), respectively]. Stratified analysis revealed significant differences among non-DR groups. ConclusionsMicrovascular damage in the choroid is associated with SIDD patients, whereas early signs of retinal neurodegeneration are evident in SIRD patients. All these changes may precede the onset of DR.

High-precision and non-invasive measurement of crestal bone level by optical coherence tomography

Background/purposeIdentifying crestal bone level (CBL) on the buccal and lingual aspects poses challenges in conventional dental radiographs. Given that optical coherence tomography (OCT) has the capability to non-invasively provide in-depth information about the periodontium, this in vitro study aimed to assess whether OCT can effectively identify periodontal landmarks and measure CBL in the presence of gingiva. Materials and methodsAn in-house handheld scanning probe connected to a 1310-nm swept-source OCT (SS-OCT) system, along with self-developed algorithms were employed to measure the CBL in dental models with artificial gingiva. Markers were positioned 0.5 mm above the artificial gingival margin (SG) and the crestal bone (SC) on both the mid-buccal and mid-lingual sides of 28 plastic teeth. The distances between the paired SG and SC were measured in the OCT images after correcting for the optical path through the covering artificial gingiva. These measurements were subsequently compared to the ground truth values obtained using a 2.5D inspection system. ResultsThe mean difference in CBL measured by SS-OCT and 2.5D was 0.008 mm (95 % CI: −0.092 to 0.108 mm). Statistical analysis using a three-way ANOVA indicated that the measurement differences were not significant across maxillary/mandible, anterior/posterior, and buccal/lingual dimensions. Furthermore, these differences were not associated with gingival thickness (α = 0.05). ConclusionThe proposed SS-OCT system demonstrated its capability to accurately and non-invasively assess CBL through artificial gingiva. Moreover, it facilitated the semi-automatic delineation of critical periodontal landmarks on OCT en face images, highlighting its potential for clinical applications.

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.].

Evaluation of Long-term Posterior Segment Parameters in Children Who Had Recovered From Multisystem Inflammatory Syndrome.

To evaluate long-term posterior segment findings in children recovering from multisystemic inflammatory syndrome (MIS-C) associated with severe acute respiratory syndrome coronavirus 2. Our study included 22 patients who were admitted to an intensive care unit with a diagnosis of MIS-C between November 2021 and March 2022, and 25 healthy controls. The study included pediatric patients who had an eye examination an average of 12.35 ± 2.18 months after recovery from MIS-C. Detailed eye examinations and measurements of all participants were obtained retrospectively from patient files. Posterior segment parameters were measured using swept-source optical coherence tomography (OCT) and OCT-angiography (OCT-A); these parameters included peripapillary retinal nerve fiber layer (pRNFL) thickness, central macular thickness (CMT), subfoveal choroidal thickness (SCT), macular vascular densities (VD), and foveal avascular zone (FAZ) area. Mean age was 9.7 ± 3.6 years in the MIS-C group and 10.6 ± 2.8 years in the healthy control group (P = 0.316). There were no statistically significant differences between the MIS-C group and the healthy control group in terms of pRNFL thickness, CMT, and SCT. However, in the MIS-C group, the macular superficial vascular plexus and deep vascular plexus showed significantly lower VD in the superior, inferior, nasal, and temporal quadrants compared to the healthy controls (P < 0.05 for all). A comparison of the superficial and deep FAZ area parameters of both groups showed no statistically significant difference (P > 0.05). We showed that patients who had recovered from MIS-C had retinal vascular damage at the long-term follow-up. Following up with these patients after recovery with OCT and OCT-A, which are noninvasive methods commonly used in the detailed evaluation of the posterior segment of the eye, could be beneficial for understanding the long-term effects of MIS-C on retinal microvasculature. [Ophthalmic Surg Lasers Imaging Retina 2024;55:518-526.].

Acute Macular Neuroretinopathy Associated with COVID-19 Pandemic: A Real-world Observation Study

PurposeTo evaluate the clinical and retinal imaging features of Chinese patients with acute macular neuroretinopathy (AMN) associated with COVID-19. DesignA prospective observational study. MethodsRetinal imaging, including color fundus photography, near-infrared imaging (NIR), swept-source optical coherence tomography (SS-OCT), optical coherence tomography angiography (OCTA), and Humphrey perimetry, were conducted for each case. ResultsAll cases were included within the first three months following the pandemic outbreak. A total of 12 male patients (36.36 %) and 21 female patients (63.64 %) were prospectively recruited, and 29 cases (87.88 %) were bilaterally affected. The median interval between the onset of fever and the appearance of ocular symptoms was two days (range, 0.5–5.0 days). Apart from the outer retinal changes typical of AMN, changes in the inner retinal layers were observed, including intraretinal hemorrhage (8.06 %), cotton wool spots (9.68 %), and paracentral acute middle maculopathy (PAMM) (8.06 %). Smaller retinal inner nuclear layer hyperreflective speckles (RIHS) (41.94 %) were identified as a distinguishing feature from typical PAMM. Voids of vessel signals were found in the superficial (11.54 %), intermediate (82.69 %), and deep capillary plexus (98.08 %), and in the choriocapillaris (19.23 %) on OCTA. Humphrey perimetry illustrated central, paracentral, and peripheral scotomas. The occult lesions associated with AMN, PAMM, and some of the RIHS illustrated by OCT were visualized topographically and further confirmed by OCTA as perfusion defects. ConclusionAn increase in AMN cases correlated with the SARS-CoV-2 outbreak. Additional features, including widespread inner retinal perfusion deficits, were observed and may serve as potential biomarkers for systemic microcirculation dysregulation in COVID-19.

Influence of Capsular Tension Rings on the IOL-Capsule Complex in Patients With Long Axial Length: A Clinical Observation Based on SS-OCT.

To evaluate the influence of a capsular tension ring (CTR) on the intraocular lens (IOL)-capsule complex after cataract surgery in patients with long axial length. This was a prospective study. Patients underwent phacoemulsification and IOL implantation, with or without CTR implantation. Swept-source optical coherence tomography was performed at 1 day, 1 week, 1 month, and 3 months postoperatively to determine the postoperative aqueous depth (PAD), capsular bend index (CBI), and IOL tilt and decentration. Spherical equivalent values were obtained through subjective refraction and autorefraction. Root mean square was adopted to evaluate the indices listed above. Forty-three patients (56 eyes) were included in the study. Generalized estimating equation analysis of PAD showed a statistical difference between groups (P = .031). The RMS of the change in PAD was smaller in the CTR group than in the non-CTR group during the 3 months after surgery (P = .015). CBI in the CTR group increased more from 1 to 3 months after surgery than that in the non-CTR group (P = .025). The RMS of the change in vertical decentration was smaller in the CTR group than in the non-CTR group during the 3-month follow-up (P = .009). CTR implantation can stabilize the axial position of the IOL within the capsular bag after cataract surgery in patients with long axial length without affecting the refractive stability. The formation of capsular bend may be slightly delayed in the early stage after CTR implantation, but it accelerates from 1 to 3 months after surgery. [J Refract Surg. 2024;40(9):e654-e661.].

The Role of Widefield Optical Coherence Tomography Angiography in Assessing the Severity of Diabetic Retinopathy.

Physicians need an accurate understanding of diabetic retinopathy (DR) severity to optimally manage patients. The aim of this prospective study is to correlate the severity of macular and peripheral retinal vascular abnormalities seen on widefield (WF) optical coherence tomography angiography (OCTA) with DR grading based on WF fundus photography. The study included 150 eyes from 82 patients with treatment-naïve DR. All patients were imaged with WF fundus photography and swept-source WF OCTA. Quantitative and qualitative analyses of the foveal avascular zone (FAZ) size and shape, and measurement of capillary nonperfusion (CNP) areas, were performed from the OCTA images. The mixed-effects model was used to compare the DR grading from WF photography with the vascular changes seen on WF-OCTA, and Bonferroni correction was applied to the gradings. The mean [± standard deviation (SD)] age of patients was 55.5 (± 9.4) years. The WF-OCTA showed that an increasing size of the FAZ (from 0.442 (± 0.059) µm to 0.933 (± 0.086) µm) correlated with increasing severity of the DR (as determined with WF photography). The deep capillary plexus, FAZ size, and CNP areas in eyes with proliferative diabetic retinopathy (PDR) differed from those with mild nonproliferative diabetic retinopathy (NPDR) (p < 0.001). Most eyes with severe nonproliferative DR were found to have CNP in four quadrants [superficial capillary plexus (SCP) 60%, deep capillary plexus (DCP) 50%]. The WF-OCTA detected subtle neovascularization of the disc (NVD) in 7 eyes (10%) and neovascularization elsewhere (NVE) in 13 eyes (18%) that had been diagnosed with only moderate NPDR on WF photography. FAZ and CNP areas as measured by WF-OCTA correlate with DR severity. WF-OCTA can also detect subtle NVE and NVD that cannot be seen with fundus photography.

Unveiling the Mysteries of the Chinese lens zonule balance tension: A statistical analysis

BackgroundThis study aims to provide an estimated dataset of lens zonule balance tension (LZBT) measurements in cataractous lenses among Chinese patients and to conduct a statistical analysis of anterior segment parameters. MethodsThis is a cross-sectional study. We included a total of 833 eyes from 833 Chinese participants aged 23–91 years who underwent cataract surgery. Anterior segment parameters were measured using swept-source anterior segment optical coherence tomography (SS-AS OCT) to calculate lens gravity (LG) and crystalline lens volume (VOL). Axial length (AL) was measured using IOL-Master 700. LZBT was calculated using force decomposition and synthesis methods. ResultsThe mean LZBT in the horizontal direction was 8.48E-05 ± 3.23E-05 N across all eyes. The LZBT in the subtemporal-supraspinal and supraspinal-temporal directions was 2 times greater than in the vertical direction. The balanced force on the suspensory ligament in the horizontal direction was twice as strong as in the vertical direction. Additionally, anterior segment parameters such as lens equivalent diameter (LE-dia), radius of the anterior lens surface curvature (RAL), radius of the posterior lens surface curvature (RPL), anterior chamber depth (ACD), iris area, iris volume, and iris thickness showed positive correlations with AL. ConclusionsAccounting for gravitational effects, we concluded that zonule force is asymmetrically distributed. Importantly, this study establishes the normal range of LZBT across different meridians using force synthesis and decomposition, offering new insights and feasibility for studying suspensory ligament biomechanics.

A Review of Radiology and Optical Coherence Tomography in Dental Diagnostics

Background: The rapid evolution of imaging technologies has significantly transformed dentistry, improving the diagnosis and treatment of various dental conditions. While traditional radiological methods such as X-rays and Cone Beam Computed Tomography (CBCT) remain the cornerstone of dental imaging, the emergence of Optical Coherence Tomography (OCT) offers a non-invasive, radiation-free alternative. This review examines the comparative efficacy of X-ray and OCT technologies in diagnosing hard tissue conditions in the oral cavity. Methods: The review analyzed the application of OCT and radiology in dental diagnostics through a custom-built Swept-Source OCT system, assessing its performance against traditional radiological methods. The study utilized both in vivo and ex vivo evaluations, considering variables such as resolution, depth penetration, and image clarity across different dental conditions. Results: OCT demonstrated superior capabilities in detecting early-stage cavities, fractures, and minor imperfections, particularly when high-resolution imaging was required. However, its limited penetration compared to X-rays restricted its application in comprehensive bone assessments. Radiology, especially CBCT, provided essential volumetric data crucial for evaluating bone density, fractures, and post-surgical conditions, though it posed concerns related to radiation exposure. Combining both modalities proved beneficial, offering complementary insights that enhanced overall diagnostic accuracy. Conclusion: While X-ray-based radiology remains indispensable for broad evaluations of dental and bone structures, OCT presents a valuable adjunct, particularly for high-precision assessments of soft tissues and small surface defects. The synergistic use of these technologies can provide a more holistic approach to dental diagnostics, potentially improving patient care and treatment outcomes. Future advancements in OCT could further expand its role in routine dental practice, enhancing diagnostic accuracy while minimizing radiation exposure risks.

Quantitative assessment of chlorine gas inhalation injury based on endoscopic OCT and spectral encoded interferometric microscope imaging with deep learning.

Chlorine exposure can cause severe airway injuries. While the acute effects of chlorine inhalation are well-documented, the structural changes resulting from the post-acute, high-level chlorine exposure remain less understood. Airway sloughing is one of the standards for doctors to evaluate the lung function. Here, we report the application of a high-resolution swept-source optical coherence tomography system to investigate the progression of injury based on airway sloughing evaluation in a chlorine inhalation rabbit model. This system employs a 1.2mm diameter flexible fiberoptic endoscopic probe via an endotracheal tube to capture in vivo large airway anatomical changes before and as early as 30minafter acute chlorine exposure. We conducted an animal study using New Zealand white rabbits exposed to acute chlorine gas (800 ppm, 6min) during ventilation and monitored them using optical coherence tomography (OCT) for 6h. To measure the volume of airway sloughing induced by chlorine gas, we utilized deep learning for the segmentation task on OCT images. The results showed that the volume of chlorine induced epithelial sloughing on rabbit tracheal walls initially increased, peaked around 30min, and then decreased. Furthermore, we utilized a spectral encoded interferometric microscopy system to study ex vivo airway cilia beating dynamics based on Doppler shift, aiding in elucidating how chlorine gas affects cilia beating function. Cilia movability and beating frequency were decreased because of the epithelium damage. This quantitative approach has the potential to enhance the diagnosis and monitoring of injuries from toxic gas inhalation and to evaluate the efficacy of antidote treatments for these injuries.

Clinical utility of swept-source optical coherence tomography angiography for the diagnosis of exudative maculopathy.

To assess the feasibility of swept-source optical coherence tomography angiography (SS-OCTA) to differentiate macular diseases, including nonpolypoidal macular neovascularization (MNV), polypoidal choroidal vasculopathy (PCV), type 3 MNV, and chronic central serous chorioretinopathy (CSC) without indocyanine green angiography (ICGA). Retrospective observational study. This study examined 63 eyes of 63 patients with treatment-naive neovascular age-related macular degeneration(AMD), including 23 eyes with nonpolypoidal MNV, 17 eyes with PCV, and 1 eye with type 3 MNV and 22 eyes with chronic CSC. Two independent retina specialists, blinded to the clinical diagnosis, assessed each case of neovascular AMD and chronic CSC using only B-scan and en face images of SS-OCTA without referring to other examination outcomes. By SS-OCTA alone, 19 eyes were diagnosed with nonpolypoidal MNV, 17 eyes with PCV, 2 eyes with type 3 MNV, and 22 eyes with chronic CSC, indicating high sensitivity (82.6%, 94.1%, 100%, and 100%, respectively) and specificity (100%, 97.8%, 98.4%, and 100%, respectively); however, three eyes could not be diagnosed because of obscure images. The agreement of diagnosis with SS-OCTA alone was high between the two specialists (κ = 0.82). SS-OCTA showed high sensitivity and specificity in the differentiation of nonpolypoidal MNV, PCV, type 3 MNV, and chronic CSC. The differential criteria based on SS-OCTA could be a substitute for the ICGA-based diagnoses.

Novel hyperparallel optical coherence tomography for angle closure assessment: comparison with swept-source OCT and gonioscopy

AimTo evaluate reproducibility and agreement of angle closure assessment by a novel hyperparallel optical coherence tomography (OCT) system (HP-OCT, Cylite Optics, Melbourne, Australia), in comparison with swept-source OCT (SS-OCT, CASIA...

Neurovascular changes of the retina and optic nerve head in episodic migraine

To investigate neurovascular changes; including macular vascular density (VD), thickness of the ganglion cell layer (GCL) and optic nerve head (ONH) parameters in episodic migraine patients. 80 eyes of 40 episodic migraine patients were recruited. Thirty patients having a dominant side of migraine headache were statistically analyzed (5 male and 25 female; mean age 31.67 ± 9.54 years) and compared to 25 eyes of 25 healthy volunteers (5 male and 20 female; mean age of 34.4 ± 12.11 years, p = 0.361). The posterior segment was imaged with Topcon DRI optical coherence tomography (OCT) (Triton Swept source OCT Topcon, Japan), and OCT angiography (OCTA). Comparing the dominant side of migraine patients to controls we found a significant decrease of the VD in the central zone of the superficial and deep capillary plexus (SCP, p = 0.01; DCP, p = 0.004) and an enlarged foveal avascular zone (FAZ, p = 0.054). The GCL thickness was significantly reduced in the central ring (GCL + p = 0.042, GCL + + p = 0.029), as well as the retinal nerve fiber layer (RNFL) thickness in the temporal quadrant (p = 0.021) and border tissue of Elschnig diameter (BTE, p = 0.035). The duration of migraine showed an inverse correlation with SCP in the nasal quadrant (p = 0.016, r = − 0.445) and with all DCP regions [DCP superior (p = 0.004, r = − 0.519), DCP inferior (p = 0.004, r = − 0.519), DCP nasal (p = 0.006, r = − 0.496), DCP temporal (p = 0.005, r = − 0.508), DCP CSF (p < 0.001, r = − 0.634)]. The dominant side compared to the non-dominant side showed a significant deterioration of the VD in the inferior (p = 0.04) and temporal quadrants (p = 0.023); furthermore, a significant decrease in the GCL + + inner ring thickness (p = 0.046). Microvascular damage and consequent structural alterations of the retina and optic nerve head occur in the eyes of episodic migraine patient in association with the lateralization of the headache.

Quantitative assessment of choroidal parameters in type 1 macular neovascularization linked to central serous chorioretinopathy and neovascular age-related macular degeneration

ObjectiveTo use ultra-widefield swept-source optical coherence tomography angiography (UWF SS-OCTA) to evaluate the choroidal features of neovascular age-related macular degeneration (nAMD) and type 1 macular neovascularization (MNV) attributable to central serous chorioretinopathy (CSC). MethodA cross-sectional research was carried out to examine patients with type 1 MNV due to CSC (50 eyes) and nAMD (98 eyes) utilizing UWF SS-OCTA examinations. The scan procedure covered a vertical 20 mm × horizontal 24 mm region with 9 subfields. A typical set of 68 healthy eyes was used for comparison. The effects of different diagnoses on choroidal parameters were assessed using covariance tests, using gender and age as variables. ResultsThe research showed that all choroidal characteristics were age-related (all p < 0.05). The calculated marginal averages of choroidal thickness (ChT) and choroidal volume (CV) in the central area were substantially lower in the nAMD group than in the CSC group and the normal group after age differences were taken into account (all p < 0.05). In both the superotemporal and temporal areas, the CSC group had a greater choroidal vascular index (CVI) compared to the nAMD group (p < 0.05). Additionally, the CSC group had a greater temporal area choriocapillaris density (CCD) than the nAMD group (p < 0.05). ConclusionAt the choroidal level, type 1 MNV due to CSC and nAMD may be distinguished by UWF SS-OCTA. Compared to the nAMD affected eyes, the CSC affected eyes had increased ChT, CV, CVI, and CCD in several areas. The two diseases could be distinguished based on ChT and CV.

Trajectories of choriocapillaris perfusion in healthy individuals and patients with diabetes mellitus: a prospective cohort study

PurposeTo evaluate the longitudinal rate of choriocapillaris flow deficits (CFD) in healthy participants and patients with diabetes mellitus.MethodsThis prospective cohort study included healthy individuals and diabetic patients without diabetic retinopathy...