Fluid In Optical Coherence Tomography Research Articles

FNeXter: A Multi-Scale Feature Fusion Network Based on ConvNeXt and Transformer for Retinal OCT Fluid Segmentation.

The accurate segmentation and quantification of retinal fluid in Optical Coherence Tomography (OCT) images are crucial for the diagnosis and treatment of ophthalmic diseases such as age-related macular degeneration. However, the accurate segmentation of retinal fluid is challenging due to significant variations in the size, position, and shape of fluid, as well as their complex, curved boundaries. To address these challenges, we propose a novel multi-scale feature fusion attention network (FNeXter), based on ConvNeXt and Transformer, for OCT fluid segmentation. In FNeXter, we introduce a novel global multi-scale hybrid encoder module that integrates ConvNeXt, Transformer, and region-aware spatial attention. This module can capture long-range dependencies and non-local similarities while also focusing on local features. Moreover, this module possesses the spatial region-aware capabilities, enabling it to adaptively focus on the lesions regions. Additionally, we propose a novel self-adaptive multi-scale feature fusion attention module to enhance the skip connections between the encoder and the decoder. The inclusion of this module elevates the model's capacity to learn global features and multi-scale contextual information effectively. Finally, we conduct comprehensive experiments to evaluate the performance of the proposed FNeXter. Experimental results demonstrate that our proposed approach outperforms other state-of-the-art methods in the task of fluid segmentation.

Enhancing point annotations with superpixel and confident learning guided for improving semi-supervised OCT fluid segmentation

Automatic segmentation of fluid in Optical Coherence Tomography (OCT) images is beneficial for ophthalmologists to make an accurate diagnosis. Although semi-supervised OCT fluid segmentation networks enhance their performance by introducing additional unlabeled data, the performance enhancement is limited. To address this, we propose Superpixel and Confident Learning Guide Point Annotations Network (SCLGPA-Net) based on the teacher-student architecture, which can learn OCT fluid segmentation from limited fully-annotated data and abundant point-annotated data. Specifically, we use points to annotate fluid regions in unlabeled OCT images and the Superpixel-Guided Pseudo-Label Generation (SGPLG) module generates pseudo-labels and pixel-level label trust maps from the point annotations. The label trust maps provide an indication of the reliability of the pseudo-labels. Furthermore, we propose the Confident Learning Guided Label Refinement (CLGLR) module identifies error information in the pseudo-labels and leads to further refinement. Experiments on the RETOUCH dataset show that we are able to reduce the need for fully-annotated data by 94.22%, closing the gap with the best fully supervised baselines to a mean IoU of only 2%. Furthermore, we constructed a private 2D OCT fluid segmentation dataset for evaluation. Compared with other methods, comprehensive experimental results demonstrate that the proposed method can achieve excellent performance in OCT fluid segmentation.

Deep learning assisted fluid volume calculation for assessing anti-vascular endothelial growth factor effect in diabetic macular edema

ObjectiveTo develop an algorithm using deep learning methods to calculate the volume of intraretinal and subretinal fluid in optical coherence tomography (OCT) images for assessing diabetic macular edema (DME) patients’ condition changes. DesignCross-sectional study. ParticipantsTreatment-naive patients diagnosed with DME recruited from April 2020 to November 2021. MethodsThe deep learning network, which was built for autonomous segmentation utilizing an encoder-decoder network based on the U-Net architecture, was used to calculate the volume of intraretinal fluid (IRF) and subretinal fluid (SRF). The alterations of retinal vessel density and thickness, and the correlation between best-corrected visual acuity (BCVA) and OCT parameters were analyzed. Results2,955 OCT images of fourteen eyes from DME patients with IRF and SRF who received anti-vascular endothelial growth factor (VEGF) agents were obtained. The area under the curve (AUC) of the receiver operating characteristic (ROC) curve of the algorithm was 0.993 for IRF and 0.998 for SRF. The volumes of IRF and SRF were significantly decreased from 1.93 ± 0.58 /1.14 ± 0.25 mm3 (baseline) to 0.26 ± 0.13 /0.26 ± 0.18 mm3 (post-injection), respectively (p = 0.0170 for IRF, and p = 0.0004 for SRF). The Spearman correlation demonstrated that the reduction of IRF volume was negatively correlated with age (coefficient = −0.698, p = 0.006). ConclusionWe developed a deep learning assisted fluid volume calculation algorithm with high sensitivity and specificity for assessing the volume of IRF and SRF in DME patients. Key words: deep learning; diabetic macular edema; optical coherence tomography.

BASELINE SPECTRAL DOMAIN OPTICAL COHERENCE TOMOGRAPHIC RETINAL LAYER FEATURES IDENTIFIED BY ARTIFICIAL INTELLIGENCE PREDICT THE COURSE OF CENTRAL SEROUS CHORIORETINOPATHY.

To identify optical coherence tomography (OCT) features to predict the course of central serous chorioretinopathy (CSC) with an artificial intelligence-based program. Multicenter, observational study with a retrospective design. Treatment-naïve patients with acute CSC and chronic CSC were enrolled. Baseline OCTs were examined by an artificial intelligence-developed platform (Discovery OCT Fluid and Biomarker Detector, RetinAI AG, Switzerland). Through this platform, automated retinal layer thicknesses and volumes, including intaretinal and subretinal fluid, and pigment epithelium detachment were measured. Baseline OCT features were compared between acute CSC and chronic CSC patients. One hundred and sixty eyes of 144 patients with CSC were enrolled, of which 100 had chronic CSC and 60 acute CSC. Retinal layer analysis of baseline OCT scans showed that the inner nuclear layer, the outer nuclear layer, and the photoreceptor-retinal pigmented epithelium complex were significantly thicker at baseline in eyes with acute CSC in comparison with those with chronic CSC ( P < 0.001). Similarly, choriocapillaris and choroidal stroma and retinal thickness (RT) were thicker in acute CSC than chronic CSC eyes ( P = 0.001). Volume analysis revealed average greater subretinal fluid volumes in the acute CSC group in comparison with chronic CSC ( P = 0.041). Optical coherence tomography features may be helpful to predict the clinical course of CSC. The baseline presence of an increased thickness in the outer retinal layers, choriocapillaris and choroidal stroma, and subretinal fluid volume seems to be associated with acute course of the disease.

Multimodality imaging features of different properties in multifocal choroiditis

Objective To observe multimodality imaging features of different properties in multifocal choroiditis (MFC). Methods Twenty-eight patients (51 eyes) with MFC were enrolled in this study. There were 10 males and 18 females. The patients aged from 31 to 49 years, with the mean age of (41.5±0.8) years. There were 23 bilateral patients and 5 unilateral patients. All patients underwent best corrected visual acuity (BCVA), slit-lamp biomicroscopy, indirect ophthalmoscopy, fundus colorized photography, infrared fundus photography, fundus autofluorescence (FAF), fundus fluorescein angiography (FFA) and optical coherence tomography (OCT) examinations. The lesions were classified as active inflammatory lesion, inactive inflammatory lesion, active choroidal neovascularization (CNV) and inactive CNV. The multimodality imaging features of different properties in MFC was observed. Results In fundus colour photography, the boundaries of active inflammatory lesions were blurry, while inactive inflammatory lesions had relatively clear boundaries. Secondary active CNV showed mild uplift and surrounding retinal edema; Secondary active CNV lesions showed mild uplift, retinal edema around the lesion; Secondary non-active CNV had no retinal exudate edema lesions, but had lesions fibrosis and varying degrees of pigmentation. Infrared fundus examination revealed that both active and inactive inflammatory lesions showed a uniform punctate or sheet-like fluorescence. The fluorescence of CNV lesions was not uniform; there was a bright ring around the strong fluorescence. FAF found that active inflammatory lesions showed weak autofluorescence (AF), surrounded by a strong fluorescence ring; inactive inflammatory lesions showed AF loss. Secondary active CNV lesions showed strong AF with a bright ring along the edge, and obscured fluorescence for co-occurred hemorrhagic edema; secondary non-active CNV lesions were strong AF, surrounded by a weak AF ring. FFA revealed that active inflammatory lesions showed weak fluorescence in the early stage, and fluorescence gradually increased in the late stage with slight leakage. Inactive inflammatory lesions showed typical transmitted fluorescence. Fluorescein leakage secondary to active CNV was significant; lesions secondary to inactive CNV showed scar staining. In OCT, the active inflammatory lesions showed moderately weak reflex signals in the protruding lesions under the retinal pigment epithelium (RPE). The inactive inflammatory lesions showed penetrable RPE defects or choroidal scar, it also showed clear RPE uplift lesions with a strong reflection signal. Secondary active CNV showed subretinal fluid retention; secondary non-active CNV showed RPE defects and choroidal scarring. Conclusions Active inflammatory lesions in MFC have blurred boundary, retinal edema and fluorescein leakage in FFA; inactive inflammatory lesions have clear boundary and typical transmitted fluorescence in FFA, and no retinal edema. Secondary active CNV showed subretinal fluid in OCT; and secondary non-active CNV showed RPE defects and choroidal scarring. Key words: Choroiditis/diagnosis; Fluorescein angiography; Tomography, optical coherence

Supervised learning and dimension reduction techniques for quantification of retinal fluid in optical coherence tomography images.

PurposeThe purpose of the present study is to develop fast automated quantification of retinal fluid in optical coherence tomography (OCT) image sets.MethodsWe developed an image analysis pipeline tailored towards OCT images that consists of five steps for binary retinal fluid segmentation. The method is based on feature extraction, pre-segmention, dimension reduction procedures, and supervised learning tools.ResultsFluid identification using our pipeline was tested on two separate patient groups: one associated to neovascular age-related macular degeneration, the other showing diabetic macular edema. For training and evaluation purposes, retinal fluid was annotated manually in each cross-section by human expert graders of the Vienna Reading Center. Compared with the manual annotations, our pipeline yields good quantification, visually and in numbers.ConclusionsBy demonstrating good automated retinal fluid quantification, our pipeline appears useful to expert graders within their current grading processes. Owing to dimension reduction, the actual learning part is fast and requires only few training samples. Hence, it is well-suited for integration into actual manufacturer's devices, further improving segmentation by its use in daily clinical life.

[Half-Dose Verteporfin Photodynamic Therapy (hdPDT) in the Treatment of Central Serous Chorioretinopathy].

To estimate the efficacy and safety profile of half-dose photodynamic therapy (hdPDT) for treating central serous chorioretinopathy (CSC). An interventional, retrospective case series of patients with CSC (symptoms ≧ 3 months) receiving half-dose PDT (3 mg/m2 verteporfin). The ophthalmic examination at baseline and at 8 and 16 weeks after treatment included slit-lamp biomicroscopy, indirect ophthalmoscopy, measurement of intraocular pressure (IOP), ETDRS best-corrected visual acuity (BCVA), Amsler grid screening and contrast visual acuity (CVA). Fluorescein angiography (FA), autofluorescence (FAF) and optical coherence tomography (OCT) were measured at each visit. Central macular thickness (CMT) was measured automatically. 12 eyes of 12 patients (10 male and 2 female patients; mean age 46.6 ± 7.91 years) were included in this study. Anatomical resolution was obtained in 10 eyes (83.4 %) at week 16, but 2 eyes (16.6 %) exhibited persistent SRD throughout the follow-up period. Baseline CMT decreased from initially 330.1 µm ± 131.3 to 205.6 µm ± 97.6 (p = 0.034) at week 8 and to 220.3 µm ± 120.1 (p = 0.05) at week 16. Visual acuity (number of total letters read) significantly improved from initially 82.8 ± 11.5 to 86.8 ± 13.9 at week 8 and 91.3 ± 13.8 at week 16 (p = 0.012). Contrast visual acuity (calculated decimal visual acuity) significantly improved from initially 0.14 ± 0.09 to 0.38 ± 0.28 (p = 0.002) at week 16. After therapy, no significant changes in RPE could be detected with FAF and no ocular adverse events were observed. PDT with half-dose verteporfin resulted in reduced leakage in FA, enhanced visual acuity and resolution of subretinal fluid in OCT in patients with CSC, with no detected side effects of treatment.

INTERLEUKIN 8 PROMOTER POLYMORPHISM PREDICTS THE INITIAL RESPONSE TO BEVACIZUMAB TREATMENT FOR EXUDATIVE AGE-RELATED MACULAR DEGENERATION

To study the association of single-nucleotide polymorphisms of interleukin 8, vascular endothelial growth factor, erythropoietin, complement factor H, complement component C3, and LOC387715 genes with the response to bevacizumab treatment in exudative age-related macular degeneration. Clinical records, smoking history, optical coherence tomography, and angiographies of 96 bevacizumab-treated exudative age-related macular degeneration patients were analyzed retrospectively. Blood DNA was collected. Based on the disappearance of intra- or subretinal fluid in optical coherence tomography, patients were graded as responders, partial responders, or nonresponders after 3 initial treatment visits and a median time of 3.5 months. Interleukin 8 promoter polymorphism -251A/T was significantly associated with persisting fluid in optical coherence tomography. The A allele was more frequent in nonresponders than in responders (P = 0.033). In multivariate modeling, the AA genotype of -251A/T (P = 0.043) and occult (P = 0.042) or predominantly classic (P = 0.040) lesions predicted poorer outcome. Visual acuity change was better in responders than in nonresponders (P = 0.006). Baseline lesion size (P = 0.006) and retinal cysts after the treatment (P < 0.001) correlated with less visual acuity gain. The A allele and the homozygous AA genotype of interleukin 8 -251A/T were associated with anatomical nonresponse to bevacizumab treatment.

Interleukin‐8 promoter polymorphism is associated with the initial repose to bevacizumab in AMD treatment

AbstractPurpose To study the association of potential key single‐nucleotide polymorphisms with the short‐term anatomic response to bevacizumab treatment in exudative age‐related macular degeneration (AMD).Methods Clinical data of 96 bevacizumab‐treated exudative age‐related macular degeneration patients were analyzed retrospectively. Blood DNA was collected. Based on the disappearance of intra‐ or subretinal fluid in optical coherence tomography, patients were graded as responders, partial responders, or nonresponders after 3 initial treatment visits and a median time of 3.5 months. Representative single‐nucleotide polymorphisms of interleukin 8, vascular endothelial growth factor, erythropoietin, complement factor H, complement component C3, and LOC387715 genes were analysed.Results Interleukin 8 promoter polymorphism −251A/T,conferring a more acitve interleuking‐8 system, was significantly associated with persisting fluid in optical coherence tomography. The A allele was more frequent in nonresponders than in responders (P = 0.033). In multivariate modeling, the AA genotype of −251A/T (P = 0.043) and occult (P = 0.042) or predominantly classic (P = 0.040) lesions predicted a poorer outcome.Conclusion The interleukin ‐8 pathway may modulate the early anatomic response to anti‐VEGF treatment in AMD. A possible activation of interleukin ‐8 production in patients may represent a compensatory mechanism to chronic blockade of VEGF signalling in AMD lesions

Automated Segmentation of Intraretinal Cystoid Fluid in Optical Coherence Tomography

Cystoid macular edema (CME) is observed in a variety of ocular disorders and is strongly associated with vision loss. Optical coherence tomography (OCT) provides excellent visualization of cystoid fluid, and can assist clinicians in monitoring the progression of CME. Quantitative tools for assessing CME may lead to better metrics for choosing treatment protocols. To address this need, this paper presents a fully automated retinal cyst segmentation technique for OCT image stacks acquired from a commercial scanner. The proposed method includes a computationally fast bilateral filter for speckle denoising while maintaining CME boundaries. The proposed technique was evaluated in images from 16 patients with vitreoretinal disease and three controls. The average sensitivity and specificity for the classification of cystoid regions in CME patients were found to be 91% and 96%, respectively, and the retinal volume occupied by cystoid fluid obtained by the algorithm was found to be accurate within a mean and median volume fraction of 1.9% and 0.8%, respectively.

Automated Segmentation of Intraretinal Cystoid Fluid in Optical Coherence Tomography

Automated Segmentation of Intraretinal Cystoid Fluid in Optical Coherence Tomography

Retinal pigment epithelial tears following ranibizumab therapy for fibrovascular retinal pigment epithelial detachment due to occult age-related macular degeneration

SummaryBackgroundThe aim of this paper is to report the incidence of retinal pigment epithelial (RPE) tears in patients treated with ranibizumab for subfoveal fibrovascular retinal pigment epithelial detachment (FVPED) due to occult age-related macular degeneration (AMD).Material/MethodsThirty patients were treated according to the following schedule: saturation phase, further treatment was based on activity of the degeneration process. Visual acuity (VA), optical coherence tomography (OCT) and fluorescein angiography (FA) parameters were evaluated and compared.ResultsPatients had a mean improvement of +4.7±8.1 letters at month 12. The mean number of needed injections was 6.8±1.8 (range, 3 to 9). RPE tears in fovea occurred in 8 cases (27% of all patients). Analysis of variance revealed significant upper mean values of ETDRS letters for the subgroup without RPE tears. Mean values of PED height were significant upper for RPE tears without baseline. Statistical analysis revealed that in the subgroup without RPE tears mean values of VA significantly differed in succeeding periods compare to baseline (P<0.001). Visual improvement or stabilization was observed in 90.9% of patients without RPE tears (significant improvement of 15 or more letters in 22.7%–5/22) and in 87.5% of patients with RPE tears (significant improvement was not observed). Baseline leakage parameters, lesion and leakage parameters at month 12 were significantly higher in patients with RPE tears. The chi-square test revealed statistically significant associations between RPE tears and subretinal fluid in OCT (P<0.05) at month 12.ConclusionsIn eyes with FVPED and RPE tears treated with ranibizumab, stabilization of visual acuity without significant improvement is predictable. One of the risk factors common to RPE tears may be baseline leakage parameters and pretreatment distorted RPE contour in OCT. During ranibizumab therapy in eyes with RPE tears, upper parameters of FVPED height may occur without significant differences in fovea and macula volume compare to eyes without RPE tears.

Contrast sensitivity after intravitreal antivascular endothelial growth factor therapy for myopic choroidal neovascularization

To evaluate contrast sensitivity (CS) using Pelli-Robson charts after intravitreal ranibizumab (IVR) (Lucentis, Novartis, Basel, Switzerland) or bevacizumab (IVB) (Avastin, Genentech, South San Francisco, California, USA) in eyes with myopic choroidal neovascularization (mCNV). A retrospective review was performed of 17 consecutive patients treated with IVR (n = 10; 0.5 mg) or IVB (n = 7; 1.25 mg) for mCNV from July, 2006 with follow-ups through September, 2009. Re-treatment was performed at monthly or longer intervals if there was fluorescein leakage in fluorescein angiogram (FAG) and or apparent subretinal fluid in optical coherence tomography (OCT) persisted. CS improved by a mean of one letter at 1 month (n = 17; p = 0.32), four letters at 3 months (n = 17; p = 0.02), four letters at 6 months (n = 15; p = 0.01), five letters at 9 months (n = 14; p = 0.04) and six letters at 12 months (n = 13; p = 0.03). The mean number of IVR/IVB was 1.6/1.6, 2.6/2.3, 3.1/3.2, 4.1/4.2 and 4.5/4.6 at 1 month, 3 months, 6 months, 9 months, and 12 months, respectively. Improvements in Pelli-Robson CS scores were observed during the first year after IVR/IVB in eyes with mCNV.

Optical Coherence Tomography in Neovascular Age-Related Macular Degeneration Compared to Fluorescein Angiography and Visual Acuity

To assess the sensitivity and specificity of optical coherence tomography (OCT) for monitoring patients with choroidal neovascularization (CNV) after photodynamic therapy (PDT) in comparison to fluorescein angiography (FA). Prospective study of 14 patients with CNV secondary to age-related macular degeneration receiving PDT. Best-corrected visual acuity (BCVA), fluorescein angiography, and OCT (Zeiss Stratus OCT3) were performed before and at 2, 6, 12, and 24 weeks after treatment. FA images were assessed for leakage and presence of subretinal or intraretinal fluid was assessed on OCT images. Retinal thickness was measured automatically. OCT sensitivity and specificity levels for detecting leaking CNV were calculated. Retinal thickness was correlated with visual acuity. Mean follow-up time was 14.1 weeks. Sixty-one OCT/FA examinations were analyzed. Thirty-one examinations presented leakage (51%). OCT showed intraretinal fluid in 46 (75%) and subretinal fluid in 30 cases (49%). In 49 cases (80%), either intraretinal or subretinal fluid was present. Sensitivity for detecting intraretinal fluid in OCT was 90% (specificity 40%) and 71% (specificity 73%) for subretinal fluid. Combined sensitivity for intraretinal or subretinal fluid was 97% (specificity 37%). Increased central foveal thickness correlated with decreased BCVA. Correlations were significant (p<0.05). OCT showed good sensitivity in detecting active CNV. Specificity was only moderate. Central foveal thickness correlated negatively with visual acuity. Owing to different aspects of active CNV shown by FA and OCT, OCT should be combined with other examinations, and may not substitute FA for indication/reindication of PDT but can be a valuable addition in difficult cases.

Intravitreal bevacizumab therapy for neovascular age-related macular degeneration associated with poor initial visual acuity

Aim:The aim of the study was to assess the efficacy of intravitreal bevacizumab injections for eyes with neovascular age-related macular degeneration (NVAMD) and poor initial visual acuity (VA).Methods:A retrospective study...

Intravitreal Bevacizumab for Choroidal Neovascularization Attributable to Pathological Myopia: One-Year Results

To assess the potential effect of intravitreal bevacizumab (IVB) (Avastin) on retinal function and anatomic recovery in eyes with choroidal neovascularization attributable to pathological myopia (mCNV). Retrospective case series. setting: Institutional. patient population: Sixty-three eyes of 63 patients were treated with IVB for mCNV. intervention procedure: 1 mg of bevacizumab was injected into the vitreous via the pars plana. IVB was repeated after two to three months if there was fluorescein leakage in fluorescein angiogram (FA), apparent subretinal fluid in optical coherence tomography (OCT) persisted, or both. main outcome measurement: Best-corrected visual acuity (BCVA) and CNV size measured on FA. IVB was performed one to six times during the first 12 months (mean, 2.4 +/- 1.4 times). The size of the mCNV decreased and the BCVA improved significantly (P < .01 for both comparisons). The BCVA improved more than three lines in 25 eyes (40%), worsened more than three lines in three eyes (5%), and was unchanged in 35 (56%) eyes 12 months after. Fluorescein leakage from the mCNV ceased in 30 eyes (48%), diminished in 28 (44%), and was unchanged in five (8%) eyes. Stepwise analysis showed that the number of IVB (P < .01), macular atrophy associated with mCNV (P < .05), and myopic atrophy (P < .05) were significant predictive factors for BCVA at 12 months. Although the current study lacked a control group, IVB seems to be an effective treatment for mCNV after a long-term. The absence of chorioretinal atrophy and that of recurrence and persistency of mCNV are positive predictive factors.

Indocyanine green-mediated photothrombosis as a new technique of treatment for persistent central serous chorioretinopathy

Purpose. To evaluate the potential benefit and complications of indocyanine green-mediated photothrombosis (IMP) in the management of patients with persistent central serous chorioretinopathy (CSC). Methods. Interventional noncomparative case series. Eleven patients with CSC presenting with persistent subretinal fluid in optical coherence tomography (OCT) four months after presentation and decrease in visual acuity (VA) were submitted to a single IMP session with 2 mg/kg body weight ICG and application of 5.6 W/cm 2 light at 810 nm. A continuous follow-up was provided with best-corrected ETDRS VA assessment, and angiographic and OCT documentation 72 hours before and at 2 days, 1 and 2 weeks, 1, 3, 6, and 12 months after treatment. Results. Pretreatment VA levels ranged from 20/32 - 1 to 20/100 (mean, 20/63 + 2 [logMAR equivalent, 0.460 ±0.155]); post treatment levels ranged from 20/25 - 2 to 20/20 (mean, 20/20 - 2 [logMAR equivalent, 0.038 ± 0.048]). Ten out of eleven patients presented with VA levels of =20/25 2 weeks after treatment; the mean logMAR VA change of 0.345 at that time was statistically significant (p < 0.05, Friedman test). OCT disclosed resolution of persistent subretinal fluid in all eyes. No recurrence was observed after 12 months of follow-up. Complications included transient retinal whitening in two patients, and associated occlusion of retinal capillaries in one. Conclusions. Photothrombosis using low-intensity 810 nm light to direct laser energy continuously at the active leakage sites after intravenous ICG infusion induced rapid VA recovery in patients with persistent CSC; accordingly, restoration of the macular architecture was evidenced on OCT, and no recurrence was noted 12 months after IMP.