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Elevated intracranial pressure (ICP) in patients with cerebral lesions has garnered considerable attention in research. It often manifests as a common symptom in conditions such as intracranial tumors, intracerebral hemorrhage, and cerebral edema. This paper provides an overview of ICP concepts, discusses the advantages and disadvantages of traditional monitoring methods, explores the physiological and anatomical aspects of the optic nerve sheath, examines the utility of ultrasound measurement of optic nerve sheath diameter (ONSD) in both nervous system and nonnervous system disorders, and outlines the cutoff values and normal ranges for assessing elevated ICP using ultrasound measurement of ONSD. The review underscores ultrasound measurement of ONSD as a promising noninvasive, safe, straightforward, and repeatable examination technique for various diseases. Nevertheless, the lack of standardized cutoff values for elevated ICP remains a challenge. Summarizing studies on optic nerve sheaths is crucial for enhancing the efficacy of ultrasound measurement of ONSD in assessing ICP. [ABSTRACT FROM AUTHOR]

Treatment of primary open-angle glaucoma has centered on the lowering of intraocular pressure that damages the optic nerve; however, this strategy is not uniformly successful, especially in normal tension glaucoma, and there is interest in antioxidant, anti-inflammatory, and other neuroprotective strategies. Vegetarian diets are known to be rich in antioxidant and anti-inflammatory components and have a number of established health benefits. Thus, it would be reasonable to assume that vegetarian diets would be beneficial in glaucoma, but this approach has not been well studied. We examine the possible role of vegetarian diets and their components in the incidence and progression of glaucoma. [ABSTRACT FROM AUTHOR]

A 60-year-old man presented to an outside ophthalmology clinic with 1 month of progressive vision loss in the right eye (OD). Right optic disc edema was noted. Brain and orbit magnetic resonance imaging revealed right optic nerve and left occipital lobe enhancement. He was seen initially by neurology and neurosurgery and subsequently referred to neuro-ophthalmology for consideration of optic nerve biopsy. He was seen 3 months after his initial symptom onset where vision was light perception OD and a relative afferent pupillary defect with optic nerve edema. OS was unremarkable. A lumbar puncture with flow cytometry was negative for multiple sclerosis and lymphoma. At his oculoplastic evaluation for optic nerve biopsy, his vision was noted to be no light perception OD. Optic nerve biopsy demonstrated non-caseating granulomatous inflammation consistent with neurosarcoidosis. The patient was started on high-dose oral steroids with improvement of disc edema, as well as significant improvement in optic nerve and intracranial parenchymal enhancement, although his vision never improved. [ABSTRACT FROM AUTHOR]

Neurosurgical interventions and trauma are common causes of damage to the optic nerve. This determines the relevance of research for solutions aimed at restoration of the nerve's anatomical integrity, electrical conductivity, and subsequently – restoration of its function. Restore a damaged (cut) optic nerve using n. suralis autograft in vivo. The experiment involved reconstruction of the optic nerve through injury modulation, graft placement and restored nerve harvest and evaluation. Injury modulation included removal of a fragment of the optic nerve. Autograft harvesting and placement involved resection of a fragment of the sural (sensory) nerve and its subsequent anastomosis in place of the removed fragment of the optic nerve. As an experimental model, a rabbit of the "Burgundy" breed was used. The animal was previously examined for the presence of infectious and other diseases to confirm its health. Four months post operatively when stimulating the operated right eye, low-amplitude components altered in shape are registered. Thus, signs of mild restoration of electrical conductivity on the treated optic nerve were seen. Our initial experience shows the technical feasibility of reconstructing the optic nerve using an autograft, the possibility of axonal growth through the graft and, in the future, using this method for direct optic nerve reconstruction, as well as a bypass method for damage to the optic nerve with various tumor diseases of the optic nerve, tumors of the chiasmatic-sellar localization, orbital injuries. [ABSTRACT FROM AUTHOR]

The measurement of optic nerve sheath diameter is a noninvasive, practical, and economical method used to identify increased intracranial pressure. The purpose of this study is to detect the preoperative and postoperative changes in optic nerve sheath diameter in patients with intracranial mass, to correlate these changes with optic nerve diameter variations, and to evaluate the impact of hydrocephalus on these alterations. This study was conducted with patients who presented to our clinic with complaints of intracranial mass, were decided for surgery, and underwent surgical procedures. The optic nerve and optic nerve sheath diameter measurement values were different preoperatively and postoperatively, with a significant decrease in the optic nerve sheath diameter in all groups in postoperative measurements, while the optic nerve diameter significantly increased. Although there was no significant difference between the effects of hydrocephalus and intracranial mass-related increase in intracranial pressure on the optic nerve and optic nerve sheath, it was observed that hydrocephalus increased intracranial pressure when considering the Evans ratio. It has been determined that as ventricular dilatation increases, so does intracranial pressure, which leads to an increase in the diameter of the optic nerve sheath, resulting in papilledema and thinning of the optic nerve. These findings indicate the importance of early cerebrospinal fluid diversion and monitoring optic nerve sheath diameter in the management [ABSTRACT FROM AUTHOR]

Management of patients with optic nerve sheath meningiomas (ONSMs) is controversial and the treatment strategy in this patient group is still up for discussion. Transnasal endoscopic orbital and optic nerve decompression aims to reduce the pressure in the orbit and on the optic nerve and thereby prevent vision loss. This article presents material from 7 cases of transnasal endoscopic orbital decompression. The study design is a retrospective cohort study. The aim was to include all patients with a meningioma residing along the nerve sheath and who were operated using endoscopic transnasal decompression of the orbit and if needed the optic canal at Odense University Hospital. Data from the medical records were collected and pre- and postoperative eye examinations were compared. In addition, it was recorded whether there were complications to the procedure and whether additional treatments were given. In total, 4 women and 3 men were included in the study. Four out of 7 patients experienced improvement in vision after the operation. One patient experienced unchanged vision and 2 patients experienced deterioration of vision after surgery. The current report of 7 patients with ONSM shows promising results for this surgical procedure as 4 out of 7 patients experienced improvement in their vision at follow-up examinations. The 2 patients who experienced deterioration of vision already had severely reduced vision preoperatively, which indicates that surgery should be considered before the vision becomes significantly reduced. [ABSTRACT FROM AUTHOR]

Middle fossa arachnoid cysts (MFACs) are rare, congenital lesions that may rupture and cause symptoms of elevated intracranial pressure. We sought to describe the presence of and factors associated with optic nerve edema in MFACs, focusing on the utility of ophthalmologic evaluations for guiding cyst management. We reviewed clinical and radiographic information for all patients with MFACs with ophthalmologic evaluations at our institution. Headache, cranial nerve palsy, emesis, altered mental status, fatigue, and seizures were considered MFAC-related symptoms. Univariate and multivariable analyses evaluated factors associated with optic edema. Fifty-one patients between 2003 and 2022 were included. Cysts were a median volume of 169.9 cm3 (interquartile range: 70.5, 647.7). Evidence of rupture with subdural hematoma/hygroma occurred in 19 (37.3%) patients. Eighteen (35.3%) patients underwent surgery for their cyst and/or rupture-associated intracranial bleed. Eleven (21.6%) patients had optic edema; all were symptomatic and experienced cyst rupture. Ten of these patients received surgery. Postoperatively, optic edema resolved in 80% of cases. Cyst volume and symptoms were not associated with optic edema; however, patients with ruptured cysts, particularly those with traumatic rupture, were more likely to have optic edema and receive surgery (P < 0.001). We found optic edema in 21.6% of evaluated MFACs, and this comprised of 57.9% of ruptured cases. Optic edema was not found in unruptured cysts. Cyst fenestration improved optic edema and patient symptoms. In conjunction with clinical history and neuroimaging, optic edema may help guide MFAC management, particularly in patients with cyst rupture. [ABSTRACT FROM AUTHOR]

A 71-year-old woman developed sudden, painful, decreased vision in the left eye accompanied by progressive instability. Initial examination revealed left optic disc edema, and macular optical coherence tomography confirmed the presence of intraretinal and subretinal fluid, as well as hyperreflective material under the retinal pigment epithelium. Subsequent investigations, including brain magnetic resonance imaging and a comprehensive serological analysis, ruled out infectious and autoimmune causes, further complicating the diagnostic picture. The patient's vision in both eyes continued to deteriorate, prompting empirical corticosteroid treatment. While the vision improved, the case took an unexpected turn with worsening neurological symptoms. Ultimately a brain biopsy was consistent with diffuse large B-cell lymphoma. [ABSTRACT FROM AUTHOR]

To determine whether more severe baseline damage impedes measurement of minimum rim width (MRW) and peripapillary retinal nerve fiber layer thickness (RNFLT) change in glaucoma patients because of a floor effect. Prospective, longitudinal cohort study in a hospital-based setting. The study included patients with open-angle glaucoma and healthy control subjects. Participants had at least 5 years of follow-up with OCT every 6 months. Baseline global and sectorial MRW and RNFLT values were classified as within normal limits, borderline, or outside normal limits based on reference normative values. Regression analysis was used to determine the magnitude and significance of MRW and RNFLT change. Additionally, the follow-up period for each participant was divided into 2 equal halves (first and second periods) to determine whether there was attenuation of MRW and RNFLT change with follow-up time. Rates of global and sectoral MRW and RNFLT changes (slopes). A total of 97 patients with glaucoma (median age, 70.3 years) and 42 healthy subjects (median age, 64.8 years) were followed for a median of 6.9 years and 7.0 years, respectively. The median mean deviation of the visual field in glaucoma patients was –4.30 decibels (dB) (interquartile range, –7.81 to –2.06 dB; range, –20.68 to 1.37 dB). Statistically significant changes in global and sectoral MRW and RNFLT were detected across all baseline classifications; however, there was a tendency for less change with increasing baseline damage. In glaucoma patients, RNFLT slopes, but not MRW slopes, were significantly more positive (less change) in the second period compared with the first. There were also no differences in MRW or RNFLT slopes in the first and second periods in healthy subjects. Significant MRW and RNFLT changes were detected at all levels of baseline damage. However, an attenuation in the rate of RNFLT change compared with MRW indicates an earlier floor effect in RNFLT measurements globally and in equivalent sectors. Because the axonal component of these measurements should be equivalent, our results suggest important differences in tissue remodeling at the level of the optic nerve head and peripapillary retina. Proprietary or commercial disclosure may be found after the references. [ABSTRACT FROM AUTHOR]

In recent years, the endoscopic transorbital (TO) approach has gained increasing interest for the treatment of middle cranial fossa lesions. We propose a technical refinement to the conventional superior eyelid TO approach, which improves the surgical exposure and augments the working angles when targeting the opticocarotid region. Four embalmed adult cadaveric specimens (8 sides) were dissected at the Laboratory of Surgical Neuroanatomy of our institution. A TO approach was performed, with removal of the anterior clinoid process and the lateral orbital rim. Subsequently, the MacCarty keyhole was drilled in the superolateral orbital wall. Given that the lesser sphenoid wing was already drilled in the conventional TO craniectomy, the opening of the keyhole was essentially a lateral extension of the craniectomy. The procedure was successfully conducted in all 4 orbits. Clinoidectomy was performed either before or after extending the craniectomy to the MacCarty point. Extending the craniectomy made anterior clinoidectomy easier, by increasing the surgical exposure, and allowing a more lateral entrance for the endoscope. The extension also facilitated frontal lobe retraction, and it facilitated the optic nerve and carotid artery manipulation. Postoperative computed tomography scans showed a minimal 10-mm craniectomy extension, which remained covered by the temporal muscle after reconstruction. The modified endoscopic TO approach with the extension of the craniectomy to MacCarty point improves surgical access and visualization of the opticocarotid region. This facilitates anterior clinoidectomy and optic nerve decompression. Although it implies judicious instrument manipulation and a larger incision size, further studies can define its potential benefits. [ABSTRACT FROM AUTHOR]

Intraretinal or subretinal fluid in the peripapillary area can be clinically visualized in conditions such as peripapillary choroidal neovascularization, optic disc pit maculopathy, and optic nerve head tumors and granulomas. Optical coherence tomography (OCT) helps to visualize peripapillary fluid in many other chorioretinal conditions such as peripapillary pachychoroid syndrome, posterior uveitis, central retinal vein occlusion, malignant hypertension, hypotonic maculopathy as well as neuro-ophthalmological conditions such as glaucoma, microcystic macular edema and disc edema due papilledema, non-arteritic anterior ischemic optic neuropathy, neuroretinitis, and diabetic papillopathy. Often, the differential diagnosis of peripapillary fluid is a bit tricky and may lead to misdiagnosis and improper management. We describe a diagnostic algorithm for peripapillary fluid on OCT and outline the salient features and management of these conditions. [ABSTRACT FROM AUTHOR]

To investigate the clinical value of two-dimensional shear-wave elastography (2D-SWE) in detecting optic nerve elasticity and in-frame adipose tissue elasticity in patients with type 2 diabetic retinopathy (DR). 2D-SWE was used to detect SWE values of the optic nerve and adipose tissue in adjacent optic nerve frames in 30 healthy participants, 30 patients with diabetic non-retinopathy (NDR), 35 patients with non-proliferative diabetic retinopathy (NPDR), and 30 patients with proliferative diabetic retinopathy (PDR). The correlation between SWE values and blood glucose, blood lipid, age, body mass index (BMI) was analysed. Receiver operating characteristic (ROC) curve analysis was performed for SWE values. The SWE values of the optic nerve and in-frame adipose tissue increased with the progression of DR, and analysis of variance was compared with groups: the SWE values of the optic nerve and in-frame adipose tissue in each group were significantly different (all p <0.001). The SWE values of the optic nerve and in-frame adipose tissue correlated positively with BMI, age, triglyceride, and fasting blood glucose, and correlated negatively with high-density lipoprotein. The SWE values of the optic nerve and in-frame adipose tissue had higher diagnostic efficacy. The combination of the two had higher diagnostic accuracy. The elastic modulus of optic nerve and in-frame adipose tissue can effectively predict and grade of DR, that is, 2D-SWE can be used as a non-invasive imaging diagnostic method for DR. The combined diagnostic efficacy of optic nerve SWE value and in-frame adipose tissue SWE value is significantly better than that of single use. This study found that increased BMI, age, triglyceride, and fasting blood glucose, and decreased high-density lipoprotein are risk factors for DR. • This study is the first to evaluate the optic nerve in DR patients using SWE. • The SWE value of the optic nerve increases as DR progresses. • Elevated BMI and triglycerides are risk factors for DR. • Elevated Age and fasting glucose are risk factors for DR. • Decreased high-density lipoprotein is a risk factor for DR. [ABSTRACT FROM AUTHOR]

The molecular mechanism of how reduced mobile zinc (Zn2+) affected retinal ganglion cell (RGC) survival and optic nerve regeneration after optic nerve crush (ONC) injury remains unclear. Here, we used conditionally knocked out ZnT-3 in the amacrine cells (ACs) of mice (CKO) in order to explore the role of reactive oxygen species (ROS), nuclear factor erythroid 2-related factor 2 (NFE2L2, Nrf2) and autophagy in the protection of RGCs and axon regeneration after ONC injury. We found that reduced Zn2+ can promote RGC survival and axonal regeneration by decreasing ROS, activating Nrf2, and inhibiting autophagy. Additionally, autophagy after ONC is regulated by ROS and Nrf2. Visual function in mice after ONC injury was partially recovered through the reduction of Zn2+, achieved by using a Zn2+ specific chelator N,N,Nʹ,Nʹ-tetrakis-(2-Pyridylmethyl) ethylenediamine (TPEN) or through CKO mice. Overall, our data reveal the crosstalk between Zn2+, ROS, Nrf2 and autophagy following ONC injury. This study verified that TPEN or knocking out ZnT-3 in ACs is a promising therapeutic option for the treatment of optic nerve damage and elucidated the postsynaptic molecular mechanism of Zn2+-triggered damage to RGCs after ONC injury. Schematic summary of results and potential signaling pathway. (A) Transsynaptic process of Zn2+ from ACs to RGCs in retinas after ONC injury. (B) Overload Zn2+ damaged mitochondrial and increased ROS level after ONC injury. Zn2+ inhibited Nrf2 and its downstream of NQO1 and HO-1, which also resulted in the higher production of ROS. Changes in ROS and Nrf2 promoted the formation of autophagosomes after ONC injury. [Display omitted] • Elimination of Zn2+, by its specific chelator (TPEN) or ZnT-3 deletion in ACs (CKO), promoted RGCs survival and axon regeneration after ONC injury by reducing ROS. • Reduced Zn2+ promoted RGCs survival and axon regeneration after ONC injury by increasing the expression of Nrf2 pathway. • Reduced Zn2+ promoted RGCs survival and axon regeneration after ONC injury through inhibiting autophagy. • Autophagy after ONC injury was regulated by ROS and Nrf2. [ABSTRACT FROM AUTHOR]

Timely diagnosis and management of elevated intracranial pressure (ICP) in patients with traumatic brain injury (TBI) can significantly reduce mortality rates. Ultrasound examination of the optic nerve sheath diameter (ONSD) is considered a potential, noninvasive, and effective method for assessing ICP. We conducted a systematic review and meta-analysis of ONSD ultrasound detection and invasive ICP monitoring methods to compare and evaluate the diagnostic accuracy of ONSD ultrasound detection methods for intracranial hypertension (IH) in patients with TBI. We searched the Web of Science, PubMed, and Embase databases to assess the diagnostic accuracy of ONSD sonography for predicting increased ICP. The 2 authors independently extracted the collected data. Simultaneously, the QUADAS-2 tool was used to evaluate the bias risk of each study and conducted random-effects meta-analyses for the accuracy and specificity of diagnosis, and calculated pooled estimates. Ten studies with 512 patients were included. The diagnostic accuracy of ONSD sonography for IH was revealed as a pooled sensitivity of 0.85 (95% confidence interval [CI], 0.79–0.89) and specificity of 0.88 (95% CI, 0.80–0.93), compared with the invasive ICP monitoring standard for patients with TBI. ONSD sonography may be a useful method for predicting increased ICP in adult patients with TBI. Further clinical studies are required to confirm the diagnostic value of ONSD sonography. [ABSTRACT FROM AUTHOR]

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The optic nerve head (ONH) region at the posterior pole of the eye is supported by a fibrous structure of collagen fiber bundles. Discerning how the fibrous structure determines the region biomechanics is crucial to understand normal physiology, and the roles of biomechanics on vision loss. The fiber bundles within the ONH structure exhibit complex three-dimensional (3D) organization and continuity across the various tissue components. Computational models of the ONH, however, usually represent collagen fibers in a homogenized fashion without accounting for their continuity across tissues, fibers interacting with each other and other fiber-specific effects in a fibrous structure. We present a fibrous finite element (FFE) model of the ONH that incorporates discrete collagen fiber bundles and their histology-based 3D organization to study ONH biomechanics as a fibrous structure. The FFE model was constructed using polarized light microscopy data of porcine ONH cryosections, representing individual fiber bundles in the sclera, dura and pia maters with beam elements and canal tissues as continuum structures. The FFE model mimics the histological in-plane orientation and width distributions of collagen bundles as well as their continuity across different tissues. Modeling the fiber bundles as linear materials, the FFE model predicts the nonlinear ONH response observed in an inflation experiment from the literature. The model also captures important microstructural mechanisms including fiber interactions and long-range strain transmission among bundles that have not been considered before. The FFE model presented here advances our understanding of the role of fibrous collagen structure in the ONH biomechanics. The microstructure and mechanics of the optic nerve head (ONH) are central to ocular physiology. Histologically, the ONH region exhibits a complex continuous fibrous structure of collagen bundles. Understanding the role of the fibrous collagen structure on ONH biomechanics requires high-fidelity computational models previously unavailable. We present a computational model of the ONH that incorporates histology-based fibrous collagen structure derived from polarized light microscopy images. The model predictions agree with experiments in the literature, and provide insight into important microstructural mechanisms of fibrous tissue biomechanics, such as long-range strain transmission along fiber bundles. Our model can be used to study the microstructural basis of biomechanical damage and the effects of collagen remodeling in glaucoma. [Display omitted] [ABSTRACT FROM AUTHOR]

The ophthalmic artery normally travels with the optic nerve through the optic canal. However, sometimes, the ophthalmic artery travels through a foramen within the optic strut named an accessory optic canal, double optic canal, or ophthalmic canal. This variant puts individuals at an increased risk for blindness or death during anterior clinoidectomy due to unforeseen hemorrhage of the ophthalmic artery or internal carotid artery when the optic strut is separated from the body of the sphenoid bone. Several features make the accessory optic canal difficult to recognize on imaging: its variant nature, small size, and ability to masquerade as a caroticoclinoid foramen or a pneumatized sphenoidal structure. Hence, improved methods of presurgical identification are warranted. The aim of this study was to assess the size and shape of the optic canal, with and without a concomitant accessory optic canal, to determine whether measurement of the optic canal may provide useful information regarding the presence of an accessory optic canal. In 191 dry crania, optic canals with and without concomitant accessory optic canals were assessed for the following parameters: canal area, canal perimeter, circularity, solidity, the axes and aspect ratio of a best-fit ellipse, and roundness. Normal optic canals were found to have a larger area (P = 0.036), perimeter (P = 0.043), and minor axis of a best-fit ellipse (P = 0.031) than the optic canals that occurred alongside accessory optic canals. Asymmetry in optic canal size can help indicate the presence of a unilateral accessory optic canal before surgery. [ABSTRACT FROM AUTHOR]

For unilateral Dodge Class Ⅰ optic pathway glioma (OPG-uDCⅠ) without neurofibromatosis type 1, unilateral isolated optic nerve gliomas before the optic chiasm have been confirmed to possibly cause visual deterioration and poor prognosis. For this type of highly selective localized tumor, we explored surgery as the only treatment method. This article retrospectively analyzed and summarized the clinical data of this case series, with the aim of exploring the main technical details and clinical prognosis. Included were patients with OPG-uDCⅠ without neurofibromatosis type 1 and experiencing vision loss on the affected side. The fronto-orbital approach was used, which was mainly divided into 3 parts: intraorbital, optic canal, and intracranial. All patients underwent prechiasmatic resection without any adjuvant treatments. The follow-up period was 3 months after surgery, and magnetic resonance imaging and contralateral visual acuity were reviewed annually after surgery. All OPG-uDCⅠ cases were completely removed without any adjuvant treatments, and there was no recurrence during the follow-up period. Pathological results showed that, except for 1 adult patient with pilomyxoid astrocytoma (World Health Organization grade Ⅱ), the others all had pilocytic astrocytoma (World Health Organization grade Ⅰ). Five patients experienced transient ptosis, and all recovered 3 months after surgery. For OPG-uDCⅠ without neurofibromatosis type 1, radical prechiasmatic resection of the tumor is possible, without the need for postoperative radiotherapy and chemotherapy. [ABSTRACT FROM AUTHOR]

To investigate best-corrected visual acuity (BCVA) outcomes in patients with optic nerve hypoplasia (ONH)/septo-optic-pituitary dysplasia (SOD). Our primary hypothesis was that BCVA in patients with ONH/SOD does not change significantly over time. A chart review was undertaken in patients with a confirmed diagnosis of ONH/SOD. Demographic and clinical ophthalmologic data were extracted. Quantitative BCVA data were investigated across clinic visits after converting acuities to the logarithm of the minimum angle of resolution (logMAR). There were 102 patients (56 males). Median age at the end of the study was 12.7 years. Median duration of follow-up was 4.5 years. BCVA significantly worsened slightly in the most affected eyes (0.056 average increase in logMAR/year, 95% confidence interval [CI]: 0.037 to 0.075) and significantly improved mildly in the lesser or equally affected eyes (0.014 average decrease in logMAR/year, 95% CI: 0.009 to 0.019) (P < 0.0001). Although the overall BCVA data showed a statistically significant change with time, the actual changes were small and are of doubtful meaningful clinical significance (less than one line change on a Snellen chart). Our data suggest that ONH/SOD are nonprogressive neurodevelopmental disorders. The mild worsening of BCVA in the most affected eyes may be caused by amblyopia, whereas the small improvement in the lesser or equally affected eyes may be caused by developmental maturation. In addition, the changes in BCVA may also be due to increasing reliability of visual assessments with increasing age. [ABSTRACT FROM AUTHOR]

Methyl alcohol intoxication causes severe morbidity and mortality, especially in developing countries. Formic acid is formed as a result of methanol metabolism. Formic acid accumulation and inhibition of adenosine triphosphate synthesis result in ophthalmic issues. This study aimed to demonstrate that the optic nerve sheath diameter (ONSD) measurement is an accurate prognostic marker and can be helpful in the diagnosis of methanol intoxication. This prospective study was conducted with 52 patients who were admitted to the emergency department after alcohol consumption and agreed to participate in the study. Age, gender, comorbid diseases, vital signs, ONSD ultrasonography measurements, hospitalization and discharge status, in-hospital mortality status, dialysis need, presence of visual impairment, blood gas parameters, respiratory status, time since alcohol intake, ethanol levels, urea levels, and creatinine levels were analyzed. ROC curve analysis was performed to evaluate the predictive power of ONSD to diagnose methanol intoxication. The area under the curve was 0.857 for the cut-off value of 5.05 mm (95 % CI: 0.728–0.985; p < 0.001), with a sensitivity of 80.8 % and a specificity of 100 %. In the regression analysis performed to determine the prognostic value of the parameters in estimating mortality in methanol intoxication cases, an increase in ONSD (OR: 3.619; 95 % CI: 0.057–0.199; p = 0.001), an increase in lactate levels (OR: 5.653; 95 % CI: 0.040–0.085; p < 0.001), and increased duration after alcohol intake (OR: 2558; 95 % CI: 0.004–0.034; p = 0.014) were identified as independent predictors of mortality, but pH, HCO 3 , and base deficit levels were not significant predictors. We believe that ONSD can be helpful for the differential diagnosis and prognosis of patients with suspected methanol toxicity who presented with alcohol intake. • As a result of our study, it was observed that ONSD increased in cases of methanol intoxication, but there was no increase in ONSD in patients who took ethyl alcohol. • ONSD can be used in the differential diagnosis of cases with suspected methanol intoxication due to alcohol intake. • We think that ONSD can be used to predict the prognosis of cases with suspected methanol intoxication and admitted due to alcohol consumption. [ABSTRACT FROM AUTHOR]

To evaluate the causative and risk factors for optic neuropathy with mucocele via imaging studies. We included 21 patients with rhinogenous optic neuropathy with mucocele. We collected data on the sinus involved, age, sex, number of days from the onset of visual impairment to surgery, and computed tomography (CT) imaging findings (bone defects in the lamina papyracea, Onodi cell mucocele, exophthalmos, and optic nerve deviation). The results were compared between two groups, the one having nine patients with pre-operative visual acuity of <0.1 (the poor group) and the other having 12 patients with pre-operative visual acuity of ≥0.1 (the fair group). Whether or not there was a difference in pre-operative visual acuity between patients with and without Onodi cell mucocele was determined. After surgery, visual acuity improved in 16/21 (76.2%) patients, and a correlation analysis showed a significant positive correlation between pre-operative and post-operative visual acuity. In imaging, the causative sinuses accounted for 85.7% of both posterior ethmoid and sphenoid sinuses. Bone defects of the lamina papyracea at the optic canal and the vertical downward deviation of the optic nerve at each location, especially in 6/9 patients with Onodi cell mucocele, were characteristic in the poor group. In these conditions, increasing the contact areas of the optic nerve and mucocele can leads to more chances of direct downward compression of the optic nerve and infection occurring, and it may lead to severe pre-operative visual impairment. Imaging studies of optic neuropathy with mucocele help to determine the risk factors and perform early and precise diagnostic imaging and decision-making for surgery. [ABSTRACT FROM AUTHOR]

Aplasia of the inferior rectus and inferior oblique muscles is extremely rare. Failure of the normal embryologic development of the inferior mesodermal complex can lead to agenesis of inferior rectus, inferior oblique, and lower sections of the lateral rectus muscles. This rare condition is usually seen in association with craniofacial syndromes or in conjunction with microcornea, microphthalmos, Axenfeld-Rieger syndrome, and coloboma. The usual treatment for this condition is a reverse Knapp procedure to improve the vertical alignment; however, this procedure can lead to complications, such as anterior segment ischemia, undercorrection, and torsional problems. To our knowledge, unilateral inferior rectus and inferior oblique muscle aplasia has not been described previously in a patient with congenital facial nerve palsy and optic nerve hypoplasia. In the present case, the patient was successfully treated with a modified minimally invasive horizontal rectus muscle transposition procedure. [ABSTRACT FROM AUTHOR]

To assess the prevalence of nonglaucomatous optic nerve atrophy (NGOA) in highly myopic individuals. Population-based study. The Ural Eye and Medical Study included 5899 (80.5%) of 7328 eligible individuals (80.5%). Nonglaucomatous optic nerve atrophy, graded into 5 arbitrary stages, was characterized by decreased visibility of the retinal nerve fiber layer (RNFL) on photographs, neuroretinal rim pallor, abnormally thin retinal arteriole diameter, and abnormally thin peripapillary RNFL as measured by OCT. Nonglaucomatous optic nerve atrophy prevalence and degree. Of 5709 participants (96.9%) with axial length measurements, 130 individuals (2.3%) were highly myopic, of whom 116 individuals (89.2%; age, 57.8 ± 11.1 years; axial length, 27.0 ± 1.2 mm) had available fundus photographs and OCT images and were included into the study. Nonglaucomatous optic nerve atrophy prevalence was 34/116 individuals (29.3%; 95% confidence interval [CI], 21.0–38.0), and mean NGOA degree in eyes with NGOA was 1.7 ± 1.0 arbitrary units. Higher NGOA degree correlated (multivariable analysis; regression coefficient, r 2 = 0.59) with longer axial length (β, 0.22; P = 0.007), wider temporal parapapillary γ zone width (β, 0.50; P < 0.001), higher prevalence of diabetes (β, 0.20; P = 0.005), and higher systolic blood pressure (β, 0.15; P = 0.03). Higher NGOA prevalence was associated with longer axial length (odds ratio [OR], 7.45; 95% CI, 2.15–25.7), wider temporal parapapillary γ zone (OR, 6.98; 95% CI, 2.61–18.7), and higher systolic blood pressure (OR, 1.05; 95% CI, 1.01–1.10). In this ethnically mixed population from Russia with an age of 40 years or more, high axial myopia showed a relatively high prevalence of NGOA, increasing with longer axial length and wider temporal parapapillary γ zone. For each 1 mm of axial elongation and γ zone widening, the odds for NGOA increased 7.45-fold and 6.98-fold, respectively. The axial elongation–associated and γ zone–related increase in the distance between the retinal ganglion cells and the optic disc may lead to a lengthening and stretching of the retinal ganglion cell axons and may be of importance pathogenetically. In highly myopic eyes, NGOA may be a reason for visual field and central visual acuity loss, unexplainable by myopic macular pathologic features. Proprietary or commercial disclosure may be found in the Footnotes and Disclosures at the end of this article. [ABSTRACT FROM AUTHOR]

The anterior clinoid process (ACP) is surrounded by nerves and vessels that, together, constitute an intricate anatomical structure with variations that challenges the performance of individualized anterior clinoidectomy in treating lesions with different extents of invasion. In the present study, we established a 6-surface system for the ACP based on anatomical landmarks and analyzed its value in guiding ACP drilling and resection of paraclinoid meningiomas. Using the anatomical characteristics of 10 dry skull specimens, we set 9 anatomical landmarks to delineate the ACP into 6 surfaces. Guided by our 6-surface system and eggshell technique, 5 colored silicone-injected anatomical specimens were dissected via a frontotemporal craniotomy to perform anterior clinoidectomy. Next, 3 typical cases of paraclinoid meningioma were selected to determine the value of using our 6-surface system in tumor resection. Nine points (A–H and T) were proposed to delineate the ACP surface into frontal, temporal, optic nerve, internal carotid artery, cranial nerve III, and optic strut surfaces according to the adjacent tissues. Either intradurally or extradurally, the frontal and temporal surfaces could be identified and drilled into depth, followed by skeletonization of the optic nerve, cranial nerve III, internal carotid artery, and optic strut surfaces. After the residual bone was removed, the ACP was drilled off. In surgery of paraclinoid meningiomas, our 6-surface system provided great benefit in locating the dura, nerves, and vessels, thus, increasing the safety of opening the optic canal and relaxing the oculomotor or optic nerves and allowing for individualized ACP drilling for meningioma removal. Our 6-surface system adds much anatomical information to the classic Dolenc triangle and can help neurosurgeons, especially junior ones, to increase their understanding of the paraclinoid spatial structure and accomplish individualized surgical procedures with high safety and minimal invasiveness. [ABSTRACT FROM AUTHOR]

Despite growing interest in the endoscopic endonasal approach (EEA) to the medial orbital apex (OA), a comprehensive description of the multilayer topology lying at the intersection of the regional compartments is missing. An EEA to the OA, pterygopalatine fossa, and cavernous sinus was performed in 20 specimens. A 360° layer-by-layer dissection was performed taking into consideration relevant anatomical aspects of the interface and documented with 3-dimensional technologies. Endoscopic landmarks were analyzed to provide an outline of the compartments and identify critical structures. Additionally, the consistency of a previously described reference called orbital apex convergence prominence was analyzed and a method to identify its position was introduced. The orbital apex convergence prominence was an inconsistent finding (15%). However, a craniometric method introduced in this study proved to be reliable to reach the orbital apex convergence point. Additional structures such as the sphenoethmoidal suture and a 3-suture junction (sphenoethmoidal-palatoethmoidal-palatosphenoidal) helped to identify the posterior limit of the OA and define a keyhole to access the compartments of the interface. We defined the bone limits of the "optic risk zone," an area where the optic nerve is more susceptible to damage. Furthermore, an orbital fusion line (periorbita-dura-periosteum) was identified and divided into 4 segments according to adjacent structures: optic, cavernous, pterygopalatine, and infraorbital. Understanding cranial landmarks and the folds of the layers covering the orbito-cavernous-pterygopalatine interface can facilitate tailoring an EEA to the medial orbital space and avoid unnecessary exposure of sensitive anatomy in the vicinity. [ABSTRACT FROM AUTHOR]

The purpose of this study was to evaluate our novel ultrasound vibro-elastography (UVE) technique for assessing patients with papilledema by non-invasively measuring shear wave speed (SWS), elasticity and viscosity properties of the optic nerve and sclera. Shear wave speeds were measured at three frequencies—100, 150 and 200 Hz—on the optic nerve and sclera tissues for assessing patients with papilledema resulting from idiopathic intracranial hypertension (IIH). The method was evaluated in six papilledema patients and six controls on two separate locations for each participant (i.e., optic nerve and posterior sclera). SWSs of the optic nerve and sclera were analyzed by using a 2-D speed map technique within a circular region of interest (ROI) (i.e., the diameter of the ROI was 1.5 mm × 3.0 mm at the optic nerve and sclera, respectively). Elasticity and viscosity were then analyzed using the wave speed dispersion over the three frequencies. We measured values of SWS at both locations, optic nerve and sclera, of the right eye and left eye at three different frequencies in IIH patients and controls. The SWS (mean ± standard deviation [m/s]) of the right eye was significantly higher at the sclera in IIH patients compared with controls (i.e., patients vs. controls: 5.91 ± 0.54 vs. 3.86 ± 0.56, p < 0.0001 at 100 Hz), but there was no significant difference at the optic nerve (i.e., patients vs. controls: 3.62 ± 0.39 vs. 3.36 ± 0.35, p = 0.1100 at 100Hz). We observed increased elasticity (kPa) in IIH patients, indicating there are significant differences in elasticity between patients and controls at the optic nerve and sclera (i.e., right eye [patients vs. controls]: 14.42 ± 6.59 vs. 6.5 ± 5.71, p = 0.0065 [optic nerve]; 33.04 ± 10.62 vs. 9.16 ± 7.15, p < 0.0001 [sclera]). Viscosity was also (Pa·s) higher in the sclera and optic nerve of the left eye (i.e., left eye [patient vs. control]: 8.89 ± 4.37 vs. 7.27 ± 5.01, p = 0.3790 (optic nerve); 16.05 ± 10.79 vs. 8.49 ± 6.09, p < 0.0194 [sclera]). This research illustrates the feasibility of using our UVE system to evaluate stiffness of different tissues in the eye non-invasively. It suggests that the viscoelasticity of the posterior sclera is higher than that of the optic nerve. We found that the posterior sclera is stiffer than the optic nerve in patients with papilledema resulting from IIH, making UVE a potential non-invasive technique for assessing papilledema. [ABSTRACT FROM AUTHOR]

Diffusion-weighted magnetic resonance imaging (dMRI) is the only available method to measure the tissue properties of white matter tracts in living human brains and has opened avenues for neuroscientific and clinical studies on human white matter. However, dMRI using conventional simultaneous multi-slice (SMS) single-shot echo planar imaging (ssEPI) still presents challenges in the analyses of some specific white matter tracts, such as the optic nerve, which are heavily affected by susceptibility-induced artifacts. In this study, we evaluated dMRI data acquired by using SMS readout-segmented EPI (rsEPI), which aims to reduce susceptibility-induced artifacts by dividing the acquisition space into multiple segments along the readout direction to reduce echo spacing. To this end, we acquired dMRI data from 11 healthy volunteers by using SMS ssEPI and SMS rsEPI, and then compared the dMRI data of the human optic nerve between the SMS ssEPI and SMS rsEPI datasets by visual inspection of the datasets and statistical comparisons of fractional anisotropy (FA) values. In comparison with the SMS ssEPI data, the SMS rsEPI data showed smaller susceptibility-induced distortion and exhibited a significantly higher FA along the optic nerve. In summary, this study demonstrates that despite its prolonged acquisition time, SMS rsEPI is a promising approach for measuring the tissue properties of the optic nerve in living humans and will be useful for future neuroscientific and clinical investigations of this pathway. [ABSTRACT FROM AUTHOR]

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Characterization of the optic nerve through measurement of optic nerve diameter (OND) and optic nerve sheath diameter (ONSD) using transorbital sonography (TOS) has proven to be a useful tool for the evaluation of intracranial pressure (ICP) and multiple neurological conditions. We describe a deep learning–based system for automatic characterization of the optic nerve from B-mode TOS images by automatic measurement of the OND and ONSD. In addition, we determine how the signal-to-noise ratio in two different areas of the image influences system performance. A UNet was trained as the segmentation model. The training was performed on a multidevice, multicenter data set of 464 TOS images from 110 subjects. Fivefold cross-validation was performed, and the training process was repeated eight times. The final prediction was made as an ensemble of the predictions of the eight single models. Automatic OND and ONSD measurements were compared with the manual measurements taken by an expert with a graphical user interface that mimics a clinical setting. A Dice score of 0.719 ± 0.139 was obtained on the whole data set merging the test folds. Pearson's correlation was 0.69 for both OND and ONSD parameters. The signal-to-noise ratio was found to influence segmentation performance, but no clear correlation with diameter measurement performance was determined. The developed system has a good correlation with manual measurements, proving that it is feasible to create a model capable of automatically analyzing TOS images from multiple devices. The promising results encourage further definition of a standard protocol for the automatization of the OND and ONSD measurement process using deep learning–based methods. The image data and the manual measurements used in this work will be available at 10.17632/kw8gvp8m8x.1. [ABSTRACT FROM AUTHOR]

To investigate causes of childhood blindness in the United States using the IRIS® Registry (Intelligent Research in Sight). Cross-sectional study. Patients ≤ 18 years of age with visual acuity (VA) 20/200 or worse in their better-seeing eye in the IRIS Registry during 2018. Causes of blindness were classified by anatomic site and specific diagnoses. Percentages of causes of blindness. Of 81 164 children with 2018 VA data in the IRIS Registry, 961 (1.18%) had VA 20/200 or worse in their better-seeing eye. Leading causes of blindness were retinopathy of prematurity (ROP) in 301 patients (31.3%), nystagmus in 78 patients (8.1%), and cataract in 64 patients (6.7%). The retina was the leading anatomic site (47.7%) followed by optic nerve (11.6%) and lens (10.0%). A total of 52.4% of patients had treatable causes of blindness. This analysis offers a unique cross-sectional view of childhood blindness in the United States using a clinical data registry. More than one-half of blind patients had a treatable cause of blindness. Proprietary or commercial disclosure may be found in the Footnotes and Disclosures at the end of this article. [ABSTRACT FROM AUTHOR]

Adenosine A1 receptors (AA1R) have been shown to counteract N-methyl- D -aspartate (NMDA)–mediated glutamatergic excitotoxicity. In the present study, we investigated the role of AA1R in neuroprotection by trans -resveratrol (TR) against NMDA-induced retinal injury. In total, 48 rats were divided into the following four groups: normal rats pretreated with vehicle; rats that received NMDA (NMDA group); rats that received NMDA after pretreatment with TR; and rats that received NMDA after pretreatment with TR and 1,3-dipropyl-8-cyclopentylxanthine (DPCPX), an AA1R antagonist. Assessment of general and visual behaviour was performed using the open field test and two-chamber mirror test, respectively, on Days 5 and 6 post NMDA injection. Seven days after NMDA injection, animals were euthanized, and eyeballs and optic nerves were harvested for histological parameters, whereas retinae were isolated to determine the redox status and expression of pro- and anti-apoptotic proteins. In the present study, the retinal and optic nerve morphology in the TR group was protected from NMDA-induced excitotoxic damage. These effects were correlated with the lower retinal expression of proapoptotic markers, lipid peroxidation, and markers of nitrosative/oxidative stress. The general and visual behavioural parameters in the TR group showed less anxiety-related behaviour and better visual function than those in the NMDA group. All the findings observed in the TR group were abolished by administration of DPCPX. • Adenosine A1 receptors (AA1R) involves in retinal protection by trans-resveratrol (TR). • TR improves visual behaviour in rats with NMDA-induced retinal injury. • AA1R-mediated neuroprotection by TR is associated with reduced oxidative stress. • AA1R-mediated neuroprotection by TR is associated with reduced nitrosative stress. • AA1R-mediated neuroprotection by TR is associated with reduced apoptosis. [ABSTRACT FROM AUTHOR]

Anterior skull base meningioma produces symptoms as a result of mass effect and neurovascular compression. The bony anatomy of the anterior skull base is complex and houses the critical cranial nerves and vessels. Traditional microscopic approaches remove these tumors effectively but require extensive brain retraction and bone drilling. Endoscope assistance offers the advantages of a smaller incision, less brain retraction, and bone drilling. The most significant advantage of endoscope-assisted microneurosurgery for lesions invading the sella and optic foramen is the complete resection of the sellar and foraminal components frequently responsible for recurrence. In this report, we describe the technique of endoscope-assisted microneurosurgical resection of anterior skull base meningiomas invading the sella and foramen. We present 10 cases and 3 case examples of endoscope-assisted microneurosurgery for meningiomas invading the sella and optic foramen. This report presents the operating room setup and surgical details to resect sellar and foraminal tumors. The surgical procedure is presented as a video. Endoscope-assisted microneurosurgery yielded excellent clinical and radiologic results and no recurrence at the last follow-up of meningiomas invading the sella and optic foramen. The present article discusses the challenges faced with endoscope-assisted microneurosurgery, techniques, and challenges in the procedure. Endoscope assistance enables complete tumor excision under vision with less retraction and bone drilling in anterior cranial fossa meningioma, invading the chiasmatic sulcus, optic foramen, and sella. The mixed use of microscope and endoscope makes it safer and saves time and is like bringing out the best of both worlds. [ABSTRACT FROM AUTHOR]

Congenital aniridia is a rare, panocular disorder with a main phenotypic characteristic of a partial or complete absence of the iris existing alongside other ocular morbidities such as cataract, keratopathy, optic nerve and foveal hypoplasia, and nystagmus. The iris abnormality, however, often leads to symptoms such as photophobia, glare, and decreased visual acuity, as well as cosmetic dissatisfaction. Current management options for the iris deficit include colored iris contact lenses, corneal tattooing, and tinted contact lenses. Symptoms arising from small iris defects can be resolved with surgical management using micro-tying suture techniques such as McCannel or Siepser. Currently, larger iris defects can be treated with artificial iris implants. New prosthetic options range from colored intraocular lenses to flexible custom-made silicone iris implants. With a range of therapeutic options available and given the challenges of multiple comorbidities in aniridia, we evaluate the literature relating to the use of artificial iris implants in congenital aniridia, with a focus on the different surgical implantation techniques, the clinical outcomes achieved, complications occurred, and risk of bias of the studies included. [ABSTRACT FROM AUTHOR]

The hypothalamic region is susceptible to involvement of several processes. 1 Lesions in this region remain challenging for surgical access and treatment. Strategies include both endoscopic and microsurgical approaches. 2 A cranio-orbital approach with extradural clinoidectomy and optic canal unroofing provides the necessary corridor to visualize and decompress the optic nerve/chiasm and remains an important tool in achieving complete tumor resection with favorable functional and visual outcomes. 3-12 Endoscope assistance in transcranial surgery is well established, used to provide direct visualization of hidden adjacent tissues. 13 A 25-year-old woman presented with headache and progressive visual loss to blindness (hand waving and light perception) on admission. Magnetic resonance imaging demonstrated a 28-mm-diameter tumor in the hypothalamic region with no significant postcontrast enhancement. She underwent right cranio-orbital craniotomy, extradural anterior clinoidectomy, and optic canal unroofing with a 2-mm high-speed diamond drill and copious irrigation. After ipsilateral falciform ligament release, the tumor capsule was coagulated, sharply opened, and resected in a piecemeal fashion. Endoscopic assistance warranted the removal of hidden parts and confirmed tumor removal. Histopathology and next-generation sequencing confirmed the diagnosis of rosette-forming glioneural tumor. Follow-up revealed gross total tumor removal on magnetic resonance imaging and complete recovery of visual function as per ophthalmologist examination. Rosette-forming glioneural tumors are considered rare and classified as World Health Organization grade I tumors usually found in the fourth ventricle. 14 To our knowledge, we present the first operative video (Video 1) demonstrating the removal of rosette-forming glioneural tumor in the hypothalamic region with endoscopic assistance. [ABSTRACT FROM AUTHOR]

The responses of astrocytes in the optic nerve head (ONH) to mechanical and biochemical stimuli are important to understanding the degeneration of retinal ganglion cell axons in glaucoma. The ONH in glaucoma is vulnerable to stress produced by the intraocular pressure (IOP). Notably, after three days of elevated IOP in a mouse model, the junctions between the astrocytic processes and the peripapillary sclera were altered and the structural compliance of the ONH increased. In order to simulate this aspect of glaucomatous remodeling, explanted mouse eyes were treated with TrypLE, a recombinant trypsin enzyme. Treatment with TrypLE caused the periphery of the astrocytic lamina to contract radially by 0.044 ± 0.038. Transmission electron microscopy showed that TrypLE caused a separation of the end-feet of the astrocyte processes from the basement membrane at the junction with the sclera. Inflation testing after treatment with TrypLE caused an increased strain response in the astrocytic lamina compared to the strain response before treatment. The greatest increase was in the radial Green-Lagrange strain, E rr = 0.028 ± 0.009, which increased by 340%. The alterations in the microstructure and in the strain response of the astrocytic lamina reported in mouse experimental glaucoma were partially reproduced by experimental treatment of mouse eyes with TrypLE. The results herein suggest that separation of junctions between the astrocyte processes and the sclera may be instrumental in increasing the structural compliance of the ONH after a period of elevated IOP. Astrocytes of the optic nerve of the eye spread out from edge to edge across the optic nerve in a region referred to as the astrocytic lamina. In an experimental model of glaucoma caused by elevated eye-pressure, there is disruption of the connections between astrocytes and the edge of the astrocytic lamina. We caused a similar event in the lamina by incubating explanted mouse eyes with an enzyme. Disruption of the astrocyte connections to the edge of their tissue caused the tissue to stretch more when we increased the eye-pressure, compared to the control tissue. This work is the first on the tissue of the optic nerve to demonstrate the importance of cell connections in preventing the over-stretching of the astrocytic lamina. [Display omitted] [ABSTRACT FROM AUTHOR]

Lamb-Shaffer syndrome, caused by haploinsufficiency of SOX5, leads to a unique constellation of dysmorphic features and intellectual delay. The SOX5 family of proteins plays an integral role in neuronal development. We present the clinical traits of an 11-year-old boy with Lamb-Shaffer syndrome and highlight the ocular findings of the syndrome reported thus far in the literature. Approximately 55% of all patients reviewed had some form of ocular abnormality associated with Lamb-Shaffer syndrome, including, predominantly, strabismus as well as optic nerve abnormalities, epicanthal folds, and refractive errors, highlighting the potential significance of SOX5 on neurologic development.▪ [ABSTRACT FROM AUTHOR]

Every year millions of children are exposed to general anesthesia while undergoing surgical and diagnostic procedures. In the field of ophthalmology, 44,000 children are exposed to general anesthesia annually for strabismus surgery alone. While it is clear that general anesthesia is necessary for sedation and pain minimization during surgical procedures, the possibility of neurotoxic impairments from its exposure is of concern. In animals there is strong evidence linking early anesthesia exposure to abnormal neural development. but in humans the effects of anesthesia are debated. In humans many aspects of vision develop within the first year of life, making the visual system vulnerable to early adverse experiences and potentially vulnerable to early exposure to general anesthesia. We attempt to address whether the visual system is affected by early postnatal exposure to general anesthesia. We first summarize key mechanisms that could account for the neurotoxic effects of general anesthesia on the developing brain and review existing literature on the effects of early anesthesia exposure on the visual system in both animals and humans and on neurocognitive development in humans. Finally, we conclude by proposing future directions for research that could address unanswered questions regarding the impact of general anesthesia on visual development. [ABSTRACT FROM AUTHOR]

Determination of optic nerve sheath diameter (ONSD) with transbulbar sonography has become an easily accessible and time-effective tool in the assessment of increased intracranial pressure. The aim of our study was to evaluate the usefulness of transbulbar sonography in the initial diagnosis and in follow-up examinations of children and adolescents with the diagnosis of pseudotumor cerebri syndrome (PTCS). We retrospectively reviewed imaging results of 24 patients aged 0.75–17 years with PTCS. Serial transbulbar sonography examinations were performed between 2011 and 2021. Sonographic evaluation included the ONSD, papilledema and subarachnoid space. 240 sonographic measurements taken at 108 time points in 17 patients met the inclusion criteria. All patients underwent serial lumbar punctures and routine fundoscopy in close relation to transbulbar sonography. We found that ONSD values remained high in all patients. The longest follow-up period was dated 2498 days (6.84 years) after initial diagnosis. Papilledema resolved in close correlation to fundoscopy normalization. In 16/17 patients the subarachnoid space remained cystic in appearance. These findings were independent of clinical symptoms and lumbar puncture opening pressure. We conclude that transbulbar sonography is a useful diagnostic tool in the initial diagnostic workup of children with PTCS. On follow-up however ONSD values and the cystic transformation of the subarachnoid space remained pathologic in the majority of cases while papilledema resolved parallel to fundoscopy findings. Serial measurements of ONSD are therefore of limited value in the follow-up of patients with PTCS and cannot be considered a reliable tool in subsequent therapeutic decisions. • Transbulbar sonography is useful for diagnosis of pediatric pseudotumor cerebri. • On follow-up optic nerve sheath diameter and subarachnoid space remain enlarged. • Sonographic papillary changes normalize parallel to fundoscopy findings. • Serial ONSD measurements are of limited value. • ONSD measures in follow-up are not a reliable tool for subsequent therapy decisions. [ABSTRACT FROM AUTHOR]

Visual impairment has been reported as the most common clinical manifestation of pituitary adenoma (PA) due to the compressive effect of the tumor. This prospective study aimed to evaluate the predictive role of diffusion tensor imaging (DTI) in the visual improvement of patients with PA, who were candidates for endoscopic endonasal surgery. A total of 13 patients (male, 8; female, 5) with visual impairment due to pituitary macroadenoma were enrolled in this study. The DTI findings and visual parameters, including visual acuity (VA), visual field (VF), and visual evoked potential (VEP), were recorded for all participants before and 3 months after surgery. Significant recovery was reported in both VA and VF following PA surgery (P < 0.001). The results of perimetry indicated recovery in all quadrants, except for the lower nasal quadrant of the right eye. The tumor volume showed no significant association with the preoperative optic nerve, optic tract, and chiasm fractional anisotropy (FA) or mean diffusivity (MD). The VA and VF recoveries were more likely in patients with a lower preoperative optic nerve MD. Besides, increased preoperative FA of the optic nerve was associated with a higher probability of VA recovery. No significant correlation was found between the optic tract MD and FA values and visual improvement. Overall, MD values below 0.0021 and FA values above 0.1689 could predict a good prognosis of VA recovery after surgery. DTI may have a predictive value in estimating visual improvement in patients with PA preoperatively. [ABSTRACT FROM AUTHOR]

We aimed to characterize the ocular phenotype of patients with ROSAH (retinal dystrophy, optic nerve edema, splenomegaly, anhidrosis, and headache) syndrome and their response to therapy. Single-center observational case study. Eleven patients with a diagnosis of ROSAH syndrome and mutation in ALPK1 were included. Patients with molecularly confirmed ROSAH syndrome underwent ophthalmic evaluation, including visual acuity testing, slit-lamp and dilated examinations, color fundus and autofluorescence imaging, fluorescein angiography, OCT, and electrophysiologic testing. Visual acuity, electrophysiology, fluorescein angiography, and OCT findings. Eleven individuals (6 female and 5 male patients) from 7 families ranging in age from 7.3 to 60.2 years at the time of the initial evaluation were included in this study. Seven patients were followed up for a mean of 2.6 years (range, 0.33–5.0 years). Best-corrected visual acuity at baseline ranged from 20/16 to no light perception. Variable signs or sequelae of intraocular inflammation were observed in 9 patients, including keratic precipitates, band keratopathy, trace to 2+ anterior chamber cells, cystoid macular edema, and retinal vasculitis on fluorescein angiography. Ten patients were observed to show optic disc elevation and demonstrated peripapillary thickening on OCT. Seven patients showed retinal degeneration consistent with a cone–rod dystrophy, with atrophy tending to involve the posterior pole and extending peripherally. One patient with normal electroretinography findings and visual evoked potential was found to have decreased Arden ratio on electro-oculography. Leveraging insights from the largest single-center ROSAH cohort described to date, this study identified 3 main factors as contributing to changes in visual function of patients with ROSAH syndrome: optic nerve involvement; intraocular inflammation, including cystoid macular edema; and retinal degeneration. More work is needed to determine how to arrest the progressive vision loss associated with ROSAH syndrome. Proprietary or commercial disclosure may be found after the references. [ABSTRACT FROM AUTHOR]

To carry out a comprehensive critical appraisal of image-guided intensity-modulated proton therapy practice for craniospinal irradiation (CSI). An image-guided intensity-modulated proton therapy database of 45 consecutive paediatric patients with central nervous system embryonal malignancies treated between January 2019 and April 2022 were critically appraised for demography, diagnosis, treatment planning strategy and treatment delivery accuracy. Most patients (median age: 7.5 years; male:female ratio: 34:11) had medulloblastoma (56%), followed by recurrent ependymoma (19%), pinealoblastoma (5%), germ cell (5%) and others (15%). The dose to the planning target volume-craniospinal (PTV-CS; length 39.06–79.59 cm) varied from 21 to 35 GyRBE, whereas the combined median dose to craniospinal and boost was 54 GyRBE. In all patients, the 95% isodose line covered the cribriform plate completely and optic nerves mostly, with a median V95% of 100% and 82.96%, keeping Dmax to the lens <3.9 GyRBE. In skeletally immature patients (88.38%), the anterior vertebral body was completely covered in 18.18% and underdosed in 70.15% of the cases, resulting in a median Dmean of 10.11 GyRBE to the oesophagus. Lateral spine coverage was maintained on the edges of the vertebral body in 52.2%, whereas it extended beyond in 48.8%. The median V98% for clinical target volumes and V95% for PTVs of the brain, spine and craniospinal were >97%, with excellent conformity (0.89) and homogeneity (0.07) indices for PTV-CS. All neurological organs at risk received a median Dmax ranging from 36 to 44 GyRBE from the combined CSI and boost regimens. Analysis of patient-specific quality assurance results revealed that 545 (97.67%) planar dosage verification had gamma (3% at 3 mm) values >95%. The online patient set-up verification showed translational and rotational deviation within 2 mm and 0.5° in 88–94% and 97% of the cases. Systematic and random error were within 0.90 mm and 1.71 mm in translation and 0.1° and 0.2° in rotation. A change in practice pattern was observed. The findings from our comprehensive critical appraisal add to the growing library of CSI practice and may serve as a reference for inter-institutional comparison. • First comprehensive critical appraisal of image guided IMPT practice for CSI. • Novel treatment planning technique. • Detailed report on treatment planning and delivery accuracy of large patient cohort. • Highlights variation in practice pattern. [ABSTRACT FROM AUTHOR]

Obesity is a chronic condition, affecting central and peripheral nervous system. Studies on cranial nerve conduction in obesity are scarce and unclear; therefore, we planned this study. The aim of this study was to evaluate optic and auditory nerve conductions in obesity. It was a case-control study, with inclusion of 40 young males (20 obese and 20 controls) in age group of 18–30 years. We recorded pattern reversal visual evoked potential (PRVEP) and brainstem auditory evoked potential (BAEP). The PRVEP P100 latency and BAEP absolute and interpeak latencies were analyzed. In obese individuals, BAEP absolute latencies of wave V were significantly prolonged in both the ears and wave I in left ear. In addition, significant prolongation of interpeak latency III–V was observed in both the ears and I–V latency, in right ear among obese cases. A positive correlation was seen between body mass index and interpeak latency I–V. In PRVEP recordings, P100 latency did not show any significant difference in both the groups. Therefore, we can conclude that obesity does not affect optic nerve conduction, but auditory nerve conduction is affected. BAEP I–V interpeak latency may be an indicator of subclinical auditory conduction defects in young obese males. [ABSTRACT FROM AUTHOR]

• Changes of retinal function after treatment with PNU-282987. • PNU-282987 affects ERG activity after blast trauma. • Retinal ganglion cells extend axons into optic nerve after PNU-282987 treatment. • PNU-282987 induces changes of retinal neurons after blast exposure. • PNU-282987 prevents amplitude decrease in ERG waveforms after blast. Currently, there is a lack of treatments for retinal neurotrauma. To address this issue, this study uses an alpha7 nAChR agonist, PNU-282987, to determine it effects on functional activity in the retina shortly after a traumatic blast exposure. The objectives of this research include: (1) examination of the cellular and functional damage associated with ocular blast exposure, and (2) evaluation of structural and functional changes that occur post PNU-282987 treatment. Significant ocular blast damage was induced in adult mice after exposure to a single blast of 35 psi to the left eye. Blast-exposed transgenic mice expressing tdTomato Müller glia were treated daily with eyedrops containing PNU-282987 for 4 weeks following the blast exposure. Antibody staining studies in these transgenic mice was conducted to examine lineage tracing and electroretinograms (ERGs) were obtained to examine functional changes. Blast exposure caused a significant loss of cells in all retinal layers after 4 weeks. Immunohistochemical analysis demonstrated tdTomato-positive labeled photoreceptors and retinal ganglion cells in blast-exposed mice treated with PNU-282987. ERG recordings were taken from control animals, from blast-damaged animals and from animals exposed to blast followed by 4 weeks of PNU-282987 treatment. Scotopic ERG recordings from blast-exposed mice had significantly decreased amplitudes of a-wave, b-wave, oscillatory potentials and flicker frequencies, which were prevented after PNU-282987 treatment. In photopic experiments, the PhNR response was reduced significantly after blast exposure but the decrease was prevented after treatment with PNU-282987. These are the first experiments that demonstrate preservation of retinal function after blast exposure using an alpha7 nAChR agonist. [ABSTRACT FROM AUTHOR]

Hereditary optic neuropathies result from defects in the human genome, both nuclear and mitochondrial. The two main and most recognised phenotypes are dominant optic atrophy and Leber hereditary optic neuropathy. Advances in modern molecular diagnosis have expanded our knowledge of genotypes and phenotypes of inherited disorders that affect the optic nerve, either alone or in combination, with various forms of neurological and systemic degeneration. A unifying feature in the pathophysiology of these disorders appears to involve mitochondrial dysfunction, suggesting that the retinal ganglion cells and their axons are especially susceptible to perturbations in mitochondrial homoeostasis. As we better understand the pathogenesis behind these genetic diseases, aetiologically targeted therapies are emerging and entering into clinical trials, including treatments aimed at halting the cascade of neurodegeneration, replacing or editing the defective genes or their protein products, and potentially regenerating damaged optic nerves, as well as preventing generational disease transmission. [ABSTRACT FROM AUTHOR]

We describe gross and histopathological features of multiple ocular and neuro-ophthalmic abnormalities in a fox squirrel (Sciurus niger). Ophthalmic findings included severe bilateral microphthalmos, with the right eye more affected than the left. Histopathology confirmed severe microphthalmia, aphakia, disorganized retinal tissue and small optic nerves, as well as agenesis of the optic chiasm and optic tract. This combination of neuro-ophthalmic abnormalities has not been previously described in wild animals. [ABSTRACT FROM AUTHOR]

To study the associations between optic nerve head (ONH) strains under intraocular pressure (IOP) elevation with retinal sensitivity in patients with glaucoma. Clinic-based cross-sectional study. Two hundred twenty-nine patients with primary open-angle glaucoma (subdivided into 115 patients with high-tension glaucoma [HTG] and 114 patients with normal-tension glaucoma [NTG]). For 1 eye of each patient, we imaged the ONH using spectral-domain OCT under the following conditions: (1) primary gaze and (2) primary gaze with acute IOP elevation (to approximately 35 mmHg) achieved through ophthalmodynamometry. A 3-dimensional strain-mapping algorithm was applied to quantify IOP-induced ONH tissue strain (i.e., deformation) in each ONH. Strains in the prelaminar tissue (PLT), the retina, the choroid, the sclera, and the lamina cribrosa (LC) were associated (using linear regression) with measures of retinal sensitivity from the 24-2 Humphrey visual field test (Carl Zeiss Meditec). This was performed globally, then locally according to a previously published regionalization scheme. Associations between ONH strains and values of retinal sensitivity from visual field testing. For patients with HTG, we found (1) significant negative linear associations between ONH strains and retinal sensitivity (P < 0.001; on average, a 1% increase in ONH strains corresponded to a decrease in retinal sensitivity of 1.1 decibels [dB]), (2) that high-strain regions colocalized with anatomically mapped regions of high visual field loss, and (3) that the strongest negative associations were observed in the superior region and in the PLT. In contrast, for patients with NTG, no significant associations between strains and retinal sensitivity were observed except in the superotemporal region of the LC. We found significant negative associations between IOP-induced ONH strains and retinal sensitivity in a relatively large glaucoma cohort. Specifically, patients with HTG who experienced higher ONH strains were more likely to exhibit lower retinal sensitivities. Interestingly, this trend in general was less pronounced in patients with NTG, which could suggest a distinct pathophysiologic relationship between the two glaucoma subtypes. [ABSTRACT FROM AUTHOR]

To evaluate the clinical presentation, treatment, and outcomes in adult patients with histiocytic disorders with ocular, orbital, optic nerve, or cavernous sinus involvement. Observational, retrospective chart review. Adult patients (age ≥ 18 years) at Mayo Clinic from January 1, 1996, to July 1, 2021, with histiocytic disorders. Inclusion criteria were (1) histiocytic disorder by biopsy and appropriate clinical phenotype; (2) available medical records; and (3) ocular, orbital, optic nerve, or cavernous sinus involvement. Retrospective chart review. Response to therapy, measured in clinical and radiographic impact. Thirty-two patients were identified: 7 with Langerhans cell histiocytosis (LCH); 15 with Erdheim-Chester disease (ECD); 1 with mixed LCH/ECD phenotype; 8 with Rosai-Dorfman disease (RDD); and 1 with mixed RDD/ECD phenotype. Ophthalmologic involvement was part of the initial presentation in 69% of patients (22/32). Eyelid edema (13/32, 41%) and proptosis (12/32, 38%) were the most frequent presentations. Isolated orbital or cavernous sinus involvement was present in 3 of 7 patients with LCH and 1 of 8 patients with RDD. Optic nerve sheath involvement was present in 2 of 7 LCH patients, 14 of 15 ECD patients, and 1 RDD/ECD patient. Diffuse (> 75%) orbital involvement was seen in 12 of 15 ECD patients and 1 of 7 LCH patients. Ocular involvement was seen in 1 of 15 ECD patients, 6 of 8 RDD patients, and 1 of 1 mixed RDD/ECD patient. The cavernous sinuses were involved in 1 of 7 LCH patients, 5 of 15 ECD patients, and both mixed phenotype patients. Visual acuity was affected in 14 patients (14/24, 58%) with a median logarithm of the minimum angle of resolution visual acuity of 0.1 (range, –0.12 to 3). BRAF V600E mutations were found in 75% (3/4) of LCH patients and 91% (10/11) of ECD patients. Patients received a variety of treatment, and response was variable across disease types. Orbital involvement was more commonly seen in LCH and ECD, whereas ocular involvement was more common in RDD. Visual acuity may be impacted from ocular involvement or compression of the optic nerve with diffuse orbital involvement. [ABSTRACT FROM AUTHOR]

Glaucoma is a leading cause of irreversible vision impairment globally, and cases are continuously rising worldwide. Early detection is crucial, allowing timely intervention that can prevent further visual field loss. To detect glaucoma an examination of the optic nerve head via fundus imaging can be performed, at the center of which is the assessment of the optic cup and disc boundaries. Fundus imaging is noninvasive and low-cost; however, image examination relies on subjective, time-consuming, and costly expert assessments. A timely question to ask is: "Can artificial intelligence mimic glaucoma assessments made by experts?" Specifically, can artificial intelligence automatically find the boundaries of the optic cup and disc (providing a so-called segmented fundus image) and then use the segmented image to identify glaucoma with high accuracy? We conducted a comprehensive review on artificial intelligence-enabled glaucoma detection frameworks that produce and use segmented fundus images and summarized the advantages and disadvantages of such frameworks. We identified 36 relevant papers from 2011 to 2021 and 2 main approaches: 1) logical rule-based frameworks, based on a set of rules; and 2) machine learning/statistical modeling-based frameworks. We critically evaluated the state-of-art of the 2 approaches, identified gaps in the literature and pointed at areas for future research. [ABSTRACT FROM AUTHOR]

To corroborate whether vessels on the surface of the optic nerve head can provide protection against the loss of underlying axons in subjects with manifest glaucoma. In this pilot study, thirty-six glaucomatous eyes with a perimetric defect in the Bjerrum area were included. The retinal nerve fiber layer (RNFL) thickness was measured in each of the sectors of the clock-hour map obtained by Cirrus HD-OCT considering the presence or absence of blood vessels. These sectors were related with their corresponding areas of the retina examined in the visual field using a mathematical model of the retina introduced by Jansonius, in order to determine the values of threshold sensitivity in those areas in the presence or absence of vessels. We corroborated the protective role of the blood vessel for peripapillary RNFL thickness of clock-hour 12 despite obtaining a p-value (p = 0.023; w = 228.5) close to the acceptance zone (p ≥ 0.05). The mean ± standard deviation with vessel and without vessel were 70.95 ± 24.35 and 88.46 ± 23.96, respectively. No differences were found between the mean values of threshold sensitivity to the presence or absence of blood vessels in each of the sectors considered. Our findings do not allow us to affirm that there is an association between the presence of a vessel and protection against glaucomatous damage in subjects with an advanced manifestation of the disease. In the future, more extensive studies are needed to study this relationship in subjects with early glaucoma. [ABSTRACT FROM AUTHOR]