Search

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]

Background: Auto‐segmentation of organs‐at‐risk (OARs) in the head and neck (HN) on computed tomography (CT) images is a time‐consuming component of the radiation therapy pipeline that suffers from inter‐observer variability. Deep learning (DL) has shown state‐of‐the‐art results in CT auto‐segmentation, with larger and more diverse datasets showing better segmentation performance. Institutional CT auto‐segmentation datasets have been small historically (n < 50) due to the time required for manual curation of images and anatomical labels. Recently, large public CT auto‐segmentation datasets (n > 1000 aggregated) have become available through online repositories such as The Cancer Imaging Archive. Transfer learning is a technique applied when training samples are scarce, but a large dataset from a closely related domain is available. Purpose: The purpose of this study was to investigate whether a large public dataset could be used in place of an institutional dataset (n > 500), or to augment performance via transfer learning, when building HN OAR auto‐segmentation models for institutional use. Methods: Auto‐segmentation models were trained on a large public dataset (public models) and a smaller institutional dataset (institutional models). The public models were fine‐tuned on the institutional dataset using transfer learning (transfer models). We assessed both public model generalizability and transfer model performance by comparison with institutional models. Additionally, the effect of institutional dataset size on both transfer and institutional models was investigated. All DL models used a high‐resolution, two‐stage architecture based on the popular 3D U‐Net. Model performance was evaluated using five geometric measures: the dice similarity coefficient (DSC), surface DSC, 95th percentile Hausdorff distance, mean surface distance (MSD), and added path length. Results: For a small subset of OARs (left/right optic nerve, spinal cord, left submandibular), the public models performed significantly better (p < 0.05) than, or showed no significant difference to, the institutional models under most of the metrics examined. For the remaining OARs, the public models were inferior to the institutional models, although performance differences were small (DSC ≤ 0.03, MSD < 0.5 mm) for seven OARs (brainstem, left/right lens, left/right parotid, mandible, right submandibular). The transfer models performed significantly better than the institutional models for seven OARs (brainstem, right lens, left/right optic nerve, left/right parotid, spinal cord) with a small margin of improvement (DSC ≤ 0.02, MSD < 0.4 mm). When numbers of institutional training samples were limited, public and transfer models outperformed the institutional models for most OARs (brainstem, left/right lens, left/right optic nerve, left/right parotid, spinal cord, and left/right submandibular). Conclusion: Training auto‐segmentation models with public data alone was suitable for a small number of OARs. Using only public data incurred a small performance deficit for most other OARs, when compared with institutional data alone, but may be preferable over time‐consuming curation of a large institutional dataset. When a large institutional dataset was available, transfer learning with models pretrained on a large public dataset provided a modest performance improvement for several OARs. When numbers of institutional samples were limited, using the public dataset alone, or as a pretrained model, was beneficial for most OARs. [ABSTRACT FROM AUTHOR]

Background and Objectives: Various ear, nose, and throat (ENT) conditions can result in vision loss. The purpose of this study is to identify the etiologies, presentations, and radiological findings associated with impaired vision in the context of ENT. Additionally, this article discusses management protocols, including optic nerve decompression and orbital decompression. Methods: In a retrospective study, we examined the period from 2016 to 2022 at a tertiary care hospital in Mumbai, India. The analysis included 11 patients who presented with progressive diminution of vision. All patients received a regimen of broad-spectrum intravenous antibiotics and high-dose intravenous steroids. This was followed by either endoscopic optic nerve decompression or orbital decompression. Subsequent improvements in vision were documented, and any complications were evaluated. Results: A total of 11 patients were treated with medical management followed by successful surgery, with 10 patients demonstrating significant vision improvement. Conclusion: Identifying the etiology of vision loss and managing the condition can present challenges for otorhinolaryngologists. A thorough grasp of the underlying pathophysiology, combined with active surveillance of clinical and radiological indicators, can enable these clinicians to achieve effective and rewarding outcomes. [ABSTRACT FROM AUTHOR]

Background: Activated microglia release harmful substances to retinal ganglion cells (RGCs), but may also benefit by removing cellular debris and secreting neurotrophic factors. These paradoxical roles remain controversial because the nature and time-course of the injury that defines their role is unknown. The aim of this study was to determine if pharmacological manipulation of microglia to acquire a pro-inflammatory or pro-survival phenotype will exacerbate or enhance neuronal survival after injury.Material and methods: Treated HAP I (highly aggressively proliferating immortalized) microglia were injected into the vitreous or tail vein (T V) of female Sprague-Dawley rats. Retinas were examined at 4-14 days following optic nerve crush (ONC) and the number of surviving RGCs was determined.Results: Injection of untreated HAP I cells resulted in the greater loss of RGCs early after ONC when injected into the vitreous and later after ONC when injected into the T V. LP S activated HAP I cells injected into the vitreous resulted in greater RGC loss with and without injury. When injected into the T V with ONC there was no loss of RGCs 4 days after ONC but greater loss afterwards. Minocycline treated HAP I cells injected into the vitreous resulted in greater RGC survival than untreated HAP I cells. However, when injected into the T V with ONC there was greater loss of RGCs. These results suggest that optic nerve signals attract extrinsic microglia to the retina, resulting in a proinflammatory response.Conclusion: Neuroprotection or cytotoxicity of microglia depends on the type of activation, time course of the injury, and if they act on the axon or cell body. HAPI microglia migrate to the retina or optic nerve following optic nerve injury when injected into the vitreous or tail vein, respectively. Pretreatment with LPS or minocycline differentially effects retinal ganglion cell survival. In most cases, the result late in the injury process is greater retinal ganglion cell loss. We show here that neuroprotection is not solely determined by the microglial activation state but factors such as the environment and time-course of the injury. Culture microglia can be treated in vitro and then injected in vivo. The cells migrate to the site of injury, cell body of retinal ganglion cells if in the vitreous or to the optic nerve if injected in the tail vein. Retinal ganglion cell death is dependent on the location the microglia act, time-course of injury, and activation state. Proinflammatory microglia can be neuroprotective early in the injury when the primary site of action is on the axons whereas hypoactivated microglia are neuroprotective early in injury when they act on the soma. Later in the injury, both become detrimental. [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]

Purpose: The aim of this study is to compare the diagnostic performance in differentiating patients with glaucoma from those with presumed large physiological optic disc cupping (LPC), using optic nerve head hemoglobin levels (ONH Hb), as a screening method, versus the evaluation of general ophthalmologists. Patients and Methods: Twenty general ophthalmologists evaluated PowerPoint images of 40 patients with glaucoma and 40 presenting LPC. Presentation of patient's exams were distributed as follows: Group 1 (GI): color retinography (CR), Group 2 (GII): CR + visual field (VF), Group 3 (GIII): CR + optical coherence tomography (OCT), Group 4 (GIV): CR + VF + OCT. The Laguna ONhE software was used to estimate ONH Hb based on CR. Main outcomes were the comparison of sensitivity and accuracy between general ophthalmologists' evaluation and the glaucoma discriminant function (GDF) index from Laguna ONhE and also the agreement between examiners (Kappa statistics). Results: Laguna ONhE GDF index demonstrated higher sensitivity values (GI- 90%; GII-90%; GIII-100%; GIV-100%) comparing to all groups (GI-59%; GII-86.5%; GIII-86.5%; GIV-68.5%). In GI, in which it was observed the worst accuracy result (64.8%), we found 75% for GDF. In GII, the accuracy was 81.3% and we found 55% for GDF. The highest agreement was in GII (Kappa=0.63; 95% CI=0.53– 0.72), and the lowest in GI (Kappa=0.30; 95% CI=0.20– 0.39). Conclusion: Laguna ONhE software, a low-cost and non-invasive method, showed good sensitivity and great utility as a screening method in differentiating patients with glaucoma from those with LPC, compared with evaluation of general ophthalmologists. [ABSTRACT FROM AUTHOR]

Background: Idiopathic intracranial hypertension (IIH) is a rare medical condition in children. Based on the different radiological findings reported in various studies in pediatric IIH, this study was conducted to determine the diagnostic value of MRI findings in diagnosing IIH in children. Methods: In this retrospective study, the medical records of all children aged 1 to 18 years who visited Ghaem Hospital in Mashhad, Iran, between 2012 and 2022 and were diagnosed with IIH were gathered. Forty-nine cases of children with IIH and 48 control cases of children with the first unprovoked seizure with no indications of increased intracranial pressure for comparison were selected. Patient demographic information and MRI findings were extracted. The comparison between different MRI findings in the case and control groups was conducted using statistical tests. Results: In the case group, the mean diameter of the subarachnoid space expansion around the optic nerve was 5.96 ± 1.21, compared to 4.79 ± 0.33 in the control group, with statistically significant difference (P < 0.001). All the patients with flattening of the posterior globe or transverse sinus stenosis were in the case group, and the frequency of these findings in the case group was significantly higher than in the control group (P < 0.001). The majority of patients (95.5%) classified under category 3 and 4 of empty sella were part of the case group, and the statistical test results indicated a significant difference between the two groups (P < 0.001). The optic nerve sheath diameter cut-off of 5.35 mm, when used for expansion of the subarachnoid space around the optic nerve, with a sensitivity of 82% and a specificity of 100% in diagnosing IIH. Conclusion: The most reliable diagnostic indicators for diagnosing IIH in children are perioptic subarachnoid space expansion with high sensitivity, and posterior globe flattening and transverse sinus stenosis with high specificity. [ABSTRACT FROM AUTHOR]

Advanced glycation end-products (AGEs) form through non-enzymatic glycation of various proteins. Optic nerve degeneration is a frequent complication of diabetes, and retinal AGE accumulation is strongly linked to the development of diabetic retinopathy. Type 2 diabetes mellitus is a major risk factor for Alzheimer's disease (AD), with patients often exhibiting optic axon degeneration in the nerve fiber layer. Notably, a gap exists in our understanding of how AGEs contribute to neuronal degeneration in the optic nerve within the context of both diabetes and AD. Our previous work demonstrated that glyceraldehyde (GA)-derived toxic advanced glycation end-products (TAGE) disrupt neurite outgrowth through TAGE–β-tubulin aggregation and tau phosphorylation in neural cultures. In this study, we further illustrated GA-induced suppression of optic nerve axonal elongation via abnormal β-tubulin aggregation in mouse retinas. Elucidating this optic nerve degeneration mechanism holds promise for bridging the knowledge gap regarding vision loss associated with diabetes mellitus and AD. [ABSTRACT FROM AUTHOR]

Introduction: Recent diagnostic criteria for optic neuritis include T2-hyperintensity of the optic nerve (ON), even without associated contrast enhancement. However, isolated ON-T2-hyperintensity is a nonspecific finding found in any optic neuropathy or severe retinopathy. We applied the 2022 optic neuritis diagnostic criteria to a cohort of patients with noninflammatory optic neuropathy and ON-T2-hyperintensity in at least one eye, to assess the rate of optic neuritis misdiagnosis using these criteria. Methods: Retrospective study of consecutive patients who underwent brain/orbit MRI with/without contrast between 07/01/2019 and 06/30/2022. Patients with ON-T2-hyperintensity in at least one eye were included. The 2022 optic neuritis diagnostic criteria were applied to patients with noninflammatory optic neuropathies who had an ophthalmologic examination available for review. Results: Of 150 patients included, 85/150 had compressive optic neuropathy; 32/150 had glaucoma; 12/150 had papilledema; 8/150 had hereditary (3), radiation-induced (3), nutritional (1), traumatic (1) optic neuropathies (none fulfilled the criteria); 13/150 had ischemic optic neuropathy and 4 fulfilled the criteria as definite optic neuritis due to contrast enhancement of the ON head. Seven additional patients would have satisfied the diagnostic criteria if red flags for alternative diagnoses had been overlooked. Discussion: The application of the 2022 optic neuritis diagnostic criteria in patients with noninflammatory optic neuropathy and ON-T2-hyperintensity in at least one ON resulted in misdiagnosis of optic neuritis in only 4 patients because of ON head enhancement, all with nonarteritic anterior ischemic optic neuropathy. Neuro-ophthalmologic evaluation and exclusion of the ON head as a location in the MRI criteria would have prevented optic neuritis misdiagnosis in our study. [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]

Background: Sphenoid sinus is a midline single paranasal sinus. Its development is variable with consequent anatomical variations. For sinus surgeons and endoscopists, it is very important to consider the anatomical variations of the sinus and its relation with optic nerve and other structures to avoid mishaps and hazardous serious complications. The objective: was anatomical and radiological evaluation of the sphenoid sinus Materials and methods: The study was conducted on 100 patients and 25 dried skulls. CT scan was conducted to all patients to evaluate pneumatization, septation of the sinus, presence of Onodi cells and optic nerve relation to it. All results were statistically analyzed. Results: With CT scanning, the commonest type of pneumatization was the sellar (64%), followed by the pre-sellar (22%), the post-sellar (11%) and the least common was the conchal pneumatization (3%). The findings were matched with those of dried skulls examination except that the conchal type wasn't shown. Examinations of CT images of the patients showed absence of intersphenoid sinus septum in 3% with Inter-sphenoid sinus septation found in 97%. Out of them, (39%) had single inter-sphenoid sinus septum (main septum) with no accessory septa. Accessory septa were either vertical or horizontal and ranges from 1 to 4. Studying the relations between optic nerve and sphenoid sinus, the optic nerve was bilaterally symmetrical in 92.8% and asymmetrical in 7.2%. Conclusions: Anatomy of sphenoid sinus is very variable and as compared with previous literature it showed some variations with gender so it should be considered during surgery and endoscopy and well pre-assessed before any intervention. [ABSTRACT FROM AUTHOR]

Glaucoma remains the primary cause of long-term blindness. While diabetes mellitus (DM) and hypertension (HTN) are known to influence glaucoma, other factors such as age and sex may be involved. In this retrospective study, we aimed to investigate the associations between age, sex, DM, HTN, and glaucoma risk. We employed optical coherence tomography (OCT) conducted using a 200 × 200-pixel optic cube (Cirrus HD OCT 6000, version 10.0; Carl Zeiss Meditec, Dublin, CA, USA). Effects obscured by low-test signals were disregarded. Data were amassed from 1337 patients. Among them, 218 and 402 patients had DM and HTN, respectively, with 133 (10%) exhibiting both. A sex-based comparison revealed slightly greater retinal nerve fiber layer (RNFL) and ganglion cell–inner plexiform layer (GCIPL) thickness in females. Patients without DM and HTN were predominantly in their 50 s and 60 s, whereas DM and HTN were most prevalent in those in their 60 s and 70 s. Both RNFL and GCIPL thicknesses decreased with advancing age in most patients. The study revealed that older individuals were more prone to glaucoma than younger individuals, with a higher incidence among patients with DM and HTN and reduced RNFL and GCIPL thicknesses. Furthermore, early detection before advancing age could furnish valuable preventive insights. [ABSTRACT FROM AUTHOR]

Purpose: Intracranial hypertension (IH) frequently complicates cerebral venous thrombosis (CVT). Distinct neuroimaging findings are associated with IH, yet their discriminative power, reversibility and factors favoring normalization in prospective CVT patients are unknown. We determined test performance measures of neuroimaging signs in acute CVT patients, their longitudinal change under anticoagulation, association with IH at baseline and with recanalization at follow-up. Methods: We included 26 consecutive acute CVT patients and 26 healthy controls. Patients were classified as having IH based on CSF pressure > 25 cmH2O and/or papilledema on ophthalmological examination or ocular MRI. We assessed optic nerve sheath diameter (ONSD), optic nerve tortuousity, bulbar flattening, lateral and IVth ventricle size, pituitary configuration at baseline and follow-up, and their association with IH and venous recanalization. Results: 46% of CVT patients had IH. ONSD enlargement > 5.8 mm, optic nerve tortuousity and pituitary grade ≥ III had highest sensitivity, ocular bulb flattening and pituitary grade ≥ III highest specificity for IH. Only ONSD reliably discriminated IH at baseline. Recanalization was significantly associated with regressive ONSD and pituitary grade. Other neuroimaging signs tended to regress with recanalization. After treatment, 184.9 ± 44.7 days after diagnosis, bulbar flattening resolved, whereas compared with controls ONSD enlargement (p < 0.001) and partially empty sella (p = 0.017), among other indicators, persisted. Conclusion: ONSD and pituitary grading have a high diagnostic value in diagnosing and monitoring CVT-associated IH. Given their limited sensitivity during early CVT and potentially persistent alterations following IH, neuroimaging indicators can neither replace CSF pressure measurement in diagnosing IH, nor determine the duration of anticoagulation. [ABSTRACT FROM AUTHOR]

Purpose: Morning glory disc anomaly (MGDA) is a rare congenital ophthalmologic disorder. Historically it has been diagnosed fundoscopically, with little in the literature regarding its imaging findings. The purpose of this study is to further characterize the orbital and associated intracranial magnetic resonance imaging (MRI) findings of MGDA in our tertiary pediatric center. Methods: A retrospective review was performed of fundoscopically-diagnosed cases of MGDA, that had been referred for MRI. All MRI studies were scrutinized for orbital and other intracranial abnormalities known to occur in association with MGDA. Results: 18 of 19 cases of MGDA showed three characteristic MRI findings: funnel-shaped morphology of the posterior optic disc, abnormal soft tissue associated with the retrobulbar optic nerve, and effacement of adjacent subarachnoid spaces. The ipsilateral (intraorbital) optic nerve was larger in one patient and smaller in six. The ipsilateral optic chiasm was larger in two patients and smaller in one. Conclusion: This study represents a comprehensive radiological-led investigation into MGDA. It describes the most frequently-encountered MRI findings in MGDA and emphasizes the importance of MRI in this cohort, i.e., in distinguishing MGDA from other posterior globe abnormalities, in assessing the visual pathway, and in screening for associated intracranial abnormalities – skull base/cerebral, vascular, and facial. It hypothesizes neurocristopathy as an underlying cause of MGDA and its associations. Caliber abnormalities of the ipsilateral optic nerve and chiasm are a frequent finding in MGDA. Optic pathway enlargement should not be labeled "glioma". (239/250). [ABSTRACT FROM AUTHOR]

Objectives: To assess the diagnostic accuracy of nerve thickening on MRI to predict early-stage postlaminar optic nerve invasion (PLONI) in retinoblastoma. Furthermore, this study aimed to incorporate measurements into a multiparametric model for radiological determination of PLONI. Methods: In this retrospective multicenter case–control study, high-spatial-resolution 3D T2-weighted MR images were used to measure the distal optic nerve. Histopathology was the reference standard for PLONI. Two neuroradiologists independently measured the optic nerve width, height, and surface at 0, 3, and 5 mm from the most distal part of the optic nerve. Subsequently, PLONI was scored on contrast-enhanced T1-weighted and 3D T2-weighted images, blinded for clinical data. Optic nerve measurements with the highest diagnostic accuracy for PLONI were incorporated into a prediction model for radiological determination of PLONI. Results: One hundred twenty-four retinoblastoma patients (median age, 22 months [range, 0–113], 58 female) were included, resulting in 25 retinoblastoma eyes with histopathologically proven PLONI and 206 without PLONI. ROC analysis of axial optic nerve width measured at 0 mm yielded the best area under the curve of 0.88 (95% confidence interval: 0.79, 0.96; p < 0.001). The optimal width cutoff was ≥ 2.215 mm, with a sensitivity of 84% (95% CI: 64, 95%) and specificity of 83% (95% CI: 75, 89%) for detecting PLONI. Combining width measurements with the suspicion of PLONI on MRI sequences resulted in a prediction model with an improved sensitivity and specificity of respectively up to 88% and 92%. Conclusion: Postlaminar optic nerve thickening can predict early-stage postlaminar optic nerve invasion in retinoblastoma. Clinical relevance statement: This study provides an additional tool for clinicians to help determine postlaminar optic nerve invasion, which is a risk factor for developing metastatic disease in retinoblastoma patients. Key Points: • The diagnostic accuracy of contrast-enhanced MRI for detecting postlaminar optic nerve invasion is limited in retinoblastoma patients. • Optic nerve thickening can predict postlaminar optic nerve invasion. • A prediction model combining MRI features has a high sensitivity and specificity for detecting postlaminar optic nerve invasion. [ABSTRACT FROM AUTHOR]

Objectives: To investigate the pathological interplay between immunity and the visual processing system (VPS) in thyroid eye disease (TED). Methods: A total of 24 active patients (AP), 26 inactive patients (IP) of TED, and 27 healthy controls (HCs) were enrolled. Orbital magnetic resonance imaging (MRI) and resting-state functional MRI (rs-fMRI) were conducted for each participant. Multiple MRI parameters of the intraorbital optic nerve (ON) were assessed. The amplitude of low-frequency fluctuations (ALFF) and regional homogeneity (ReHo) were calculated. Correlation analyses were carried out on the above parameters and clinical characteristics. Results: Visual functioning scores differentiated between the AP and IP groups. The ON subarachnoid space and ON sheath diameter were significantly higher in AP than in IP. Six vision-related brain regions were identified in TED patients compared with HCs, including right calcarine (CAL.R), right cuneus (CUN.R), left postcentral gyrus (PoCG.L), right middle temporal gyrus (MTG.R), left superior frontal gyrus (SFG.L), and left caudate (CAU.L). The brain activity of MTG.R, SFG.L, and CAU.L differentiated between the AP and IP groups. The correlation analysis revealed a close association among the vision-related brain regions, MRI parameters of ON, and clinical characteristics in AP and IP, respectively. Conclusions: Combined orbital and brain neuroimaging revealed abnormalities of the VPS in TED, which had a close correlation with immune statuses. Vision-related brain regions in TED might be possibly altered by peripheral immunity via a direct or indirect approach. Clinical relevance statement: The discovery of this study explained the disparity of visual dysfunction in TED patients with different immune statuses. With the uncovered neuroimaging markers, early detection and intervention of visual dysfunction could be achieved and potentially benefit TED patients. Key Points: • Patients with different immune statuses of thyroid eye disease varied in the presentation of visual dysfunction. • The combined orbital and brain neuroimaging study identified six altered vision-related brain regions, which had a significant correlation with the MRI parameters of the intraorbital optic nerve and immunological characteristics. • Peripheral immunity might possibly give rise to alterations in the central nervous system part of the visual processing system via a direct or indirect approach. [ABSTRACT FROM AUTHOR]

Background: Hypothyroidism and primary open-angle glaucoma (POAG) are common disorders affecting various systems of the body, including the endocrine and visual systems. While previous studies have suggested a potential association between hypothyroidism and POAG, the precise nature of this relationship remains unclear. This case-control study aims to investigate the association between hypothyroidism and the risk of developing POAG. Methods: A total of 50 participants were enrolled in this study, comprising 25 individuals with hypothyroidism and 25 age- and sex-matched controls without hypothyroidism. All participants underwent comprehensive ophthalmic examination, including intraocular pressure measurement, optic nerve head assessment, and visual field testing. Clinical data, including thyroid function tests, were collected from medical records. The association between hypothyroidism and POAG was analyzed using appropriate statistical methods, adjusting for potential confounders. Results: Among the 25 participants with hypothyroidism, 8 (32%) were diagnosed with POAG, whereas only 2 (8%) of the control group had POAG. The difference in the prevalence of POAG between the two groups was statistically significant (p < 0.05). After adjusting for age, sex, and other potential confounders, hypothyroidism was found to be independently associated with a significantly higher risk of developing POAG, with an odds ratio of 4.50 (95% confidence interval: 1.32-15.34, p = 0.017). Conclusion: This case-control study provides evidence of a significant association between hypothyroidism and the risk of developing POAG. These findings suggest that individuals with hypothyroidism may have an increased susceptibility to POAG, highlighting the importance of regular ophthalmic screening in this population. Further research is warranted to elucidate the underlying mechanisms linking hypothyroidism and POAG and to explore potential therapeutic interventions targeting this association. [ABSTRACT FROM AUTHOR]

To report a rare case of bilateral optic neuropathy in a patient with diffuse cutaneous systemic sclerosis with interstitial lung disease. Retrospective case report. A middle-aged female, who was a known case of systemic sclerosis with interstitial lung disease, was presented with sudden painless bilateral loss of vision for a month. The fundoscopy findings were suggestive of bilateral optic atrophy. Anti-topoisomerase I was found in the serum. Serum B12 and folate levels were reduced. HRCT Chest was suggestive of interstitial lung disease. MRI brain was normal and MRI orbit showed kinking of the left optic nerve. The findings were suggestive of diffuse cutaneous systemic sclerosis with interstitial lung disease and bilateral optic neuropathy. This is a rare case of bilateral optic neuropathy in a patient with diffuse cutaneous systemic sclerosis and interstitial lung disease with profound vision loss, in the absence of renal or cardiac involvement. [ABSTRACT FROM AUTHOR]

To report the first series of tubulointerstitial nephritis (TINU) syndrome from the Middle East. We retrospectively included patients with elevated urine beta-2 microglobulin, and a diagnosis of TINU based on anterior uveitis with or without posterior involvement. Multimodal imaging, duration of follow-up, local and systemic treatment used were recorded. 24 eyes of 12 patients (8 male, mean age 20.3 years) met the criteria for TINU. The most common posterior segment clinical finding was optic nerve head edema (41.7%), while on fluorescein angiography 58.3% and 75% of eyes had peripheral vascular and optic disc leakage, respectively. The mean follow-up was 2.5 years and all patients required immunomodulatory treatment. Middle Eastern patients with TINU seem to have a male predominance, a bimodal distribution in terms of age, and present with ocular involvement first. Multimodal imaging is paramount in detecting subclinical inflammation and tailoring immunomodulatory treatment. [ABSTRACT FROM AUTHOR]

Aims: To investigate the alterations of the optic nerve and visual cortex in dysthyroid optic neuropathy (DON), a subgroup of thyroid eye disease (TED). Methods: Multiple orbital imaging biomarkers related to optic nerve compression and the amplitude of low‐frequency fluctuations (ALFF) of the brain were obtained from 47 patients with DON, 56 TED patients without DON (nDON), and 37 healthy controls (HC). Correlation analyses and diagnostic tests were implemented. Results: Compared with HC, the nDON group showed alterations in orbital imaging biomarkers related to optic nerve compression in posterior segments, as well as ALFF of the right inferior temporal gyrus and left fusiform gyrus. DON differed from nDON group mainly in the modified muscle index of the posterior segment of optic nerve, and ALFF of orbital part of right superior frontal gyrus, right hippocampus, and right superior temporal gyrus. Orbital and brain imaging biomarkers were significantly correlated with each other. Diagnostic models attained an area under a curve of 0.80 for the detection of DON. Conclusion: The combined orbital and brain imaging study revealed alterations of the visual pathway in patients with TED and DON as well as provided diagnostic value. The initiation of alterations in the visual cortex in TED may precede the onset of DON. [ABSTRACT FROM AUTHOR]

Copyright of Current Retina Journal / Güncel Retina Dergisi is the property of Anadolu Kitabevi Basim Yayim Medikal Turizm Kirtasiye Tic. Ltd. Sti. and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Diffusion-weighted MRI (dMRI) provides a unique non-invasive view of human brain tissue properties. The present review article focuses on tractometry analysis methods that use dMRI to assess the properties of brain tissue within the long-range connections comprising brain networks. We focus specifically on the major white matter tracts that convey visual information. These connections are particularly important because vision provides rich information from the environment that supports a large range of daily life activities. Many of the diseases of the visual system are associated with advanced aging, and tractometry of the visual system is particularly important in the modern aging society. We provide an overview of the tractometry analysis pipeline, which includes a primer on dMRI data acquisition, voxelwise model fitting, tractography, recognition of white matter tracts, and calculation of tract tissue property profiles. We then review dMRI-based methods for analyzing visual white matter tracts: the optic nerve, optic tract, optic radiation, forceps major, and vertical occipital fasciculus. For each tract, we review background anatomical knowledge together with recent findings in tractometry studies on these tracts and their properties in relation to visual function and disease. Overall, we find that measurements of the brain’s visual white matter are sensitive to a range of disorders and correlate with perceptual abilities. We highlight new and promising analysis methods, as well as some of the current barriers to progress toward integration of these methods into clinical practice. These barriers, such as variability in measurements between protocols and instruments, are targets for future development. [ABSTRACT FROM AUTHOR]

Objectives: The objectives of the study are to assess the peripapillary choroidal thickness (PPCT), retinal nerve fiber layer (RNFL), and optic nerve head (ONH) parameters in multiple sclerosis (MS) patients compared to healthy subjects. Methods: One hundred and twenty-eight eyes from 64 patients were included in this cross-sectional study. Eighty-two eyes of 41 MS patients and 46 eyes of 23 healthy subjects were examined. PPCT and RNFL were measured using spectral-domain optical coherence tomography (OCT). PPCT was measured from the four quadrants around the optic disc at a distance of 1 mm (PPCT-1) and 2 mm (PPCT-2) from the edge of the ONH and the beginning of the retinal pigment epithelium. ONH parameters were measured with Heidelberg retinal tomography (HRT-3). Disease duration, the number of episodes, MS subtypes, and Expanded Disability Status Scale (EDSS) scores were recorded. Results: The RNFL measurements and the mean PPCT-1 and PPCT-2 were significantly lower in MS patients compared to healthy individuals. PPCT-1 and PPCT-2 were measured as the thickest in the temporal quadrant, followed by the superior, nasal, and inferior quadrants, respectively, in both groups. When the ONH parameters were evaluated, cup/disc area ratio, cup area, and cup volume values were significantly higher, whereas optic rim volume and rim area values were significantly lower in MS patients compared to healthy subjects (p<0.05). We observed significant changes in RNFL and ONH parameters of MS patients in parallel with disease severity determined by EDSS scores and the presence of optic neuritis. Conclusion: There were significant changes in RNFL thickness, PPCT, and ONH parameters when MS patients were compared with healthy subjects. Assessment of RNFL and PPCT with OCT and ONH with HRT-3 may be useful in the follow-up of MS patients. [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]

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]

Restoring visual function after damage or complete destruction of the optic nerve in adult patients involves many natural barriers to neuroregeneration. Research on restoring vision has focused on maintaining retinal ganglion cells (RGC), stimulating the growth of axons towards the brain, and restoring their correct synaptic connections. Unfortunately, mammalian RGC axons in normal conditions do not regenerate after injury, and ultimately they die. This review summarizes the currently known mechanisms of RGC survival and axon regeneration in mammals, including specific intrinsic signal pathways, key transcription factors, reprogramming of genes, inflammation-related regeneration factors, and stem cell therapy. The current understanding of phenomena impeding optic nerve regeneration is reviewed, along with possible ways to overcome these obstacles. The most important research results obtained in recent decades may be informative for the development of methods for treating the damaged visual system. [ABSTRACT FROM AUTHOR]

Objective: To report a threshold optic nerve area on magnetic resonance imaging (MRI) that predicts the clinical diagnosis of optic nerve atrophy in the population made by ophthalmologist. Those values could further clinically apply. Materials and Methods: The authors evaluated 23 clinical consistent patients with optic nerve atrophy. Among 46 patients' eyes, 33 "affected" eyes were clinically diagnosed with optic nerve atrophy and 13 "unaffected" eyes were used for analyses. Twenty-three controls were also included, and their 46 eyes were used for analyses. Images from the coronal sequence on MRI, excluding the optic nerve sheath, at an image slice along the intraorbital portion of the optic nerve were used to measure optic nerve area. A freeform ROI measurement tool on the PACS was used to outline and measure the cross-sectional optic nerve areas. Results: There was a statistically significant difference in optic nerve area among patients' eyes with optic nerve area (mean 1.35±0.41 mm²), patients' unaffected eyes (mean 2.55±0.48 mm², p<0.001), and control eyes (mean 4.21±1.08 mm², p<0.001). In addition, a statistically significant difference in optic nerve area was observed between patients' unaffected eyes and control eyes (p<0.001). Selecting a threshold MRI-measured optic nerve area was 2.7 mm² yielded a sensitivity of 100% and a specificity of 97.8% in predicting the presence of optic nerve atrophy by clinical diagnosis. Conclusion: The present study data suggests that MRI-measured optic nerve area of 2.7 mm² or less has both high sensitivity and high specificity for predicting the presence of optic nerve atrophy, making it a potential diagnostic tool for radiologists. [ABSTRACT FROM AUTHOR]

Copyright of Journal of Guangdong Pharmaceutical University is the property of Journal of Guangdong Pharmaceutical University and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Myelin oligodendrocyte glycoprotein (MOG)-IgG-associated disease (MOGAD) is a relatively uncommon autoantibody demyelinating disorder of the central nervous system (CNS) with heterogeneous clinical manifestations and magnetic resonance imaging (MRI) findings. In recent years, a rare MOGAD subtype characterized by distinct clinical and MRI findings has been described. Seizures and cortical hyperintensities best seen on MRI T2-weighted fluid-attenuated inversion recovery (FLAIR) sequences, associated with headache and cerebral spine fluid (CSF) pleocytosis, are the most important characteristics of this MOGAD entity that is named FLAMES (FLAIR hyperintense cortical lesions in MOG-associated encephalitis with seizures). Because of its rarity and the peculiarities of the brain damage and clinical manifestations, it can be under-recognized and confused with focal viral encephalitis, meningitis, subarachnoid hemorrhage, CNS vasculitis, or mitochondrial cytopathy. We described the case of a 4-year-old previously healthy girl who was admitted for focal-onset, tonic-clonic seizures, fever, and headache, combined with optic neuritis. MRI was characterized by FLAIR imaging showing hyperintense cortical lesions, and a mild leukocytosis in the CSF was detected. Efficacy and rapid response to steroid therapy was observed, and no recurrences of neurological problems or further seizures were reported in the following 12 months. This case report can help in understanding FLAMES characteristics in pediatrics in order to favor early diagnosis and prompt therapy. [ABSTRACT FROM AUTHOR]

PURPOSE: To compare rates of change (RoC) of peripapillary retinal nerve fiber layer (RNFL) and Bruch membrane opening-based minimum rim width (BMO-MRW) thickness in moderate-to-advanced glaucoma. DESIGN: Prospective cohort study. METHODS: Longitudinal optical coherence tomography (OCT) optic nerve head volume scans of 113 eyes of 113 glaucoma patients with moderate-to-advanced or central damage were exported. This study estimated and compared global and sectoral RoC with linear mixed effects models and simple linear regression (SLR) of RNFL and BMO-MRW thickness. Permutation analyses were used to test significance of RoC in the SLR model. It also compared longitudinal signal-to-noise ratios (LSNR) defined as RoC divided by residual standard deviation (SD) between the two groups. RESULTS: Mean (SD) follow-up and median (IQR) OCT scan sessions were 5.2 (1.3) years and 10 (8-11), respectively. Baseline average (SD) visual field mean deviation was -9.2 (5.8) dB. Based on SLR, a higher proportion of significant negative RNFL RoC was observed compared to BMO-MRW in the inferotemporal (35% vs 20%; P = .015) and inferonasal (42% vs 17%; P < .001) sectors. Permutation analyses also demonstrated a higher proportion of worsening RNFL RoC than BMO-MRW in the inferotemporal (P = .026) and inferonasal (P < .001) sectors along with overall lower positive RoC. Longitudinal signal-to-noise ratios for RNFL were significantly more negative than for BMO-MRW globally, and in the inferotemporal, inferonasal, and superonasal sectors (P ≤ .01). CONCLUSIONS: Longitudinal RNFL OCT measurements are more likely to detect structural change and demonstrate better LSNR compared with BMO-MRW in eyes with central or moderate-to-advanced glaucoma damage at baseline.

Chronic neurodegeneration and acute injuries lead to neuron losses via diverse processes. We compared retinal ganglion cell (RGC) responses between chronic glaucomatous conditions and the acute injury model. Among major RGC subclasses, αRGCs and intrinsically photosensitive RGCs (ipRGCs) preferentially survive glaucomatous conditions, similar to findings in the retina subject to axotomy. Focusing on an αRGC intrinsic factor, Osteopontin (secreted phosphoprotein 1 [Spp1]), we found an ectopic neuronal expression of Osteopontin (Spp1) in other RGCs subject to glaucomatous conditions. This contrasted with the Spp1 downregulation subject to axotomy. αRGC-specific Spp1 elimination led to significant αRGC loss, diminishing their resiliency. Spp1 overexpression led to robust neuroprotection of susceptible RGC subclasses under glaucomatous conditions. In contrast, Spp1 overexpression did not significantly protect RGCs subject to axotomy. Additionally, SPP1 marked adult human RGC subsets with large somata and SPP1 expression in the aqueous humor correlated with glaucoma severity. Our study reveals Spp1's role in mediating neuronal resiliency in glaucoma.

Magnetic resonance imaging (MRI) was used to measure in vivo local strains in the optic nerve (ON) associated with horizontal duction in humans. Axial and coronal MRI were collected in target-controlled gazes in 24 eyes of 12 normal adults (six males and six females, 59 ± 16 years) during large (~28°) and moderate (~24°) ductions. The ON, globe, and extraocular muscles were manually identified, and the pixels were converted to point-sets that were registered across different imaging planes and eye positions. Shape of the ON was parameterized based on point-sets. Displacements and strains were computed by comparing deformed with initial ON configurations. Displacements were the largest in the most anterior region. However, strains from adduction were uniform along the length of the ON, while those during abduction increased with distance from the globe and were maximal near the orbital apex. For large gaze angles, ON strain during abduction was primarily due to bending near the orbital apex that is less transmitted to the eye, but during adduction the ON undergoes uniform stretching that transmits much greater loading to the posterior eye, implied by greater strain on the ON.

A 4-year-old mixed-breed dog was presented for hyphema and glaucoma of the right eye. Enucleation of the right globe was carried out, and histopathology examination revealed an optic nerve glioma with incomplete surgical margins. At 8 wk after surgery, the dog had depressed mentation and a diminished pupillary light reflex of the left eye. Magnetic resonance imaging revealed an irregular, heterogeneously T2 hyperintense/T1 isointense mass in the region of the optic chiasm. Compression of the rostral thalamus was present, with effacement of the pituitary gland and involvement of the right orbit. The dog was euthanized 4.5 mo after initial presentation. An undefined glioma of the right optic nerve with extension to the diencephalon was diagnosed on necropsy. Key clinical message: Although rare, intraocular glioma is a differential diagnosis for hyphema, glaucoma, and retinal detachment. Magnetic resonance imaging should be considered in cases of intraocular neoplasia, notably in those with incomplete surgical margins of the optic nerve.

To explore the temporal profile of retinal proteomes specific to primary and secondary retinal ganglion cell (RGC) loss. Unilateral partial optic nerve transection (pONT) was performed on the temporal side of the rat optic nerve. Temporal and nasal retinal samples were collected at 1, 4 and 8 weeks after pONT (n = 4 each) for non-biased profiling with a high-resolution hybrid quadrupole time-of-flight mass spectrometry running on label-free SWATHTM acquisition (SCIEX). An information-dependent acquisition ion library was generated using ProteinPilot 5.0 and OneOmics cloud bioinformatics. Combined proteome analysis detected 2531 proteins with a false discovery rate of

ABSTRACTGlaucoma encompasses a spectrum of disorders characterized by the chronic degeneration of retinal ganglion cell (RGC) axons and the progressive loss of RGCs, resulting in visual impairment. In this study, we investigated the effect of autophagy deficiency on two glaucoma hypertensive models, the DBA/2J spontaneous glaucoma model, and the TGFβ2 (transforming growth factor β2) chronic ocular hypertensive model. For this, we used the Atg4b−/− and DBA/2J-Atg4b−/− mice, this latter generated in our laboratory via CRISPR/Cas9 technology, which display impaired autophagy. In contrast to littermate WT controls, mice deficient in Atg4B, did not develop glaucomatous elevation of intraocular pressure (IOP). Moreover, autophagy deficiency protected against RGC death and optic nerve atrophy. Collectively, our data supports a pathogenic role of autophagy in the context of ocular hypertension and glaucoma.Abbreviations: ATG4B: Autophagy-related 4B; BAX: BCL2-associated X protein; BECN1: Beclin 1; BID: BH3 interacting domain death agonist; CASP8: Caspase 8; IOP: Intraocular Pressure; MAP1LC3B: microtubule-associated proteins 1B; ON: Optic Nerve; RGC: Retinal Ganglion Cells; SQSTSM1: Sequestosome 1; TBK1: TANK-binding kinase 1; TGFβ2: Transforming Growth Factor β2; WT: Wild Type.

Glaucoma, a prevalent and potentially blinding eye disease, is linked to a variety of factors, including elevated intraocular pressure, optic nerve damage, and oxidative stress. In recent years, dietary habits, as a controllable lifestyle factor, have received increasing attention in the prevention and treatment of glaucoma. The purpose of this review was to investigate the effects of dietary factors on glaucoma, with a particular emphasis on two common dietary patterns: the high-salt diet and the Mediterranean diet. In addition, we investigated the association between many particular nutrients (including omega-3 fatty acids, vitamins, caffeine, and minerals) and glaucoma to fully assess the potential involvement of dietary variables in glaucoma pathogenesis, prevention, and treatment. This article reveals the importance of dietary components in glaucoma prevention and explores prospective possibilities for future research by conducting a comprehensive review of previous scientific studies.

Lenadogene nolparvovec is a gene therapy which has been developed to treat Leber hereditary optic neuropathy (LHON) caused by a point mutation in the mitochondrial NADH dehydrogenase 4 (ND4) gene. Clinical trials have demonstrated a significant improvement of visual acuity up to 5 years after treatment by lenadogene nolparvovec but, surprisingly, unilateral treatment resulted in bilateral improvement of vision. This contralateral effect – similarly observed with other gene therapy products in development for MT-ND4-LHON – is supported by the migration of viral vector genomes and their transcripts to the contralateral eye, as reported in animals, and post-mortem samples from two patients. In this study, we used an AAV2 encoding fluorescent proteins targeting mitochondria to investigate whether these organelles themselves could transfer from the treated eye to the fellow one. We found that mitochondria travel along the visual system (optic chiasm and primary visual cortex) and reach the contralateral eye (optic nerve and retina) in physiological conditions. We also observed that, in a rotenone-induced model of retinal damage mimicking LHON, mitochondrial transfer from the healthy to the damaged eye was accelerated and enhanced. Our results thus provide a further explanation for the contralateral beneficial effect observed during clinical studies with lenadogene nolparvovec.

Retinal ganglion cell (RGC) axons of the African clawed frog, Xenopus laevis, unlike those of mammals, are capable of regeneration and functional reinnervation of central brain targets following injury. Here, we describe a tadpole optic nerve crush (ONC) procedure and assessments of brain reinnervation based on live imaging of RGC-specific transgenes which, when paired with CRISPR/Cas9 injections at the one-cell stage, can be used to assess the function of regeneration-associated genes in vivo in F0 animals. Using this assay, we find that map3k12, also known as dual leucine zipper kinase (Dlk), is necessary for RGC axonal regeneration and acts in a dose-dependent manner. Loss of Dlk does not affect RGC innervation of the brain during development or visually driven behavior but does block both axonal regeneration and functional vision restoration after ONC. Dlk loss does not alter the acute changes in mitochondrial movement that occur within RGC axons hours after ONC but does completely block the phosphorylation and nuclear translocation of the transcription factor Jun within RGCs days after ONC; yet, Jun is dispensable for reinnervation. These results demonstrate that in a species fully capable of regenerating its RGC axons, Dlk is essential for the axonal injury signal to reach the nucleus but may affect regeneration through a different pathway than by which it signals in mammalian RGCs.

PURPOSE: Despite presumed relevance to ocular diseases, the viscoelastic properties of the posterior human eye have not been evaluated in detail. We performed creep testing to characterize the viscoelastic properties of ocular regions, including the sclera, optic nerve (ON) and ON sheath. METHODS: We tested 10 pairs of postmortem human eyes of average age 77 ± 17 years, consisting of 5 males and 5 females. Except for the ON that was tested in native shape, tissues were trimmed into rectangles. With physiologic temperature and constant wetting, tissues were rapidly loaded to tensile stress that was maintained by servo feedback as length was monitored for 1,500 sec. Relaxation modulus was computed using Prony series, and Deborah numbers estimated for times scales of physiological eye movements. RESULTS: Correlation between creep rate and applied stress level was negligible for all tissues, permitting description as linear viscoelastic materials characterized by lumped parameter compliance equations for limiting behaviors. The ON was the most compliant, and anterior sclera least compliant, with similar intermediate values for posterior sclera and ON sheath. Sensitivity analysis demonstrated that linear behavior eventually become dominant after long time. For the range of typical pursuit tracking, all tissues exhibit Debora numbers less than 75, and should be regarded as viscoelastic. With a 6.7 Deborah number, this is especially so for the ON during pursuit and convergence. CONCLUSIONS: Posterior ocular tissues exhibit creep consistent with linear viscoelasticity necessary for describing biomechanical behavior of the ON, its sheath, and sclera during physiological eye movements and eccentric ocular fixations. Running Head: Tensile Creep of Human Ocular Tissues.