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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.

Since 2019,severe acute respiratory syndrome coronavirus 2(SARS-CoV-2)posed a great threat to human health and social economy, which has brought out hundreds of millions infection and caused millions of deaths worldwide. With the increasing research on SARS-CoV-2, angiotensin-converting enzyme 2(ACE2)has been regarded as a significant functional receptor for SARS-CoV-2 invasion. ACE2 is distributed in many tissues of human body, not only expressed in lung, cardiovascular, kidney tissues, but also in conjunctiva, cornea, uvea, retina and optic nerve tissue. More and more cases of SARS-CoV-2 infection through ocular tissues have been found; however, whether ocular ACE2 plays a role in SARS-CoV-2 infection is not completely clear. Therefore, study on expression and distribution of ACE2 in the ocular tissues can not only provide an in-depth understanding of the mechanism of SARS-CoV-2 infection, but also supply a comprehensive acquaintance with the mechanism of ACE2 action in the ocular tissues. In this paper, we review recent research progress about the expression and distribution of ACE2 in ocular tissues and hope to better understand the mechanism of ACE2 in the pathophysiological processes of ocular tissues.

We aimed to review the role of different types of imaging (computed tomography [СТ], ultrasonography [US], magnetic resonance imaging [MRI]) in measuring the optic nerve diameter (OND) and optic nerve sheath diameter (ONSD) in adults and the potential advantages and limitations of each modality. A literature search was carried out using ResearchGate, Saudi Digital Library, Google Scholar, and Mendeley databases between 2010 and 2021 (papers presented in English) with the keywords “computed tomography,” “magnetic resonance imaging,” “ultrasonography,” “optic nerve sheath diameter,” and “optic nerve diameter.” Of the 60 articles analyzed, 42 were included in the review. Compared to ONSD, the evidence for OND appeared to be more limited. After comparing all three imaging modalities (CT, MRI, and US), we concluded that for the most accurate measurements of ONSD we should be using MRI (range: 4.0–6.0 mm). CT (range: 4.4–6.7 mm) would provide the second most exact measurements after MRI. Although CT and MRI provide the most consistent and accurate measurements, ultrasound is more commonly used (ONSD range: 3.4–7.7 mm) due to it’s being non-invasive, easy to use, and easily available anywhere, from big hospitals to small clinics, unlike CT and MRI. All three imaging modalities can provide good measurements, and hopefully, soon ultrasound will be as accurate as MRI in measuring the optic nerve.

In recent years, the measurement of optic nerve sheath diameter with ultrasound to detect the presence of increased intracranial pressure has widely spread. It can be qualitatively and effectively used to identify intracranial hypertension. Intracranial pressure can rise due to acute injury, cerebral bleeding, hydrocephalus, brain tumors and other space-occupying abnormalities, and it is linked to a high death rate. The purpose of this review is to give a general overview of the most relevant scientific publications on ultrasonographic evaluation of the optic nerve in case of brain injuries published in the last 30 years, as well as to analyze the limits of the most extensively used B-scan approach. Fifty-two papers chosen from the PubMed medical database were analyzed in this review. Our findings revealed that ocular ultrasound is an useful diagnostic tool in the management of intracranial hypertension when it exceeds a certain value or after head trauma. As a result, an ultrasound of the optic nerve can be extremely helpful in guiding diagnosis and treatment. The blooming effect is one of the most critical restrictions to consider when using B-scan ultrasonography. Since amplitude-scan ultrasound, also known as A-scan, does not have this limit, these two diagnostic techniques should always be used together for a more full, accurate, and trustworthy ultrasound examination, ensuring more data objectivity.

Objective: to study the characteristics of orbital soft tissues in health. Material and methods. Computed tomography scans of 210 individuals (266 orbits) with no orbital abnormality were examined. Results. The paper presents the volumetric characteristics and parameters of the soft tissue density of the orbit and its apex (extraocular muscles, retrobulbar fat, optic nerve, lacrimal gland, eye, and vitreous body) in health. The internal surgical space fat at the orbital apex is estimated to be 75.35 and 73.83% of the total volume at the apex in men and women, respectively. The paper shows that individual asymmetry of orbital fat volumes in health is encountered in 47.61% of the men and in 51.42% of the women and ranges from 0.5 to 2.0 cm3. Conclusion. The volumes of orbital soft tissues in health are statistically significant different in the men and in the women. The asymmetry of the mean orbital soft tissue volumes in health is within the limits of statistical error.

Glaucoma is one of the most complicated disorder in human eye that causes permanent vision loss gradually if not detect in early stage. It can damage the optic nerve without any symptoms and warnings. Different automated glaucoma detection systems were developed for analyzing glaucoma at early stage but lacked good accuracy of detection. This paper proposes a novel automated glaucoma detection system which effectively process with digital colour fundus images using hybrid classifiers. The proposed system concentrates on both Cup-to Disk Ratio (CDR) and different features to improve the accuracy of glaucoma. Morphological Hough Transform Algorithm (MHTA) is designed for optic disc segmentation. Intensity based elliptic curve method is used for separation of optic cup effectively. Further feature extraction and CDR value can be estimated. Finally, classification is performed with combination of Naive Bayes Classifier and K Nearest Neighbour (KNN). The proposed system is evaluated by using High Resolution Fundus (HRF) database which outperforms the earlier methods in literature in various performance metrics.

Peter Wostyn Department of Psychiatry, PC Sint-Amandus, Beernem, BelgiumCorrespondence: Peter WostynDepartment of Psychiatry, PC Sint-Amandus, Reigerlostraat 10, Beernem, 8730, BelgiumTel + 32-472713719Fax + 32-50-819720Email wostyn.peter@skynet.be View the original paper by Pircher and colleagues

Objective: to study the optic nerve, lacrimal gland, and superior ophthalmic vein in patients with different clinical forms of endocrine ophthalmopathy (EOP). Material and methods. 294 patients (559 orbits) with EOP were examined. Hydrodynamic disorders were detected in 43 patients. 46 patients (91 orbits) with mixed or myogenic types of edematous exophthalmos (EE) were diagnosed as having optic neuropathy (ON). Results and discussion. The paper presents the indicators of the optic nerve, lacrimal gland, and superior ophthalmic vein in patients with different clinical forms of EOP. This study provides evidence that ON in patients with EOP is characterized by specific changes in the optic nerve, as shown by computed tomography. It is ascertained that there are volumetric and structural changes in the lacrimal gland in 40.62% of the patients with mixed EE and in 33.89% of those with myogenic EE. Conclusion. The study of the extraocular muscles in patients with ON-complicated EE may confirm that enlargement of the extraocular muscles at the orbital apex plays a major role in the pathogenesis of ON in this disease. The change in the anatomictopographic relationships of the orbit leads to compression of the superior ophthalmic vein, which entails obstruction of blood outflow from the orbit and causes ocular hypertension.

Therapeutic strategies for neurological deficits and for promoting nerve regeneration after peripheral nerve injuries have received much focus in clinical research. Advances in basic research in recent years have increased our understanding of the anatomy of peripheral nerves and the importance of the microenvironment. Various new intervention methods have been developed, but with varying effectiveness. In the present study, we selected 911 papers on different repair methods for peripheral nerve injury from the Web of Science and indexed in the Science Citation Index from 2010 to 2014. We quantitatively examine new repair methods and strategies using bibliometrics, and we discuss the present state of knowledge and the problems and prospects of various repair methods, including nerve transfer, neural transplantation, tissue engineering and genetic engineering. Our findings should help in the study and development of repair methods for peripheral nerve injury.

Introduction. The clinical diagnostic of Graves ophthalmopathy is based on the association of ocular signs and the disease of the thyroid gland. The evolution of the disease involves the development of eye globe protrusion, extraocular muscle thickening pressuring the optic nerve, which can result in its thickness. Objective. The aim of the paper is to find whether the retrobulbar optic nerve thickened and if there was a correlation between its possible thickening and the thickness of the muscles in Graves ophthalmopathy. We also wished to test the theory of compressive aetiology of such thickening using a 30-degree test. Methods. We examined 28 patients with Graves ophthalmopathy. The thickness of the retrobulbar optic nerve was measured by ultrasound on a B-scan using the Schraeder's method and by the largest thickness of the internal muscle. Results. The thickness of the retrobulbar portion of the optic nerve in the 52 analyzed eyes with signs of the disease ranged between 3.24 mm to 6.30 mm, with median of 5.13 mm, indicating that the majority of the patients had optic nerve thickening rating at this value. Forty-eight eyes had a marked retrobulbar optic nerve thickening, with the thickening over 4 mm, while in 4 eyes with signs of Graves ophthalmopathy the thickness of the optic nerve was within normal limits. We detected that 92.3% of the patients with muscular thickening also had a directly proportional thickening of the retrobulbar optic nerve. By using the 30-degree test we confirmed the diagnosis of compressive neuropathy. Conclusion. Patients with Graves ophthalmopathy and thickened muscles, also have a thickening of the retrobulbar optic nerve; the rate of the thickness directly depends on the degree of the muscular thickness. The word is of compressive neuropathy, i.e. the thickness of the optic nerve is the result of subarachnoid fluid stasis caused by the compression on the optic nerve.

The paper presents the first results of thirty cases of contusion injuries of optic nerve : an analysis of symptoms and the aspect of visual impairment. Indirect injury may damage the optic nerve and this leads to optic nerve contusions. In such cases, the fractures of the base of the skull, involving or not the optic canal, immediately leads to uni or bilateral blindness, stationary or slightly regressive.