ETDRS grading with CLARUS ultra-widefield images shows agreement with 7-fields colour fundus photography.

BACKGROUND: To analyse and compare the grading of diabetic retinopathy (DR) severity level using standard 35° ETDRS 7-fields photography and CLARUS™ 500 ultra-widefield imaging system. METHODS: A cross-sectional analysis of retinal images of patients with type 2 diabetes (n = 160 eyes) was performed for this study. All patients underwent 7-fields colour fundus photography (CFP) at 35° on a standard Topcon TRC-50DX® camera, and ultra-widefield (UWF) imaging at 200° on a CLARUS™ 500 (ZEISS, Dublin, CA, USA) by an automatic montage of two 133° images (nasal and temporal). 35° 7-fields photographs were graded by two graders, according to the Early Treatment Diabetic Retinopathy Study (ETDRS). For CLARUS UWF images, a prototype 7-fields grid was applied using the CLARUS review software, and the same ETDRS grading procedures were performed inside that area only. Grading of DR severity level was compared between these two methods to evaluate the agreement between both imaging techniques. RESULTS: Images of 160 eyes from 83 diabetic patients were considered for analysis. According to the 35° ETDRS 7-fields images, 22 eyes were evaluated as DR severity level 10-20, 64 eyes were evaluated as DR level 35, 41 eyes level 43, 21 eyes level 47, 7 eyes level 53, and 5 eyes level 61. The same DR severity level was achieved with CLARUS 500 UWF images in 92 eyes (57%), showing a perfect agreement (k > 0.80) with the 7-fields 35° technique. Fifty-seven eyes (36%) showed a higher DR level with CLARUS UWF images, mostly due to a better visualization of haemorrhages and a higher detection rate of intraretinal microvascular abnormalities (IRMA). Only 11 eyes (7%) showed a lower severity level with the CLARUS UWF system, due to the presence of artifacts or media opacities that precluded the correct evaluation of DR lesions. CONCLUSIONS: UWF CLARUS 500 device showed nearly perfect agreement with standard 35° 7-fields images in all ETDRS severity levels. Moreover, CLARUS images showed an increased ability to detect haemorrhages and IRMA helping with finer evaluation of lesions, thus demonstrating that a UWF photograph can be used to grade ETDRS severity level with a better visualization than the standard 7-fields images. TRIAL REGISTRATION: Approved by the AIBILI - Association for Innovation and Biomedical Research on Light and Image Ethics Committee for Health with number CEC/009/17- EYEMARKER.

Quantitative microbiology with widefield microscopy: navigating optical artefacts for accurate interpretations.

Time-resolved live-cell imaging using widefield microscopy is instrumental in quantitative microbiology research. It allows researchers to track and measure the size, shape, and content of individual microbial cells over time. However, the small size of microbial cells poses a significant challenge in interpreting image data, as their dimensions approache that of the microscope's depth of field, and they begin to experience significant diffraction effects. As a result, 2D widefield images of microbial cells contain projected 3D information, blurred by the 3D point spread function. In this study, we employed simulations and targeted experiments to investigate the impact of diffraction and projection on our ability to quantify the size and content of microbial cells from 2D microscopic images. This study points to some new and often unconsidered artefacts resulting from the interplay of projection and diffraction effects, within the context of quantitative microbiology. These artefacts introduce substantial errors and biases in size, fluorescence quantification, and even single-molecule counting, making the elimination of these errors a complex task. Awareness of these artefacts is crucial for designing strategies to accurately interpret micrographs of microbes. To address this, we present new experimental designs and machine learning-based analysis methods that account for these effects, resulting in accurate quantification of microbiological processes.

Spatiotemporal resonance in mouse primary visual cortex.

Human primary visual cortex (V1) responds more strongly, or resonates, when exposed to ∼10, ∼15-20, and ∼40-50 Hz rhythmic flickering light. Full-field flicker also evokes the perception of hallucinatory geometric patterns, which mathematical models explain as standing-wave formations emerging from periodic forcing at resonant frequencies of the simulated neural network. However, empirical evidence for such flicker-induced standing waves in the visual cortex was missing. We recorded cortical responses to flicker in awake mice using high-spatial-resolution widefield imaging in combination with high-temporal-resolution glutamate-sensing fluorescent reporter (iGluSnFR). The temporal frequency tuning curves in the mouse V1 were similar to those observed in humans, showing a banded structure with multiple resonance peaks (8, 15, and 33 Hz). Spatially, all flicker frequencies evoked responses in V1 corresponding to retinotopic stimulus location, but some evoked additional peaks. These flicker-induced cortical patterns displayed standing-wave characteristics and matched linear wave equation solutions in an area restricted to the visual cortex. Taken together, the interaction of periodic traveling waves with cortical area boundaries leads to spatiotemporal activity patterns that may affect perception.

In Ovo Electroporation of Embryonic Chicken Spinal Cord in Combination with Ex Vivo Slice Culture for Live Imaging of Vertebrate Neuronal Differentiation.

To investigate the cell behavior underlying neuronal differentiation in a physiologically relevant context, differentiating neurons must be studied in their native tissue environment. Here, we describe an accessible protocol for fluorescent live imaging of differentiating neurons within ex vivo embryonic chicken spinal cord slice cultures, which facilitates long-term observation of individual cells within developing tissue.

Different Vortex Vein Anomalies Observed in a Single Case: Macular Vortex Vein in One Eye and Varix of Vortex Vein Ampulla in the Other Eye.

We present a 56-year-old female with a macular vortex vein in her right eye and a varix of vortex vein ampulla in the inferior nasal fundus of her left eye. The choroidal lesions were evaluated by multimodal imaging including fundoscopy with contact lens, ultra-widefield fundus photography, swept-souse optical coherence tomography (SS-OCT), enface image of widefield optical coherence tomography (widefield enface-OCT), and ultra-widefield fundus angiography. Widefield enface-OCT revealed submacular large choroidal vessels in the right eye. Ultra-widefield indocyanine green fluorescence angiography (UWICGA) of the right eye showed the dye of those submacular choroidal vessels drained from the ampullae beneath the macula. Fundoscopy revealed an elevated lesion with crescent shadows in the inferior nasal fundus of the left eye. Dynamic fundoscopy with compression of the left eye resulted in a diminishing of the elevation and release of the compression resulted in an enlargement of the elevation. Ultra-widefield fundus photography of the left eye in the right inferior gaze revealed an elevated lesion with a crescent shadow in the inferior nasal fundus, while it is not prominent in the primary gaze. The B-scan of SS-OCT revealed a hyporeflective lesion in the choroid beneath the elevated lesion of the left eye. The elevated lesion was consistent with the vortex vein ampulla on UWICGA. This is the first case where two different choroidal vascular anomalies, macular vortex vein and varix of vortex ampulla, coexist in a single patient. Multimodal imaging is useful to visualize and diagnose choroidal vascular anomalies.

Attention-based CNN-BiLSTM for sleep state classification of spatiotemporal wide-field calcium imaging data.

BACKGROUND: Wide-field calcium imaging (WFCI) with genetically encoded calcium indicators allows for spatiotemporal recordings of neuronal activity in mice. When applied to the study of sleep, WFCI data are manually scored into the sleep states of wakefulness, non-REM (NREM) and REM by use of adjunct EEG and EMG recordings. However, this process is time-consuming, invasive and often suffers from low inter- and intra-rater reliability. Therefore, an automated sleep state classification method that operates on spatiotemporal WFCI data is desired. NEW METHOD: A hybrid network architecture consisting of a convolutional neural network (CNN) to extract spatial features of image frames and a bidirectional long short-term memory network (BiLSTM) with attention mechanism to identify temporal dependencies among different time points was proposed to classify WFCI data into states of wakefulness, NREM and REM sleep. RESULTS: Sleep states were classified with an accuracy of 84 % and Cohen's κ of 0.64. Gradient-weighted class activation maps revealed that the frontal region of the cortex carries more importance when classifying WFCI data into NREM sleep while posterior area contributes most to the identification of wakefulness. The attention scores indicated that the proposed network focuses on short- and long-range temporal dependency in a state-specific manner. COMPARISON WITH EXISTING METHOD: On a held out, repeated 3-hour WFCI recording, the CNN-BiLSTM achieved a κ of 0.67, comparable to a κ of 0.65 corresponding to the human EEG/EMG-based scoring. CONCLUSIONS: The CNN-BiLSTM effectively classifies sleep states from spatiotemporal WFCI data and will enable broader application of WFCI in sleep research.

Naturalistic movies and encoding analysis define areal borders in marmoset third-tier visual cortex.

Accurate definition of the borders of cortical visual areas is essential for the study of neuronal processes leading to perception. However, data used for definition of areal boundaries have suffered from issues related to resolution, uniform coverage, or suitability for objective analysis, leading to ambiguity. Here, we present a novel approach that combines widefield optical imaging, presentation of naturalistic movies, and encoding model analysis, to objectively define borders in the primate extrastriate cortex. We applied this method to test conflicting hypotheses about the third-tier visual cortex, where areal boundaries have remained controversial. We demonstrate pronounced tuning preferences in the third-tier areas, and an organizational structure in which the dorsomedial area (DM) contains representations of both the upper and lower contralateral quadrants, and is located immediate anterior to V2. High-density electrophysiological recordings with a Neuropixels probe confirm these findings. Our encoding-model approach offers a powerful, objective way to disambiguate areal boundaries.

Angiographic characteristics in mild familial exudative vitreoretinopathy with genetically confirmed autosomal dominant inheritance.

PURPOSE: To determine the ultra-widefield fluorescein angiographic (UWFA) characteristics of patients with mild familial exudative vitreoretinopathy (FEVR) who had been confirmed to have pathogenic variants of the autosomal dominant (AD) genes of FEVR. DESIGN: Single center, observational case series. SUBJECTS AND CONTROLS: Thirty-seven patients with mild FEVR from 27 families who had pathogenic variants of the Norrin/ß-catenin genes were studied. The controls consisted of 32 family members who had been confirmed not to carry the pathogenic variants or had heterozygous variants of the autosomal recessive inheritance gene. METHODS: Sixty-four UWFA images from the patients were compared to 60 UWFA images from the controls. The relative length of the temporal retina to the peripheral avascular retina was determined. The cut-off ratio of the relative lengths for a clinically significant avascular retina (csAR) associated with AD-FEVR was determined using the receiver operating characteristic (ROC) curves. MAIN OUTCOME MEASURES: The presence or absence of six peripheral vascular changes: csAR, V-shaped vascular notch, brushy vascular ends, vascular stain, loop vessels and/or anastomosis, and capillary telangiectasia were compared between the patients and the controls. RESULTS: The csAR was set at >12% of the length from the ora serrata to the optic disc. The AD-FEVR patients had more frequent retinal changes than the controls for the V-shaped vascular notch (69% vs 2%, P <0.001), brushy vascular ends (78% vs 3%, P <0.001), csAR (83% vs 22%, P <0.001), and vascular stain (70% vs 33%, P <0.001). Loop vessels and/or anastomosis of peripheral vessels were found significantly less frequently in the patients than in the controls (39% vs 73%, P <0.001). No significant difference was found for capillary telangiectasia between the two groups. The combination of the V-shaped vascular notches, brushy vascular ends, and csAR had a sensitivity of 82.8% and specificity of 98.3% with the highest ROC curve of 0.9. CONCLUSIONS: The combination of V-shaped vascular notch, brushy vascular ends, and csAR can be used as a biomarker for AD-FEVR patients who have pathogenic variants of the Norrin/ß-catenin genes. These findings will allow more accurate segregation analysis in FEVR families and allow better genetic counseling.

Developing an image-based grading scale for peripheral drusen to investigate associations of peripheral drusen type with age-related macular degeneration.

Age-related macular degeneration (AMD) is a leading cause of blindness. It is associated with peripheral drusen which has not been categorized. We investigated peripheral drusen to validate an image grading system and to understand possible associations between peripheral drusen and AMD. We collated clinical data, ultra-widefield (UWF) pseudocolor fundus images and Spectral-Domain Optical Coherence Tomography (SD-OCT) scans from consecutive retinal patients. SD-OCT scans were used to determine AMD stage. A masked retinal specialist recorded the types of peripheral drusen observed in UWF images. Eyes whose UWF images did not pass quality screening and those without AMD and peripheral drusen were excluded from the study. Statistical tests were utilized to determine the validity of our grading system and associations of peripheral drusen with AMD. A total of 481 eyes (283 subjects) were included in the study (mean age 73.1 ± 1.2years, 64.3% female). Interobserver and test-retest statistical analyses to evaluate the UWF image grading system resulted in Cohen's Kappa 0.649 (p < 0.001) and 0.922 (p < 0.001) respectively. A total of 284 (59.0%), 28 (5.8%), 15 (3.1%), 22 (4.6%), 4 (0.8%), 39 (8.1%), and 32 (6.7%) eyes had hard, soft, reticular, cuticular, atrophic, mixed drusen, and mixed drusen and atrophy respectively in at least one peripheral retinal quadrant. Hard peripheral drusen was significantly associated with the presence of AMD (p = 0.010). Peripheral drusen types were variably seen in retinal patients with and without AMD. We validated a peripheral drusen grading system and provided an image library to assist in the identification of peripheral drusen. Our study found an association between peripheral hard drusen and an AMD diagnosis but did not find a link between peripheral drusen and severity of AMD.

Refining hemodynamic correction in in vivo wide-field fluorescent imaging through linear regression analysis.

Accurate interpretation of in vivo wide-field fluorescent imaging (WFFI) data requires precise separation of raw fluorescence signals into neural and hemodynamic components. The classical Beer-Lambert law-based approach, which uses concurrent 530-nm illumination to estimate relative changes in cerebral blood volume (CBV), fails to account for the scattering and reflection of 530-nm photons from non-neuronal components leading to biased estimates of CBV changes and subsequent misrepresentation of neural activity. This study introduces a novel linear regression approach designed to overcome this limitation. This correction provides a more reliable representation of CBV changes and neural activity in fluorescence data. Our method is validated across multiple datasets, demonstrating its superiority over the classical approach.

Wide-Field Polarimetric Second-Harmonic Imaging for Rapid and Nondestructive Investigation of Laser-Induced Crystallization Phenomena.

The selective and controlled formation of nanocrystals in glass is emerging as a versatile method to achieve functional photonics, optoelectronics, and quantum devices, such as single-photon emitters. Here, we investigate the use of wide-field polarimetric second-harmonic (SH) microscopy as a method to rapidly and nondestructively examine nanoscale crystal arrangements in laser-processed glass. As a case study, we investigate tellurite glass, where the formation of a trigonal tellurium (t-Te) nanocrystalline phase after femtosecond laser exposure was recently demonstrated. Combined with theoretical models, we show that wide-field polarimetric SH microscopy offers comprehensive information on the nanocrystals' orientation, distribution, and chirality. With its high imaging throughput and spatial resolution, this method has the potential not only to significantly accelerate investigations on laser-induced glass crystallization processes but also to provide a valuable tool for in situ process monitoring.

Clinical and genetic features in autosomal recessive bestrophinopathy in Chinese cohort.

PURPOSE: To provide a genotype and phenotype characterization of the BEST1 mutation in Chinese patients with autosomal recessive bestrophinopathy (ARB) through multimodal imaging and next-generation sequencing (NGS). METHODS: Seventeen patients from 17 unrelated families of Chinese origin with ARB were included in a retrospective cohort study. Phenotypic characteristics, including anterior segment features, were assessed by multimodal imaging. Multigene panel testing, involving 586 ophthalmic disease-associated genes, and Sanger sequencing were performed to identify disease-causing variants. RESULTS: Among 17 ARB patients, the mean follow-up was 15.65 months and average onset age was 30.53 years (range: 9-68). Best corrected visual acuity ranged from light perception to 0.8. EOG recordings showed a typically decreased Arden ratio in 12 patients, and a normal or slightly decreased Arden ratio in two patients. Anterior features included shallow anterior chambers (16/17), ciliary pronation (16/17), iris bombe (13/17), iridoschisis (2/17), iris plateau (1/17), narrow angles (16/17) and reduced axial lengths (16/17). Sixteen patients had multiple bilateral small, round, yellow vitelliform deposits distributed throughout the posterior pole, surrounding the optic disc. Initial diagnoses included angle-closure glaucoma (four patients), Best disease (three patients), and central serous chorioretinopathy secondary to choroidal neovascularization (CNV) (one patient), with the remainder diagnosed with ARB. Fourteen patients underwent preventive laser peripheral iridotomy, four of whom also received combined trabeculectomy and iridotomy in both eyes for uncontrolled intraocular pressure. One patient received intravitreal conbercept for CNV. Overall, 15 distinct disease-causing variants of BEST1 were identified, with 14 (82.35%) patients having missense mutations. Common mutations included p. Arg255-256 and p. Ala195Val (both 23.68%), with the most frequent sites in exons 7 and 5. CONCLUSIONS: This study provides a comprehensive characterization of anterior segment and genetic features in ARB, with a wide array of morphological abnormalities. Findings are relevant for refining clinical practices and genetic counseling and advancing pathogenesis research.

Automated early detection of acute retinal necrosis from ultra-widefield color fundus photography using deep learning.

BACKGROUND: Acute retinal necrosis (ARN) is a relatively rare but highly damaging and potentially sight-threatening type of uveitis caused by infection with the human herpesvirus. Without timely diagnosis and appropriate treatment, ARN can lead to severe vision loss. We aimed to develop a deep learning framework to distinguish ARN from other types of intermediate, posterior, and panuveitis using ultra-widefield color fundus photography (UWFCFP). METHODS: We conducted a two-center retrospective discovery and validation study to develop and validate a deep learning model called DeepDrARN for automatic uveitis detection and differentiation of ARN from other uveitis types using 11,508 UWFCFPs from 1,112 participants. Model performance was evaluated with the area under the receiver operating characteristic curve (AUROC), the area under the precision and recall curves (AUPR), sensitivity and specificity, and compared with seven ophthalmologists. RESULTS: DeepDrARN for uveitis screening achieved an AUROC of 0.996 (95% CI: 0.994-0.999) in the internal validation cohort and demonstrated good generalizability with an AUROC of 0.973 (95% CI: 0.956-0.990) in the external validation cohort. DeepDrARN also demonstrated excellent predictive ability in distinguishing ARN from other types of uveitis with AUROCs of 0.960 (95% CI: 0.943-0.977) and 0.971 (95% CI: 0.956-0.986) in the internal and external validation cohorts. DeepDrARN was also tested in the differentiation of ARN, non-ARN uveitis (NAU) and normal subjects, with sensitivities of 88.9% and 78.7% and specificities of 93.8% and 89.1% in the internal and external validation cohorts, respectively. The performance of DeepDrARN is comparable to that of ophthalmologists and even exceeds the average accuracy of seven ophthalmologists, showing an improvement of 6.57% in uveitis screening and 11.14% in ARN identification. CONCLUSIONS: Our study demonstrates the feasibility of deep learning algorithms in enabling early detection, reducing treatment delays, and improving outcomes for ARN patients.

Excellent accuracy of trained neonatal nurses in the detection of referral-warranted retinopathy of prematurity within an established telemedicine screening programme.

AIM: To evaluate level of agreement of specialist trained retinopathy of prematurity (ROP) nurses compared with an experienced paediatric ophthalmologist in detection of referral-warranted ROP (RWROP) using wide-field digital retinal imaging. METHODS: This is a prospective, observational, blinded study of neonates in a level III neonatal intensive care unit, from July 2020 to November 2022. Image capture using wide-field digital retinal imaging followed by ROP grading and staging was completed by trained ROP nurses. This was then compared with findings by an experienced paediatric ophthalmologist. The primary outcome was presence of RWROP in either eye. RESULTS: One hundred and ninety-five neonates (55% male) with a total of 768 screening visits were included. At the initial screen, nurse and ophthalmologist agreed about presence of RWROP for 191 of 195 neonates (98%, kappa = 0.79, P < 0.0001), with 100% sensitivity for RWROP detection. Including all 768 screening episodes, agreement was 98% for RWROP. There was disagreement in 16 screenings (2%) for 11 (6%) neonates. Of the five screenings (0.7%) that the ophthalmologist thought were RWROP and the nurse did not, three were disagreements about whether the zone was posterior zone 2 or zone 1. CONCLUSIONS: We found excellent levels of agreement and add evidence that interpretations by specialist trained nurses could be safely integrated into a 'hybrid ROP screening system'.

Sex differences in choroidal vessels using novel wide-field choroidal en-face images from optical coherence tomography.

This study aims to develop a method to quantify choroidal vessels in normal eyes using wide-field optical coherence tomography (OCT) en-face images. The study included participants with normal eyes in whom wide-angle OCT images were acquired to generate planarized choroidal en-face and thickness map images. The images were segmented into central, midperipheral, and peripheral areas, and the midperipheral and peripheral areas were further segmented into supratemporal, infratemporal, supranasal, and infranasal sectors. The mean planarized choroidal-vessel density (p-CVD), planarized choroidal-vessel size (p-CVS), and choroidal thickness (CT) were calculated in each sector. Sex differences were analyzed using the Mann-Whitney U test. The study included 162 participants comprising 84 female (mean age, 43.5 years; axial length, 24.0 mm) and 78 male (mean age, 44.4 years; axial length, 24.2 mm) participants with no significant differences in demographics (P ≥ 0.107). Men had a higher mean p-CVD in all regions (P < 0.001). The mean p-CVS was greater in men in all regions except for the supratemporal sector (P < 0.001). No significant differences in sex in the mean CT were observed in all regions (P ≥ 0.106). The p-CVD and p-CVS in normal eyes differ between sexes. This finding may contribute to the understanding of the pathophysiology of choroidal diseases.

Quantitative Biomarkers of Diabetic Retinopathy Using Ultra-Widefield Fluorescein Angiography.

Introduction: Diabetic retinopathy (DR) is a leading cause of blindness. Retinal imaging is an important tool to monitor the progression of DR. While seven-standard retinal fields are the traditional method for evaluating DR, ultra-widefield (UWF) imaging allows for improved visualization of peripheral areas of nonperfusion (NP) and neovascularization (NV), which could be used as biomarkers to monitor and predict progression of DR. Methods: A retrospective, cross-sectional study was conducted on 651 eyes from 363 patients diagnosed with type 1 or type 2 diabetes who received UWF-FA over 10 years. Fluorescein Angiography (FA) images were segmented, and surface areas of NP and NV were analyzed using multivariate regression to determine if biomarkers of DR and DR severity are associated with increasing areas of NP and NV. Results: Each additional year with a diagnosis of DR was associated with a 10.75 mm2 increase in the total NP (95% CI, 1.94-19.56; P = 0.02) and 7.87 mm2 increase in NP far-periphery (95% CI, 1.62-14.13; P = 0.01). A one-unit change in severity as defined by the Early Treatment of Diabetic Retinopathy Study (ETDRS) classification was associated with a 25.75 mm2 increase in total NP (95% CI, 11.16-40.33; P = 0.001), a 13.15 mm2 increase in mid-periphery NP (95% CI, 6.93-19.38; P < 0.0001), and a 12.29 mm2 increase in far-periphery NP (95% CI, 3.62-20.97; P = 0.01). Discussion: Biomarkers identified through UWF imaging such as total and regional areas of NP can be used to monitor and predict the progression of DR. This may provide a quantitative method for prognostication in patients with DR.

The Usefulness of 55° Wide-Field Spectral-Domain Optical Coherence Tomography in Monitoring the Features of Peripheral Subretinal Fluid Remnants after Rhegmatogenous Retinal Detachment Surgery.

BACKGROUND: This study aimed to assess the effectiveness of 55° wide-field (WF) spectral-domain (SD) optical coherence tomography (OCT) for detecting peripheral subretinal fluid (SRF) after surgery for rhegmatogenous retinal detachment (RRD). METHODS: In this retrospective observational study, the retinal periphery was examined to evaluate the possible presence of persistent SRF after surgery. OCT scans were acquired in infrared mode to use any peripheral vessel as a landmark for better repeatability in monitoring fluid remnants. RESULTS: A total of 80 patients (10% with high myopia) were examined using 55° WF SD OCT after successful pars plana vitrectomy (83.8%) or scleral buckling (16.3%) for RRD. A total of 18 patients (22.5%), 16 of whom underwent pars plana vitrectomy and 2 who underwent scleral buckling, showed SRF at the OCT examination during the follow-up. Potential risk factors associated with SRF persistence were analyzed, revealing a significative association with young age (p = 0.009). After a follow-up period of 7.05 ± 2.44 months (ranging from 3 to 12 months), a complete resorption in all patients (100%) within 12 months was observed. Best-corrected visual acuity significantly improved in both groups over time. CONCLUSION: Using 55° WF SD-OCT successfully assessed the course of SRF reabsorption, offering a viable alternative for all those realities where technologies such as ultra-wide-field (UWF) OCT are not available.

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

PURPOSE: 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. METHODS: 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. RESULTS: 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. CONCLUSION: 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.

Silicone oil emulsification: A literature review and role of widefield imaging and ultra-widefield imaging with navigated central and peripheral optical coherence tomography technology.

Silicone oil (SO) emulsification is a significant concern in vitreoretinal surgery, leading to various complications. Despite the high prevalence of SO emulsification within the eye, there is currently no standardized method for its early detection. The recent introduction of widefield (WF) imaging and ultra-WF (UWF) imaging with navigated central and peripheral optical coherence tomography (OCT) techniques have shown promising results in providing high-resolution images of the peripheral vitreous, vitreoretinal interface, retina, and choroid. This enhanced visualization capability enables the early identification of emulsified SO droplets, facilitating a proactive therapeutic approach, and mitigating associated adverse events. This comprehensive literature review aims to provide an updated overview of the topic, focusing on the role of WFimaging and UWF imaging and navigated central and peripheral swept-source OCT (SS-OCT) in the early detection and management of SO emulsification. The review discusses the current understanding of SO emulsification, its associated complications, and the limitations of existing detection methods. In addition, it highlights the potential of WF and UWF imaging and peripheral OCT as advanced imaging modalities for improved visualization of SO emulsification. This review serves as a valuable resource for clinicians and researchers, providing insights into the latest advancements in the field of vitreoretinal surgery and the promising role of WF imaging and UWF imaging and navigated central and peripheral SS-OCT in the management of SO.

Peripheral retinal lesions in diabetic retinopathy on ultra-widefield imaging.

Peripheral retinal imaging plays a crucial role in the diagnosis, management, and prognosis of diabetic retinopathy (DR). Traditional fundus imaging techniques have limited coverage of the retina, resulting in missed peripheral lesions. The advent of ultra-widefield (UWF) imaging has revolutionized the assessment of the peripheral retina. UWF imaging modalities provide comprehensive visualization of the retina, enabling the detection of peripheral lesions without the need for mydriasis. Integration of UWF imaging with other modalities, including fluorescein angiography (FA), indocyanine green angiography, pseudocolor imaging, and fundus autofluorescence, further enhances our understanding of peripheral retinal lesions. UWF imaging has demonstrated improved detection of DR lesions and presumably more accurate management of DR compared to traditional fundus photography and dilated fundus examination. UWF-FA and UWF-optical coherence tomography angiography have emerged as valuable tools for assessing retinal and choroidal vascular abnormalities, nonperfusion areas, neovascularization, and microvascular abnormalities. The presence and increasing extent of predominantly peripheral lesions detected using UWF FA are associated with a higher risk of DR progression and proliferative DR. UWF imaging provides a comprehensive evaluation of DR severity, aiding in more accurate risk stratification and treatment decision-making. Overall, UWF imaging modalities have significantly advanced our understanding of peripheral retinal lesions in DR, facilitating early detection and targeted management for better visual outcomes.