Optic Nerve Thickness Research Articles

Evaluation of the Differences in Parameters Obtained from the Computed Tomography Images of the Eyeball and the Structures in the Orbit by Age and Gender

Objective: The aim of this study is to show the variation of eyeball and orbital structures according to different age groups and gender. Methods: The study was carried out on 4 age groups over 30-40, 41-50, 51-60, 61. The parameters were, the angle between the optic nerve and axis of eyeball (A-Cr2AA), the length of the medial rectus muscle (MRML) and the length of the lateral rectus muscle (LRML) up to the Zinn ring, the thickness of the lens (LT),), the length of the optic nerve from the Zinn ring (Cr2L), optic nerve thickness (Cr2T), distance between two eyeballs (BOD) and the others. Results: As a result of the study, in the comparison of males in four groups, significant difference was found between the groups in LT, Cr2L, A-Cr2AA, MRML parameters in the right eyeball and Cr2L and LRML parameters in the left eyeball (p

HISTOLOGICAL FEATURES OF ETHAMBUTOL INDUCED MICE EYES: A PRE- EXPERIMENTAL STUDY ON TOXIC OPTIC NEUROPATHY CASE

Abstract
 Introduction & Objectives : Toxic Optic Neuropathy (TON) is a visual disease caused by toxic substances damaging the optic nerve. It can be caused by inflammation, infection, or long-term drug use. Over 10% of ethambutol- treated optic neuropathy patients developed major complications. Cellular changes should be observed histologically. This study examines ethambutol-induced mice's eye histology in the fibrous, vasculous, nervous tunica, optical media, and optic nerve tissue.
 Methods : This pre-experimental study used 20 eyes of 10 white mice aged 1-2 weeks weighing 50-65 grams. Group 1 consisted of healthy mice without therapy and group 2 received 35 mg/kgBW/day of ethambutol for 60 days. (group 2). Hematoxylin eosin staining was used to observe binocular experimental animal eyes after enucleation. All measurements used Olympus® CX-20 microscope with 40x objective resolution.
 Results : The average thickness of the cornea was 72.238 ± 10.542 and 60.572 ± 10.25, while the sclera was 336.533±40.851 μm and 331.339±34.219 μm. In groups 1 and 2, no significant changes were foundin the cell layer morphology of both tissues (p > 0.05). Iris, ciliary body, and choroid were observedin the tunica vasculosa. Groups 1 and 2 had eye and ciliary body lengths of 595.148±137.805 μm and 497.705±213.866 μm, respectively, and choroid thicknesses of 161.369±37.925 and 162.605±25.160 (p>0.05). Group 1 had 402.268±55.666 μm retinal thickness in the tunica nervosa, while group 2 had 399.854±27.585 (p>0.05).
 Conclusion : Ethambutol-induced and normal experimental animals had substantial histological differences in optic nerve thickness, but no significant difference in the other ocular structures.

Echographic Optic Nerve Evaluation: A Novel Diagnostic Modality in Glaucoma

Introduction: Primary Open-Angle Glaucoma (POAG) is considered a leading cause of blindness among all others. Different technologies such as Scanning Laser Polarimetry (SLP) and Optical Coherence Tomography (OCT) closely correlate in measuring structural parameters of the Retinal Nerve Fiber Layer (RNFL) and Optic Nerve Head (ONH). Visual impairment related to glaucomatous damage is attributed to the RNFL. Earlier studies have shown that retro-bulbar optic nerve thickness is reduced in glaucoma and have suggested that this is also the result of RNFL destruction. Aim: To investigate the correlation between the orbital and intraocular portions of the optic nerve among POAG patients. Materials and Methods: This was a hospital-based crosssectional study done in a tertiary care ophthalmic institute from October 2019 to February 2021. One eye of 32 volunteers with newly diagnosed POAG underwent optic disc analysis using OCT and echographic measurements of the retrobulbar optic nerve. For statistical calculations, Statistical Package for Social Sciences (SPSS) Statistics version 20.0 software (IBM Corp., Armonk, NY, USA) was used. Spearman’s rho (rs) was used as the index of correlation between retrobulbar optic nerve dimensions and ONH topographical data. A correlation between OCT-based RNFL and optic disc parameters was compared with retrobulbar optic nerve dimensions measured with the help of Ultrasonography- Brightness (USG B) Scan. Results: Orbital Optic Nerve Diameter (OND) and Optic Nerve Cross-sectional Area (ONCSA) significantly and positively correlated with Neuro-retinal Rim (NR) area (OND: p-value=0.00001; ONCSA: p-value=0.00001) and average nerve fiber layer thickness (OND: p-value=0.0001; ONCSA: p-value=0.00002). The Retrobulbar ONCSA-to-disc area ratio (ONCSA/D) was found to have a statistically demonstrable positive correlation with Neuro-retinal Rim Area/Disc area ratio (NR/D) (p=0.00003). Conclusion: This study showed that retrobulbar optic nerve dimensions correlate well with SD-OCT-based ONH parameters. Echographic measurements of the retrobulbar optic nerve add a new biomarker in the diagnosis of glaucoma.

A comparative analysis of biometric parameters of optic nerves obtained by ultrasonic sensors of varied frequencies

Purpose: a comparative analysis of biometric parameters of the optic nerve obtained by different diagnostic ultrasound sensors.Material and methods. We examined 20 healthy volunteers with emmetropia aged 20 to 40 years (40 eyes), average age 30.5 ± 5.4 years, who had no complaints or ophthalmic pathologies. Ultrasound scanning was performed on a multifunctional Voluson E8 (GE) scanner (11–18 MHz linear sensor), ophthalmic ultrasound device Ellex Eyecubed (a conventional 10 MHz transducer) and an ophthalmic scanner Absolu «Quantel Medical» (a 20 MHz transducer). All examinations were carried out by one operator who used the same scanning technique and measured the optic nerve sheath diameter (ONSD) and optic nerve diameter (OND) without sheaths in both eyes. Six consequent measurements of the ONSD and the OND parameters were performed to ascertain the reproducibility of the examinations and evaluate the variation coefficient.Results. The analysis revealed no statistically significant differences in the ONSD and in the OND obtained with 11–18 MHz, 10 MHz and 20 MHz transducers in the B-mode (р > 0.05). The minimum variation coefficient of the optic nerve thickness parameters was registered using a high-frequency 20 MHz transducer on the ophthalmic scanner. The biometry obtained with a high frequency 20 MHz transducer could be considered as the most reproducible.Conclusion. A high frequency 20 MHz transducer can be recommended for optimal visualization and precise evaluation of biometric parameters of the retrobulbar part of the optic nerve. Transducers of multifunctional scanners with the frequency range from 11 to 20 MHz can be used for measurements of the optic nerve sheath diameter.

Pediatric Ocular Health and Obstructive Sleep Apnea Syndrome: A Review.

Obstructive sleep apnea (OSA) affects neurobehavioral, cognitive, and cardiovascular aspects, particularly in children, by obstructing the upper airways during sleep. While its impact in adult ocular health is recognized, there is ongoing debate about OSA's relevance in pediatrics. This review explores the relationship between OSA and ocular health in children, focusing on the effects and potential improvements through treatment. A systematic search found 287 articles through PubMeD/MEDLINE, Scopus, Web of Science, and ScienceDirect; 94.4% were excluded. After careful selection, six English articles were included, addressing the effects of OSA on children's eyes. Three studies examined choroidal alterations, three explored retinal and optic nerve changes, and two analyzed ocular changes following otorhinolaryngological intervention. The immediate correlation in children is inconclusive, but age may be a contributing factor. Pediatric OSA patients exhibit corneal anomalies and increased optic nerve thickness, possibly due to intermittent hypoxia. OSA influences retinal vascular density in children, with increased density after treatment and reduced choroidal thickness in cases of adenotonsillar hypertrophy. This review emphasized OSA's significant impact on children's ocular health, revealing alterations in the optic nerve, choroid, retina, and cornea. While the direct correlation with the optic nerve is not always evident, OSA raises intraocular pressure and induces structural changes. Treatment holds promise, highlighting the need for regular monitoring to promptly address childhood OSA.

Optical coherence tomography angiography findings in pediatric patients with graves ophthalmopathy.

The aim of this study was to evaluate peripapillary, macular microvascular structure, and retinal nerve fiber layer (RNFL) thickness profile in children with Graves Ophthalmopathy (GO). Thirty-six eyes of 18 children with GO were prospectively compared with 40 eyes of 20-age and sex-matched controls. The severity and activity of the disease were evaluated according to the criteria of the European Group on Graves' Ophthalmopathy (EUGOGO) and Clinical Activity Score (CAS). After complete ophthalmologic and endocrinologic examination, all patients underwent optical coherence tomography (OCT) and optical coherence tomography angiography (OCTA) measurements. Retinal nerve fiber layer (RNFL) thickness, macular superficial capillary plexus (SCP), deep capillary plexus (DCP), foveal avascular zone (FAZ) area, acircularity index (AI) of the FAZ and peripapillary microvascular structure were analyzed. The mean age was 12.1 ± 2.4years in the GO group and 11.2 ± 2.6years in healthy control group (p = 0.11). Duration of disease was 8.9 ± 4.2months in the GO group. All patients in GO group had mild and inactive ophthalmopathy. In temporal inferior quadrant, RNFL thickness was significantly thinner in the GO group compared to the control group (p = 0.03). No significant difference was seen between groups both peripapillary and macular microvascular structure (all p > 0.05). GO has no effect on optic nerve thickness, peripapillary and macular vascular parameters except inferior temporal RNFL in children.

Echographic criteria for the assessment of the optic nerve condition in intracranial hypertension

Purpose: to develop objective acoustic criteria of the condition of the optic nerve and its sheaths for an early diagnosis of intracranial hypertension (IH). Material and methods. The research involved 24 patients (average age 35.8 ± 8.5 years) with suspected IH. The control group consisted of 48 healthy subjects (average age 28.5 ± 9.5 years). Ultrasound examination of the retrobulbar part of the optic nerve (ON) included the measurement of the ON thickness with sheaths (ONSD) and without sheaths (OND) and the calculation of the ratio K = ONSD/ OND. Echodensitometry was used to evaluate the echographic density of the parenchyma and the sheaths of the optic nerve. All patients were tested with magnetic resonance imaging (MRI) to analyse brain images. Results. The biometrical parameters of ON in healthy subjects were as follows: ONS 2.64 ± 0.21 mm and ONSD — 4.60 ± 0.34 mm. In patients with suspected IH the average parameters of the ON diameter were as follows: ONS — 2.57 ± 0.25 mm and ONSD — 5.81 ± 0.42 mm. A comparative assessment of the ON thickness with and without sheaths showed that in the control group the values of ONS did not exceed 3.5 mm and ONSD did not exceed 5.0 mm. In patients with IH, the values of ONSD were significantly higher than those in the control group (p < 0.05). The ratio coefficient (K)=ONSD/ONS in the group of healthy subjects ranged from 1.53 to 2.0 and averaged 1.75 ± 0.14. In patients with IH the values of K exceeded 2.0 (2,40 ± 0.18). The analysis of acoustic density data showed a significant variability in the parameters of the ON sheaths echodensitometry in IH patients as compared to the norm. Conclusion. The echography of the ON makes it possible to determine the acoustic and biometric parameters of the ON with high accuracy, to assess its structure and relationship with the surrounding tissues. The ratio coefficient (K) of ONSD/ONS makes it possible to determine IH in the early stages of the disease, even in the absence of objective clinical criteria.

Exercise‐induced changes in optic nerve and choroidal thickness

AbstractPurpose: The influence of physical exercise on the choroidal thickness and optic nerve has been investigated repeatedly, but the results obtained have been somewhat contradictory. This study aims to explore optic nerve (ON) and choroidal changes in healthy people after high‐intensity exercise.Methods: Nine men and 11 females aged 25.25 ± 2.03 years underwent exercise on a cycloergometer. Measurements of heart rate, intraocular pressure (IOP), and blood pressure were taken before and after exercise. Choroidal thickness (CT) and ON prelaminar and retrolaminar dimensions were measured using high‐resolution B‐scan ultrasound (Absolu, Quantel, Cournon d'Auvergne., France).Results: There was a significant increase in HR (74.40 ± 9.06 vs. 172.00 ± 8.35; p < 0.01), systolic (125.95 ± 9.37 vs. 153.60 ± 14.95; p < 0.01), and diastolic pressure after exercise (74.70 ± 8.77 vs. 81.60 ± 9.51; p = 0.03). At the same time, IOP decreased after the exercise (14.85 ± 1.98 vs. 13.35 ± 1.63). The diameter of the ON measured prelaminar was significantly decreased before and after the exercise (3.85 ± 0.23 to 3.75 ± 0.28 mm) p < 0.01. However, there was no significant difference in the mean CT nor retrolaminar dimensions of the ON before and after the exertion. No changes were observed in the measured parameters by B‐scan except for prelaminar ON.Conclusions: We demonstrated no changes in CT while preliminary ON significantly changed its diameter. Our results add to the growing evidence suggesting that different blood supply can impact the changes seen after exercises.

Effects of Androgen Deprivation Therapy on Extraocular Muscles, Retrobulbar Orbital Fat, and the Optic Nerve in Patients with Prostate Cancer

Introduction: The aim of this study was to evaluate radiologically the effects of long-term luteinizing hormone-releasing hormone (LHRH) agonist therapy on extraocular muscle thickness, retrobulbar orbital fat (ROF), and the optic nerve (ON) in prostate cancer (PCa) patients. Methods: The retrospective study included patients with primary or recurrent PCa who received androgen deprivation therapy (ADT) for at least 12 months. Each patient underwent gallium-68 prostate-specific membrane antigen positron emission tomography-computed tomography both before and at the end of the 12-month treatment. Thickness of the ON, lateral rectus muscle, medial rectus muscle, superior rectus muscle, and inferior rectus muscle were measured by using the coronal CT sections in soft tissue window. ROF, ocular protrusion, and ON length were measured in sagittal and coronal planes. Changes in these anatomical structures induced by LHRH analogs were investigated by comparing pre- and post-treatment measurements. Results: A total of 57 patients were included in the study. Median PSA and TT values ​​of the patients before treatment were 36.5 (range, 19.6–51.2) ng/mL and 614.0 (range, 472.0–743.0) ng/dL, respectively, and these values ​​decreased significantly after the treatment (10.6 [range, 5.2–14.2] ng/mL and 36.5 [range, 19.6–51.2] ng/dL, respectively, p < 0.001 for both). After the treatment, there was a statistically significant decrease in the areas of inferior rectus muscle, superior rectus muscle, lateral rectus muscle, and medial rectus muscle (p < 0.001 for all), while significant increases were observed in ROF (11.9%, p < 0.001) and ON thickness (14.3%, p = 0.004). The amount of ocular protrusion also showed a significant increase of approximately 14% after the treatment (14.0 [range, 12.0–16.0] mm vs. 16.0 [range, 14.0–17.2] mm, p < 0.001). Discussion/Conclusion: Our findings, for the first time in the literature, indicated that ADT causes a decrease in extraocular muscle mass and an increase in ROF with ocular protrusion. It can be asserted that these changes are similar to the changes in skeletal muscle and fat mass in other body parts. Further studies with a higher level of evidence are needed to clinically evaluate the increase in ocular protrusion and ON enlargement, which are likely to be caused by the increase in ROF.

Glaucoma Retinal Image Detection and Classification using Machine Learning Algorithms

The diseases correlated with retina are categorized into Diabetic Retinopathy (DR) and Glaucoma. Glaucoma is irreversible and one of the leading causes of blindness and it is very important to detect in its early stage because late diagnose will result in permanent vision loss. It is mainly characterized by the malfunctioning of ganglion cells, which changes the structure of the optic nerve head and thickness of retinal nerve fiber layer. Therefore, it is very important to detect the Glaucoma in order to prevent earlier vision loss. In this paper, the Glaucoma disease is detected using various machine learning classification algorithms Support Vector Machine (SVM), Neural Network (NN) and Adaptive Neuro Fuzzy Inference System (ANFIS) classifiers. These classifiers are used to classify the source retinal image into either normal or abnormal. The proposed methods are applied and tested on the retinal images which are available from Retinal fundus images for Glaucoma Analysis (RIGA) and High-Resolution Fundus (HRF) dataset. The Glaucoma detection method using ANFIS classifier obtains 97.2% of Precision, 97.3% of Recall and 97.1% Accuracy.

Machine learning for comprehensive prediction of high risk for Alzheimer’s disease based on chromatic pupilloperimetry

Currently there are no reliable biomarkers for early detection of Alzheimer's disease (AD) at the preclinical stage. This study assessed the pupil light reflex (PLR) for focal red and blue light stimuli in central and peripheral retina in 125 cognitively normal middle age subjects (45–71 years old) at high risk for AD due to a family history of the disease (FH+), and 61 age-similar subjects with no family history of AD (FH−) using Chromatic Pupilloperimetry coupled with Machine Learning (ML). All subjects had normal ophthalmic assessment, and normal retinal and optic nerve thickness by optical coherence tomography. No significant differences were observed between groups in cognitive function and volumetric brain MRI. Chromatic pupilloperimetry-based ML models were highly discriminative in differentiating subjects with and without AD family history, using transient PLR for focal red (primarily cone-mediated), and dim blue (primarily rod-mediated) light stimuli. Features associated with transient pupil response latency (PRL) achieved Area Under the Curve Receiver Operating Characteristic (AUC-ROC) of 0.90 ± 0.051 (left-eye) and 0.87 ± 0.048 (right-eye). Parameters associated with the contraction arm of the rod and cone-mediated PLR were more discriminative compared to parameters associated with the relaxation arm and melanopsin-mediated PLR. Significantly shorter PRL for dim blue light was measured in the FH+ group in two test targets in the temporal visual field in right eye that had highest relative weight in the ML algorithm (mean ± standard error, SE 0.449 s ± 0.007 s vs. 0.478 s ± 0.010 s, p = 0.038). Taken together our study suggests that subtle focal changes in pupil contraction latency may be detected in subjects at high risk to develop AD, decades before the onset of AD clinical symptoms. The dendrites of melanopsin containing retinal ganglion cells may be affected very early at the preclinical stages of AD.

The correlation of acoustic and morphometric parameters of the optic nerve and anthropometric data in healthy young people

Purpose: to study the correlation between the acoustic and morphometric parameters of the optic nerve (ON) and anthropometric data in healthy young people.Material and methods. The research involved 24 healthy volunteers (48 eyes), including 9 men and 15 women, the average age was 25.0 ± 1.9 years. Anthropometry included measurements of height, weight, and body mass index (BMI). Ultrasound examination of the retrobulbar part of the ON included measurement of the thickness of the ON with and without sheath, echodensitometry of the ON, and ocular biometry. Using optical coherence tomography, we measured the intraocular part of the ON, including the registration of Bruch's membrane opening and ovality index.Results. The average ON thickness with the sheath was 4.6 ± 0.3 mm, and without sheath, 2.6 ± 0.2 mm. In men, ON with the sheath was thicker than in women (p = 0.001). The acoustic density of the parenchyma of the orbital part of ON was 101.2 ± 11.4 r.u. in women, the mean acoustic density of the ON was significantly higher than that in men. Correlation analysis revealed a statistically significant correlation between the height and the thickness of the ON with the sheath (r = 0.480). The strongest reliable correlation was established between the index of the ON thickness and body weight (r = 0.712) and BMI (r = 0.509) (p &lt; 0.05). No statistically significant correlation was found between the morphometric parameters of the optic disc, anthropometry data and acoustic parameters of the ON.Conclusion. Studying the acoustic and morphometric characteristics of the intraocular and intraorbital parts of the ON in healthy young people, which included anthropometric data and gender characteristics, will contribute to the development more accurate diagnostic criteria of ON state evaluations.

Инновационный подход к комплексной диагностике внутричерепной гипертензии при нейроинфекциях у детей

Objective. To develop an algorithm of structural and functional non-invasive diagnosis of different stages of intracranial hypertension (ICH) in children with acute meningitis and encephalitis. Patients and methods. We examined 115 patients aged 1 month to 17 years. We used neurosonography (NSG), transcranial duplex scanning (TCD), ultrasound examination of the optic nerve (ON), and fundus examination by an ophthalmologist. We have developed a comprehensive structural and functional diagnostic algorithm for different ICH stages in children with suspected neuroinfections. This algorithm should be applied within a day upon admission to the intensive care unit and includes NSG, TCD, ON ultrasound, and fundus examination by an ophthalmologist. The exact diagnostic criteria were developed for each method. NSG: clear contours of the brain stem; lateral ventricles between 12 and 16 mm in size; bone-brain diastasis between 1 and 4 mm. TCD: systolic flow rate in the middle cerebral artery between 60 and 180 cm/s; systolic flow rate in the veins of Rosenthal between 10 and 20 cm/s; arterial resistance index up to 0.8; venous resistance index up to 0.5. ON ultrasound: ON thickness up to 5.5 mm in children aged 1 month to 5 years and up to 5.8 mm in children aged 5–17 years. Fundus examination: dilated veins in the fundus. Decompensated ICH: deformed brain stem pattern; lateral ventricles up to 11 mm, bone-brain diastasis &lt;1 mm; systolic flow rate in the middle cerebral artery up to 60 mm/s; systolic flow rate in the veins of Rosenthal up to 10 mm/s; reverberation pattern; ON thickness 6.5 ± 0.43 mm with unclear ON contours; stagnant disk of the optic nerve. We provide clinical examples that illustrate the effectiveness of the new algorithm, as well as the effectiveness of comprehensive therapy with cytoflavin during acute disease. Cytoflavin has multiple effects on the organism, improves cerebral hemodynamics and metabolism. Key words: intracranial hypertension, children, duplex, optic nerve, meningitis, neurosonography, ultrasound, encephalitis, cytoflavin

Stable Gastric Pentadecapeptide BPC 157 Therapy of Rat Glaucoma

Cauterization of three episcleral veins (open-angle glaucoma model) induces venous congestion and increases intraocular pressure in rats. If not upgraded, one episcleral vein is regularly unable to acquire and take over the whole function, and glaucoma-like features persist. Recently, the rapid upgrading of the collateral pathways by a stable gastric pentadecapeptide BPC 157 has cured many severe syndromes induced by permanent occlusion of major vessels, veins and/or arteries, peripherally and centrally. In a six-week study, medication was given prophylactically (immediately before glaucoma surgery, i.e., three episcleral veins cauterization) or as curative treatment (starting at 24 h after glaucoma surgery). The daily regimen of BPC 157 (0.4 µg/eye, 0.4 ng/eye; 10 µg/kg, 10 ng/kg) was administered locally as drops in each eye, intraperitoneally (last application at 24 h before sacrifice) or per-orally in drinking water (0.16 µg/mL, 0.16 ng/mL, 12 mL/rat until the sacrifice, first application being intragastric). Consequently, all BPC 157 regimens immediately normalized intraocular pressure. BPC 157-treated rats exhibited normal pupil diameter, microscopically well-preserved ganglion cells and optic nerve presentation, normal fundus presentation, normal retinal and choroidal blood vessel presentation and normal optic nerve presentation. As leading symptoms, increased intraocular pressure and mydriasis, as well as degeneration of retinal ganglion cells, optic nerve head excavation and reduction in optic nerve thickness, generalized severe irregularity of retinal vessels, faint presentation of choroidal vessels and severe optic nerve disc atrophy were all counteracted. In conclusion, we claim that the reversal of the episcleral veins cauterization glaucoma appeared as a consequence of the BPC 157 therapy of the vessel occlusion-induced perilous syndrome.

Liraglutide Treatment Does Not Induce Changes in the Peripapillary Retinal Nerve Fiber Layer Thickness in Patients with Diabetic Retinopathy.

Purpose: Liraglutide treatment has shown promising anti-inflammatory and nerve regenerative results in preclinical and clinical trials. We sought to assess if liraglutide treatment would induce nerve regeneration through its anti-inflammatory and neurotrophic mechanisms by increasing peripapillary retinal nerve fiber layer (RNFL) thickness in individuals with long-term type 1 diabetes. Methods: Secondary analyses were performed on a prospective, double-blinded, randomized, placebo-controlled trial on adults with type 1 diabetes, distal symmetric polyneuropathy (DSPN), and confirmed diabetic retinopathy, who were randomized 1:1 to either 26 weeks placebo or liraglutide treatment. The primary endpoint was a change in peripapillary RNFL thickness between treatments, assessed by optical coherence tomography. Results: Thirty-seven participants were included in the secondary analysis. No differences in mean peripapillary RNFL thickness (overall ΔMean RNFL thickness; liraglutide -1 (±8) μm (-1%) vs. placebo -1 (±5) μm (-1%), P = 0.78, n = 37) or any of the quadrants. Peripapillary RNFL thicknesses were shown between treatments in either nonproliferative (ΔMean RNFL thickness; liraglutide -1 (±5) μm (-1%) vs. placebo 0 (±4) μm (0%), P = 0.80, N = 26) or proliferative diabetic retinopathy subgroup (ΔMean RNFL thickness; liraglutide -2 (±14) μm (-3%) vs. placebo -1 (±6) μm (-2%), P = 0.88, N = 11). Conclusions: In this study, 26 weeks of liraglutide treatment did not induce measurable changes in the assessed optic nerve thickness. Thus, this methodology does not support the induction of substantial nerve regeneration in this cohort with established retinopathy and DSPN. The trial was approved by the Danish Health and Medicines Authority. Informed consent was obtained from all participants. TODINELI study: EUDRA CT: 2013-004375-12, Ethics Ref: N-20130077 Clinical trial registration number: clinicaltrials.gov NCT02138045.

Effects of Venoconstrictive Thigh Cuffs on Dry Immersion-Induced Ophthalmological Changes.

Neuro-ophthalmological changes named spaceflight associated neuro-ocular syndrome (SANS) reported after spaceflights are important medical issues. Dry immersion (DI), an analog to microgravity, rapidly induces a centralization of body fluids, immobilization, and hypokinesia similar to that observed during spaceflight. The main objectives of the present study were 2-fold: (1) to assess the neuro-ophthalmological impact during 5 days of DI and (2) to determine the effects of venoconstrictive thigh cuffs (VTC), used as a countermeasure to limit headward fluid shift, on DI-induced ophthalmological adaptations. Eighteen healthy male subjects underwent 5 days of DI with or without VTC countermeasures. The subjects were randomly assigned into two groups of 9: a control and cuffs group. Retinal and optic nerve thickness were assessed with spectral-domain optical coherence tomography (OCT). Optic nerve sheath diameter (ONSD) was measured by ocular ultrasonography and used to assess indirect changes in intracranial pressure (ICP). Intraocular pressure (IOP) was assessed by applanation tonometry. A higher thickness of the retinal nerve fiber layer (RNFL) in the temporal quadrant was observed after DI. ONSD increased significantly during DI and remained higher during the recovery phase. IOP did not significantly change during and after DI. VTC tended to limit the ONSD enlargement but not the higher thickness of an RNFL induced by DI. These findings suggest that 5 days of DI induced significant ophthalmological changes. VTC were found to dampen the ONSD enlargement induced by DI.

Retinal Thickness Analysis in Progressive Multiple Sclerosis Patients Treated With Epigallocatechin Gallate: Optical Coherence Tomography Results From the SUPREMES Study.

Background: Epigallocatechin gallate (EGCG) is an anti-inflammatory agent and has proven neuroprotective properties in animal models of multiple sclerosis (MS). Optical coherence tomography (OCT) assessed retinal thickness analysis can reflect treatment responses in MS.Objective: To analyze the influence of EGCG treatment on retinal thickness analysis as secondary and exploratory outcomes of the randomized controlled Sunphenon in Progressive Forms of MS trial (SUPREMES, NCT00799890).Methods: SUPREMES patients underwent OCT with the Heidelberg Spectralis device at a subset of visits. We determined peripapillary retinal nerve fiber layer (pRNFL) thickness from a 12° ring scan around the optic nerve head and thickness of the ganglion cell/inner plexiform layer (GCIP) and inner nuclear layer (INL) within a 6 mm diameter grid centered on the fovea from a macular volume scan. Longitudinal OCT data were available for exploratory analysis from 31 SUPREMES participants (12/19 primary/secondary progressive MS (PPMS/SPMS); mean age 51 ± 7 years; 12 female; mean time since disease onset 16 ± 11 years). We tested the null hypothesis of no treatment*time interaction using nonparametric analysis of longitudinal data in factorial experiments.Results: After 2 years, there were no significant differences in longitudinal retinal thickness changes between EGCG treated and placebo arms in any OCT parameter (Mean change [confidence interval] ECGC vs. Placebo: pRNFL: −0.83 [1.29] μm vs. −0.64 [1.56] μm, p = 0.156; GCIP: −0.67 [0.67] μm vs. −0.14 [0.47] μm, p = 0.476; INL: −0.06 [0.58] μm vs. 0.22 [0.41] μm, p = 0.455).Conclusion: Retinal thickness analysis did not reveal a neuroprotective effect of EGCG. While this is in line with the results of the main SUPREMES trial, our study was probably underpowered to detect an effect.Clinical Trial Registration: www.ClinicalTrials.gov, identifier: NCT00799890.

Assessment of the orbital structures using computed tomography in healthy adults.

In this study, we retrospectively evaluated the orbital and ocular dimensions using computed tomography (CT) scans in healthy adults. This retrospective study included 302 Turkish adult individuals aged 20-76 years (158 males and 144 females), who underwent paranasal sinus or craniofacial CT due to headache or suspicion of sinusitis, but abnormal orbital or cranial CT findings were not detected. Linear and volumetric measurements of the orbital structures were performed in the sagittal, coronal, and axial planes on CT slices. The volume was estimated in cubic centimeters using the equation of the ellipsoid method. A total of 34 parameters were measured from both eyes of each individual using 14 different anatomical landmarks and analyzed by gender and age. Parameter values of orbital structures in males and females are shown in millimeters or cubic centimeters. In most of the 34 parameters that we evaluated, it was seen that males had statistically significant higher mean values than females (P < 0.05). Also, there was no statistically significant difference between the measurements of right and left orbits. The correlation with age was varied according to the 34 parameters. Interestingly enough, there were no statistically significant differences between the two genders for extraocular muscles thickness (except superior muscles group thickness-SMT) and left optic nerve thickness (LOT) (p > 0.05). The mean right superior muscles group thickness was 5.35 ± 0.85 mm in the male subjects and 4.64 ± 1.10 mm in the female subjects (P < 0.001). The mean left superior muscles group thickness (LSMT) was 5.28 ± 0.88 mm in the male subjects and 4.67 ± 1.16 mm in the female subjects (P < 0.001). The mean LOT was 6.15 ± 0.97 and 5.88 ± 1.07 mm in males and females, respectively (P = 0.099). This study can be applied to the standardization of orbital morphometry in healthy adults.

An Evaluation of the Relationship between Retinal Nerve Fiber Thickness, Cochlear Nerve Thickness, the Level of Tinnitus, and Hearing Loss in Unilateral Tinnitus Patients

Background: In this study, optic coherence tomography (OCT) examination was performed to check whether there was any interaction between ophthalmic axonal structures in unilateral tinnitus patients, and the relationship between optic nerve thickness and cochlear nerve thickness was evaluated. Objective: The aim of the study was to evaluate the relatioship between hearing loss, tinnitus, and nerve thicknesses. Study Design: Prospective study. Setting: Tertiary referral university hospital. Patients: The study included 88 patients with unilateral tinnitus, for which no organic cause could be found in physical examination, psychiatric evaluation, or with imaging methods. Study groups were formed of the tinnitus side and control groups were formed of the healthy side as follows: Group 1 (Non-tinnitus side normal hearing values – n = 30), Group 2 (non-tinnitus side minimal hearing loss – n = 27), Group 3 (non-tinnitus side moderate hearing loss – n = 31), Group 4 (tinnitus side normal hearing values – n = 25), Group 5 (tinnitus side minimal hearing loss – n = 25), and Group 6 (tinnitus side moderate hearing loss – n = 38). Intervention: Retinal nerve fiber layer (RNFL) thickness was evaluated with OCT, and the cochlear nerve cross-sectional area was evaluated with MRI. Main Outcome Measures: RNFL measurements were taken with OCT from the subfoveal area (RNFL-SF) and 1.5 mm temporal to the fovea (RNFL-T µm) and nasal (RNFL-N µm) sectors. On MRI, 3 measurements were taken along the nerve from the cerebellopontine angle as far as the internal auditory canal, and the mean value of these 3 measurements was calculated. Results: When the groups were evaluated in respect of cochlear nerve thickness, a significant difference was seen between Group 1 and both the groups with hearing loss and the tinnitus groups. In the subgroup analysis, a statistically significant difference was determined between Group 1 and Groups 3, 4, 5, and 6 (p = 0.013, p = 0.003, p < 0.001, and p < 0.001, respectively). When the groups were evaluated in respect of the RNFL-SF (µm), RNFL-T (µm), and RNFL-N (µm) values, the differences were determined to be statistically significant (p < 0.001 for all). In the correlation analysis, a negative correlation was determined between hearing loss and cochlear nerve diameter (r: −0.184, p = 0.014), and RNFL-N (r: −0.272, p < 0.001) and between tinnitus and cochlear nerve diameter (r: −0.536, p < 0.001), and RNFL-T (r: −0.222, p < 0.009). Conclusion: The study results clearly showed a relationship between cochlear nerve fiber thickness and hearing loss and the severity of tinnitus in cases with unilateral tinnitus and that there could be neurodegenerative factors in the disease etiology. A similar relationship seen with the RNFL supports the study hypothesis.

Role of ultrasound as diagnostic tool in evaluation of optic nerve thickness in cases of raised intracranial pressure

Head trauma and intracranial pathologies can result in the increased Intra Cranial Pressure (ICP). Early diagnosis is important in the clinical outcome. As the optic nerve has a dural continuation, any increase in ICP will increase the thickness of Optic nerve Sheath Diameter (ONSD). Ultrasound plays a vital role, as it is a non-invasive, portable, reliable, and an economical tool to measure the ONSD. We aim to assess the role of ultrasound as a diagnostic tool in the measurement of ONSD in subjects with raised ICP All patients with CT signs of raised intracranial pressure were taken as cases. Normal CT brain patients were considered as the control group. It was a prospective study that included data of 60 patients (30 Test, 30 Control) for 1 year. Linear probe of high resolution 10MHz on Philips HD 15 ultrasound machine was employed in the evaluation of ONSD in both groups. From the entry point of optic nerve to globe 3mm distance was considered standard in measurement of ONSD. In the control group 14(46.6%) were females, 16(53.3%) were males and in the test group 11(36.6%) females, 19(63.3%) were males. In the control group upper limit of ONSD was 4.8 mm, lower limit 4.3mm, and mean was 4.49 mm. In the test group, the upper limit of ONSD was5.7mm, lower limit 4.8mm, and mean 5.14mm. There is an obvious raise in the thickness of ONSD in the individuals with positive signs of raised ICP in comparison with normal individuals. Being a non-invasive, and economical, portable ultrasound has a pivot role in the diagnosis of the thickness of ONSD thickness earlier than the onset of papilledema.