Eyeball Muscles Research Articles

Morphological aspects of eyeball extrinsic muscles and other anatomical aspects in a tapir (Tapirus terrestris): Case report

The aim was to describe the morphological aspects of the eyeball and associated anatomical components of Tapirus terrestris. The study was performed with two heads, with unknown origin, donated to the Laboratory of Morphological studies of Veterinary Medicine College in Araçatuba city. SP. External aspects revealed similarities with other mammals; however, the orbit cavity has area of 20-mm3 ± 1.4 mm3 considered higher than horse per example. The description of eyeball muscles followed what has been described for other species, with origin and insertion defined. Tapir is a mammal found in South America, and in almost all biomes, but with tiny literary information about macro and microscopic morphology. Thus, it justifies the choice of this species for the study, based on their macro morphological features, which, notably, are fundamental to the biological knowledge of the species. This kind of research contributes with relevant data about this species is still poorly studied.

BRAIN AND EYE AS POTENTIAL TARGETS FOR IONIZING RADIATION IMPACT. PART IV - FETAL RADIATION-INDUCED BINOCULAR VISION DISORDERS: A PILOT STUDY. IMMUNOHISTOCHEMICAL CHANGES OF NON/IRRADIATED EYEBALL MUSCLES AFFECTED BY STRABISMUS. EVIDENCE OF A POSSIBLE MECHANISM OF THE STRABISMUS DEVELOPMENT IN PERSONS EXPOSED TO FETAL RADIATION.

to assess the peculiarities of the development of strabismus and binocular vision disorders in people who were exposed to ionizing radiation in utero; to investigate the changes in distribution and appearance of myosin, dystrophin, and collagen IV between non-irradiated persons with normal binocular vision and patients with strabismus. 583 persons, irradiated in utero because of the Chornobyl disaster were examined (at the time of examination average age was 11.3 ± 0.1 years). The control group - 808 people - Kyiv residents. Overall, 15 non-irradiated eyeball muscle samples were examined. 10 were from strabismus patients and 5 were controls. To evaluate morphological structure haematoxylin and eosin staining were used. For the detection of myosin, dystrophin, and collagen IV biotin-avidin (IMH) immunohistochemistry method was performed. Semi-quantitative grading method was used for the evaluation of immunoreactive structure appearance and local distribution. An increased frequency of divergent strabismus (p = 0.04190) and heterophoria (p = 0.002603) was found in the group exposed to prenatal (fetal) radiation because of the Chornobyl disaster compared to the control group. The relative risk of heterophoria was 5.08 (1.42 - 18.13). A decrease in dystrophin, myosin, and collagen IV positive structures was observed in non-irradiated strabismus-affected eyeball muscles compared to the control group. Detected changes indicate an increased probability in the development of strabismus in persons who had been exposed to fetal radiation. Non-irradiated strabismus-affected eyeball muscles are characterized by diminished myosin, dystrophin, and collagen IV immunohistochemical structures. Additionally, determined qualitative morphological changes in skeletal striated muscle fibers lead to the changed structural organization, indicating possible muscular dystrophy. Thereby, the presence of dystrophic processes in the eyeball muscles may play a significant role in the morphopatogenesis of strabismus. Further morphological studies are necessary to clarify the development of binocular vision disorder and the methods of their correction. These studies would be especially important to populations that were exposed to radiation.

Peculiarities of morphogenesis of orbit and organ of vision structures in human fetuses

The aim of this work is to elucidate the features of morphogenesis, syntopic and morphometric changes in the structures of the orbit, neurovascular and muscular structures of the organ of vision in the fetal period of human ontogenesis.Material and methods. By means of complex of methods of morphological research (anthropometry, morphometry, microscopy, preparation, three-dimensional computer reconstruction and statistical analysis), 30 specimens of human fetuses of both sexes aged from 4 to 10 months of intrauterine development (IUD) (160.0-460.0 mm parietal-coccygeal length (PCL)) were studied. Computer tomography was used to study 17 human fetuses aged from 4 to 9 months of IUD (180.0-440.0 mm PCL).Results. At the end of the 5th month of IUD, an orbital index is 75%, which is noted in the transformation of the shape of orbit from flattened to rounded due to an increase in its vertical size relative to the horizontal one. We associate this transformation of the orbit with syntopic influence of adjacent regions: the growth of the lateral wall of the nasal cavity, development of the paranasal sinuses, and facial skeleton. At the end of the 5th week of intrauterine development, external eyeball muscles are finally differentiated from the common muscle rudiment. The analysis of changes in morphometric parameters of muscles of the eyeball made it possible to derive mathematical functions, that describe normal dynamics of growth of their length, as well as to reveal critical periods of their development in terms of the rate of changes in their thickness and width.Conclusions1. The development of the organ of vision in the fetal period of human ontogenesis is a complex process due to the coordinated interaction between morphological and morphometric changes in the orbit, eyeball and its muscles, nerves and vessels.2. Critical periods of development of the orbit and its structures is the 6th month of intrauterine development, during which there is an uneven growth rate of the size of the muscles of the eyeball, as well as the size of the orbit.3. At the 6th month of intrauterine development, uneven growth rates of the horizontal size of the orbit relative to the vertical one are observed, as a result of which its shape begins to return to the mesoconchal type characteristic of such prefetuses. Such age-related transformations of shape and size of the orbit are due to the growth of the eyeball, skull and face, which generally determines the shape of the orbit.4. Starting from the 8th month of fetal period of development, structure and topography of the structures of the orbit acquire signs of a definitive condition, the shape of the orbit is finally established, and uniform growth rates of all structures of the organ of vision are observed, except for the growth of the circumference of the orbit at the end of prenatal period of human ontogenesis.

Rehabilitation after surgical treatment of retrobulbar tumors.

The authors propose a set of rehabilitation exercises concerning the muscles which are responsible for movement of the eyeball. After surgical treatments of retrobulbar tumors, the function of the eyeball muscles is often inadequate. Some compensation should be created at the level of the central nervous system, which means trigging adaptation, substitution and habituation. The exercises should be started just after the patient is awakened: first in the horizontal position, then sitting position and finally standing position. The highest number of exercises should be done in the direction of extreme diplopia.

Rectus and oblique muscles of eyeball: a morphometric study of Indian population.

During the strengthening and weakening procedures of intraocular muscles, distance of insertion from the sclerocorneal junction is an important determinant in the identification of muscles. During repositioning of the aponeurosis of the muscles, it is desired that the width should not change in order to avoid diversion of forces. Available anatomic studies on insertions of extraocular muscles are few, date back to early twentieth century and have been conducted on mostly white population. The present study is an attempt to document the insertions of recti and oblique muscles in Indian population. Forty eyeballs were removed from orbit. Insertion of recti and obliqui were cleaned and eyeballs were perfused with normal saline to regain the volume (hence shape and size) before recording observations. Insertion of recti and obliqui muscles were observed under various study parameters. The distance of insertion of recti from the limbus were found to be 7.3 mm, 8.06 mm, 8.71 mm, and 8.74 mm for medial, inferior, lateral, and superior rectus, respectively. The superior oblique was aponeurotic and found to be more variable in mode of insertion as compared to inferior oblique which had a fleshy and relatively constant insertion. The observations on insertion of recti and obliqui as obtained in present study differ from earlier studies to the tune of 1-1.5 mm. This may be attributed to adoption of method of reperfusion of eyeball before recording observations thus maintaining size close to in vivo. The observations are expected to be closer to actual.

Ocular system involvement in the course of human trichinellosis. Pathological and diagnostic aspects.

Pathomechanism of lesions in the course of trichinellosis was discussed, representing a sum of immunopathologicaI, pathomorphological and biochemical phenomena. Particular attention was devoted to clinical pathology of the visual organ, which prevails at the acute stage of trichinellosis. In evaluation of clinical signs/symptoms manifested in the visual organ traits of its anatomic, morphological structure, function of the eyeball muscles and eyeball vascular system were taken into account. Ocular lesions in the course of trichinellosis reflect in principle angiomyositis due to immunopathology resulting from migration of Trichinella larvae to many organs and to structures of visual system.

Application of MRI in several special forms of strabismus

Magnetic resonance imaging(MRI) is a non-invasive imaging technique of biological spin.MRI shows more advantages in imaging of orbital and ocular muscle than B-type sonography and X ray.MRI plays important roles in the study on anatomy of eye muscle,eye movements,survey of strabismus cause,also identification and diagnosis of strabismus.The imaging features,analysis of MRI,application of MRI in several special forms of strabismus were reviewed. Key words: extrinsic eyeball muscle; MRI; strabismus; Pulley

Eyeball Muscles’ Diameters versus Volume Estimated by Numerical Image Segmentation

To determine the clinical usefulness of the numerical segmentation image technique (NSI) in estimating the volume of extraocular muscles and to compare this value to widely used measurements of single diameters of the muscles. Forty-five patients underwent magnetic resonance examinations in 1.5-T scanner. SE T1 sequences in transversal and coronal planes were provided and data were sent to a personal computer, where the degree of exophthalmos, horizontal diameter of medial rectus muscles, and vertical diameter of inferior rectus muscles were determined on the basis of two-dimensional images. The quantity estimation of all eye muscles volumes using NSI application in three-dimensional space was carried out with use of level set segmentation algorithm. A strong correlation between the total eye muscle volume and degree of exophthalmos was determined. The usefulness of measuring single diameters for estimating the muscles' enlargement was confirmed. The difference between a single muscle's volume and its width also was confirmed. Estimates of muscle volume correlate with the degree of exophthalmos more accurately than measurements of single diameters. The NSI technique is a clinically useful application, providing objective data calculated individually for each orbit. It allows an objective estimation of the pathologic processes leading to exophthalmos and may be especially helpful in monitoring discrete changes in the muscles volume during treatment.

アモルファス磁歪ワイヤのＳＩ効果加速度センサーによる脳活動時系列計測

A time series reflecting human brain activities was detected by using a sensitive micro-acceleration · inclined-angle sensor composed of a CoSiB magnetostrictive amorphous wire connected to a CMOS IC circuit with a resolution of about 0.1 Gal and 0.2°. A small sensor head using a glass specimen of 0.16 mm thick, 3 mm wide, and 15 mm long to which were attached a CoSiB amorphous wire of 20 μm diameter and 5 mm length and an inertia mass of 0.1 g was fixed to the center of a subject’s forehead.The detected waveforms of the sensor output for subjects with both eyelids closed differ from the microvibration would be classified into the following four kinds of states:(1) An almost flat waveform indicates that the subject is in a resting state or a sleeping state.(2) Passively stressful states such as recalling sad memories, being obliged to perform an unpleasant task, or performing a mental calculation generate a large stepwise wave with some irregular pulsing waves.(3) Actively stressful states such as finding a good idea and focusing on inventing something are indicated by high-frequency pulsing waves.(4) Pleasant states such as recalling happy memories of childhood or thinking about a favorite hobby are indicated by rhythmical waves without pulses.These signals reflecting a subject’s mental and emotional states (which we call a mechano-encephalogram) are considered to be due to micro-deformation and acceleration of the measurement position with some movement of eyeball muscles, arrector pili muscles and muscles corrugator supercilii. Microvibrations of small amplitude were also detected.

Fixation tremor in relation to eyeball-muscle mechanics.

THE fixation tremor of the eyes can be recorded by using a small accelerometer which is fixed to a contact lens1. This technique has made it possible to determine the changes in the spectral composition of the tremor in various circumstances. In particular, we report here the results obtained when weights are fixed to the lens, so increasing the effective moment of inertia of the eyeball. These results yield information about the mechanics of the eyeball–muscle system.