Nerve Tortuosity Research Articles

Segmentation and multiparametric evaluation of corneal whorl-like nerves for in vivo confocal microscopy images in dry eye disease

ObjectiveTo establish an automated corneal nerve analysis system for corneal in vivo confocal microscopy (IVCM) images from both the whorl-like corneal nerves in the inferior whorl (IW) region and the...

A narrative review of magnetic resonance imaging findings in pediatric idiopathic intracranial hypertension.

Idiopathic intracranial hypertension (IIH) is a rare neurological disorder in the pediatric population which is defined as an increase in intracranial pressure (ICP) without the presence of brain parenchymal lesions, hydrocephalus, or central nervous system infection. In this study, we have determined the magnetic resonance imaging (MRI) findings in IIH patients. A comprehensive literature search was conducted using the electronic databases including Web of Sciences, Scopus, and Pubmed to identify suitable and relevant articles using keyword search methods. The search included keywords such as "idiopathic intracranial hypertension," "pseudotumor cerebri," "MRI," and "pediatrics." The search was limited to the available publications up to January 2024. MRI plays a crucial role in diagnosing IIH by excluding secondary causes and revealing neuroimaging findings associated with elevated ICP. Despite fewer studies in children compared to adults, MRI serves as a cornerstone in identifying traditional neuroradiological markers such as empty sella turcica, posterior globe flattening, optic nerve tortuosity, optic nerve sheath distension, and transverse venous sinus stenosis. Additional subtle markers include increased Meckel's cave length, cerebellar tonsillar herniation, and slit-like ventricles, although these are less reliable. Diffusion-weighted imaging does not typically show cerebral ADC value changes indicative of cerebral edema in pediatric IIH. MRI findings provide valuable non-invasive diagnostic indicators that facilitate early detection, clinical management, and potential surgical intervention in pediatric IIH. The reliability of these MRI markers underscores their importance in clinical practice.

Topical and oral peroxisome proliferator-activated receptor-α agonist ameliorates diabetic corneal neuropathy

Diabetic corneal neuropathy (DCN) is a common diabetic ocular complication with limited treatment options. In this study, we investigated the effects of topical and oral fenofibrate, a peroxisome proliferator-activated receptor-α agonist, on the amelioration of DCN using diabetic mice (n = 120). Ocular surface assessments, corneal nerve and cell imaging analysis, tear proteomics and its associated biological pathways, immuno-histochemistry and western blot on PPARα expression, were studied before and 12 weeks after treatment. At 12 weeks, PPARα expression markedly restored after topical and oral fenofibrate. Topical fenofibrate significantly improved corneal nerve fibre density (CNFD) and tortuosity coefficient. Likewise, oral fenofibrate significantly improved CNFD. Both topical and oral forms significantly improved corneal sensitivity. Additionally, topical and oral fenofibrate significantly alleviated diabetic keratopathy, with fenofibrate eye drops demonstrating earlier therapeutic effects. Both topical and oral fenofibrate significantly increased corneal β-III tubulin expression. Topical fenofibrate reduced neuroinflammation by significantly increasing the levels of nerve growth factor and substance P. It also significantly increased β-III-tubulin and reduced CDC42 mRNA expression in trigeminal ganglions. Proteomic analysis showed that neurotrophin signalling and anti-inflammation reactions were significantly up-regulated after fenofibrate treatment, whether applied topically or orally. This study concluded that both topical and oral fenofibrate ameliorate DCN, while topical fenofibrate significantly reduces neuroinflammation.

Is foramen magnum decompression for acquired Chiari I malformation like putting a finger in the dyke? - A simplistic overview of artificial intelligence in assessing critical upstream and downstream etiologies.

Missed diagnosis of evolving or coexisting idiopathic (IIH) and spontaneous intracranial hypotension (SIH) is often the reason for persistent or worsening symptoms after foramen magnum decompression for Chiari malformation (CM) I. We explore the role of artificial intelligence (AI)/convolutional neural networks (CNN) in Chiari I malformation in a combinatorial role for the first time in literature, exploring both upstream and downstream magnetic resonance findings as initial screening profilers in CM-1. We have also put together a review of all existing subtypes of CM and discuss the role of upright (gravity-aided) magnetic resonance imaging (MRI) in evaluating equivocal tonsillar descent on a lying-down MRI. We have formulated a workflow algorithm MaChiP 1.0 (Manjila Chiari Protocol 1.0) using upstream and downstream profilers, that cause de novo or worsening Chiari I malformation, which we plan to implement using AI. The PRISMA guidelines were used for "CM and machine learning and CNN" on PubMed database articles, and four articles specific to the topic were encountered. The radiologic criteria for IIH and SIH were applied from neurosurgical literature, and they were applied between primary and secondary (acquired) Chiari I malformations. An upstream etiology such as IIH or SIH and an isolated downstream etiology in the spine were characterized using the existing body of literature. We propose the utility of using four selected criteria for IIH and SIH each, over MRI T2 images of the brain and spine, predominantly sagittal sequences in upstream etiology in the brain and multiplanar MRI in spinal lesions. Using MaChiP 1.0 (patent/ copyright pending) concepts, we have proposed the upstream and downstream profilers implicated in progressive Chiari I malformation. The upstream profilers included findings of brain sagging, slope of the third ventricular floor, pontomesencephalic angle, mamillopontine distance, lateral ventricular angle, internal cerebral vein-vein of Galen angle, and displacement of iter, clivus length, tonsillar descent, etc., suggestive of SIH. The IIH features noted in upstream pathologies were posterior flattening of globe of the eye, partial empty sella, optic nerve sheath distortion, and optic nerve tortuosity in MRI. The downstream etiologies involved spinal cerebrospinal fluid (CSF) leak from dural tear, meningeal diverticula, CSF-venous fistulae, etc. AI would help offer predictive analysis along the spectrum of upstream and downstream etiologies, ensuring safety and efficacy in treating secondary (acquired) Chiari I malformation, especially with coexisting IIH and SIH. The MaChiP 1.0 algorithm can help document worsening of a previously diagnosed CM-1 and find the exact etiology of a secondary CM-I. However, the role of posterior fossa morphometry and cine-flow MRI data for intracranial CSF flow dynamics, along with advanced spinal CSF studies using dynamic myelo-CT scanning in the formation of secondary CM-I is still being evaluated.

Effects of full-thickness wedge resection on ocular surface and in vivo confocal microscopy findings in floppy eyelid syndrome patients.

To evaluate the effect of full-thickness wedge resection (FTWR) on ocular surface and in vivo confocal microscopy (IVCM) findings in patients with floppy eyelid syndrome (FES). The study included two groups: a surgical treatment (ST) group (26 eyes) consisting of patients who underwent FTWR surgery, and a conservative treatment (CT) group (30 eyes). Pre-treatment and post-treatment ocular surface disease index (OSDI), tear break-up time (TBUT), corneal fluorescein staining (CFS), IVCM findings along with the body mass index (BMI), FES grade, the presence and the treatment of obstructive sleep apnea syndrome (OSAS) were recorded and compared between the groups. The groups were comparable in terms of BMI, FES grade, and OSAS data. After six months, TBUT in the ST group significantly increased to 12.92 ± 1.15, compared to 8.10 ± 1.60 in the CT group (p = 0.000). The CFS and OSDI scores were significantly lower in the ST group (0.15 ± 0.37, 18.0 ± 8.3, respectively) compared to the CT group (0.90 ± 0.61, 27.3 ± 9.3, respectively) (p = 0.000). IVCM analysis revealed a significant decrease in dendritic cell count (ST: 22.0 ± 12.4, CT: 39.5 ± 15.1, p = 0.000) and nerve tortuosity (ST: 1.38 ± 0.64, CT: 2.00 ± 0.59, p = 0.000), with a significant increase in total nerve density (ST: 4.27 ± 0.83, CT: 3.57 ± 0.90, p = 0.002) in the ST group compared to the CT group after six months. In our retrospective cohort, FTWR surgery was shown to be an effective and reliable surgical treatment for FES, improving both ocular surface and IVCM findings. Patients with moderate to severe stages of FES not responding to conservative treatment may benefit from eyelid tightening.

Correlation between Diagnostic Magnetic Resonance Imaging Criteria and Cerebrospinal Fluid Pressure in Pediatric Idiopathic Intracranial Hypertension

Purpose: Idiopathic intracranial hypertension (IIH) is a clinical syndrome that mimics brain tumors with increased intracranial pressure. The present study is designed to investigate the diagnostic criteria of magnetic resonance imaging (MRI) and the severity of cerebrospinal fluid (CSF) pressure to understand the relationship and frequency of these criteria with the level of CSF pressure.Methods: The present cross-sectional study was conducted on children diagnosed with IIH between the years 2011 and 2020, who were admitted to the pediatric neurology department of Ghaem Hospital, Mashhad, Iran. Clinical manifestations and imaging findings of the patients were recorded through a checklist. Results: Forty-nine patients were included in the study; 27 (55.1%) were male, and 22 (44.9%) were female. The average CSF pressure was 40.64±20.63 cmH<sub>2</sub>O. The mean diameter distension of the perioptic subarachnoid space was 6.02±1.21 mm. Six (10.8%) patients had unilateral transverse sinus stenosis with an average CSF pressure of 20.47±36.80 cmH<sub>2</sub>O and 11 (21.4%) patients had bilateral transverse sinus stenosis with an average pressure of 48.22±21.04 cmH<sub>2</sub>O. In 22 (44.89%) patients, flattening of the posterior globe with the CSF pressure of 48.80±17.94 cmH<sub>2</sub>O was reported. Twenty-four (49%) patients had optic nerve tortuosity, with an average CSF pressure of 46.52±20.33 cmH<sub>2</sub>O. Among the diagnostic criteria, the pressure had a significant relationship with the flattening of the posterior globe (<i>P</i><0.022).Conclusion: Since MRI is a non-invasive method for examining IIH, the findings of this study may aid in diagnosing and monitoring these patients.

MRI features of idiopathic intracranial hypertension are not prognostic of visual and headache outcome

BackgroundIn idiopathic intracranial hypertension (IIH), certain MRI features are promising diagnostic markers, but whether these have prognostic value is currently unknown.MethodsWe included patients from the Vienna-Idiopathic-Intracranial-Hypertension (VIIH) database with IIH according to Friedman criteria and cranial MRI performed at diagnosis. Presence of empty sella (ES), perioptic subarachnoid space distension (POSD) with or without optic nerve tortuosity (ONT), posterior globe flattening (PGF) and transverse sinus stenosis (TSS) was assessed and multivariable regression models regarding visual outcome (persistent visual impairment/visual worsening) and headache outcome (headache improvement/freedom of headache) were fitted.ResultsWe included 84 IIH patients (88.1% female, mean age 33.5 years, median body mass index 33.7). At baseline, visual impairment was present in 70.2% and headache in 84.5% (54.8% chronic). Persistent visual impairment occurred in 58.3%, visual worsening in 13.1%, headache improvement was achieved in 83.8%, freedom of headache in 26.2%.At least one MRI feature was found in 78.6% and 60.0% had ≥3 features with POSD most frequent (64.3%) followed by TSS (60.0%), ONT (46.4%), ES (44.0%) and PGF (23.8%).In multivariable models, there was no association of any single MRI feature or their number with visual impairment, visual worsening, headache improvement or freedom.Visual impairment at baseline predicted persistent visual impairment (odds ratio 6.3, p<0.001), but not visual worsening. Chronic headache at baseline was significantly associated with lower likelihood of headache freedom (odds ratio 0.48, p=0.013), but not with headache improvement.ConclusionsMRI features of IIH are neither prognostic of visual nor headache outcome.

Impact of rater experience and referral question on detecting magnetic resonance imaging features of idiopathic intracranial hypertension.

In idiopathic intracranial hypertension (IIH), magnetic resonance imaging (MRI) features are promising diagnostic markers, but the impact of rater experience and the specific referral question is unknown. From the Vienna Idiopathic Intracranial Hypertension database, patients were included with definitive IIH and routine cranial MRI performed during diagnostic work-up. Frequencies of partial empty sella (ES), optic nerve sheath distension (ONSD), optic nerve tortuosity (ONT), posterior globe flattening (PGF) and transverse sinus stenosis (TSS) were compared in three settings: (i) real-world rating, (ii) junior neuroradiologist without special IIH training and (iii) senior neuroradiologist with experience in IIH imaging (gold standard). Magnetic resonance imaging scans of 84 IIH patients (88% female, mean age 33.5 years) were evaluated. By gold standard, ONSD was the most frequent (64.3%) followed by TSS (60.0%), ONT (46.4%), ES (44.4%) and PGF (23.8%). Compared to the gold standard, IIH features were described significantly less frequently in routine MRI reports (ONSD 28.6%, ONT 13.1%, PGF 4.8%, TSS 42.9%, p < 0.01 respectively) except for ES (42.9%, p = 0.9). A specific referral question regarding IIH increased detection rates in routine reports, but rates remained significantly lower than by gold standard. In contrast, a rating by a neuroradiologist without special training produced significantly higher frequencies of ONSD (81.0%, p < 0.01) and ONT (60.7%, p < 0.01) but not of ES (47.6%), PGF (29.8%) and TSS (68.1%). Idiopathic intracranial hypertension MRI features are underestimated in routine MRI reports and partly overcalled by less experienced neuroradiologists, driven by features less well known or methodologically difficult. Reevaluation of MRI scans by an experienced rater (and to a lesser degree a specific referral question) improves diagnostic accuracy.

Clinicoradiological profile of idiopathic intracranial hypertension

Objectives: Idiopathic intracranial hypertension (IIH) is a condition of raised intracranial pressure (ICP) in the absence of a space-occupying lesion. IIH patients usually present with typical symptoms and signs of increased ICP, such as headache, vomiting, neck pain, double vision, transient visual obscuration (TVO), and papilledema. Typical magnetic resonance imaging (MRI) findings include empty sella turcica, optic nerve tortuosity, globe flattening, and transverse sinus stenosis. Material and Methods: All patients from July 2021 to June 2022 presented to the super-specialty neuroclinic with symptoms suggestive of IIH were included in this study after consent. Clinical patterns and MRI brain findings along with other risk factors and comorbidities were studied. Results: Total 12 patients were studied out of which all were female. The most common age group was 31–40 years (41.6%). The most common clinical presentations were headache and TVOs followed by painless loss of vision, visual field changes and double vision. In this study, 7 out of 12 cases presented with headache (58.3%) out of which only 3 were migrainous. TVOs were presenting complaints of 7 patients (58.3%). Painless visual loss was there in 3 patients (25%), out of which only one case was bilateral (33%). In all cases (100%), MRI was suggestive of IIH. Transverse sinus stenosis in 3 cases (25%) and scleral flattening in 1 case (14.2%) were seen, respectively. Conclusion: Clinical suspicion followed by MRI brain is of utmost importance. Prompt diagnosis and treatment are essential in IIH patients to prevent permanent visual loss.

Magnetic Resonance Imaging Findings in Idiopathic Intracranial Hypertension With and Without Pulsatile Tinnitus: An Age-Matched Cohort Study

Many but not all patients with idiopathic intracranial hypertension (IIH) have pulsatile tinnitus (PT). However, little is known about why some patients with IIH develop PT and others do not. The purpose of this study was to determine if any of the classic magnetic resonance imaging (MRI)-detectable markers of IIH differ between patients with and without PT, thereby shedding light on potential pathophysiology. A retrospective age-matched cohort study of patients with documented IIH (diagnosed by neuro-ophthalmologist) was performed. All patients had MRI performed around the time of diagnosis. MRIs were assessed for 16 variables known to be associated with IIH (e.g., pituitary displacement/empty sella, optic nerve tortuosity, transverse sinus stenosis, inferior cerebellar tonsils, arachnoid granulations, slit-like ventricles) by two blinded neuroradiologists. All binary variables were analyzed via χ2 test with Yates correction, or Fisher exact when appropriate. Continuous variables were analyzed via Student t test. Inter-rater reliability for binary variables was assessed by Cohen κ . For continuous variables, intraclass correlation coefficient was calculated. Forty age-matched patients with IIH met the inclusion criteria (20 with PT, 20 without PT). For all known binary MRI findings associated with IIH, there were no statistically significant differences between groups. Likewise, there were no statistically significant differences for continuous variables. The classic MRI findings associated with IIH do not differ between patients with and without PT, suggesting that systemic (rather than localized intrinsic or extrinsic) factors may play a critical role in the pathophysiology.

Effects of lipid-containing eye drops on the ocular surface and in vivo confocal microscopy findings in patients using systemic isotretinoin

Objective To evaluate the effects of lipid-containing Rohto Dry Aid eye drops and sodium hyaluronate eye drops on the ocular surface and in vivo confocal microscopy (IVCM) findings in patients using systemic isotretinoin. Methods This retrospective study included 71 patients using systemic isotretinoin for acne vulgaris. Ocular surface and tear functions were evaluated with the tear break-up time (TBUT), corneal fluorescein staining (CFS), and the ocular surface disease index questionnaire (OSDI). Meibography was used for the staging of Meibomian gland dysfunction (MGD) while IVCM was used for the analysis of corneal micro-structural changes. The data of 36 patients using Rohto Dry Aid (the Rohto group) and 35 patients using sodium hyaluronate (the SH group) were recorded. Pre-treatment, first month and third month data were analyzed. Results Longer TBUT, lower OSDI score, and less CFS were observed in the first and third months after treatment in the Rohto group (p < 0.001). There was no significant change in TBUT and CFS in the first month (p > 0.05) in the SH group (p < 0.05) but lower TBUT and more CFS were observed in the third month. There was no significant change in the OSDI score in the SH group. There was a significant decrease in dendritic cells, activated keratocytes, and nerve tortuosity with IVCM in both groups. However, no significant difference was found between the two groups. Conclusion Rohto Dry Aid, with its support of the lipid layer, is an effective and safe treatment agent that can improve both ocular surface and IVCM findings in evaporative dry eye cases with MGD.

Katarakt Cerrahisi Sonrası Oküler Yüzey İnflamasyonu ve Kuru Göz Hastalığı Tedavisinde Dekspantenol/Sodyum Hyaluronat Fiks Kombinasyonuna Karşı Sodyum Hyaluronat Damla Etkinliği: Karşılaştırmalı Çalışma

Objective: To compare the efficacy of dexpanthenol/ sodium hyaluronate fixed combination with sodium hyaluronate eye drops in the treatment of dry eye disease (DED) and ocular surface inflammation (OSI) following cataract surgery. Material and Methods: Sixty-three patients who underwent cataract surgery were included in this study. In addition to the standard postoperative treatment, one group (study group, n=30 eyes) received dexpanthenol/sodium hyaluronate fixed combination eye drops, while the other group was given sodium hyaluronate eye drops (control group, n=33 eyes). The 2 groups were compared in terms of best-corrected visual acuity, tear break-up time (TBUT), corneal flourescein staining, ocular surface disease index (OSDI) and in vivo confocal microscopy (IVCM) findings. Results: While TBUT was significantly greater in the study group than the control group (11.2, 8.9, respectively), corneal floresein staining (0.13, 0.48, respectively) and OSDI (10.8, 17.1, respectively) were significantly lower in the study group compared to the control group at postoperative 4 months. In IVCM, the number of dendritic cells and activated keratocytes were significantly lower in the study group (40.8, 13.9 respectively) compared to the control group (51.2, 18.0, respectively). In addition, while the total number of nerves in the study group (4.57) was higher than that of the control group (3.91), the nerve tortuosity was lower in the study group (1.57, 2.18, respectively). Conclusion: Dexpanthenol/sodium hyaluronate fixed combination eye drops could be preferred as an adjuvant for the treatment of DED and OSI following cataract surgery.

Evaluation of Corneal Alterations After Short-Term Silicone Hydrogel Contact Lens Use by Confocal Microscopy.

To evaluate the corneal subbasal nerve morphology, corneal sensitivity, and anterior segment alterations in short-term silicone hydrogel contact lens (SiHCL) users by confocal microscopy. The study included 25 right eyes of 25 male volunteers aged 25-30 years who had never used SiHCLs before. ocular surface disease index (OSDI), tear break-up time, Schirmer test, tear meniscus area, strip meniscometry tube, corneal sensitivity, and corneal subbasal nerve morphology were evaluated before and after 1 month of CL use. OSDI was 10.6±1.1 before CL use and 17.2±1.2 after 1 month of CL use (p<0.01). Schirmer test distance was 16.3±2.3 mm before and 14.3±1.9 mm after 1 month of CL use (p>0.05). Tear film break-up time was 7.1±0.4 s before and 6.2±0.3 s after CL use (p>0.05). The tear meniscus area was 0.026±0.002 mm2 before and 0.024±0.001 mm2 after 1 month of CL use (p>0.05). Strip meniscometry tube results were 5.4±0.9 mm before and 4.9±0.8 mm after 1 month of CL use (p>0.05). Corneal sensitivity values were 3.2±0.4 mm before and 2.95±0.3 mm after 1 month of CL use (p>0.05). Dendritic cell density evaluated by confocal microscopy was 14.84±3.1 cells/mm2 before and 32.57±4.2 cells/mm2 after 1 month of CL use (p<0.01). Subbasal nerve tortuosity was 0.92±0.2 before and 1.03±0.2 after 1 month of CL use (p>0.05). Subbasal nerve density was measured as 4726±310 pixels/frame before and 4570±272 pixels/frame after 1 month of CL use (p>0.05). After a month of SiHCL use, no significant changes were observed in tear secretion, corneal sensitivity, tear meniscus volume, subbasal corneal nerve density, reflectivity, or tortuosity, while a significant increase was found in OSDI and dendritic cell density.

Corneal Confocal Analysis after Scleral Lens Wear in Keratoconus Patients: A Pilot Study.

Scleral lenses rely on the scleroconjunctival region without bearing the cornea, which could improve the symptoms and modify the corneal nerve plexus morphology. This study aimed to evaluate symptoms and changes in corneal nerve plexus morphology and density of Langerhans cells in keratoconus patients with and without intrastromal corneal ring before and after scleral lens wear. Sixteen scleral lens wearers with keratoconus were recruited for this short-term experimental pilot study. Subjects were divided into two groups: keratoconus group and intrastromal corneal ring segment group. All subjects were examined in two visits: baseline (before scleral lens wear) and after 6 months of scleral lens wear, after lens removal. The Schirmer I test, the Ocular Surface Disease Index, tear breakup time, and in vivo confocal microscopy were evaluated. The mean age was 42.33 ± 11.27 years. A significant decrease in tear breakup time was found in the total group ( P = .01, Wilcoxon) compared with baseline. Ocular Surface Disease Index score had decreased after 6 months of scleral lens wear in the keratoconus with intrastromal corneal ring segment subgroup ( P = .03, Wilcoxon) and in the total group ( P = .001, Wilcoxon). No statistical changes in nerve density, tortuosity, and ramification were found for either the total group or the subgroup. However, the mean nerve length was higher in all groups, especially in the keratoconus subgroup ( P = .03, Wilcoxon) after 6 months of scleral lens wear. Regarding optical density, the total group showed a significant increase after 6 months of wearing ( P = .02, Wilcoxon). Finally, Langerhans cell density was not statistically different in any group. These results suggest that scleral lens wearing improves the symptoms and increased the mean length nerves after 6 months of wear use in keratoconus patients.

New Method for the Automated Assessment of Corneal Nerve Tortuosity Using Confocal Microscopy Imaging

An automated tool for corneal nerve fiber tortuosity quantification from in vivo confocal microscopy (IVCM) is described and evaluated. The method is a multi-stage process based on the splitting of the corneal nerve fibers into individual segments, whose endpoints are an extreme or intersection of white pixels on a binarized image. Individual segment tortuosity is quantified in terms of the arc-chord ratio. Forty-three IVCM images from 43 laser-assisted in situ keratomileusis (LASIK) surgery patients were used for evaluation. Images from symptomatic dry eye disease (DED) post-LASIK patients, with (n=16) and without (n=7) ocular pain, and non-DED post-LASIK controls (n=20) were assessed. The automated tortuosity measure was compared to a manual grading one, obtaining a moderate correlation (Spearman’s rank correlation coefficient = 0.49, p=0.0008). The new tortuosity index was significantly higher in post-LASIK patients with ocular pain than in control patients (p=0.001), while no significant differences were detected with manual measurement (p&gt;0.28). The tortuosity quantification was positively correlated with the ocular surface disease index (OSDI) and a numeric rating scale (NRS) assessing pain (p=0.0012 and p=0.0051, respectively). The results show good performance of the proposed automated methodology for the evaluation of corneal nerve tortuosity.

Idiopathic intracranial hypertension: an illustrated guide for the trainee radiologist.

Idiopathic intracranial hypertension is characterized by increased intracranial pressure, headache, and visual perturbations. Although the pathophysiology of idiopathic intracranial hypertension is obscure, several mechanisms have been proposed, such as increased cerebral blood volume, excessive cerebrospinal fluid volume (due to high production or impaired resorption), and inflammatory mechanisms as a likely cause of or contributor to impaired cerebrospinal fluid circulation. It predominantly affects women of reproductive age who are overweight or obese. The most common symptoms are daily headache, synchronous pulsatile tinnitus, transient visual perturbations, and papilledema with visual loss. The main neuroimaging findings are a partially empty sella turcica; flattening of the posterior sclera; transverse sinus stenosis (bilateral or in the dominant sinus); a prominent perioptic subarachnoid space, with or without optic nerve tortuosity; and intraocular protrusion of the optic nerve head. The main complication of idiopathic intracranial hypertension is visual loss. Within this context, neuroimaging is a crucial diagnostic tool, because the pathology can be reversed if properly recognized and treated early.

Investigation of anterior segment structures of the eye in Behçet's disease using in vivo confocal microscopy.

We sought to investigate alterations in the corneal subbasal nerve plexus and endothelium in patients with Behçet's disease (BD). This cross-sectional study included 64 patients with BD and 30 age- and gender-matched healthy control subjects. Those with BD were classified as having ocular or non-ocular disease. All subjects underwent a corneal endothelial and subbasal nerve density evaluation using in vivo confocal microscopy (IVCM). The differences among groups were analyzed using the Kruskal-Wallis test followed by Dunn's multiple comparison procedure. The mean age of study participants was 35.7 ± 10.2years (16-58) in the ocular BD group, 39.6 ± 14.9years (11-66) in the non-ocular BD group, and 34.1 ± 11.2years (21-55) in the control group. No statistical significance was found in terms of age (p = 0.259) or sex (p = 0.560) between groups. The mean endothelial cell density determined with IVCM was 2124.9 [Formula: see text] 417.4 cells/mm2 (1811-3275) in the ocular group and 2546 [Formula: see text] 335 cells/mm2 (1798-3280) in the control group (p = 0.000). In the ocular group, the mean density of the subbasal nerve plexus was significantly lower (p = 0.004), and nerve tortuosity was significantly higher (p = 0.002). Ocular BD could be responsible for changes in the corneal layers, especially endothelial and corneal nerve structures. Nerve density and tortuosity differences could be inflammatory indicators for BD.

Clinically Based Automated Tracing and Tortuosity Estimation of Corneal Nerve Fibers From Confocal Microscopy Images

The purpose of this study was the development of an algorithm able to automatically trace corneal nerves and to estimate a nerve tortuosity index that is useful in clinical practice. In vivo confocal microscopy is an imaging technique that allows the clinical assessment of corneal and systemic diseases. Many studies have demonstrated a correlation between the tortuosity level of nerve fibers in the subbasal plexus layer and some pathologies. We developed an algorithm that provides fully automatic tracing of nerve fibers. It also includes a new way of dealing with bifurcations, separating the main paths from the secondary ones. Based on this automated tracing, the tortuosity was estimated as the absolute curvature, tortuosity density, and fractal dimension. These metrics were considered first individually and then as a linear combination of 2 or 3 of them. We investigated the capability of the estimated tortuosity to emulate the clinical classification into low, mid, and high tortuosity levels. Furthermore, we investigated its ability to distinguish healthy subjects from pathological subjects. Excellent agreement between manual and automated grouping of tortuosity (96.6% accuracy) was obtained. Moreover, the proposed algorithm could differentiate between healthy and pathological subjects with an accuracy of 77.1% by analyzing each image individually. The accuracy improved to 86.31% by considering 3 images of the same subject simultaneously. The proposed framework provides completely automated analysis of corneal nerve images. The results demonstrate the ability of our method to emulate the clinical classification of tortuosity levels and its potential for identifying healthy and pathological subjects.

Corneal subbasal nerve analysis in patients with primary Sjogren's syndrome: a novel objective grading method and clinical correlations.

To investigate corneal sub-basal nerve morphology changes in primary Sjogren's syndrome (SS) dry eye (SSDE) patients and determine the association with disease severity at microstructural level. Twenty-eight eyes of 17 SSDE and 82 eyes of 47 age- and sex-matched non-SS dry eye (NSSDE) patients were included. The Ocular Surface Disease Index questionnaire (OSDI), Schirmer's test (ST), tear meniscus height (TMH), non-invasive breakup time (NIBUT), meibomian gland (MG) morphology, and ocular staining score (OSS) were assessed. In vivo confocal microscopy was performed to observe corneal sub-basal nerve morphology (length, reflectivity, width, and tortuosity). Associations between clinical features and nerve parameters were analysed. SSDE patients more frequently had increased nerve reflectivity (151.12 ± 17.07 vs. 139.37 ± 14.31 grey value), width (4.45 ± 0.87 vs. 3.92 ± 0.81μm), tortuosity (132.90 ± 8.04 vs. 129.50 ± 7.33 degree), and higher reflectivity, width, and total nerve grades than NSSDE individuals (all P < 0.05). Significant associations were found between nerve reflectivity/width and anti-SSA [OR = 1.139 (1.013-1.281)/1.802 (1.013-4.465)]/labial gland biopsy [OR = 1.046 (1.002-1.161)/1.616 (1.020-3.243)]. Higher nerve width was associated with increased OSDI [β = 0.284 (0.187-0.455)], MG score [β = 0.185 (0.109-0.300)] and OSS [β = 0.163 (0.020-0.345)], but decreased NIBUT [β = - 0.247 (- 0.548 ~ - 0.154)]. Higher nerve total grade was associated with increased OSDI [β = 0.418 (0.157-0.793)] and OSS [β = 0.287 (0.027-0.547)], but decreased ST [β = - 0.410 (-0.857 ~ - 0.138)]. Corneal nerve morphology changes associated with clinical features in SS patients. These changes may facilitate severity evaluation and management of the disease.

Accuracy and reliability of magnetic resonance imaging in the diagnosis of idiopathic intracranial hypertension

PurposeTo determine the diagnostic utility of brain magnetic resonance imaging (MRI) findings in patients with idiopathic intracranial hypertension (IIH) and to investigate the significance of evaluating radiological findings together with neurological and ophthalmological data in the diagnosis of IIH. Materials and MethodsAll consecutive patients diagnosed with IIH in our tertiary neuro-ophthalmology center between January 1, 2018 and March 15, 2020, were included in the study. The clinical, radiological, and ophthalmological findings of IIH patients were compared with the control group with similar demographic characteristics. ResultsA total of 98 patients, 49 cases and 49 controls, were included in the study. Lateral ventricular index had the highest area under the curve (AUC) value (0.945) for prediction of disease group followed by sella height category (AUC = 0.915) and optic nerve tortuosity (AUC = 0.855) According to the multivariate model we developed, caudate index (OR = 0.572, 95% CI 0.329–0.996), lateral ventricle index (OR = 3.969, 95% CI 1.851–8.509) and bilateral optic nerve tortuosity (OR = 22,784, 95% CI 2.432–213.450) were significant predictors for disease group. ConclusionTortuosity in the optic nerve, lateral ventricular index and caudate index can be used as MRI parameters supporting the diagnosis of IIH in clinically suspicious cases. A holistic approach to the clinical and radiological findings of the cases in the diagnosis of IIH can prevent overdiagnosis and enable early correct diagnosis.