Outer Folds Research Articles

Retinal detachments associated with choroidal colobomas

Abstract To summarize the characteristics of the retinal detachments (RDs) that are associated with choroidal colobomas that occur in pediatric and adult patients. A choroidal coloboma is a rare disorder that results from an incomplete closure of the embryonic optic fissure, and their size can range from small colobomas with isolated chorioretinal involvement to large colobomas affecting the iris, choroid, retina, and optic nerve. A RD is occasionally associated with choroidal colobomas, and histological studies of the area of the choroidal coloboma show an absence of normal choroidal tissue, retinal pigment epithelium (RPE), and retina. Near the margin of the coloboma, the inner retinal layer has a central continuation of the marginal intercalary membrane (ICM) within the coloboma. The outer layer folds back, becomes disorganized, and fuses with the RPE. The inner retina gradually thins and merges with the marginal ICM with a high incidence of tears of the ICM developing along the edge of the coloboma or toward the center. Because of the high association of the causative retinal breaks being located within the colobomatous area, vitrectomy, endolaser photocoagulation around the margin of coloboma, and long-term tamponade with silicone oil or gas are recommended treatments. In addition, the presence of the macula within the area of the laser photocoagulation should be considered. However, the recurrence rate is high and multiple surgeries are required to reattach the detached retina.

Metamorphopsia after surgery for rhegmatogenous retinal detachment.

Improvements in surgical techniques have led to 90% success in the surgical repair of rhegmatogenous retinal detachment (RRD). However, anatomical reattachment of the retina does not ensure complete recovery of visual function. The incidence of metamorphopsia remains the most common postoperative complaint, from 24% to 88.6%. Currently, the risk factors of metamorphopsia are categorized into macular involvement, retinal shift, outer retinal folds, subretinal fluid, secondary epiretinal membrane, outer retinal layer damage, and surgical approach. The associations of metamorphopsia with postoperative best-corrected visual acuity and postoperative vision-related quality of life were still controversial. The most popular methods for assessment of metamorphopsia remain the Amsler grid and M-Charts. Most treatments cannot progress beyond the management of negative visual sensations, through methods such as occlusion therapy and aniseikonia-correcting spectacles. The main treatment approach involves RRD prevention and the management of risk factors that can lead to postoperative metamorphopsia after RRD repair. Additional research concerning metamorphopsia treatment, further upgrades of auxiliary inspection methods, and more accurate microstructural assessments are needed to address this common complication.

In-Office Suprachoroidal Viscopexy for Acute Rhegmatogenous Retinal Detachment

In-office suprachoroidal viscopexy (SCVEXY) is a relatively new procedure for rhegmatogenous retinal detachment (RRD), but minimal information is available regarding outcomes and safety. To report outcomes with in-office SCVEXY for primary acute RRD. This retrospective case series was conducted at St Michael's Hospital in Toronto, Ontario, Canada from June 2023 to February 2024 among consecutive patients with primary acute RRDs who presented with retinal tears that were reachable with the current in-office SCVEXY technique in the temporal or nasal retina. Suprachoroidal injection of 0.6 mL of sodium hyaluronate, 2.3%, at the break location using a 30-gauge needle with a custom-made guard leaving 1 mm of the needle exposed. Laser retinopexy was applied around the break once reattachment was achieved. The primary outcome was primary anatomic reattachment rate with SCVEXY and recovery of function and anatomic integrity. Among 6 patients, 2 patients (33.3%) were female, and mean (SD) patient age was 52.5 (19.7) years. The final follow-up duration for each patient was 510, 420, 360, 360, 330, and 320 days, respectively. Baseline VAs were hand motions, counting fingers, 20/100, 20/100, 20/25, and hand motions for patients 1 through 6, respectively. A dome-shaped suprachoroidal buckle was present in all cases after the procedure. Five of 6 patients (83.3%) achieved anatomic reattachment with no retinal displacement or outer retinal folds, and these patients could resume normal activity immediately after the procedure with no restrictions. The mean (SD) logMAR VA at 3 months was +0.46 (0.34) (Snellen 20/57). The viscoelastic persisted in the suprachoroidal space as confirmed by multimodal imaging for 10, 14, 21, 13, 24, and 14 days, respectively, and the retina remained attached during the entire postoperative follow-up period. One patient's SCVEXY failed due to inadequate viscoelastic at the posterior edge of the retinal break, and this patient underwent a successful pneumatic retinopexy. One patient developed a localized choroidal effusion unrelated to the SCVEXY site following laser retinopexy that resolved in 1 week associated with topical prednisolone, 1%, 4 times daily and cyclopentolate, 1%, twice daily. In this case series, the outcomes of these 6 cases suggest that SCVEXY may offer durable retinal reattachment in RRD. However, randomized clinical trial data, larger sample sizes, and longer-term follow-up are necessary to assess the risk-benefit profile of SCVEXY compared with the standard of care.

Machine-learning models for shoulder rehabilitation exercises classification using a wearable system.

The objective of this study is to train and test machine-learning (ML) models to automatically classify shoulder rehabilitation exercises. The cohort included both healthy and patients with rotator-cuff (RC) tears. All participants performed six shoulder rehabilitation exercises, following guidelines developed by the American Society of Shoulder and Elbow Therapists. Each exercise was repeated six times, while wearing a wearable system equipped with three magneto-inertial sensors. Six supervised machine-learning models (k-Nearest Neighbours, Support Vector Machine, Decision Tree, Random Forest (RF), Logistic Regression and Adaptive Boosting) were trained for the classification. The algorithms' ability to accurately classify exercise activities was evaluated using the nested cross-validation method, with different combinations of outer and inner folds. A total of 19 healthy subjects and 17 patients with complete RC tears were enroled in the study. The highest classification performances were achieved by the RF classifier, with an accuracy of 89.91% and an F1-score of 89.89%. The results of this study highlight the feasibility and effectiveness of using wearable sensors and ML algorithms to accurately classify shoulder rehabilitation exercises. These findings suggest promising prospects for implementing the proposed wearable system in remote home-based monitoring scenarios. The ease of setup and modularity of the system reduce user burden enabling patient-driven sensor positioning. Level III.

Comparative Analysis of Snowmelt-Driven Streamflow Forecasting Using Machine Learning Techniques

The rapid advancement of machine learning techniques has led to their widespread application in various domains, including water resources. However, snowmelt modeling remains an area that has not been extensively explored. In this study, we propose a state-of-the-art (SOTA) deep learning sequential model, leveraging a Temporal Convolutional Network (TCN), for snowmelt forecasting of the Hindu Kush Himalayan (HKH) region. To evaluate the performance of our proposed model, we conducted a comparative analysis with other popular models, including Support Vector Regression (SVR), Long Short-Term Memory (LSTM), and Transformer models. Furthermore, nested cross-validation (CV) was used with five outer folds and three inner folds, and hyperparameter tuning was performed on the inner folds. To evaluate the performance of the model, the Mean Absolute Error (MAE), Root-Mean-Square Error (RMSE), R square (R2), Kling–Gupta Efficiency (KGE), and Nash–Sutcliffe Efficiency (NSE) were computed for each outer fold. The average metrics revealed that the TCN outperformed the other models, with an average MAE of 0.011, RMSE of 0.023, R2 of 0.991, KGE of 0.992, and NSE of 0.991 for one-day forecasts of streamflow. The findings of this study demonstrate the effectiveness of the proposed deep learning model as compared to traditional machine learning approaches for snowmelt-driven streamflow forecasting. Moreover, the superior performance of this TCN highlights its potential as a promising deep learning model for similar hydrological applications.

Influence of Vitreous Cortex Remnants on Normal Retinal Anatomy in Eyes with Primary Rhegmatogenous Retinal Detachment

To investigate the influence of vitreous cortex remnants (VCRs) removal on normal retinal anatomy in eyes with rhegmatogenous retinal detachment (RRD). Prospective cohort study. Patients with primary RRD operated with pars plana vitrectomy (PPV). Blue fundus autofluorescence and spectral-domain optical coherence tomography were obtained pre-operatively, and at 1 and 6 months after operation. Primary outcomes: rate of retinal displacement and outer retinal folds at 1 month after operation. continuity of the external limiting membrane (ELM) and ellipsoid zone (EZ), and the logarithm of the minimum angle of resolution best-corrected visual acuity (logMAR BCVA) at 6 months after operation. One hundred three eyes were included. Intra-operatively, peripheral (p)VCRs were found in 42 eyes (40.8%) and successfully peeled off from ≥ 2 quadrants in 37 eyes. Macular (m)VCRs were detected in 37 (35.9%) and successfully peeled off in 29 eyes. At the end of operation 44.7% and 55.3% of the eyes were tamponaded with 20% sulfur hexafluoride gas and silicone oil 1000 centistokes, respectively. The only variable significantly associated with displacement was the use of gas tamponade vs. silicone oil (p=0.001) whereas no significant association was found between retinal displacement and pVCRs (p=0.58) or number of quadrants from which pVCRs were peeled off (p=0.39). At 1 month post-operatively ORFs were globally detected in 24 eyes (23.3%). Regression analysis showed a direct correlation between ORFs and the intraoperative detection of mVCRs (p=0.02) and an indirect correlation between ORFs and mVCRs peeling (p= 0.004). Macular VCRs peeling did not influence the continuity of ELM and EZ at the 6- month follow-up (FU). Intraoperative absence of mVCRs (p=0.0016) and peeling of mVCRs (p=0.003) were associated with logMAR BCVA ≤ 0.3 at the 6-month FU. Peeling of pVCRs did not seem to influence the rate of retinal displacement while peeling of mVCRs was associated with a reduced risk of developing ORFs without detrimental effect on the continuity of ELM/EZ at 6 month FU. The patients without mVCRs detected intraoperatively or who underwent mVCRs peeling during operation, showed a significantly better VA at the 6-month FU.

Face-down positioning or posturing after pars plana vitrectomy for macula-involving rhegmatogenous retinal detachments.

Face-down positioning or posturing after pars plana vitrectomy for macula-involving rhegmatogenous retinal detachments.

Evaluating Outcome Prediction via Baseline, End-of-Treatment, and Delta Radiomics on PET-CT Images of Primary Mediastinal Large B-Cell Lymphoma.

Accurate outcome prediction is important for making informed clinical decisions in cancer treatment. In this study, we assessed the feasibility of using changes in radiomic features over time (Delta radiomics: absolute and relative) following chemotherapy, to predict relapse/progression and time to progression (TTP) of primary mediastinal large B-cell lymphoma (PMBCL) patients. Given the lack of standard staging PET scans until 2011, only 31 out of 103 PMBCL patients in our retrospective study had both pre-treatment and end-of-treatment (EoT) scans. Consequently, our radiomics analysis focused on these 31 patients who underwent [18F]FDG PET-CT scans before and after R-CHOP chemotherapy. Expert manual lesion segmentation was conducted on their scans for delta radiomics analysis, along with an additional 19 EoT scans, totaling 50 segmented scans for single time point analysis. Radiomics features (on PET and CT), along with maximum and mean standardized uptake values (SUVmax and SUVmean), total metabolic tumor volume (TMTV), tumor dissemination (Dmax), total lesion glycolysis (TLG), and the area under the curve of cumulative standardized uptake value-volume histogram (AUC-CSH) were calculated. We additionally applied longitudinal analysis using radial mean intensity (RIM) changes. For prediction of relapse/progression, we utilized the individual coefficient approximation for risk estimation (ICARE) and machine learning (ML) techniques (K-Nearest Neighbor (KNN), Linear Discriminant Analysis (LDA), and Random Forest (RF)) including sequential feature selection (SFS) following correlation analysis for feature selection. For TTP, ICARE and CoxNet approaches were utilized. In all models, we used nested cross-validation (CV) (with 10 outer folds and 5 repetitions, along with 5 inner folds and 20 repetitions) after balancing the dataset using Synthetic Minority Oversampling TEchnique (SMOTE). To predict relapse/progression using Delta radiomics between the baseline (staging) and EoT scans, the best performances in terms of accuracy and F1 score (F1 score is the harmonic mean of precision and recall, where precision is the ratio of true positives to the sum of true positives and false positives, and recall is the ratio of true positives to the sum of true positives and false negatives) were achieved with ICARE (accuracy = 0.81 ± 0.15, F1 = 0.77 ± 0.18), RF (accuracy = 0.89 ± 0.04, F1 = 0.87 ± 0.04), and LDA (accuracy = 0.89 ± 0.03, F1 = 0.89 ± 0.03), that are higher compared to the predictive power achieved by using only EoT radiomics features. For the second category of our analysis, TTP prediction, the best performer was CoxNet (LASSO feature selection) with c-index = 0.67 ± 0.06 when using baseline + Delta features (inclusion of both baseline and Delta features). The TTP results via Delta radiomics were comparable to the use of radiomics features extracted from EoT scans for TTP analysis (c-index = 0.68 ± 0.09) using CoxNet (with SFS). The performance of Deauville Score (DS) for TTP was c-index = 0.66 ± 0.09 for n = 50 and 0.67 ± 03 for n = 31 cases when using EoT scans with no significant differences compared to the radiomics signature from either EoT scans or baseline + Delta features (p-value> 0.05). This work demonstrates the potential of Delta radiomics and the importance of using EoT scans to predict progression and TTP from PMBCL [18F]FDG PET-CT scans.

Dosiomics and radiomics-based prediction of pneumonitis after radiotherapy and immune checkpoint inhibition: The relevance of fractionation

ObjectivesPost-therapy pneumonitis (PTP) is a relevant side effect of thoracic radiotherapy and immunotherapy with checkpoint inhibitors (ICI). The influence of the combination of both, including dose fractionation schemes on PTP development is still unclear. This study aims to improve the PTP risk estimation after radio(chemo)therapy (R(C)T) for lung cancer with and without ICI by investigation of the impact of dose fractionation on machine learning (ML)-based prediction. Materials and MethodsData from 100 patients who received fractionated R(C)T were collected. 39 patients received additional ICI therapy. Computed Tomography (CT), RT segmentation and dose data were extracted and physical doses were converted to 2-Gy equivalent doses (EQD2) to account for different fractionation schemes. Features were reduced using Pearson intercorrelation and the Boruta algorithm within 1000-fold bootstrapping. Six single (clinics, Dose Volume Histogram (DVH), ICI, chemotherapy, radiomics, dosiomics) and four combined models (radiomics + dosiomics, radiomics + DVH + Clinics, dosiomics + DVH + Clinics, radiomics + dosiomics + DVH + Clinics) were trained to predict PTP. Dose-based models were tested using physical dose and EQD2. Four ML-algorithms (random forest (rf), logistic elastic net regression, support vector machine, logitBoost) were trained and tested using 5-fold nested cross validation and Synthetic Minority Oversampling Technique (SMOTE) for resampling in R. Prediction was evaluated using the area under the receiver operating characteristic curve (AUC) on the test sets of the outer folds. ResultsThe combined model of all features using EQD2 surpassed all other models (AUC = 0.77, Confidence Interval CI 0.76–0.78). DVH, clinical data and ICI therapy had minor impact on PTP prediction with AUC values between 0.42 and 0.57. All EQD2-based models outperformed models based on physical dose. ConclusionsRadiomics + dosiomics based ML models combined with clinical and dosimetric models were found to be suited best for PTP prediction after R(C)T and could improve pre-treatment decision making. Different RT dose fractionation schemes should be considered for dose-based ML approaches.

Morphology of ctenostome bryozoans: 7. Hislopia, Echinella andTimwoodiellina.

Ctenostome bryozoans are a small group of gymnolaemates comprising less than 400 recent species. They are paraphyletic and ctenostome-grade ancestors gave rise to Cheilostomata, the most dominant and speciose taxon of Bryozoa in the present day. Investigations into ctenostomes are important for reconstructing character evolution among Gymnolaemata. As a continuation of studies on a morphological series of ctenostome bryozoans, we herein investigate six species of hislopiids, a small clade of threegenera occurring in freshwater habitats. The general morphology of all species is similar in having primarily uniserial chains of encrusting zooids, which are mostly oval to ellipsoid and have a flattened frontobasal axis. Hislopia prolixa and Echinella placoides often have more slender zooids with a higher frontobasal axis. Apertures of hislopiids are quadrangular, lined by a thickened cuticle. Apertural spines are present in various lengths in E. placoides, Hislopia lacustris and Hislopia corderoi. The remaining cuticle is rather thin except at lateral areas, close to the pore-plates which are prominent in hislopiids because of abundant special and limiting cells. All species except H. corderoi and Timwoodiellina natans have a prominent collar obstructing the vestibulum, whereas the latter two species instead have an 'external collar' as cuticular, outer folds projecting over the aperture. Hislopiid lophophores carry eight, or more commonly 12-18 tentacles. The digestive tract is distinguished by an often highly elongated esophagus and/or cardia, with the latter always having a prominent bulbous part in the form of a proventriculus-or gizzard in E. placoides. The caecum is extensive in all species. In Hislopia the intestine is characteristically two-chambered with a proximal and distal part before entering an anal tube of various length. The latter is present in all species except T. natans and terminates in mid-lophophoral area. Oocytes in E. placoides are large and macrolecithal indicating brooding and the production of lecithotrophic larvae. Hislopia species produce small, oligolecithal ones, which suggests zygote spawning and planktotrophy. In general, the morphology is similar among the different hislopiids with characters of the gut aiding in delineating the genera Echinella and Timwoodiellina.

The Value of Equivalent Dose Calculation for Dosiomics and Radiomics-Based Prediction of Pneumonitis after Thoracic Radiotherapy with Immune Checkpoint Inhibition.

Post-therapy pneumonitis (PTP) is a relevant side effect after thoracic radiotherapy (RT) and immunotherapy with checkpoint inhibitors (ICI). The impact of the combination of both is unclear. We aim to improve risk estimation by prediction of PTP with and without ICI therapy. To analyze the influence of different fractionation schemes, the value of voxel-wise 2 Gy equivalent dose (EQD2) is investigated. Clinical data from 100 patients who received fractionated RT (single dose ≤ 3Gy) RT were collected. 36 patients received additional ICI therapy. PTP of all grades were monitored. Planning Computed tomographies (CTs), segmentations and 3D dose data were extracted and converted to EQD2. Dosiomics and radiomics features were extracted using 1000-fold bootstrapping using Pearson intercorrelation and the Boruta algorithm for 5 single and 4 combined predictive models. Machine learning algorithms (random forest (rf), logistic elastic net regression, support vector machine, logitBoost) were trained and tested using a 5-fold nested cross validation approach and Synthetic Minority Oversampling Technique resampling in R. Analysis was performed using the area under the receiver operating characteristic curve (AUC) on the test sets of the outer folds. All investigated models predicted PTP better than random (AUC>.5) (Table 1). Dosiomics+Radiomics models based on EQD2 using rf classifier resulted in the highest predictive performance (AUC = .83 (95% Confidence Interval .83-.84)) and performed worse on physical dose data (AUC = .72 (.71-.73)). For single models, radiomics and dosiomics achieved the best prediction (AUC = .73 (.72-.74), AUC = .8 (.79-.81)) for physical dose and EQD2, respectively. Clinical factors and ICI therapy (AUC = .6 (.59-.62)) had minor impact on PTP prediction. Table 1: AUC and 95% confidence intervals (CI) for all investigated Machine Learning models for EQD2 and physical doses (D). Dosiomics+Radiomics machine learning models have strong capability of PTP prediction and could contribute to pre-treatment decision making. Fractionation schemes should be considered for dose-based prediction strategies. Additional ICI therapy has limited impact on PTP prediction.

Effectiveness of botanical insecticides on larval stage of red palm weevil Rhynchophorous ferrugineus and survival of entomopathogenic nematodes

Botanical oils are considered ecofriendly compounds with insecticidal characteristics. In this study, the effects of basil (Ocimum basilicum), camphor (Cinnamomum camphora), cinnamon (Cinnamomum verum), lemon (Citrus limon), clove (Syzygium aromaticum), ginger (Zingiber officinale), black pepper (Piper nigrum), and orange (Citrus sinensis var balady) oil extracts on the survival of four entomopathogenic nematode strains belonging to the Steinernema and Heterorhabditis genera, as well as their impacts on Rhynchophorus ferrugineus egg hatching and larvae, were assessed. The results for the camphor, lemon, black pepper, and orange oils were promising as 50 μL/mL of each resulted in 0%, 0%, 16%, and 0% hatchability for the R. ferrugineus eggs, respectively. Furthermore, the mortality of R. ferrugineus larvae was up to 95% with the similar concentrations and an exposure time of 48 h, for the other investigated oils. Various morphohistopathological alterations were found in the cuticle; outer cuticle folds swelling or shrinkage and subcuticular muscle degeneration, as well as midgut; fat globules in the epithelial lining with marked degeneration and/or necrosis, of the R. ferrugineus larvae when compared with those of controls replicates. Mortality percentage of infective juveniles (IJs) of Steinernema carpocapsae (S2) was significantly lower than Heterorhabditis marelatus (D1), Steinernema riobravae (Sr) and Steinernema carpocapsae (All) when using camphor oil compared to the other oils (50%). From the obtained observations on oils lethal effects, the target of developing integral biocontrol product formulated from combinations of essential oils and nematode with insecticidal properties against R. ferrugineus (not nematode survival) is possible; a sustainable and ecofriendly product for pest management.

In-Office Suprachoroidal Viscopexy for Rhegmatogenous Retinal Detachment Repair

In-office suprachoroidal viscopexy (SCVEXY) is a minimally invasive technique for rhegmatogenous retinal detachment (RRD) repair that can be performed with no incision, no tamponade agent, and no positioning requirements. This technique has the potential to be a step forward in the armamentarium to treat RRDs. To describe in-office SCVEXY for RRD repair. In this single-case report with short follow-up, a man in his 50s with pseudophakia and recent visual loss presented to St Michael's Hospital, Unity Health Toronto, with a fovea-off RRD in the right eye, extending from 6 to 10 o'clock, with no visible causative retinal break. Injection of suprachoroidal sodium hyaluronate, 1%, in the region of the suspected break, using a 30-gauge needle with a custom-made guard that exposed only 1 mm of the needle. Ability to perform in-office SCVEXY and to obtain a visible choroidal indentation. After the procedure, a dome-shaped choroidal convexity was present in the superior temporal area. The patient achieved macular reattachment in less than 24 hours with no postoperative abnormalities, such as outer retinal folds, residual subfoveal fluid, or retinal displacement, with rapid recovery of the outer retinal bands on optical coherence tomography. The optical coherence tomography scans acquired in the area of the choroidal convexity demonstrated the location of the viscoelastic material in the suprachoroidal space. Laser retinopexy was applied in the suspected region of the retinal tear, and the patient was able to resume normal activity immediately after the procedure with no restrictions. Suprachoroidal viscopexy is feasible as an in-office technique to create a temporary choroidal buckle for RRD repair. It is a minimally invasive procedure with the potential to maximize anatomical outcomes of integrity and postoperative functional outcomes in RRD because its mechanism of action does not require drainage of subretinal fluid or intraocular gas tamponade. Nevertheless, this was a single-case report with short follow-up, which limits the ability to determine the procedure's benefits, potential adverse events, failure rates, and best-case selection. Further work is required to refine the procedure and assess its efficacy and safety.

Systematic cortical thickness and curvature patterns in primates

Humans are known to have significant and consistent differences in thickness throughout the cortex, with thick outer gyral folds and thin inner sulcal folds. Our previous work has suggested a mechanical basis for this thickness pattern, with the forces generated during cortical folding leading to thick gyri and thin sulci, and shown that cortical thickness varies along a gyral–sulcal spectrum in humans. While other primate species are expected to exhibit similar patterns of cortical thickness, it is currently unknown how these patterns scale across different sizes, forms, and foldedness. Among primates, brains vary enormously from roughly the size of a grape to the size of a grapefruit, and from nearly smooth to dramatically folded; of these, human brains are the largest and most folded. These variations in size and form make comparative neuroanatomy a rich resource for investigating common trends that transcend differences between species. In this study, we examine 12 primate species in order to cover a wide range of sizes and forms, and investigate the scaling of their cortical thickness relative to the surface geometry. The 12 species were selected due to the public availability of either reconstructed surfaces and/or population templates. After obtaining or reconstructing 3D surfaces from publicly available neuroimaging data, we used our surface-based computational pipeline (https://github.com/mholla/curveball) to analyze patterns of cortical thickness and folding with respect to size (total surface area), geometry (i.e. curvature, shape, and sulcal depth), and foldedness (gyrification). In all 12 species, we found consistent cortical thickness variations along a gyral–sulcal spectrum, with convex shapes thicker than concave shapes and saddle shapes in between. Furthermore, we saw an increasing thickness difference between gyri and sulci as brain size increases. Our results suggest a systematic folding mechanism relating local cortical thickness to geometry. Finally, all of our reconstructed surfaces and morphometry data are available for future research in comparative neuroanatomy.

En Face OCT in Diagnosis of Persistent Subretinal Fluid and Outer Retinal Folds after Rhegmatogenous Retinal Detachment Repair

To evaluate the role of en face OCT as a diagnostic tool for the detection of persistent subretinal fluid (PSRF) and outer retinal folds (ORFs) after successful rhegmatogenous retinal detachment (RRD) repair. Observational post hoc analysis of 2 prospective surgical trials. All patients with gradable (signal strength ≥ 5 and no segmentation error) 6× 6-mm2 macular cube scans obtained using spectral-domain OCT (Carl Zeiss Meditec) between 1 and 2 months after surgery were included in this study. The scans were assessed for the presence or absence of PSRF or ORFs using en face OCT and cross-sectional B scans by 2 masked graders, with any disagreements adjudicated by a third senior masked grader. The sensitivity, specificity, and predictive accuracy (using area under the curve [AUC]) of en face OCT were compared with those of cross-sectional OCT, which is considered the gold standard. Two hundred twenty-three patients were included in this study. The Cohen kappa between the graders in the diagnosis of PSRF and ORFs using en face OCT was 0.84 and 0.86, respectively. The sensitivity of en face OCT was 100% (95% confidence interval [CI], 100%-100%) in the diagnosis of PSRF and 98.8% (95% CI, 96.5%-101.1%) in the diagnosis of ORFs. Similarly, the specificity of en face OCT was 98.7% (95% CI, 96.8%-100.5%) and 84.2% (95% CI, 78.1%-90.2%) in the diagnosis of PSRF and ORFs, respectively. The AUC was 0.99 for PSRF and 0.91 for ORFs. En face OCT has good sensitivity, specificity, and predictive accuracy (using AUC) in the diagnosis of PSRF and ORFs. En face OCT is an efficient screening tool for postoperative anatomic abnormalities, such as PSRF and ORFs, after RRD repair. The author(s) have no proprietary or commercial interest in any materials discussed in this article.

A paradigm shift in retinal detachment repair: The concept of integrity.

The management of rhegmatogenous retinal detachment has rapidly evolved over recent decades. A range of surgical techniques exist, all of which can achieve retinal reattachment in most cases. In recent years there have also been vast technical advances in retinal imaging that have introduced novel ways of visualizing and studying the retinal macro and microstructural anatomy following retinal detachment repair. Recent clinical trial data demonstrates that functional and patient-reported outcomes of retinal reattachment differ with surgical technique, accompanied by differences in anatomic biomarkers of retinal recovery or 'integrity'. We discuss recent insights into the physiology of retinal reattachment gleaned from multimodal imaging, which shed light on the pathophysiology of various post-operative anatomic abnormalities. The ideal scenario is to achieve retinal reattachment as soon as possible, without retinal displacement, outer retinal folds or discontinuity of the external limiting membrane, ellipsoid zone and interdigitation zone, with an intact foveal bulge. To this end, we present an in-depth contemporary account of current concepts and mechanisms involved during retinal reattachment surgery, supported by clinical data and mathematical modelling, awareness of which can help the vitreoretinal surgeon achieve better post-operative outcomes. In this review we substantiate the case for a paradigm shift in rhegmatogenous retinal detachment repair; beyond the emphasis on single-operation reattachment rates, and instead striving to maximize functional outcomes using minimally invasive techniques. This can only be achieved if vitreoretinal surgeons embrace all of the available techniques, with individualized selection of surgical approach and the resolute goal of optimizing the 'integrity' of retinal reattachment.

Clinical and imaging characteristics of outer retinal folds in eyes with retinitis.

To describe clinical and imaging characteristics of the outer retinal folds (ORF) in cases of retinitis, retinochoroiditis, and chorioretinitis. Retrospective review of retinitis cases with presence of ORFs either at presentation or during follow up. ORFs were seen adjacent to retinitis lesions in 16 eyes of 14 cases (retinitis post-febrile illness n = 10, toxoplasma retinochoroiditis n = 2, fungal chorioretinitis n = 2) either at presentation (n = 2) or during follow up (n = 14). Optical coherence tomography (OCT) appearance was outer retinal vertical stout lesions involving ellipsoid, external limiting membrane, and outer nuclear layer. All the cases had a presence of past or concurrent subretinal fluid and/or subretinal hyperreflective material when ORF was seen. ORF resolved with variable outer retinal atrophy over a mean period of 2.86 months. ORF is observed in cases of retinitis with subretinal fluid either at presentation or during resolution. It is not specific to any etiological disease. Differentiation of this sign from vertical outer retinal stripes in viral retinitis on OCT is important to avoid misinterpretation.

Form and function of the mantle edge in Protobranchia (Mollusca: Bivalvia)

We analyzed, by optical and transmission electron microscopy, the morphology and function of the mantle edge, including the formation of the periostracum, of ten species of protobranchs. Five species from the order Nuculida, four species from the order Nuculanida and one species from the order Solemyida were studied. A second outer fold, which seems to function as a template for the internal marginal crenulations of the valves, is present in the crenulated species of Nucula. The minute non-crenulated Ennucula aegeensis shows the glandular basal cells displaced toward the periostracal groove, resembling a minute additional fold between the outer and middle folds. Intense secretion of glycocalyx, together with active uptake of particles, have been observed in the inner epithelium of the middle mantle fold and the whole epithelium of the inner mantle fold in all the studied species. Contrary to the rest of the bivalves, all the protobranchs analyzed have two basal cells involved in the formation of the external nanometric pellicle of the periostracum, a character that would support the monophyly of protobranchs. A three-layered pattern is the general rule for the periostracum in protobranchs, like for other bivalves. The presence of pouches of translucent layer inside the tanned dark layer under periostracal folds is characteristic of the species with a folded periostracum; its function is unclear but could give flexibility to the periostracum. The non-nacreous internal shell layer and the presence of translucent pouches under periostracal folds in Sarepta speciosa resemble those found in nuculanids. However, the free periostracum is rather similar to those of N. hanleyi and E. aegeensis, with a continuous vesicular layer. All the latter supports the inclusion of Sarepta in the order Nuculanida but could indicate either a basal lineage or that the translucent vesicular layer is an adaptive trait.

A StAR‐like gene involved in carotenoid metabolism and inner shell color in the freshwater pearl mussel, Hyriopsis cumingii

AbstractCarotenoids play key roles in organism coloration and have been found to have an effect on shell color. Steroidogenic acute regulatory protein‐like (StAR‐like) is a key gene involved in the accumulation of carotenoids. In this study, the full‐length cDNA sequence of HcStAR‐like, containing 994 nucleotides with an open reading frame encoding 307 amino acid residues, was isolated from the freshwater pearl mussel, Hyriopsis cumingii. HcStAR‐like expression levels were significantly higher in all tissues examined in golden (G‐) mussels compared with white (W‐) and purple (P‐) mussels (p < .05). Moreover, although HcStAR‐like expression levels were higher in P‐mussels than W‐mussels, this difference was only significant in the hepatopancreas (p < .05). Our in situ hybridization assay indicated that StAR‐like was localized to the outer fold of the mantle and the joint of the outer and middle folds of the mantle. The dsRNA interference of HcStAR‐like expression in G‐mussels was effective with an interference rate of 79.89% (p < .05). The total carotenoid content (TCC) in the mantle of the RNAi group decreased by 48.63% (p < .05). Our findings suggested that HcStAR‐like was involved in the accumulation of carotenoids and inner shell pigmentation in H. cumingii.

Cortical thickness systematically varies with curvature and depth in healthy human brains.

Cortical thickness varies throughout the cortex in a systematic way. However, it is challenging to investigate the patterns of cortical thickness due to the intricate geometry of the cortex. The cortex has a folded nature both in radial and tangential directions which forms not only gyri and sulci but also tangential folds and intersections. In this article, cortical curvature and depth are used to characterize the spatial distribution of the cortical thickness with much higher resolution than conventional regional atlases. To do this, a computational pipeline was developed that is capable of calculating a variety of quantitative measures such as surface area, cortical thickness, curvature (mean curvature, Gaussian curvature, shape index, intrinsic curvature index, and folding index), and sulcal depth. By analyzing 501 neurotypical adult human subjects from the ABIDE‐I dataset, we show that cortex has a very organized structure and cortical thickness is strongly correlated with local shape. Our results indicate that cortical thickness consistently increases along the gyral–sulcal spectrum from concave to convex shape, encompassing the saddle shape along the way. Additionally, tangential folds influence cortical thickness in a similar way as gyral and sulcal folds; outer folds are consistently thicker than inner.