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Parks–Bielschowsky Three-step Test
The Parks–Bielschowsky three-step test, also known as Park's three-step test or Bielschowsky head tilt test, is a method used to isolate the paretic extraocular muscle, particularly superior oblique muscle and trochlear nerve (IVth cranial nerve), in acquired vertical double vision. It was originally described by Marshall M. Parks. Bielschowsky's head tilt test * Step 1: Determine which eye is hypertropic in primary position. If there is right hypertropia in primary position, then the depressors of the R eye (IR/SO) or the elevators of the L eye are weak (SR/IO). * Step 2: Determine whether the hypertropia increases on right or left gaze. The vertical rectus muscles have their greatest vertical action when the eye is abducted. The oblique muscles have their greatest vertical action when the eye is adducted. * Step 3: Determine whether the hypertropia increases on right or left head tilt. During right head tilt, the right eye intorts (SO/SR) and the left eye extorts (IO/IR). W ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Extraocular Muscle
The extraocular muscles (extrinsic ocular muscles), are the seven extrinsic muscles of the human eye. Six of the extraocular muscles, the four recti muscles, and the superior and inferior oblique muscles, control movement of the eye and the other muscle, the levator palpebrae superioris, controls eyelid elevation. The actions of the six muscles responsible for eye movement depend on the position of the eye at the time of muscle contraction. Structure Since only a small part of the eye called the fovea provides sharp vision, the eye must move to follow a target. Eye movements must be precise and fast. This is seen in scenarios like reading, where the reader must shift gaze constantly. Although under voluntary control, most eye movement is accomplished without conscious effort. Precisely how the integration between voluntary and involuntary control of the eye occurs is a subject of continuing research."eye, human."Encyclopædia Britannica from Encyclopædia Britannica 2006 Ultim ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Extraocular Muscle
The extraocular muscles (extrinsic ocular muscles), are the seven extrinsic muscles of the human eye. Six of the extraocular muscles, the four recti muscles, and the superior and inferior oblique muscles, control movement of the eye and the other muscle, the levator palpebrae superioris, controls eyelid elevation. The actions of the six muscles responsible for eye movement depend on the position of the eye at the time of muscle contraction. Structure Since only a small part of the eye called the fovea provides sharp vision, the eye must move to follow a target. Eye movements must be precise and fast. This is seen in scenarios like reading, where the reader must shift gaze constantly. Although under voluntary control, most eye movement is accomplished without conscious effort. Precisely how the integration between voluntary and involuntary control of the eye occurs is a subject of continuing research."eye, human."Encyclopædia Britannica from Encyclopædia Britannica 2006 Ultim ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Superior Oblique Muscle
The superior oblique muscle, or obliquus oculi superior, is a fusiform muscle originating in the upper, medial side of the orbit (i.e. from beside the nose) which abducts, depresses and internally rotates the eye. It is the only extraocular muscle innervated by the trochlear nerve (the fourth cranial nerve). Structure The superior oblique muscle loops through a pulley-like structure (the trochlea of superior oblique) and inserts into the sclera on the posterotemporal surface of the eyeball. It is the pulley system that gives superior oblique its actions, causing depression of the eyeball despite being inserted on the superior surface. The superior oblique arises immediately above the margin of the optic foramen, superior and medial to the origin of the superior rectus, and, passing forward, ends in a rounded tendon, which plays in a fibrocartilaginous ring or pulley attached to the trochlear fossa of the frontal bone. The contiguous surfaces of the tendon and ring are lined by ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Trochlear Nerve
The trochlear nerve (), ( lit. ''pulley-like'' nerve) also known as the fourth cranial nerve, cranial nerve IV, or CN IV, is a cranial nerve that innervates just one muscle: the superior oblique muscle of the eye, which operates through the pulley-like trochlea. CN IV is a motor nerve only (a somatic efferent nerve), unlike most other CNs. The trochlear nerve is unique among the cranial nerves in several respects: * It is the ''smallest'' nerve in terms of the number of axons it contains. * It has the greatest intracranial length. * It is the only cranial nerve that exits from the dorsal (rear) aspect of the brainstem. * It innervates a muscle, the superior oblique muscle, on the opposite side (contralateral) from its nucleus. The trochlear nerve decussates within the brainstem before emerging on the contralateral side of the brainstem (at the level of the inferior colliculus). An injury to the trochlear nucleus in the brainstem will result in an contralateral superior obliqu ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Diplopia
Diplopia is the simultaneous perception of two images of a single object that may be displaced horizontally or vertically in relation to each other. Also called double vision, it is a loss of visual focus under regular conditions, and is often voluntary. However, when occurring involuntarily, it results in impaired function of the extraocular muscles, where both eyes are still functional, but they cannot turn to target the desired object. Problems with these muscles may be due to mechanical problems, disorders of the neuromuscular junction, disorders of the cranial nerves ( III, IV, and VI) that innervate the muscles, and occasionally disorders involving the supranuclear oculomotor pathways or ingestion of toxins. Diplopia can be one of the first signs of a systemic disease, particularly to a muscular or neurological process, and it may disrupt a person's balance, movement, or reading abilities. Causes Diplopia has a diverse range of ophthalmologic, infectious, autoimmune, neu ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Marshall M
Marshall may refer to: Places Australia * Marshall, Victoria, a suburb of Geelong, Victoria Canada * Marshall, Saskatchewan * The Marshall, a mountain in British Columbia Liberia * Marshall, Liberia Marshall Islands * Marshall Islands, an island nation in the Pacific Ocean United States of America * Marshall, Alaska * Marshall, Arkansas * Marshall, California * Lotus, California, former name Marshall * Marshall Pass, a mountain pass in Colorado * Marshall, Illinois * Marshall, Indiana * Marshall, Michigan * Marshall, Minnesota * Marshall, Missouri * Marshall, New York * Marshall, North Carolina * Marshall, North Dakota * Marshall, Oklahoma * Marshall, Texas, the largest U.S. city named Marshall * Marshall, Virginia * Marshall, Wisconsin (other) ** Marshall, Dane County, Wisconsin ** Marshall, Richland County, Wisconsin ** Marshall, Rusk County, Wisconsin Businesses * Marshall of Cambridge, a British holding company encompassing aerospace, fleet management, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Superior Rectus Muscle
The superior rectus muscle is a muscle in the orbit. It is one of the extraocular muscles. It is innervated by the superior division of the oculomotor nerve (III). In the primary position (looking straight ahead), its primary function is elevation, although it also contributes to intorsion and adduction. It is associated with a number of medical conditions, and may be weak, paralysed, overreactive, or even congenitally absent in some people. Structure The superior rectus muscle originates from the annulus of Zinn. It inserts into the anterosuperior surface of the eye. This insertion has a width of around 11 mm. It is around 8 mm from the corneal limbus. Nerve supply The superior rectus muscle is supplied by the superior division of the oculomotor nerve (III). Relations The superior rectus muscle is related to the other extraocular muscles, particularly to the medial rectus muscle and the lateral rectus muscle. The insertion of the superior rectus muscle is around 7.5 mm ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Alfred Bielschowsky
Alfred Bielschowsky (December 11, 1871 – April 5, 1940) was a German ophthalmologist. His specialty was physiology and pathology of the eye, particularly in regards to research of eye movement, space perception and diagnosis of oculomotor anomalies. Bielschowsky was born in Namslau (Namysłów), Prussian Silesia. After attending the Königliches Katholisches Gymnasium of Glatz (Kłodzko), he studied medicine at the University of Breslau (Wrocław) and at the University of Heidelberg. At Heidelberg he was a student of ophthalmologist Theodor Leber (1840-1917). Afterwards he studied medicine at the University of Berlin, attending the lectures of Karl Ernst Theodor Schweigger (1830-1905) and graduating in 1893. He received his medical license in Leipzig on March 1 of the same year. Bielschowsky subsequently studied and worked in the eye clinic at the University of Leipzig, receiving his habilitation in 1900 and becoming head physician of the clinic in 1906. While at Lei ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Diagnostic Ophthalmology
Diagnosis is the identification of the nature and cause of a certain phenomenon. Diagnosis is used in many different disciplines, with variations in the use of logic, analytics, and experience, to determine " cause and effect". In systems engineering and computer science, it is typically used to determine the causes of symptoms, mitigations, and solutions. Computer science and networking * Bayesian networks * Complex event processing * Diagnosis (artificial intelligence) * Event correlation * Fault management * Fault tree analysis * Grey problem * RPR Problem Diagnosis * Remote diagnostics * Root cause analysis * Troubleshooting * Unified Diagnostic Services Mathematics and logic * Bayesian probability * Block Hackam's dictum * Occam's razor * Regression diagnostics * Sutton's law copy right remover block Medicine * Medical diagnosis * Molecular diagnostics Methods * CDR Computerized Assessment System * Computer-assisted diagnosis * Differential diagnosis * Medical di ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Human Eye Anatomy
Humans (''Homo sapiens'') are the most abundant and widespread species of primate, characterized by bipedalism and exceptional cognitive skills due to a large and complex brain. This has enabled the development of advanced tools, culture, and language. Humans are highly social and tend to live in complex social structures composed of many cooperating and competing groups, from families and kinship networks to political states. Social interactions between humans have established a wide variety of values, social norms, and rituals, which bolster human society. Its intelligence and its desire to understand and influence the environment and to explain and manipulate phenomena have motivated humanity's development of science, philosophy, mythology, religion, and other fields of study. Although some scientists equate the term ''humans'' with all members of the genus ''Homo'', in common usage, it generally refers to ''Homo sapiens'', the only extant member. Anatomically modern huma ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Medical Signs
Signs and symptoms are the observed or detectable signs, and experienced symptoms of an illness, injury, or condition. A sign for example may be a higher or lower temperature than normal, raised or lowered blood pressure or an abnormality showing on a medical scan. A symptom is something out of the ordinary that is experienced by an individual such as feeling feverish, a headache or other pain or pains in the body. Signs and symptoms Signs A medical sign is an objective observable indication of a disease, injury, or abnormal physiological state that may be detected during a physical examination, examining the patient history, or diagnostic procedure. These signs are visible or otherwise detectable such as a rash or bruise. Medical signs, along with symptoms, assist in formulating diagnostic hypothesis. Examples of signs include elevated blood pressure, nail clubbing of the fingernails or toenails, staggering gait, and arcus senilis and arcus juvenilis of the eyes. Indicatio ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
