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The diameter of the optic nerve sheath is an important indicator for assessing the intracranial pressure in critically ill patients. The methods for measuring the optic nerve sheath diameter are generally divided into invasive and non-invasive methods. Compared to the invasive methods, the non-invasive methods are safer and have thus gained popularity. Among the non-invasive methods, using deep learning to process the ultrasound images of the eyes of critically ill patients and promptly output the diameter of the optic nerve sheath offers significant advantages. This paper proposes a CBC-YOLOv5s optic nerve sheath ultrasound image segmentation method that integrates both local and global features. First, it introduces the CBC-Backbone feature extraction network, which consists of dual-layer C3 Swin-Transformer (C3STR) and dual-layer Bottleneck Transformer (BoT3) modules. The C3STR backbone's multi-layer convolution and residual connections focus on the local features of the optic nerve sheath, while the Window Transformer Attention (WTA) mechanism in the C3STR module and the Multi-Head Self-Attention (MHSA) in the BoT3 module enhance the model's understanding of the global features of the optic nerve sheath. The extracted local and global features are fully integrated in the Spatial Pyramid Pooling Fusion (SPPF) module. Additionally, the CBC-Neck feature pyramid is proposed, which includes a single-layer C3STR module and three-layer CReToNeXt (CRTN) module. During upsampling feature fusion, the C3STR module is used to enhance the local and global awareness of the fused features. During downsampling feature fusion, the CRTN module's multi-level residual design helps the network to better capture the global features of the optic nerve sheath within the fused features. The introduction of these modules achieves the thorough integration of the local and global features, enabling the model to efficiently and accurately identify the optic nerve sheath boundaries, even when the ocular ultrasound images are blurry or the boundaries are unclear. The Z2HOSPITAL-5000 dataset collected from Zhejiang University Second Hospital was used for the experiments. Compared to the widely used YOLOv5s and U-Net algorithms, the proposed method shows improved performance on the blurry test set. Specifically, the proposed method achieves precision, recall, and Intersection over Union (IoU) values that are 4.1%, 2.1%, and 4.5% higher than those of YOLOv5s. When compared to U-Net, the precision, recall, and IoU are improved by 9.2%, 21%, and 19.7%, respectively. [ABSTRACT FROM AUTHOR]

Glaucoma is an eye disease that damages the optic nerve (or retina) and impairs vision. This disease can be prevented with regular checkups, but this increases the workload for professionals and the time it takes to get results. So an automated method using deep learning would be helpful for detection of disease. In order to shorten the diagnosis time for glaucoma, this paper proposed a deep learning based method for automatic glaucoma detection. The experiments are conducted on glaucoma datasets available on Kaggle. This paper used transfer learning based pretrained models namely DenseNet169, MobileNet, InceptionV3, Xception, ReseNet152V2,and VGG19. Among all models DenseNet169 gives best result with accuracy 0.993590 and precision and recall of 0.993671 and 0.9935895 respectively. A comparison of the best model results with existing work shows that the proposed model provides better results. [ABSTRACT FROM AUTHOR]

Background: Optic neuropathies represent one of the most frequent causes of vision loss, and they can manifest alone or in conjunction with neurological or systemic symptoms and signs. In recent years, the diagnostic techniques used to detect optic neuropathies have significantly improved, facilitating diagnosis and improving treatment. Among these, ocular ultrasound has assumed a fundamental role, although with conflicting results in the published scientific literature. For this reason, the aim of this review is to analyze the role of ocular ultrasound in the precise and targeted diagnosis of optic neuropathies to better understand the presumed potential of this precious diagnostic tool in the management of these ocular and neurological disorders. Methods: We carried out a search on PubMed and Scopus utilizing terms related to optic neuropathies and ocular ultrasound, including only relevant English full-length research articles, case reports, or case series. Results: Most of the papers published in the scientific literature use only the B-scan ultrasound technique without considering the more precise and objective standardized A-scan technique that allows for performing more accurate diagnostic tests, such as the "30-degree test" and the "optic nerve exercise test". Conclusions: Future clinical trials and research on optic neuropathies should also consider the use of the standardized A-scan technique in order to compare clinical findings not only with B-scan ultrasonography but also with other noninvasive procedures that could be helpful in reaching the correct diagnosis. [ABSTRACT FROM AUTHOR]

Relative pupillary afferent disorder (RAPD) plays a crucial role in diagnosing optic nerve dysfunction. This paper introduces an innovative equipment design with a high-speed pupil detection algorithm and a binocular independent stimulation optical path. The proposed algorithm utilizes the grayscale characteristics of the pupil region to achieve rapid and accurate pupil detection and tracking. Initially, a pupil threshold is estimated using eigenvalues, enabling the calculation of the pupil centroid. Subsequently, leveraging the unique characteristics of the pupil region, a dynamic tracking algorithm, a second-order partial derivative threshold algorithm, and a pupil diameter extraction algorithm are employed to precisely locate the centroid. By incorporating a binocular independent stimulus light path design, the algorithm overcomes limitations associated with the current measurement equipment. The experimental results demonstrate the algorithm's high robustness and fast detection speed, meeting the tracking speed requirement of 1250 frames per second for a single eye. These advancements have the potential to significantly enhance the diagnosis and assessment of optic nerve dysfunction. [ABSTRACT FROM AUTHOR]

This paper reviews the current insights into, and prospects for better understanding of, the pathogenesis of optic nerve edema or swelling in the presence of inflammatory or ischemic optic neuropathy. Forty-six Ukrainian and foreign publications on the subject were reviewed and considered. There are several theories of optic nerve damage due to swelling (edema); these include biomechanical theories (features of structural components, a change in the optic nerve architecture, and stretching of the Bruch membrane) and an ischemic theory (abnormal perfusion and axonal transport stasis). Of importance are also abnormal vascular permeability and exudation of plasma and blood cells, which results in accumulation of fluid, inflammatory mediators and metabolic products between peripapillary retinal layers, impeding the outflow and metabolism in the posterior segment of the eye. Current neuroimaging techniques (optical coherence tomography (OCT) and OCT angiography) facilitate improved understanding of structural changes in the optic nerve head. Therefore, studies on optic disc architecture, fluid circulation in the posterior segment, and interaction of optic nerve head components in optic nerve edema or swelling will facilitate (a) improved understanding of the pathogenesis and (b) the differential diagnosis of acute optic neuropathies, and, consequently, will enable treatment for inflammatory and ischemic optic nerve lesions. [ABSTRACT FROM AUTHOR]

We report a lethal case of a female patient who has not undergone surgery for her giant invasive infrasellar/ endosellar/suprasellar/parasellar/retrosellar pituitary adenoma. The paper presents results of histological examination of optic nerves and considers the mechanisms of vision loss in prolonged chiasmal and optic nerve compression. [ABSTRACT FROM AUTHOR]

High-accuracy deformation monitoring is crucial for investigating landslide–pipeline interaction problems, in which the fiber optic nerve system (FONS) holds enormous potential. This paper presents a theoretical framework for interpreting landslide–pipeline interactions using the FONS and proposes a novel method for calculating characteristic parameters of pipe–soil interfaces based on distributed strain measurements. The feasibility of this method is validated through a full-scale model test, and its application for studying pipeline behaviors is demonstrated in the Xinpu landslide, situated in the Three Gorges Reservoir region, China. The field monitoring results reveal that short-duration, high-intensity rainfall events triggered immediate acceleration of landslide movements, leading to pipeline elongation and flexure. Strain measurements of the underground pipeline allow for the identification of the local slipping interface of the landslide. Furthermore, the relationships between reservoir water level (RWL) fluctuations, rainfall events, landslide deformation, and the structural response of the pipe are analyzed. The findings suggest that the deformation of the landslide in the leading and middle parts exhibits high correlations with the combined effect of rainfall and RWL drawdown. [ABSTRACT FROM AUTHOR]

Glaucoma refers to the accumulated loss of retinal cells within the optic nerve or the gradual visual loss caused by optic neuropathy. It is an illness that affects vision in the eye and is considered an irreversible condition that leads to degradation of eyesight. There are often no early warning signs of glaucoma, making it difficult to notice changes in vision due to subtle effects. To date, a large number of Deep Learning (DL) models have been developed for the accurate diagnosis of glaucoma. This work proposes an architecture for deep learning-based glaucoma detection using Convolutional Neural Networks (CNNs). CNNs can distinguish between patterns associated with glaucoma and non-glaucoma conditions, providing a hierarchical structure for classification. Using the proposed method, the disease is detected based on the optic cup-to-disc ratio. The diagnosis is further enhanced by integrating an image data generator for data augmentation. The results demonstrate that the proposed model achieved 98% accuracy, outperforming many existing algorithms. [ABSTRACT FROM AUTHOR]

Spaceflight associated neuro-ocular syndrome (SANS) alters the vision of astronauts during long-duration spaceflights. Previously, the current authors have discussed the similarities and differences between SANS and idiopathic intracranial hypertension to try to elucidate a possible pathophysiology. Recently, a theory has been advanced that SANS may occur secondary to failure of the glymphatic system caused by venous dilatation within the brain and optic nerves. There is recent evidence to suggest glymphatic obstruction occurs in childhood hydrocephalus, multiple sclerosis and syringomyelia due to venous outflow dilatation similar to that proposed in SANS. The purpose of the current paper is to discuss the similarities and differences between the known CSF and venous pathophysiology in SANS with these other terrestrial diseases, to see if they can shed any further light on the underlying cause of this microgravity-induced disease. [ABSTRACT FROM AUTHOR]

Background and Purpose: Late secondary glaucoma is an often‐severe complication after acute events like anterior segment surgery, trauma and infection. TNF‐α is a major mediator that is rapidly upregulated, diffusing also to the retina and causes apoptosis of the ganglion cells and degeneration of their optic nerve axons (mediating steps to glaucomatous damage). Anti‐TNF‐α antibodies are in animals very effective in protecting the retinal cells and the optic nerve—and might therefore be useful prophylactically against secondary glaucoma in future such patients. Here we evaluate (1) toxicity and (2) efficacy of two TNF‐α inhibitors (adalimumab and infliximab), in rabbits by subconjunctival administration. Methods: For drug toxicity, animals with normal, unburned corneas were injected with adalimumab (0.4, 4, or 40 mg), or infliximab (1, 10, or 100 mg). For drug efficacy, other animals were subjected to alkali burn before such injection, or steroids (for control). The rabbits were evaluated clinically with slit lamp and photography, electroretinography, optical coherence tomography, and intraocular pressure manometry. A sub‐set of eyes were stained ex vivo after 3 days for retinal cell apoptosis (TUNEL). In other experiments the optic nerves were evaluated by paraphenylenediamine staining after 50 or 90 days. Loss of retinal cells and optic nerve degeneration were quantified. Results: Subconjunctival administration of 0.4 mg or 4.0 mg adalimumab were well tolerated, whereas 40.0 mg was toxic to the retina. 1, 10, or 100 mg infliximab were also well tolerated. Analysis of the optic nerve axons after 50 days confirmed the safety of 4.0 mg adalimumab and of 100 mg infliximab. For efficacy, 4.0 mg adalimumab subconjunctivally in 0.08 mL provided practically full protection against retinal cell apoptosis 3 days following alkali burn, and infliximab 100 mg only slightly less. At 90 days following burn injury, control optic nerves showed about 50% axon loss as compared to 8% in the adalimumab treatment group. Conclusions: Subconjunctival injection of 4.0 mg adalimumab in rabbits shows no eye toxicity and provides excellent neuroprotection, both short (3 days) and long‐term (90 days). Our total. accumulated data from several of our studies, combined with the present paper, suggest that corneal injuries, including surgery, might benefit from routine administration of anti‐TNF‐α biologics to reduce inflammation and future secondary glaucoma. [ABSTRACT FROM AUTHOR]

Glaucoma is a highly perilous ocular disease that significantly impacts human visual acuity. This is a retinal condition that causes damage to the Optic Nerve Head (ONH) and can lead to permanent blindness if detected in a late stage. The prevention of permanent blindness is contingent upon the timely identification and intervention of glaucoma during its initial stages. This paper introduces a convolutional neural network (CNN) model that utilizes specific architectural designs to identify early-stage glaucoma by analyzing fundus images. This study utilizes publicly accessible datasets, including the Online Retinal Fundus Image Database for Glaucoma Analysis and Research (ORIGA), Structured Analysis of the Retina (STARE), and Retinal Fundus Glaucoma Challenge (REFUGE). The retinal fundus images are fed into AlexNet, VGG16, ResNet50, and InceptionV3 models for the purpose of classifying glaucoma. The ResNet50 and InceptionV3 models, both of which demonstrated a superior performance, were merged to create a hybrid model. The ORIGA dataset achieved high accuracy with an F1 Score of 97.4%, while the STARE dataset achieved higher accuracy with an F1 Score of 99.1%. The REFUGE dataset also showed excellent performance, with an F1 Score of 99.2%. The proposed methodology has established a reliable glaucoma diagnostic system, aiding ophthalmologists and physicians in conducting accurate mass screenings and diagnosing glaucoma. [ABSTRACT FROM AUTHOR]

Introduction: Anterior ischemic optic neuropathy (AION) can mimic glaucoma and consequently cause difficulties in differential diagnosis. The purpose of this paper was to summarize differences in diagnostic tests that can help perform a correct diagnosis. Methods: The search strategy was performed according to the PRISMA 2009 guidelines, and four databases were used: MEDLINE, Embase, Web of Science, and Cochrane. Totally, 772 references were eligible; 39 were included after screening with respect to inclusion criteria that included English language and published in the 20 years before search date. Results: Ninety percent (n = 35) of included studies used optical coherence tomography (OCT). Glaucomatous eyes had a significantly greater cup area, volume and depth, cup-to-disk ratio, a lower rim volume and area, and a thinner Bruch's membrane opening-minimum rim width. Retinal nerve fiber layer (RNFL) thinning in glaucomatous eyes occurred primarily at the superotemporal, inferotemporal, and inferonasal sectors, while AION eyes demonstrated mostly superonasal thinning. Glaucoma eyes showed greater macular ganglion cell layer thickness, except at the inferotemporal sector. OCT angiography measurements demonstrated a significant decrease in superficial and deep macular vessel density (VD) in glaucoma compared to AION with similar degree of visual field damage; the parapapillary choroidal VD was spared in AION eyes compared to glaucomatous eyes. Conclusion: By use of OCT imaging, optic nerve head parameters seem most informative to distinguish between glaucoma and AION. Although both diseases affect the RNFL thickness, it seems to do so in different sectors. Differences in structure and vascularity of the macula can also help in making the differential diagnosis. [ABSTRACT FROM AUTHOR]

Glaucoma is a progressive and degenerative optic neuropathy that causes severe visual impairment or even blindness if left untreated. Glaucoma is majorly caused due to stress which increases intraocular pressure that leads towards optic nerve degeneration. The degenerative optic nerve then causes irreversible loss of peripheral vision which may lead to complete blindness. Although the progression of glaucoma can harshly affect the vision, it can be prevented if diagnosed in the early stages. However, optical coherence tomography (OCT) imagery is widely used by ophthalmologist for early glaucoma diagnosis and progression tracking. Owing to this objective screening capacity of the OCT imagery, many researchers have used it as an examination procedure to verify their clinical studies or to train their autonomous systems for mass-screening glaucomatous pathologies. In this paper, we present a systematic review of the recent studies that have proposed various solutions to mitigate glaucomatous progression using OCT imagery. Initially, we have presented a review of clinical studies that looked at glaucomatous diseases in OCT images.Furthermore, this paper presents a detailed survey of the state-of-the-art techniques for glaucoma detection and grading. In future directions, ganglion cell layer as well as macular analysis and its automation will improve the diagnostic power of OCT for the early glaucoma detection and especially monitoring its progression. [ABSTRACT FROM AUTHOR]

Objectives Transorbital neuroendoscopic surgery (TONES) has ignited interest in the transorbital access corridor, increasing its use for single and multi-portal skull base interventions. However, the crowding of a small corridor and two-dimensional viewing restrict this access portal. Design Cadaveric qualitative study to assess the feasibility of transorbital microsurgery (TMS). Setting Anatomical dissection steps and instrumentation were recorded for homogeneous methodology. Participants Six cadaveric specimens were systematically dissected using TMS to the anterior cranial fossa and paramedian structures. Main Outcome Measures Anatomical parameters of the TMS craniectomy were established, and the visible and accessible neuroanatomy was highlighted. Results A superior lid crease incision achieved essential orbital rim exposure and preseptal dissection. The orbital roof craniectomy is defined by three boundaries: (1) frontozygomatic suture to the frontosphenoid suture, (2) frontal sinus and cribriform plate, and (3) frontal sinus and orbital rim. The mean (standard deviation) craniectomy was 440 mm 2 (78 mm 2). Exposing the ipsilateral optic nerve and internal carotid artery obviated the need for frontal lobe retraction to identify the A1–M1 bifurcation as well as near-complete visualization of the M1 artery. Conclusion TMS is a feasible corridor for intracranial access. Mobilization of orbital contents is imperative for maximal intracranial access and protection of the globe. TMS enables access to the frontal lobe base, ipsilateral optic nerve, and most of the ipsilateral anterior circulation. This cosmetically satisfactory approach causes minimal destruction of the anterior skull base with satisfactory exposure of the anterior cranial fossa floor without sinus invasion. [ABSTRACT FROM AUTHOR]

The Pattern Electroretinogram (PERG) is an essential tool in ophthalmic electrophysiology, providing an objective assessment of the central retinal function. It quantifies the activity of cells in the macula and the ganglion cells of the retina, assisting in the differentiation of macular and optic nerve conditions. In this study, we present the IOBA-PERG dataset, an extensive collection of 1354 transient PERG responses accessible on the PhysioNet repository. These recordings were conducted at the Institute of Applied Ophthalmobiology (IOBA) at University of Valladolid, over an extended period spanning nearly two decades, from 2003 to 2022. The dataset includes 336 records, ensuring at least one PERG signal per eye. The dataset thoughtfully includes demographic and clinical data, comprising information such as age, gender, visual acuity measurements, and expert diagnoses. This comprehensive dataset fills a gap in ocular electrophysiological repositories, enhancing ophthalmology research. Researchers can explore a broad range of eye-related conditions and diseases, leading to enhanced diagnostic accuracy, innovative treatment strategies, methodological advancements, and a deeper understanding of ocular electrophysiology. [ABSTRACT FROM AUTHOR]

Glaucoma is a leading cause of blindness worldwide and results from high eye pressure‐induced damage to the optic nerves, thereby preventing visual information from reaching the brain. While glaucoma is incurable in its advanced stages, its early detection improves the treatment outcome. Recently, computational models for image classification have enabled early detection of glaucoma from OCT scans of patients and will potentially augment the medical diagnosis of this disease. Models that are based on the convolutional neural networks (CNNs) have shown promise in the early detection of glaucoma. These models vary in their architectures and their accuracies depend largely on the intrinsic nature of the training datasets used. Hence, in this work, a comparative analysis is performed on vanilla CNN, AlexNet, GoogLeNet, and ResNet50 using two popular glaucoma datasets (ACRIMA and ORIGA). With careful attention to exhaustive image processing, an impressive training accuracy of 89% and validation accuracy of 50% was obtained from the vanilla CNN, showing a high sensitivity of 88% in detecting glaucomatous patients from OCT scans. However, the other models (AlexNet, GoogLeNet, and ResNet5) overfitted with a large difference between the obtained training accuracy and validation accuracy. The results also reveal that ResNet50 has the highest computational cost compared to the rest of the models. The obtained results demonstrate the peculiarity of the dataset, its selectiveness of the most appropriate model, and the potential of deep neural networks (DNNs) as an effective screening tool for glaucoma, enabling prompt interventions, reducing healthcare costs, and helping optometrists make swift decisions. [ABSTRACT FROM AUTHOR]

Background: During gynecological laparoscopic surgery, pneumoperitoneum and the Trendelenburg position (TP) can lead to increased intracranial pressure (ICP). However, it remains unclear whether perioperative fluid therapy impacts ICP. The purpose of this research was to evaluate the impact of restrictive fluid (RF) therapy versus conventional fluid (CF) therapy on ICP in gynecological laparoscopic surgery patients by measuring the ratio of the optic nerve sheath diameter (ONSD) to the eyeball transverse diameter (ETD) using ultrasound. Methods: Sixty-four patients who were scheduled for laparoscopic gynecological surgery were randomly assigned to the CF group or the RF group. The main outcomes were differences in the ONSD/ETD ratios between the groups at predetermined time points. The secondary outcomes were intraoperative circulatory parameters (including mean arterial pressure, heart rate, and urine volume changes) and postoperative recovery indicators (including extubation time, length of post-anaesthesia care unit stay, postoperative complications, and length of hospital stay). Results: There were no statistically significant differences in the ONSD/ETD ratio and the ONSD over time between the two groups (all p > 0.05). From T2 to T4, the ONSD/ETD ratio and the ONSD in both groups were higher than T1 (all p < 0.001). From T1 to T2, the ONSD/ETD ratio in both groups increased by 14.3%. However, the extubation time in the RF group was shorter than in the CF group [median difference (95% CI) -11(-21 to -2) min, p = 0.027]. There were no differences in the other secondary outcomes. Conclusion: In patients undergoing laparoscopic gynecological surgery, RF did not significantly lower the ONSD/ETD ratio but did shorten the tracheal extubation time, when compared to CF. Trial registration: ChiCTR2300079284. Registered on December 29, 2023. [ABSTRACT FROM AUTHOR]

Glaucoma is a group of neurodegenerative diseases that can lead to irreversible blindness. Yet, the progression can be slowed down if diagnosed and treated early enough. Optical coherence tomography angiography (OCTA) can non-invasively provide valuable information about the retinal microcirculation that has shown to be correlated with the onset of the disease. The vessel density (VD) is the most commonly used biomarker to quantify this vascular information. However, different studies showed that there is a great impact of the acquisition area on the performance of the VD to distinguish between glaucoma patients and a healthy control group. It also seems that the separate capillary plexuses are differently affected by the disease and therefore also influence the results. So in this study we investigate the impact of the acquisition area (3 × 3 mm macular scan, 6.44 × 6.4 mm macular scan, 6 × 6 mm optic nerve head (ONH) scan) and the different plexuses on the machine-learning-based distinction between glaucoma patients and healthy controls. The results yielded that the 6 × 6 mm ONH show the best performance over all plexuses. Moreover the deep learning-based approach outperforms the VD as a biomarker on every acquisition area and plexus. In addition to that, it also performs better than traditional biomarkers obtained from the OCT scans that are used in the clinical routine for diagnosis and progression tracking of glaucoma. Consequently, OCTA scans of the ONH might be a useful addition to OCT when studying glaucoma. [ABSTRACT FROM AUTHOR]

Introduction: Epilepsy is a network disorder that can cause alterations in retinal morphology due to microstructural changes in the brain. The aim of our study was to use spectral optical coherence tomography (OCT) to assess the possible effects of neuronal degeneration on the intraretinal layers and macular structures of people with epilepsy and epilepsy subgroups. Methods: We enrolled 52 consecutive people with epilepsy (37 females, 15 males; mean age 29.8±9.9 years; range, 17-48 years) and 40 healthy volunteers (27 females, 13 males; mean age 33.3±10.2 years; range, 19-49 years) in this study. Both eyes of all participants were assessed by using spectral-domain OCT. Optical coherence tomography was used to assess the thickness of the peripapillary retinal nerve fiber layer (RNFL), ganglion cell layer-inner plexiform layer (GCC-IPL), central macula, and central macular volume. Results: In comparison to healthy controls, people with epilepsy showed a thinner GCC-IPL in the superior and superior-nasal quadrants, as well as reduced macular thickness and macular volume (p<0.05). The thickness of the GCC-IPL layer in the superior and inferior subquadrants was negatively affected by frequent seizures (>5 seizures/year), polytherapy, and long-duration of epilepsy (≥10 years) (p<0.05). However, we did not find any other statistically significant associations between OCT measurements, age, sex, and epilepsy type (focal and generalized onset epilepsy). Conclusion: Individuals with epilepsy exhibited microstructural alterations in the retinal layers, primarily in the superior and inferior quadrants. Frequent seizures, polytherapy, and long-duration of epilepsy may result in neuronal damage in the afferent visual system. [ABSTRACT FROM AUTHOR]

Wagner syndrome is a rare autosomal dominant vitreoretinopathy caused by mutations in chondroitin sulphate proteoglycan 2 (CSPG2)/Versican (VCAN). Here, we present a retrospective case series of a family pedigree with genetically confirmed Wagner syndrome (heterozygous VCAN exon 8 deletion), as follows: a 34-year-old mother (P1), 12-year-old daughter (P2), and a 2-year-old son (P3). The phenotype included early-onset cataract (P1), optically empty vitreous with avascular membranes (P1, 2), nasal dragging of optic nerve heads associated with foveal hypoplasia (P1, 2), tractional retinoschisis on optical coherence tomography (P2), and peripheral circumferential vitreo-retinal interface abnormality resembling white-without-pressure (P3) progressing to pigmented chorio-retinal atrophy (P1, 2). P2 developed a macula-off retinal detachment, which was treated initially with encircling band + vitrectomy + gas, followed by vitrectomy + heavy silicone oil tamponade for re-detachment from new inferior breaks. Strong vitreo-retinal adhesion was noted intraoperatively, which prevented the separation of posterior hyaloid beyond the equator. Electroretinograms from P1&2 demonstrated attenuated b-waves, a-waves, and flicker responses in light- and dark-adapted conditions, suggestive of generalised retinal dysfunction. Our patients demonstrated the clinical spectrum of Wagner syndrome, highlighting nasal dragging with foveal disruption as a distinguishing feature from other inherited vitreoretinopathies. Surgical outcomes demonstrate significant challenges in managing vitreo-retinal traction and need for further research into strategies to prevent sight loss. [ABSTRACT FROM AUTHOR]

Glaucoma is an eye disease that often has no symptoms until it is advanced. According to the World Health Organization (WHO), after cataracts, glaucoma is the second-leading cause of permanent blindness globally and is expected to affect 111.8 million patients by 2040. Early detection of glaucoma is important to reduce the risk of permanent blindness. Detection is achieved by structural measurement of early thinning of the retinal nerve fiber layer (RNFL). The RNFL is the portion of the retina located outside the optic nerve head (ONH) and can be observed in fundus images of the retina. Analysis of retinal fundus images can be performed with computer assistance using machine learning, especially deep learning. This study proposes a deep learning-based model, a convolutional neural network (CNN) using the EfficientNet architecture combined with long short-term memory (LSTM), for laucoma detection. Using ACRIMA, DRISHTI-GS, and RIM-ONE DL datasets with k-fold cross-validation, the model achieved high performance on the ACRIMA dataset: accuracy 0.9799, loss 0.0596, precision 0.9802, sensitivity 0.9799, specificity 0.9771, and F1score 0.9799. This EfficientNet and LSTM combination (e-LSTM) outperformed previous studies, offering a promising alternative for evaluating retinal fundus images in glaucoma detection. [ABSTRACT FROM AUTHOR]

Purpose: To compare the interocular symmetry and investigate the intermachine reproducibility of optic disc and macular data measured by spectral-domain high-definition optical coherence tomography (HD-OCT) Cirrus HD-OCT 4000 and HD-OCT 5000 from healthy subjects. Patients and Methods: Forty-three volunteers were examined with both HD-OCT 4000 and HD-OCT 5000 at the same visit. Optic nerve head (ONH) and macular data were acquired using ONH Cube 200× 200 scans and macular volume cube 512× 128 scans, respectively. Results: The average age of the participants was 33 ± 8.6 years. Interocular OCT parameters of ONH and macula showed a high correlation between the right and left eyes regardless of HD-OCT models, displaying a low coefficient of variation (CV). However, the average retinal nerve fiber layer (RNFL) was thicker (96.67± 11.19μm vs 95.3± 10.89μm, p< 0.01), and the average central subfield thickness (261.51± 17.45μm vs 262.51± 17.39 μm, p< 0.01) and cube average thickness (283.91± 13.59μm vs 286.55± 13.09μm, p< 0.05) were thinner when measured by Cirrus 4000 compared to 5000. Intermachine reproducibility and reliability of RNFL and macular parameters exhibited a high intraclass correlation coefficient (ICC) (0.985) and low CV (2.4%). Ganglion cell-inner plexiform layer (GCIPL) measured by two OCT models showed similar values with an average thickness of 85 μm and had high intermachine reproducibility with high ICC (0.993) and low CV (1.2%). Conclusion: High interocular symmetry was observed across both HD-OCT models. Intermachine reproducibility for RNFL and all macular parameters was also high. GCIPL showed minimal intermachine differences with high reproducibility and reliability. Thus, the results imply that GCIPL values measured by two Cirrus OCT models may be used interchangeably. [ABSTRACT FROM AUTHOR]

Optic disc drusen (ODD) are calcium‐containing deposits in the optic nerve head, capable of causing visual field defects and sudden visual loss. The underlying pathophysiology remains inadequately understood and treatment options are missing. In this paper, we systematically reviewed prevalence studies of ODD in non‐selected populations to provide an overview of its prevalence, conducted meta‐analyses to determine modality‐specific prevalence estimates and performed a forecasting study to estimate current and future global population number of individuals with ODD. We searched 11 literature databases on 25 October 2022 for prevalence studies of ODD in non‐selected populations. Eight eligible studies provided data from a total of 27 463 individuals. Prevalence estimates were stratified according to diagnostic modalities: ophthalmoscopy 0.37% (95% CI: 0.10–0.95%), fundus photography 0.12% (95% CI: 0.03–0.24%), spectral domain optical coherence tomography with enhanced depth imaging 2.21% (95% CI: 1.25–3.42%) and histopathology 1.82% (95% CI: 1.32–2.38%). Using histopathology‐based summary prevalence estimate, we forecast 145 million individuals with ODD currently, a number expected to increase further due to world population growth. These numbers underscore the importance of including ODD in health education and highlight the necessity of continuing research in ODD. [ABSTRACT FROM AUTHOR]

The paper presents a comparative study of the pulsatile attenuation amplitude (PAA) within the optic nerve head (ONH) at four different areas calculated from retinal video sequences and its relevance to the retinal nerve fiber layer thickness (RNFL) changes in normal subjects and patients with different stages of glaucoma. The proposed methodology utilizes processing of retinal video sequences acquired by a novel video ophthalmoscope. The PAA parameter measures the amplitude of heartbeat-modulated light attenuation in retinal tissue. Correlation analysis between PAA and RNFL is performed in vessel-free locations of the peripapillary region with the proposed evaluating patterns: 360° circular area, temporal semi-circle, nasal semi-circle. For comparison, the full ONH area is also included. Various positions and sizes of evaluating patterns in peripapillary region were tested which resulted in different outputs of correlation analysis. The results show significant correlation between PAA and RNFL thickness calculated in proposed areas. The highest correlation coefficient Rtemp = 0.557 (p<0.001) reflects the highest PAA-RNFL correspondence in the temporal semi-circular area, compared to the lowest value in the nasal semi-circular area (Rnasal = 0.332, p<0.001). Furthermore, the results indicate the most relevant approach to calculate PAA from the acquired video sequences is using a thin annulus near the ONH center. Finally, the paper shows the proposed photoplethysmographic principle based on innovative video ophthalmoscope can be used to analyze changes in retinal perfusion in peripapillary area and can be potentially used to assess progression of the RNFL deterioration. [ABSTRACT FROM AUTHOR]

Background: Measurement of the optic nerve sheath diameter (ONSD) via ultrasonography has been proposed as a non-invasive metric of intracranial pressure that may be employed during in-field patient triage. However, first responders are not typically trained to conduct sonographic exams and/or do not have access to an expensive ultrasound device. Therefore, for successful deployment of ONSD measurement in-field, we believe that first responders must have access to low-cost, portable ultrasound and be assisted by artificial intelligence (AI) systems that can automatically interpret the optic nerve sheath ultrasound scan. We examine the suitability of five commercially available, low-cost, portable ultrasound devices that can be combined with future artificial intelligence algorithms to reduce the training required for and cost of in-field optic nerve sheath diameter measurement. This paper is focused on the quality of the images generated by these low-cost probes. We report results of a clinician preference survey and compare with a lab analysis of three quantitative image quality metrics across devices. We also examine the suitability of the devices in a hypothetical far-forward deployment using operators unskilled in ultrasound, with the assumption of a future onboard AI video interpreter. Results: We find statistically significant differences in clinician ranking of the devices in the following categories: "Image Quality", "Ease of Acquisition", "Software", and "Overall ONSD". We show differences in signal-to-noise ratio, generalized contrast-to-noise ratio, point-spread function across the devices. These differences in image quality result in a statistically significant difference in manual ONSD measurement. Finally, we show that sufficiently wide transducers can capture the optic nerve sheath during blind (no visible B-mode) scans performed by operators unskilled in sonography. Conclusions: Ultrasound of the optic nerve sheath has the potential to be a convenient, non-invasive, point-of-injury or triage measure for elevated intracranial pressure in cases of traumatic brain injury. When transducer width is sufficient, briefly trained operators may obtain video sequences of the optic nerve sheath without guidance. This data suggest that unskilled operators are able to achieve the images needed for AI interpretation. However, we also show that image quality differences between ultrasound probes may influence manual ONSD measurements. [ABSTRACT FROM AUTHOR]

ENGLISH SUMMARY: Corneal blindness is a leading cause of visual impairment worldwide. The most common treatment is to replace the diseased cornea by standard corneal transplantation. In eyes at high risk of graft failure, the Boston keratoprosthesis type 1 (KPro) can be used to restore vision and is currently the most frequently used artificial cornea in the world. However, glaucoma is a well‐known complication of KPro surgery and is the most important threat to vision in KPro‐implanted eyes (paper I). This chronic disease is influenced by elevated intraocular pressure (IOP) and damages the optic nerve, leading to progressive vision loss. In KPro patients, glaucoma is highly prevalent and extremely challenging to manage, yet its exact cause remains unknown. The overall purpose of this PhD Thesis (Geoffrion, 2021) was to better understand the mechanisms and how to improve management of glaucoma after KPro implantation. The approaches used in this thesis included investigating one of the largest KPro patient cohorts in North America, with a total of 157 operated patients at that time, as well as studying KPro surgery and outcomes in mice. The first objective was to identify risk factors for glaucoma development and progression after KPro implantation (paper II). Multivariate logistic regression revealed that high preoperative IOP signals a higher risk for both glaucoma development and progression. Stromal and endothelial corneal disorders were less associated with glaucoma progression, while autoimmune and ocular surface diseases precipitated glaucoma development. Second, there is no objective evidence that indicates the best order for glaucoma surgeries and KPro implantation. By comparing medical and surgical management in KPro eyes with either preexisting or de novo glaucoma (paper III), we showed that glaucoma surgery may be performed before or at the time of KPro in eyes with preexisting glaucoma to limit progression without increasing complications. In eyes with de novo glaucoma, glaucoma surgery did not increase complications compared with medications. Third, among glaucoma surgery interventions, the two most frequently implanted glaucoma drainage devices were compared in KPro patients (paper IV). Compared with the Ahmed glaucoma valve, the Baerveldt glaucoma implant was associated with lower failure rates, without increased postoperative complications. Fourth, even with aggressive management, many KPro patients suffer from progressive optic nerve damage, sometimes despite normal IOP. Inflammatory cytokines play an important role in glaucomatous optic neuropathy, but their role in KPro‐associated glaucoma is still unknown. By analysing tear fluid of KPro patients by multiplex bead immunoassay (paper V), we identified that cytokines TNF‐a, IL‐1b, FGF‐basic and IFN‐g were elevated in KPro patients with glaucoma compared to those without. These cytokines correlated with optic nerve excavation and IOP. For the first time in humans, these results concorded with the elevations of TNF‐a and IL‐1b documented in the mouse KPro model. Ocular surface inflammation may thus reflect the inflammatory processes that perpetuate glaucoma damage years after KPro surgery. Fifth, we determined that miniaturized mouse KPro implantation requires extensive practice to be used as a reproducible model of glaucoma post‐KPro (paper VI). KPro animal models with larger eyes and a full‐thickness, 360‐degree corneal excision should be prioritized to best validate human outcomes. In conclusion, glaucoma in KPro eyes is a long‐lasting and multifactorial process. Most probable mechanisms combine IOP‐independent inflammation mediated by TNF‐a and IL‐1b that prolong glaucoma damage, together with post‐surgical angle closure elevating the IOP. Altogether, our results inform glaucoma risk profiling of transplant recipients, improvement of surgical management of KPro patients with glaucoma and development of targeted treatments to minimize glaucomatous damage after KPro. Ultimately, this work has the potential to preserve the vision of thousands of patients who undergo KPro surgery every year worldwide and to provide insight for the role of inflammation in other diseases involving neuronal damage. RÉSUMÉ (FRENCH SUMMARY) La cécité cornéenne est l'une des causes les plus importantes de déficience visuelle dans le monde. Le traitement usuel est de remplacer la cornée malade par une greffe de cornée traditionnelle. Dans les yeux à haut risque d'échec de greffe, la kératoprothèse de Boston de type 1 (KPro) peut rétablir la vision et est la cornée artificielle la plus utilisée au monde. Cependant, le glaucome est une complication importante de la KPro (papier I). Cette maladie chronique est influencée par une pression intraoculaire (PIO) élevée et endommage le nerf optique, menant à une perte de vision. Chez les patients avec KPro, le glaucome est fréquent et difficile à contrôler, mais sa cause exacte demeure inconnue. L'objectif principal de cette thèse est de découvrir les mécanismes et d'optimiser la prise en charge du glaucome après l'implantation de la KPro. Pour ce faire, nous avons investigué l'une des plus grandes cohortes de patients KPro en Amérique du Nord avec un total de 157 patients, ainsi qu'un groupe de souris ayant reçu une implantation de kératoprothèse. Le premier but était d'identifier les facteurs de risque pour le développement et la progression du glaucome après la KPro (papier II). Par régression logistique multivariée, nous avons démontré qu'une PIO préopératoire élevée mène à un plus grand risque de développement et de progression du glaucome. Les maladies cornéennes stromales ou endothéliales sont moins associées à une progression, alors que les maladies autoimmunes ou de la surface oculaire précipitent le développement du glaucome. Deuxièmement, il n'existe aucune donnée objective pour indiquer le meilleur ordre des chirurgies de glaucome et de KPro. En comparant les traitements médicaux et chirurgicaux des yeux KPro avec glaucome (papier III), nous avons démontré que les chirurgies de glaucome peuvent limiter la progression en étant effectuées avant ou pendant l'implantation de KPro dans les yeux avec glaucome préexistant, sans augmenter les complications. Dans le glaucome de novo, les chirurgies de glaucome n'augmentent pas les complications en comparaison aux médicaments. Troisièmement, les deux implants de glaucome les plus communs ont été étudiés chez les patients KPro (papier IV). Comparé à la valve Ahmed, l'implant Baerveldt est associé à des taux d'échec plus bas, sans augmentation des complications. Quatrièmement, même avec une prise en charge agressive, plusieurs patients KPro souffrent de glaucome qui progresse, parfois sans PIO élevée. Les cytokines inflammatoires jouent un rôle dans la pathophysiologie du glaucome, mais leur rôle dans le glaucome associé à la KPro est inconnu. En analysant les larmes de patients KPro (papier V), nous avons identifié que les cytokines TNF‐a, IL‐1b, FGF‐basic et IFN‐g sont élevées chez les patients KPro avec glaucome comparé à ceux sans glaucome. Ces cytokines corrèlent avec l'excavation du nerf optique et la PIO. Pour la première fois chez les humains, ces résultats concordent avec les niveaux élevés de TNF‐a et IL‐1b documentés dans le modèle murin de KPro. L'inflammation de la surface oculaire pourrait donc refléter les processus inflammatoires qui perpétuent le dommage glaucomateux. Cinquièmement, nous avons déterminé que l'implantation de la KPro miniature chez la souris requiert beaucoup de pratique pour être utilisé comme modèle de glaucome post‐KPro (papier VI). Des modèles animaux avec des yeux plus larges et une excision cornéenne de pleine épaisseur sur 360 degrés devraient être priorisés pour valider les résultats chez l'humain. En conclusion, le glaucome associé à la KPro est un processus multifactoriel qui persiste à long terme. Les mécanismes probables combinent l'inflammation médiée par TNF‐a et IL‐1b et une fermeture de l'angle qui augmente la PIO. Nos résultats contribuent à établir les facteurs de risque de glaucome pour les receveurs de KPro, à améliorer leur prise en charge et à développer des thérapies ciblées. Ce travail a le potentiel de préserver la vision de milliers de patients recevant une KPro chaque année dans le monde et d'aider à mieux comprendre le rôle de l'inflammation dans d'autres maladies avec atteinte neuronale. [ABSTRACT FROM AUTHOR]

Cavernomas are histologically benign vascular malformations found at different sites in the brain. A rare site for such cavernomas, however, is the anterior optic pathway, comprising the optic nerve, chiasma, and optic tract—called optochiasmatic cavernomas (OCC). These lesions usually present with sudden onset or progressive vision loss, headache, and features mimicking pituitary apoplexy. In this paper, we describe a case of OCC operated at our center. We carry out an updated review of literature depicting cases of OCC, their clinical presentation, management, and postoperative complications. We also propose a novel classification system based on lesion location and further analyze these cavernoma types with respect to the surgical approach used and visual outcome. A 30-year-old lady had presented with a 3-week history of progressive bilateral vision loss and headache. Based on imaging, she was suspected to have a cavernous angioma of the chiasma and left optic tract. Due to progressive vision deterioration, the lesion was surgically excised using pterional craniotomy. Postoperatively, her visual symptoms improved, but she developed diabetes insipidus. Clinical and radiological follow-up has been done for 18 months after surgery. A total of 81 cases have been described in the literature, including the present case. Chiasmal apoplexy is the most common presentation. Surgical excision is the standard of care. Our analysis based on lesion location shows the most appropriate surgical approach to be used for each cavernoma type. Visual outcome correlates with the preoperative visual status. Visual outcome is good in patients presenting with acute chiasmal apoplexy, and when complete surgical excision is performed. The endonasal endoscopic approach was found to provide the best visual outcome. In addition to preoperative visual status, complete surgical excision predicts favorable visual outcomes in OCC. Our proposed classification system guides the appropriate surgical approach required for a particular location of the cavernoma. [ABSTRACT FROM AUTHOR]

Aim: To identify the risk factors for optic nerve hypoplasia (ONH) and septo‐optic dysplasia (SOD). Method: A retrospective, population‐based study with case–control design was undertaken using the Population Research Data Repository at the Manitoba Center for Health Policy in Manitoba, Canada. Cases were 111 patients (63 males, 48 females; age range 1–35 years [mean 11 years 6 months, SD 7 years 2 months]) with ONH and SOD diagnosed from 1990 to 2019, matched to 555 unrelated population‐based controls (315 males, 240 females; age range 1–35 years [mean 11 years 6 months, SD 7 years 2 months]) on year of birth, sex, and area of residence. Additionally, 75 cases (46 males, 29 females; age range 2–35 years [mean 12 years 6 months, SD 7 years 2 months]) with ONH and SOD were matched one‐on‐one with sibling controls (40 males, 35 females; age range 0–33 years [mean 11 years 7 months, SD 7 years 10 months], the rest did not have siblings). Several antenatal maternal risk factors associated with ONH and SOD were tested for their association with case and control group membership using adjusted odds ratios (ORs) and 95% confidence intervals (CIs) from a multivariate conditional logistic regression model. The outcome was the risk of developing ONH and SOD. Results: Maternal age at conception (OR = 0.91, 95% CI = 0.86–0.96), primigravida (OR = 3.39, 95% CI = 1.92–6.01), and smoking (OR = 2.86, 95% CI = 1.61–5.05) were independently associated with ONH and SOD in the cohort matched to unrelated controls (p < 0.001). In the sibling cohort, smoking was an important risk factor (OR = 3.65, 95% CI = 1.2–11.1, p = 0.02). Interpretation: Unmodifiable and modifiable antenatal maternal risk factors are associated with ONH and SOD. Our investigation suggests that several risk factors reported in previous studies may have been due to confounding bias and that maternal smoking during pregnancy is the main modifiable risk factor associated with ONH and SOD. What this paper adds: Historically, many antenatal risk factors have been associated with optic nerve hypoplasia (ONH) and septo‐optic dysplasia (SOD).Population‐based data with matched controls for potential confounding bias are lacking.Young maternal age at conception, primigravida, and smoking during pregnancy are the main risk factors for ONH and SOD using a population‐based, case–control design. [ABSTRACT FROM AUTHOR]

Introduction: Optic nerve and chiasm hemangioblastomas are rare tumors, occurring sporadically or in the context of von Hippel-Lindau (VHL) disease. They have only been portrayed in isolated case reports and small cohorts. Their natural history and therapeutic strategies are only scarcely described. To better characterize these rare tumors, we retrospectively analyzed an optic nerve and chiasm hemangioblastoma series of 12 VHL patients. By combining our own experience to a review of all known cases in literature, we intended to create treatment recommendations for optic nerve and chiasm hemangioblastomas in VHL patients. Methods: We reviewed two electronic databases in the hospitals of our senior authors, searching for VHL patients with optic nerve or chiasm hemangioblastomas. Clinical data were summarized. Tumor size and growth rate were measured on contrast enhanced MRI. Comparable data were collected by literature review of all available cases in VHL patients (Pubmed, Trip, Google and Google Scholar). Results: Of 269 VHL patients, 12 had optic nerve or chiasm hemangioblastomas. In 10 of 12 patients, tumors were diagnosed upon annual ophthalmoscopic/MRI screening. Of 8 patients who were asymptomatic at diagnosis, 7 showed absent or very slow annual progression, without developing significant vision impairment. One patient developed moderate vision impairment. Two symptomatic patients suffered from rapid tumor growth and progressive vision impairment. Both underwent late-stage surgery, resulting in incomplete resection and progressive vision impairment. One patient presented with acute vision field loss. A watchful-waiting approach was adopted because the hemangioblastoma was ineligible for vision-sparing surgery. One patient developed progressive vision impairment after watchful waiting. In the literature we found 45 patient cases with 48 hemangioblastomas. Discussion: When optic nerve and chiasm hemangioblastomas are diagnosed, we suggest annual MRI follow-up as long as patients do not develop vision impairment. If tumors grow fast, threaten the contralateral eye, or if patients develop progressive vision deficiency; surgical resection must be considered because neurological impairment is irreversible, and resection of large tumors carries a higher risk of further visual decline. [ABSTRACT FROM AUTHOR]

Traumatic optic neuropathy (TON) is a rare that causes severe visual impairment usually results from cranial or ocular trauma. TON manifests directly and indirectly, which is more common. The incidence rate ranges from 0.7% to 2.5%. Clinical indicators of TON include the presence of an afferent pupillary defect after trauma, decreased vision acuity and intact ocular structure. Surgical decompression appears to be a feasible option in cases with direct bone compression on the optic nerve or progressive vision impairment in indirect TON. However, the evidence supporting treatment efficacy for improvement in vision is still ambiguous. This review will examine surgical techniques for decompressing the optic canal. [ABSTRACT FROM AUTHOR]

The microtubule-associated protein Tau is a key player in various neurodegenerative conditions, including Alzheimer's disease (AD) and Tauopathies, where its hyperphosphorylation disrupts neuronal microtubular lattice stability. Glaucoma, a neurodegenerative disorder affecting the retina, leads to irreversible vision loss by damaging retinal ganglion cells and the optic nerve, often associated with increased intraocular pressure. Prior studies have indicated Tau expression and phosphorylation alterations in the retina in both AD and glaucoma, yet the causative or downstream nature of Tau protein changes in these pathologies remains unclear. This study investigates the impact of Tau protein modulation on retinal neurons under normal and experimental glaucoma conditions. Employing AAV9-mediated gene therapy for Tau overexpression and knockdown, both manipulations were found to adversely affect retinal structural and functional measures as well as neuroprotective Akt/Erk survival signalling in healthy conditions. In the experimental glaucoma model, Tau overexpression intensified inner retinal degeneration, while Tau silencing provided significant protection against these degenerative changes. These findings underscore the critical role of endogenous Tau protein levels in preserving retinal integrity and emphasize the therapeutic potential of targeting Tau in glaucoma pathology. [ABSTRACT FROM AUTHOR]

The development of the optic nerve and its surrounding tissues during the early fetal period is a convoluted period because it spans both the organogenesis period and the fetal period. This study details the microscopic anatomy and histoembryology of the optic nerve in embryos during the early fetal period, including the second half of the first trimester of pregnancy. Serial sections through the orbit of variously aged embryos allowed us to analyze the nerve in both longitudinal and transverse aspects. A histological assessment and description of the structures surrounding and inside the nerve were performed, highlighting the cellular subtypes involved. By employing immunohistochemical techniques, we could characterize the presence and distribution of astrocytes within the optic nerve. Our findings suggest that by the 8th gestational week (WG) the structures are homologs to all the adult ones but with an early appearance so that maturation processes take place afterward. By this age, the axons forming the nerve are definitive adult axons. The glial cells do not yet exhibit adult phenotype, but their aspect becomes adult toward the 13th week. During its development the optic nerve increases in size then, at 14 weeks, it shrinks considerably, possibly through its neural maturation process. The morphological primordium of the blood–nerve barrier can be first noted at 10 WG and at 13 WG the morphological blood–nerve barrier is definitive. The meningeal primordium can be first noted as a layer of agglomerated fibroblasts, later toward 13 WG splitting in pachymeninx and leptomeninges and leaving space for intrinsic blood vessels. [ABSTRACT FROM AUTHOR]

Introduction: Neuromonitoring represents a cornerstone in the comprehensive management of patients with traumatic brain injury (TBI), allowing for early detection of complications such as increased intracranial pressure (ICP) [1]. This has led to a search for noninvasive modalities that are reliable and deployable at bedside. Among these, ultrasonographic optic nerve sheath diameter (ONSD) measurement is a strong contender, estimating ICP by quantifying the distension of the optic nerve at higher ICP values. Thus, this scoping review seeks to describe the existing evidence for the use of ONSD in estimating ICP in adult TBI patients as compared to gold-standard invasive methods. Materials and Methods: This review was conducted in accordance with the Joanna Briggs Institute methodology for scoping reviews, with a main search of PubMed and EMBASE. The search was limited to studies of adult patients with TBI published in any language between 2012 and 2022. Sixteen studies were included for analysis, with all studies conducted in high-income countries. Results: All of the studies reviewed measured ONSD using the same probe frequency. In most studies, the marker position for ONSD measurement was initially 3 mm behind the globe, retina, or papilla. A few studies utilized additional parameters such as the ONSD/ETD (eyeball transverse diameter) ratio or ODE (optic disc elevation), which also exhibit high sensitivity and reliability. Conclusion: Overall, ONSD exhibits great test accuracy and has a strong, almost linear correlation with invasive methods. Thus, ONSD should be considered one of the most effective noninvasive techniques for ICP estimation in TBI patients. [ABSTRACT FROM AUTHOR]

Introduction: Myopia is a prevalent refractive condition associated with higher occupational groups and education. Contributing data from a region like Saudi Arabia adds to the global understanding of myopia progression, potentially uncovering patterns or risk factors that may differ from those observed in other parts of the world. Aim: To estimate myopia progression among junior medical students. Materials and Methods: This was a one-year longitudinal cohort study conducted on 85 students at King Abdulaziz University Hospital, Jeddah, Saudi Arabia. Demographics, detailed ocular history, use of electronic devices, and other related risk factors were collected at the start of the study. Students underwent a comprehensive eye examination including visual acuity, autorefraction, ocular biometry, and Spectral Domain-Optical Coherence Tomography (SD-OCT) of the macula and optic nerve at the start and end of the study. Progression of myopia over one year and its associations were assessed using pairedsamples t-test for a single group, while =two-group comparison was tested with Independent t-tests and one-way Analysis of Variance (ANOVA), respectively. Results: This cohort study involved 85 medical students (41 men and 44 women) aged between 19 and 23 years. Myopia prevalence was 76.5% (65/85) on the first visit. One participant progressed from hyperopia to myopia, five from initial emmetropia to myopia, four from mild to moderate myopia, and one from moderate to high myopia. A significant myopic shift was observed in the second visit in both eyes {Right Eye (RE): -0.3D, p-value=0.001; Left Eye (LE): -0.2 D, p-value=0.015}. The myopic shift in male participants from a mean±SD of -1.1±1.6 D (RE) and -1.0±1.5 D (LE) to -1.5±1.7 D (RE) and -1.4±1.7 D (LE) in the one year follow-up was statistically significant (RE: p-value=0.006; LE: p-value=0.004). Myopia prevalence was significantly related to the hours spent reading for learning/studying and hours spent watching TV at the first visit (p-value=0.023, p-value=0.046, respectively) and total weekly average screen time at the second visit (p-value=0.002). Conclusion: The medical students had a significant myopic shift over one year, which was associated with longer hours spent reading. The factors associated with the rapid refraction change should be identified to reduce myopic shift among medical students. [ABSTRACT FROM AUTHOR]

Background: To investigate association between optic disc parameters analyzed by optical coherence tomography (OCT) and occurrence of peripheral retinal tears in patients with symptomatic posterior vitreous detachment (PVD). Methods: This cross-sectional study enrolled 75 patients with symptoms of acute PVD, who were allocated into two groups based on whether a peripheral retinal tear occurred or not. Results: When comparing the average retinal nerve fiber layer (RNFL) thickness (μm) between retinal tear and control groups, it was shown that patients with a retinal tear have a significantly higher (87.18 [95% confidence interval (CI), 84.47 to 89.9] vs 81.14 [95% CI, 77.81 to 84.46], P = 0.005) average RNFL thickness. Furthermore, we observed a significant difference (0.13, 0.06 to 0.22 vs 0.07, 0.04 to 0.1, P = 0.036, Mann–Whitney U-test) in the size of cup volume (mm3) between the tear and control groups, respectively. Linear regression showed a significant decrease (P = 0.029) in average RNFL thickness with increasing age, but without a significant difference between the two groups. There was no statistically significant difference between the tear and control groups in terms of rim area, disc area, and average cup-to-disc ratio. Conclusion: Patients with a higher average RNFL thickness and larger cup volume measured by OCT were more prone to develop a peripheral retinal tear. Increased peripapillary average RNFL thickness due to trauma and subsequent inflammation, possibly related to the more adherent posterior hyaloid membrane to the retina, may also indicate strengthened adhesions in the areas of the peripheral retina where retinal tears occur. OCT analysis of the optic nerve head may be used in everyday clinical practice as a predictor of the development of peripheral retinal tears in patients with symptomatic PVD. [ABSTRACT FROM AUTHOR]

Background: Inherited primary open-angle glaucoma (POAG) in Beagle dogs is a well-established large animal model of glaucoma and is caused by a G661R missense mutation in the ADAMTS10 gene. Using this model, the study describes early clinical disease markers for canine glaucoma. Methods: Spectral-domain optical coherence tomography (SD-OCT) was used to assess nine adult, ADAMTS10-mutant (median age 45.6 months, range 28.8–52.8 months; mean diurnal intraocular pressure (IOP): 29.9 +/− SEM 0.44 mmHg) and three related age-matched control Beagles (mean diurnal IOP: 18.0 +/− SEM 0.53 mmHg). Results: Of all the optic nerve head (ONH) parameters evaluated, the loss of myelin peak height in the horizontal plane was most significant (from 154 +/− SEM 38.4 μm to 9.3 +/− SEM 22.1 μm; p < 0.01). There was a strong significant negative correlation between myelin peak height and IOP (Spearman correlation: −0.78; p < 0.003). There were no significant differences in the thickness of any retinal layers evaluated. Conclusions: SD-OCT is a useful tool to detect early glaucomatous damage to the ONH in dogs before vision loss. Loss in myelin peak height without inner retinal thinning was identified as an early clinical disease marker. This suggests that initial degenerative changes are mostly due to the loss of myelin. [ABSTRACT FROM AUTHOR]

Neurons pose a particular challenge to degradative processes like autophagy due to their long and thin processes. Autophagic vesicles (AVs) are formed at the tip of the axon and transported back to the soma. This transport is essential since the final degradation of the vesicular content occurs only close to or in the soma. Here, we established an in vivo live-imaging model in the rat optic nerve using viral vector mediated LC3-labeling and two-photon-microscopy to analyze axonal transport of AVs. Under basal conditions in vivo, 50% of the AVs are moving with a majority of 85% being transported in the retrograde direction. Transport velocity is higher in the retrograde than in the anterograde direction. A crush lesion of the optic nerve results in a rapid breakdown of retrograde axonal transport while the anterograde transport stays intact over several hours. Close to the lesion site, the formation of AVs is upregulated within the first 6 h after crush, but the clearance of AVs and the levels of lysosomal markers in the adjacent axon are reduced. Expression of p150Glued, an adaptor protein of dynein, is significantly reduced after crush lesion. In vitro, fusion and colocalization of the lysosomal marker cathepsin D with AVs are reduced after axotomy. Taken together, we present here the first in vivo analysis of axonal AV transport in the mammalian CNS using live-imaging. We find that axotomy leads to severe defects of retrograde motility and a decreased clearance of AVs via the lysosomal system. [ABSTRACT FROM AUTHOR]

Postmortem human eyes were subjected to optic nerve (ON) traction in adduction and elevated intraocular pressure (IOP) to investigate scleral surface deformations. We incrementally adducted 11 eyes (age 74.1 ± 9.3 years, standard deviation) from 26° to 32° under normal IOP, during imaging of the posterior globe, for analysis by three-dimensional digital image correlation (3D-DIC). In the same eyes, we performed uniaxial tensile testing in multiple regions of the sclera, ON, and ON sheath. Based on individual measurements, we analyzed eye-specific finite element models (FEMs) simulating adduction and IOP loading. Analysis of 3D-DIC showed that the nasal sclera up to 1 mm from the sheath border was significantly compressed during adduction. IOP elevation from 15 to 30 mmHg induced strains less than did adduction. Tensile testing demonstrated ON sheath stiffening above 3.4% strain, which was incorporated in FEMs of adduction tethering that was quantitatively consistent with changes in scleral deformation from 3D-DIC. Simulated IOP elevation to 30 mmHg did not induce scleral surface strains outside the ON sheath. ON tethering in incremental adduction from 26° to 32° compressed the nasal and stretched the temporal sclera adjacent to the ON sheath, more so than IOP elevation. The effect of ON tethering is influenced by strain stiffening of the ON sheath. [ABSTRACT FROM AUTHOR]

This study investigated the effect of intraocular pressure (IOP) reduction on pulsatile displacement within the optic nerve head (ONH) in primary open-angle glaucoma (POAG) patients with and without axial myopia. Forty-one POAG patients (19 without myopia, 9 with axial myopia and 13 glaucoma with no intervention) participated. Swept-source optical coherence tomography (OCT) videos of the ONH were obtained before and after IOP-lowering treatment (medical or surgical) achieving a minimum IOP drop of 3 mmHg. A demons registration-based algorithm measured local pulsatile displacement maps within the ONH. Results demonstrated a significant 14% decrease in pulsatile tissue displacement in the non-myopic glaucoma cohort after intervention (p = 0.03). However, glaucoma patients with axial myopia exhibited no statistically significant change. There were no significant changes in the pulsatile ONH deformation in the control group. These findings suggest a potential link between IOP reduction and reduced pulsatile displacement within the ONH in POAG patients without myopia, offering new insights into the disease's pathophysiology and warranting further investigation into underlying mechanisms and clinical implications. [ABSTRACT FROM AUTHOR]

Objective: The retina is a protrusion of the brain, so researchers have recently proposed retinal changes as a new marker for studying central nervous system diseases. To investigate optic nerve head neurovascular structure assessed by optical coherence tomography angiography (OCTA) in schizophrenia compared to healthy subjects. Methods: The study was conducted from 2019 to 2021 at the Ibn Sina Psychiatric Hospital in Mashhad, Iran. We enrolled 22 hospitalized known cases of schizophrenia, treated with risperidone as an antipsychotic drug, and 22 healthy subjects. The two groups were matched in age and gender. In the schizophrenic group, the positive and negative syndrome scale test was used to assess the illness severity. All subjects underwent complete ophthalmic evaluations and OCTA imaging. Results: We found that the cup/disc area ratio, vertical cup/disc ratio, and horizontal cup/disc ratio are significantly higher in patients with schizophrenia than in healthy subjects (with p‐values of 0.019, 0.015, and 0.022, respectively). No statistically significant difference in the peripapillary retinal nerve fiber layer and vascular parameters of the optic nerve head was observed between schizophrenia and healthy groups. Conclusion: We found evidence regarding the difference in the optic nerve head tomographic properties in schizophrenia compared to healthy subjects. However, ONH vascular parameters showed no significant difference. More studies are needed for a definite conclusion. [ABSTRACT FROM AUTHOR]

Background and Objectives: A magnetic resonance imaging (MRI) scan is part of the diagnostic protocol in pituitary adenoma patients. The goal of the present study is to present and analyse the MRI appearances of the sphenoid sinus (SS) in patients with non-functioning pituitary adenoma (NFPA). Materials and Methods: This is a retrospective case–control study conducted between January 2015 and December 2023 in a tertiary referral hospital. Forty NFPA patients were included in the study group, while the control group consisted of 30 age- and gender-matched cases. Results: The sellar type of SS pneumatization was the most frequently encountered pattern among both groups. The presence of the lateral recess of the SS, mucosal cysts, and sphenoethmoidal cells was similar in both patient groups. The proportion of patients with SS mucosal thickness greater than 3 mm was 42.5% in NFPA group and 3% in the control group, and this difference was statistically significant (p < 0.001). The space between the two optic nerves was significantly larger in the NFPA group as compared to the control group (p < 0.001). Conclusions: Our study was able to establish a statistically significant association between the presence of NFPA and both the thickening of the SS mucosa and increased space between optic nerves. [ABSTRACT FROM AUTHOR]

Pyroelectric infrared sensors (PIR) are widely used as infrared (IR) detectors due to their basic implementation, low cost, low power, and performance. Combined with a Fresnel lens, they can be used as a binary detector in applications of presence and motion control. Furthermore, due to their features, they can be used in autonomous intelligent devices or included in robotics applications or sensor networks. In this work, two neural processing architectures are presented: (1) an analog processing approach to achieve the behavior of a presynaptic neuron from a PIR sensor. An analog circuit similar to the leaky integrate and fire model is implemented to be able to generate spiking rates proportional to the IR stimuli received at a PIR sensor. (2) An embedded postsynaptic neuron where a spiking neural network matrix together with an algorithm based on digital processing techniques is introduced. This structure allows connecting a set of sensors to the post-synaptic circuit emulating an optic nerve. As a case study, the entire neural processing approach presented in this paper is applied to optical flow detection considering a four-PIR array as input. The results validate both the spiking approach for an analog sensor presented and the ability to retrieve the analog information sent as spike trains in a simulated optic nerve. [ABSTRACT FROM AUTHOR]

Optic never fibers in the visual pathway play significant roles in vision formation. Damages of optic nerve fibers are biomarkers for the diagnosis of various ophthalmological and neurological diseases; also, there is a need to prevent the optic nerve fibers from getting damaged in neurosurgery and radiation therapy. Reconstruction of optic nerve fibers frommedical images can facilitate all these clinical applications. Although many computational methods are developed for the reconstruction of optic nerve fibers, a comprehensive review of these methods is still lacking. This paper described both the two strategies for optic nerve fiber reconstruction applied in existing studies, i.e., image segmentation and fiber tracking. In comparison to image segmentation, fiber tracking can delineate more detailed structures of optic nerve fibers. For each strategy, both conventional and AI-based approaches were introduced, and the latter usually demonstrates better performance than the former. Fromthe review, we concluded that AI-basedmethods are the trend for optic nerve fiber reconstruction and some new techniques like generative AI can help address the current challenges in optic nerve fiber reconstruction. [ABSTRACT FROM AUTHOR]

The optic nerve is the second cranial nerve (CN II) that connects and transmits visual information between the retina and the brain. Severe damage to the optic nerve often leads to distorted vision, vision loss, and even blindness. Such damage can be caused by various types of degenerative diseases, such as glaucoma and traumatic optic neuropathy, and result in an impaired visual pathway. To date, researchers have not found a viable therapeutic method to restore the impaired visual pathway; however, in this paper, a newly synthesized model is proposed to bypass the damaged portion of the visual pathway and set up a direct connection between a stimulated visual input and the visual cortex (VC) using Low-frequency Ring-transducer Ultrasound Stimulation (LRUS). In this study, by utilizing and integrating various advanced ultrasonic and neurological technologies, the following advantages are achieved by the proposed LRUS model: 1. This is a non-invasive procedure that uses enhanced sound field intensity to overcome the loss of ultrasound signal due to the blockage of the skull. 2. The simulated visual signal generated by LRUS in the visual-cortex-elicited neuronal response in the visual cortex is comparable to light stimulation of the retina. The result was confirmed by a combination of real-time electrophysiology and fiber photometry. 3. VC showed a faster response rate under LRUS than light stimulation through the retina. These results suggest a potential non-invasive therapeutic method for restoring vision in optic-nerve-impaired patients using ultrasound stimulation (US). [ABSTRACT FROM AUTHOR]

Glaucoma is a series of linked optic diseases resulting in progressive vision loss and total blindness due to the acquired loss of retinal ganglion cells. This harm to the optic nerve results in visual impairment and, ultimately, total blindness if left untreated. Primary open-angle glaucoma (POAG) is the most frequent variety within the large family of glaucoma. It is a multifaceted and heterogeneous condition with several environmental and genetic variables aiding in its etiology. By 2040, there will be 111.8 million glaucoma patients globally, with Asia and Africa accounting for the vast majority. The goal of this review is to elaborate on the role of genes (nuclear and mitochondrial) as well as their variants in the pathogenesis of POAG. PubMed and Google Scholar databases were searched online for papers until September 2022. Prevalence and inheritance patterns vary significantly across different ethnic and geographic populations. Numerous causative genetic loci may exist; however, only a few have been recognized and characterized. Further investigation into the genetic etiology of POAG is expected to uncover novel and intriguing causal genes, allowing for a more precise pathogenesis pattern of the disease. [ABSTRACT FROM AUTHOR]

The contributions of this paper are two-fold. First, it uses machine learning tools to detect and monitor glaucoma. Second, it provides insight into medicine, which can assist healthcare professionals in improving disease diagnostic accuracy and help to reduce the progression and degeneration of retinal ganglion cells in patients. Glaucoma is a group of eye diseases that damage the optic nerve, which can cause vision loss and blindness at any age. The main symptom of glaucoma in the early stages is high internal eye pressure. It is still unknown what causes these diseases to develop, but if not treated, they result in optic nerve atrophy. For this reason, in this paper we propose a novel deep learning system for the automatic diagnosis of glaucoma using a convolutional neural network for classification, which demonstrates improved performance and records computation time for fundus images. The results showed an accuracy of 94 % and a loss value of only 0.27. The model we have created to investigate with Keras helped us achieve good results in our training and testing process. These study results demonstrate the ability of a deep learning model to identify glaucoma from fundus images. Increasing the filter size and training the model resulted in a higher accuracy rate. A population survey that was conducted in 2019 shows that most patients with glaucoma become aware of their disease late, after the disease causes a high level of optic nerve damage and a high percentage of vision loss. Early diagnosis and detection of glaucoma using optic nerve imaging technology have gained wide clinical interest in stopping or slowing the progression of the disease, allowing the development of new algorithms to automate the diagnosis of eye diseases. [ABSTRACT FROM AUTHOR]

Subacute Sclerosing Panencephalitis (SSPE) is a rare, slowly progressive disorder that affects the entire nervous system. It primarily involves the cerebral cortex, subcortex and optic nerves. Caused by a mutated strain of the measles virus, the disease is mostly irreversible and devastating. It presents with gradually progressive cognitive impairment, extrapyramidal symptoms and sometimes seizures. Although commonly seen in unvaccinated children, SSPE of adult onset is uncommon. The disease is fatal and currently has no treatment. There have been many different presentations of this disorder, ranging from optic nerve involvement to gradual cognitive decline, but none have a good prognosis; ultimately, patients may become akinetic and mute. Here, the authors present an uncommon case of SSPE occurring at an older age (26-year-old male), with a rapid and atypical presentation resembling severe post-viral syndrome, which was later diagnosed as SSPE. [ABSTRACT FROM AUTHOR]

This paper proposes ensemble strategies for the deep learning object detection models carried out by combining the variants of a model and different models to enhance the anatomical and pathological object detection performance in brain MRI. In this study, with the help of the novel Gazi Brains 2020 dataset, five different anatomical parts and one pathological part that can be observed in brain MRI were identified, such as the region of interest, eye, optic nerves, lateral ventricles, third ventricle, and a whole tumor. Firstly, comprehensive benchmarking of the nine state-of-the-art object detection models was carried out to determine the capabilities of the models in detecting the anatomical and pathological parts. Then, four different ensemble strategies for nine object detectors were applied to boost the detection performance using the bounding box fusion technique. The ensemble of individual model variants increased the anatomical and pathological object detection performance by up to 10% in terms of the mean average precision (mAP). In addition, considering the class-based average precision (AP) value of the anatomical parts, an up to 18% AP improvement was achieved. Similarly, the ensemble strategy of the best different models outperformed the best individual model by 3.3% mAP. Additionally, while an up to 7% better FAUC, which is the area under the TPR vs. FPPI curve, was achieved on the Gazi Brains 2020 dataset, a 2% better FAUC score was obtained on the BraTS 2020 dataset. The proposed ensemble strategies were found to be much more efficient in finding the anatomical and pathological parts with a small number of anatomic objects, such as the optic nerve and third ventricle, and producing higher TPR values, especially at low FPPI values, compared to the best individual methods. [ABSTRACT FROM AUTHOR]

Glaucoma is a typical neurodegenerative disease that causes permanent vision deficits. Early detection is important to prevent vision loss as the patient is unaware of the damage and severity because pain is not induced during the process and progresses gradually. To predict glaucoma, fundus image-based deep learning models are being actively developed. In the traditional approach, original fundus photographs including red, green, and blue (RGB) channels were used as a learning material of deep learning models. In this paper, we propose a new pre-processing method to produce the learning images by segmenting vascular, optic nerve papillae, and optic nerve indentation images from the original fundus images, and we built a deep learning model; previous RGB channels are replaced into our three segmented images. We test the proposed method using two datasets and confirm that proposed method shows better performance than previous approaches that use original fundus photographs. [ABSTRACT FROM AUTHOR]

Glaucoma is an asymptotic condition that damages the optic nerves of a human eye. Glaucoma is frequently caused due to abnormally high pressure in an eye that leads to permanent blindness. Detecting glaucoma at an initial phase has the possibility of curing this disease, but diagnosing accurately is considered as a challenging task. Therefore, this paper proposes a novel method known as a glaucoma detection system that performs the diagnosis of glaucoma by exploiting the prescribed characteristics. The significant intention of this paper involves diagnosing the glaucoma disease present at the top optical nerve of a human eye. The proposed glaucoma detection has used four different phases namely data preprocessing or enhancement phase, segmentation phase, feature extraction phase, and classification phase. Here, a novel classifier named fractional gravitational search-based hybrid deep neural network (FGSA-HDNN) is developed for the effective classification of glaucoma-infected images from the normal image. Finally, the experimental analysis for the proposed approach and various other techniques are performed, and the accuracy rate while diagnosing glaucoma achieved is 98.75%. [ABSTRACT FROM AUTHOR]