miR-29b-3p Affects the Hypertrophy of Ligamentum Flavum in Lumbar Spinal Stenosis and its Mechanism.

To explore the effect of miR-29b-3p on fibrosis and hypertrophy of ligamentum flavum (LF) in lumbar spinal stenosis (LSS) and its underlying mechanism. Patients with LSS and lumbar disc herniation (LDH) (control) undergoing posterior lumbar laminectomy were included in this study. Human LF samples were obtained for LF cell isolation, RNA, and protein extraction. Histomorphological analysis of LF was performed using hematoxylin-eosin (HE) staining. After isolation, culture, and transfection of primary LF cells, different transfection groups were constructed: NC-mimic, miR-29b-3p-mimic, NC-inhibitor, and miR-29b-3p-inhibitor. Quantitative real time polymerase chain reaction (qRT-PCR) was performed to detect the expression of miR-29b-3p in LF and LF cells. Western blot analysis detected the protein expressions of P16 and CyclinD1. ELISA detected the protein expressions of TGF-ß1, Smad2, Smad3, TLR4, Type I collagen, and Type III collagen. Finally, LF cell viability was detected using the Cell Counting Kit-8 (CCK8) assay. The thickness of LF was significantly thicker in the LSS group compared to the LDH group (p < 0.05), accompanied by a higher calcification degree, more fibroblasts, and a larger area of collagen fiber proliferation. miR-29b-3p expression was significantly lower in LSS-derived LF tissues and cells than in LDH-derived tissues and cells (both p < 0.05). Compared to the NC-mimic group, the miR-29b-3p-mimic group exhibited significantly higher miR-29b-3p expression, decreased protein expressions of Type I collagen, Type III collagen, TGF-ß1, Smad2, Smad3, TLR4, P16, and CyclinD1, and inhibited LF cell proliferation (all p < 0.05). As expected, the miR-29b-3p-inhibitor group displayed contrasting expression patterns (all p < 0.05). Compared to the phosphate buffer saline (PBS) group, the Trimethylamine-N-Oxide (TMAO) group showed significantly increased expressions of TGF-ß1, Smad2, Smad3, TLR4, Type I collagen, Type III collagen, P16, and CyclinD1, as well as enhanced LF cell proliferation (all p < 0.05). However, there was no significant difference between the TMAO group and the Ang II group (all p > 0.05). Upregulation of miR-29b-3p expression may play a role in improving LF fibrosis and hypertrophy in LSS by inhibiting P16 expression and suppressing the activation of the TGF-ß/Smad signaling pathway. This finding offers new insights into future gene modification therapy for this patient population.

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

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

Characteristics of paraspinal muscle degeneration in patients with adult degenerative scoliosis.

INTRODUCTION: Adult degenerative scoliosis (ADS) is a 3D deformity that greatly affects the quality of life of patients and is closely related to the quality of paraspinal muscles (PSMs), but the specific degenerative characteristics have not been described. METHODS: This study included ADS patients who were first diagnosed in our hospital from 2018 to 2022. Muscle volume (MV) and fat infiltration (FI) of PSM were measured by 3D reconstruction, and spinal parameters were assessed by X-ray. The values of convex side (CV) and concave side (CC) were compared. RESULTS: Fifty patients were enrolled with a mean age of 64.1 ± 5.8 years old. There were significant differences in MV, FI, and Cobb angle between male and female groups. The MV of MF and PS on the CC was significantly larger than that on the CV. In the apex and the segments above the apex, the FI of the MF on the CC is greater than the CV, and in the CV of the segment below the apex, the FI of the MF is greater than the CC. Besides, there was a significant positive correlation between the FI and Cobb angle in the MF of the CC-CV. CONCLUSION: There were significant differences in the MV and FI of PSM on both sides of the spine in ADS patients. It was determined that the PSM of ADS showed different degrees of degeneration in different levels of the lumbar spine and were positively correlated with Cobb angle.

COMPARISON OF INTERNAL LIMITING MEMBRANE PEELING WITH THE INVERTED INTERNAL LIMITING MEMBRANE FLAP TECHNIQUE FOR RHEGMATOGENOUS RETINAL DETACHMENT COEXISTING WITH MACULAR HOLE.

PURPOSE: To evaluate the anatomical and functional outcomes of internal limiting membrane (ILM) peeling and the inverted ILM flap technique for rhegmatogenous retinal detachment coexisting with macular hole. METHODS: This retrospective study evaluated the medical records of 79 eyes with concurrent rhegmatogenous retinal detachment and macular hole received vitrectomy and silicone oil tamponade, with ILM peeling on 56 eyes and the inverted ILM flap technique on 23 eyes. RESULTS: The Type 1 closure rate was greater in the inverted ILM flap group than the ILM peeling group (82.6% vs. 55.4%, P = 0.038). Lines of improvement were 7.8 ± 5.3 in the ILM peeling group and 8.9 ± 5.6 in the inverted ILM flap group. Postoperative epiretinal membrane and retinal reattachment rates were similar in two surgical groups (16.1% vs. 21.7%, P = 0.535 and 94.6% vs. 95.7%, P = 0.999, respectively). Type 1 closure was significantly correlated with the inverted ILM flap technique (OR = 5.568, P = 0.023). The inverted ILM flap technique showed no significant association with the final logarithm of the minimum angle of resolution best-corrected visual acuity in multivariate model analysis. CONCLUSION: The inverted ILM flap technique was more effective in restoring the macular structure in patients with rhegmatogenous retinal detachment and coexisting macular hole, but the functional outcomes of the two strategies were comparable.

Association of UCP1 and UCP2 variants with diabetic retinopathy susceptibility in type-2 diabetes mellitus patients: a meta-analysis.

BACKGROUND: Genetic association of uncoupling proteins (UCPs) variants with the susceptibility of diabetic retinopathy (DR) in diabetes mellitus (DM) patients has been reported but with controversy. Here we aimed to conduct a meta-analysis to confirm the association of different UCPs variants with DR. METHODS: Three databases (Medline Ovid, Embase Ovid and CENTRAL) were applied in the literature search. Five genetic models, including allelic, homozygous, heterozygous, dominant and recessive models, were evaluated. Odds ratios (OR) were estimated under the random or fixed-effects models. Subgroup analyses, publication bias and sensitivity analyses were also conducted. RESULTS: Eleven studies on 2 UCPs variants (UCP1 rs1800592 and UCP2 rs659366) were included. Our meta-analysis showed that UCP1 rs1800592 was not associated with DR in type-2 DM patients, and UCP2 rs659366 also showed no association with DR. In the subgroup analyses on the stage of DR, allele G of UCP1 rs1800592 significantly increased the susceptibility of proliferative diabetic retinopathy (PDR) in type-2 DM patients in the allelic (OR = 1.26, P = 0.03) and homozygous models (OR = 1.60, P = 0.04). Subgroup analysis on ethnicity did not found any significant association of rs1800592 and rs659366 with DR. CONCLUSION: Our meta-analysis confirmed the association of UCP1 rs1800592 variant with PDR in patients with type-2 DM, suggesting its potential as a genetic marker for PDR prediction in population screening.

The correlation between imaging expression of P16 and S100 in hypertrophic ligamentum flavum.

BACKGROUND: Lumbar spinal stenosis (LSS) is a common degenerative disease, which can lead to neurological dysfunction and requires surgical treatment. In the previous study, we used H&E staining and immunohistochemistry to qualitatively analyze the expression of S100 and P16 in the pathological process of ligamentum flavum (LF) hypertrophy in patients with LSS. To further explore the relationship between P16, S100 and LF hypertrophy in patients with LSS, we quantitatively detected S100 and P16 and their expressed products based on molecular biology techniques, and analyzed their imaging correlation. METHODS: Before posterior lumbar surgery, LF thickness was measured by Magnetic Resonance Imaging (MRI). Through the operation, we obtained the specimens of LF from 120 patients, all of whom were L4/5 LF. They were designated: simple lumbar disc herniation (LDH), single-segment spinal stenosis (SLSS), and double-segment LSS (DLSS). The detection of each side of LF was assessed. S100 and P16 and their expression products were detected by western blot and quantitative polymerase chain reaction (qPCR). RESULTS: The dorsal mRNA expression of P16 in DLSS group was significantly higher than that in SLSS group. On the dorsal and dural side of LF, the expression of P16 mRNA and proteins in the LDH group was significantly lower than that in SLSS and DLSS groups. We found a correlation between the thickness of LF and the expression of P16. However, there was no significant difference in the expression of S100 mRNA and S100 protein on both sides of the ligament and among the three groups, and no significant correlation between the expression of S100 and the thickness of LF. CONCLUSIONS: P16 is involved in the process of LF hypertrophy in patients with LSS, and the imaging thickness of LF is related to the expression of P16. No obvious evidence proves that S100 may be related to the hypertrophy of LF in patients with LSS.

Regional choroidal thickness estimation from color fundus images based on convolutional neural networks.

Purpose: This study aims to estimate the regional choroidal thickness from color fundus images from convolutional neural networks in different network structures and task learning models. Method: 1276 color fundus photos and their corresponding choroidal thickness values from healthy subjects were obtained from the Topcon DRI Triton optical coherence tomography machine. Initially, ten commonly used convolutional neural networks were deployed to identify the most accurate model, which was subsequently selected for further training. This selected model was then employed in combination with single-, multiple-, and auxiliary-task training models to predict the average and sub-region choroidal thickness in both ETDRS (Early Treatment Diabetic Retinopathy Study) grids and 100-grid subregions. The values of mean absolute error and coefficient of determination (R2) were involved to evaluate the models' performance. Results: Efficientnet-b0 network outperformed other networks with the lowest mean absolute error value (25.61 µm) and highest R2 (0.7817) in average choroidal thickness. Incorporating diopter spherical, anterior chamber depth, and lens thickness as auxiliary tasks improved predicted accuracy (p-value = 6.39×10-44, 2.72×10-38, 1.15×10-36 respectively). For ETDRS regional choroidal thickness estimation, multi-task model achieved better results than single task model (lowest mean absolute error = 31.10 µm vs. 33.20 µm). The multi-task training also can simultaneously predict the choroidal thickness of 100 grids with a minimum mean absolute error of 33.86 µm. Conclusions: Efficientnet-b0, in combination with multi-task and auxiliary task models, achieve high accuracy in estimating average and regional macular choroidal thickness directly from color fundus photographs.

Effect of Paravertebral Muscle Degeneration on Lumbar and Pelvic Sagittal Alignment in Patients With Degenerative Scoliosis.

STUDY DESIGN: Retrospective study. OBJECTIVES: To explore the relationship between lumbar spine muscle mass and lumbar pelvic sagittal parameters in patients with degenerative scoliosis. METHODS: This study included ADS patients who were treated in our hospital from 2019 to 2023. The spinal parameters were evaluated through X-rays, and the relative muscle volume (RMV) and fat infiltration (FI) were measured through three-dimensional reconstruction. Patients were categorized into 3 groups based on SRS-Schwab sagittal balance correction (0, +, ++), and into 3 groups based on GAP score (proportioned, moderately dis-proportioned, severely dis-proportioned). Finally, patients were classified into low-quality and high-quality groups based on the FI of Paraspinal muscles (PSM). RESULTS: The study included a total of 63 patients. Significant statistical differences were observed in the FI and RMV of MF, ES and PS among patients classified by SRS-Schwab PT classification. Additionally, significant statistical differences were found in the RMV of MF and PS among patients classified by SRS-Schwab PI-LL classification and GAP score. Furthermore, a significant correlation was found between the FI and RMV of PSM and lumbopelvic sagittal parameters. The ordinal regression model analysis revealed that FI of ES significantly impacted PT imbalance, while RMV of MF significantly impacted PI-LL imbalance. Moreover, significant differences were noted in PT and PI between the low-quality and high-quality multifidus groups. CONCLUSIONS: As sagittal imbalance worsens, PSM degeneration also intensifies, primarily characterized by an increase in FI and a decrease in RMV. Notably, PT and PI-LL are positively correlated with RMV and negatively correlated with FI.

Inter-Individual Topographic Variation of Choroidal Thickness in Healthy Eyes on Swept-Source Optical Coherence Tomography.

Purpose: To investigate the topographic characters of inter-individual variations of the macular choroidal thickness (CT). Methods: This was a retrospective study. Macular CT data for 900 0.2 × 0.2-mm grids from 410 healthy eyes were collected from swept-source optical coherence tomography. Following the analysis of factors associated with mean CT, the ß-coefficients of the included associated factors in each grid were summarized for choroidal thickness changes analysis. Additionally, the coefficient of variance (CoV), coefficient of determination (CoD), and coefficient of variance unexplained (CoVU) for CT were calculated in each individual grid to investigate the inter-individual choroidal variations pattern. Results: Sex (ß = -17.26, female vs. male), age (ß = -1.61, per 1 year), and axial length (ß = -18.62, per 1 mm) were associated with mean macular CT. Females had a thinner choroid in all 900 grids (0.5-26.9 µm). As age increased, the CT noticeably decreased (8.74-19.87 µm per 10 years) in the temporal regions. With axial length elongation, the thinning (7.94-24.91 µm per 1 mm) was more evident in subfoveal and nasal regions. Both the CoV (34.69%-58.00%) and CoVU (23.05%-40.78%) were lower in the temporal regions, whereas the CoD (18.41%-39.66%) was higher in the temporal regions. Conclusions: Choroidal thinning is more predominant in the subfoveal and nasal regions with axial length elongation, but in the temporal region with aging. The inter-individual variation of CT is higher and less determined by sex, age, or axial length in the nasal regions. Translational Relevance: Topographic variation should be considered when interpreting choroidal thickness.

Medical education and physician training in the era of artificial intelligence.

ABSTRACT: With the rise of generative artificial intelligence (AI) and AI-powered chatbots, the landscape of medicine and healthcare is on the brink of significant transformation. This perspective delves into the prospective influence of AI on medical education, residency training and the continuing education of attending physicians or consultants. We begin by highlighting the constraints of the current education model, challenges in limited faculty, uniformity amidst burgeoning medical knowledge and the limitations in 'traditional' linear knowledge acquisition. We introduce 'AI-assisted' and 'AI-integrated' paradigms for medical education and physician training, targeting a more universal, accessible, high-quality and interconnected educational journey. We differentiate between essential knowledge for all physicians, specialised insights for clinician-scientists and mastery-level proficiency for clinician-computer scientists. With the transformative potential of AI in healthcare and service delivery, it is poised to reshape the pedagogy of medical education and residency training.

A Competition for the Diagnosis of Myopic Maculopathy by Artificial Intelligence Algorithms.

Importance: Myopic maculopathy (MM) is a major cause of vision impairment globally. Artificial intelligence (AI) and deep learning (DL) algorithms for detecting MM from fundus images could potentially improve diagnosis and assist screening in a variety of health care settings. Objectives: To evaluate DL algorithms for MM classification and segmentation and compare their performance with that of ophthalmologists. Design, Setting, and Participants: The Myopic Maculopathy Analysis Challenge (MMAC) was an international competition to develop automated solutions for 3 tasks: (1) MM classification, (2) segmentation of MM plus lesions, and (3) spherical equivalent (SE) prediction. Participants were provided 3 subdatasets containing 2306, 294, and 2003 fundus images, respectively, with which to build algorithms. A group of 5 ophthalmologists evaluated the same test sets for tasks 1 and 2 to ascertain performance. Results from model ensembles, which combined outcomes from multiple algorithms submitted by MMAC participants, were compared with each individual submitted algorithm. This study was conducted from March 1, 2023, to March 30, 2024, and data were analyzed from January 15, 2024, to March 30, 2024. Exposure: DL algorithms submitted as part of the MMAC competition or ophthalmologist interpretation. Main Outcomes and Measures: MM classification was evaluated by quadratic-weighted κ (QWK), F1 score, sensitivity, and specificity. MM plus lesions segmentation was evaluated by dice similarity coefficient (DSC), and SE prediction was evaluated by R2 and mean absolute error (MAE). Results: The 3 tasks were completed by 7, 4, and 4 teams, respectively. MM classification algorithms achieved a QWK range of 0.866 to 0.901, an F1 score range of 0.675 to 0.781, a sensitivity range of 0.667 to 0.778, and a specificity range of 0.931 to 0.945. MM plus lesions segmentation algorithms achieved a DSC range of 0.664 to 0.687 for lacquer cracks (LC), 0.579 to 0.673 for choroidal neovascularization, and 0.768 to 0.841 for Fuchs spot (FS). SE prediction algorithms achieved an R2 range of 0.791 to 0.874 and an MAE range of 0.708 to 0.943. Model ensemble results achieved the best performance compared to each submitted algorithms, and the model ensemble outperformed ophthalmologists at MM classification in sensitivity (0.801; 95% CI, 0.764-0.840 vs 0.727; 95% CI, 0.684-0.768; P = .006) and specificity (0.946; 95% CI, 0.939-0.954 vs 0.933; 95% CI, 0.925-0.941; P = .009), LC segmentation (DSC, 0.698; 95% CI, 0.649-0.745 vs DSC, 0.570; 95% CI, 0.515-0.625; P < .001), and FS segmentation (DSC, 0.863; 95% CI, 0.831-0.888 vs DSC, 0.790; 95% CI, 0.742-0.830; P < .001). Conclusions and Relevance: In this diagnostic study, 15 AI models for MM classification and segmentation on a public dataset made available for the MMAC competition were validated and evaluated, with some models achieving better diagnostic performance than ophthalmologists.

Effects of low-intensity ultrasound opening the blood-brain barrier on Alzheimer's disease-a mini review.

Due to the complex pathological mechanisms of Alzheimer's disease (AD), its treatment remains a challenge. One of the major difficulties in treating AD is the difficulty for drugs to cross the blood-brain barrier (BBB). Low-intensity ultrasound (LIUS) is a novel type of ultrasound with neuromodulation function. It has been widely reported that LIUS combined with intravenous injection of microbubbles (MB) can effectively, safely, and reversibly open the BBB to achieve non-invasive targeted drug delivery. However, many studies have reported that LIUS combined with MB-mediated BBB opening (LIUS + MB-BBBO) can improve pathological deposition and cognitive impairment in AD patients and mice without delivering additional drugs. This article reviews the relevant research studies on LIUS + MB-BBBO in the treatment of AD, analyzes its potential mechanisms, and summarizes relevant ultrasound parameters.

Network pharmacology integrated with experimental validation to explore the therapeutic role and potential mechanism of Epimedium for spinal cord injury.

Objective: Epimedium (EPI) is a common Chinese herb with neuroprotective effects against a variety of central nervous system disorders, especially spinal cord injury (SCI). In this study, we performed network pharmacology and molecular docking analyses to reveal the mechanism underlying EPI treatment of SCI, then validated its efficacy using animal models. Methods: The active ingredients and targets of EPI were screened by Traditional Chinese Medicine Systems Pharmacology (TCMSP) and their targets annotated on the UniProt platform. SCI-related targets were searched from OMIM, TTD, and GeneCards databases. We employed the STRING platform to construct a protein-protein interaction (PPI) network then visualized the results using Cytoscape (3.8.2) software. We also subjected key EPI targets to ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analyses, then docked the main active ingredients with the key targets. Finally, we established an SCI rat model to evaluate efficacy of EPI in treating SCI and validate the effects of different biofunctional modules predicted by network pharmacology. Results: A total of 133 EPI targets were associated with SCI. GO terms and KEGG pathway enrichment results showed that EPI's effect in treating SCI was significantly associated with inflammatory response, oxidative stress and the PI3K/AKT signaling pathway. Molecular docking results indicated that EPI's active ingredients have a high affinity for the key targets. Results from animal experiments revealed that EPI not only markedly improved Basso, Beattie, and Bresnahan scores in SCI rats, but also significantly improved p-PI3K/PI3K and p-AKT/AKT ratio. Moreover, EPI treatment not only mediated a significant decrease in malondialdehyde (MDA) but also increased both superoxide dismutase (SOD), and glutathione (GSH). However, this phenomenon was successfully reversed by LY294002, a PI3K inhibitor. Conclusion: EPI improves behavioral performance in SCI rats through anti-oxidative stress, which may be mediated by activation of the PI3K/AKT signaling pathway.

Corrigendum: Network pharmacology integrated with experimental validation to explore the therapeutic role and potential mechanism of Epimedium for spinal cord injury.

[This corrects the article DOI: 10.3389/fnmol.2023.1074703.].

A novel prognostic 7-methylguanosine signature reflects immune microenvironment and alternative splicing in glioma based on multi-omics analysis.

Glioma is the most common type of central nervous system tumor with increasing incidence. 7-methylguanosine (m7G) is one of the diverse RNA modifications that is known to regulate RNA metabolism and its dysregulation was associated with various cancers. However, the expression pattern of m7G regulators and their roles in regulating tumor immune microenvironments (TIMEs) as well as alternative splicing events (ASEs) in glioma has not been reported. In this study, we showed that m7G regulators displayed a close correlation with each other and most of them were differentially expressed between normal and glioma tissues. Two m7G signatures were then constructed to predict the overall survival of both GBM and LGG patients with moderate predictive performance. The risk score calculated from the regression coefficient and expression level of signature genes was proved to be an independent prognostic factor for patients with LGG, thus, a nomogram was established on the risk score and other independent clinical parameters to predict the survival probability of LGG patients. We also investigated the correlation of m7G signatures with TIMEs in terms of immune scores, expression levels of HLA and immune checkpoint genes, immune cell composition, and immune-related functions. While exploring the correlation between signature genes and the ASEs in glioma, we found that EIF4E1B was a key regulator and might play dual roles depending on glioma grade. By incorporating spatial transcriptomic data, we found a cluster of cells featured by high expression of PTN exhibited the highest m7G score and may communicate with adjacent cancer cells via SPP1 and PTN signaling pathways. In conclusion, our work brought novel insights into the roles of m7G modification in TIMEs and ASEs in glioma, suggesting that evaluation of m7G in glioma could predict prognosis. Moreover, our data suggested that blocking SPP1 and PTN pathways might be a strategy for combating glioma.

Research Trends and Hotspots of Retinal Optical Coherence Tomography: A 31-Year Bibliometric Analysis.

The emergence of optical coherence tomography (OCT) over the past three decades has sparked great interest in retinal research. However, a comprehensive analysis of the trends and hotspots in retinal OCT research is currently lacking. We searched the publications on retinal OCT in the Web of Science database from 1991 to 2021 and performed the co-occurrence keyword analysis and co-cited reference network using bibliometric tools. A total of 25,175 publications were included. There has been a progressive increase in the number of publications. The keyword co-occurrence network revealed five clusters of hotspots: (1) thickness measurements; (2) therapies for macular degeneration and macular edema; (3) degenerative retinal diseases; (4) OCT angiography (OCTA); and (5) vitrectomy for macular hole and epiretinal membrane. The co-citation analysis displayed 26 highly credible clusters (S = 0.9387) with a well-structured network (Q = 0.879). The major trends of research were: (1) thickness measurements; (2) therapies for macular degeneration and macular edema; and (3) OCTA. Recent emerging frontiers showed a growing interest in OCTA, vessel density, choriocapillaris, central serous chorioretinopathy, Alzheimer's disease, and deep learning. This review summarized 31 years of retinal OCT research, shedding light on the hotspots, main themes, and emerging frontiers to assist in future research.

Direct Estimation of Choroidal Thickness in Optical Coherence Tomography Images with Convolutional Neural Networks.

Automatic and accurate estimation of choroidal thickness plays a very important role in a computer-aided system for eye diseases. One of the most common methods for automatic estimation of choroidal thickness is segmentation-based methods, in which the boundaries of the choroid are first detected from optical coherence tomography (OCT) images. The choroidal thickness is then computed based on the detected boundaries. A shortcoming in the segmentation-based methods is that the estimating precision greatly depends on the segmentation results. To avoid the dependence on the segmentation step, in this paper, we propose a direct method based on convolutional neural networks (CNNs) for estimating choroidal thickness without segmentation. Concretely, a B-scan image is first cropped into several patches. A trained CNN model is then used to estimate the choroidal thickness for each patch. The mean thickness of the choroid in the B-scan is obtained by taking the average of the choroidal thickness on each patch. Then, 150 OCT volumes are collected to evaluate the proposed method. The experiments show that the results obtained by the proposed method are very competitive with those obtained by segmentation-based methods, which indicates that direct estimation of choroidal thickness is very promising.

[Correlation analysis between C 7 slope and cervical sagittal parameters in short segment anterior cervical discectomy with fusion].

OBJECTIVE: To elucidate the relationship between preoperative C 7 slope (C 7S) and sagittal parameters in anterior cervical discectomy with fusion (ACDF) by imaging. METHODS: A retrospective analysis of 54 patients (24 males and 30 females) with ACDF for cervical spondylosis between January 2012 and January 2017 was performed. The age ranged from 23 to 71 years (mean, 46.6 years). There were 29 cases of cervical spondylotic radiculopathy and 25 cases of cervical spondylotic myelopathy. The disease duration ranged from 3 to 48 months, with an average of 16.8 months. In the 55 patients, 44 were single-segment ACDF and 10 were double-segment ACDF. Sagittal parameters of cervical spine were measured on cervical X-ray films before operation and at last follow-up, including C 2-7 Cobb angle, C 2-7 sagittal vertical axis (C 2-7 SVA), C 7S, and segment Cobb angle (SCobb), and the changes of C 2-7 Cobb angle (the difference between the last follow-up and the preoperative angle) were calculated. Pearson correlation was used to analyze the correlation between the parameters before operation and at last follow-up. According to the preoperative median value of C 7S (15°), the patients were divided into group A (C 7S<15°) and group B (C 7S≥15°). The sagittal parameters before and after operation were compared between the two groups. RESULTS: All the 54 patients were followed up 6-45 months (mean, 15.5 months). At last follow-up, C 7S, C 2-7 Cobb angle, C 2-7 SVA, and SCobb angle were significantly improved when compared with preoperative values ( P<0.05). Correlation analysis showed that the preoperative C 7S and SCobb angles were significantly correlated with C 2-7 Cobb angle and C 2-7 SVA ( P<0.05), but there was no significant correlation between C 7S and SCobb angle ( r=0.049, P=0.724). There was a significant correlation between C 7S, C 2-7 Cobb angle, and SCobb angle at last follow-up ( P<0.05), but there was no significant correlation between C 7S and SCobb angles and C 2-7 SVA ( P>0.05). According to the median value of preoperative C 7S, 28 patients in group A had C 7S of (11.82±3.60)°, while 26 patients in group B had C 7S of (20.77±4.09)°. There was no significant difference in gender and age between the two groups ( P>0.05). The preoperative C 2-7 Cobb angle and C 2-7 SVA in group A were significantly lower than those in group B ( P<0.05). There was no significant difference between preoperative SCobb angle and group B ( t=0.234, P=0.816). There were no significant differences in C 2-7 Cobb angle, C 2-7 SVA, and SCobb angle between group A and group B at last follow-up ( P>0.05). However, the change of C 2-7 Cobb angle in group A was significantly higher than that in group B ( t=2.321, P=0.024). CONCLUSION: Preoperative C 7S≥15° group has more physiological lordosis before operation, but its postoperative cervical curvature changes less, while ACDF is more conducive to correct the preoperative C 7S<15 ° cervical curvature.

Secondary Surgery after Cervical Disc Arthroplasty versus Fusion for Cervical Degenerative Disc Disease: A Meta-analysis with Trial Sequential Analysis.

The purpose of this meta-analysis was to explore whether cervical disc arthroplasty (CDA) was superior to anterior cervical discectomy and fusion (ACDF) in reducing secondary surgery. PubMed, EMBASE, and the Cochrane Library databases were systematically searched. Outcomes were reported as relative risk (RR) with the corresponding 95% confidence interval (CI). The pooled data was calculated using a random-effect model. We also used the trial sequential analysis (TSA) to further verify our results and obtain more moderate estimates. Twenty-one studies with 4208 patients were included in this meta-analysis. The results indicated that compared with ACDF, CDA had fewer frequency of secondary surgery at the index level (RR, 0.47; 95%CI, 0.36-0.63; P < 0.05) and adjacent level (RR, 0.48; 95%CI, 0.36-0.65; P < 0.05), and the differences were statistically significant. In addition, in terms of the overall frequency of secondary surgery at the index and adjacent level, CDA was also significantly superior to ACDF (RR, 0.49; 95%CI, 0.41-0.60; P < 0.05). TSA demonstrated that adequate and decisive evidence had been established. Regarding the frequency of secondary surgery, CDA was significantly superior to ACDF. It was supposed that CDA may be a better surgical intervention to reduce the rate of secondary surgery for patients with cervical degenerative disc disease.