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Fleischer Ring
Fleischer rings are pigmented rings in the peripheral cornea, resulting from iron deposition in basal epithelial cells, in the form of hemosiderin. They are usually yellowish to dark-brown, and may be complete or broken. The rings are best seen using the slit lamp under cobalt blue filter. They are named for Bruno Fleischer. Fleischer rings are indicative of keratoconus, a degenerative corneal condition that causes the cornea to thin and change to a conic shape. Confusion with Kayser–Fleischer rings Some confusion exists between Fleischer rings and Kayser–Fleischer rings. Kayser–Fleischer rings are caused by copper deposits in descemet's membrane of cornea, and are indicative of Wilson's disease, whereas Fleischer rings are caused by iron deposits in basal epithelial cells. One example of a medical condition that can present with Fleischer rings is keratoconus. See also * Hudson–Stahli line * Limbal ring A limbal ring is a dark ring around the iris of the ey ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cornea
The cornea is the transparency (optics), transparent front part of the eyeball which covers the Iris (anatomy), iris, pupil, and Anterior chamber of eyeball, anterior chamber. Along with the anterior chamber and Lens (anatomy), lens, the cornea Refraction, refracts light, accounting for approximately two-thirds of the eye's total optical power. In humans, the refractive power of the cornea is approximately 43 dioptres. The cornea can be reshaped by surgical procedures such as LASIK. While the cornea contributes most of the eye's focusing power, its Focus (optics), focus is fixed. Accommodation (eye), Accommodation (the refocusing of light to better view near objects) is accomplished by changing the geometry of the lens. Medical terms related to the cornea often start with the prefix "''wikt:kerat-, kerat-''" from the Ancient Greek, Greek word κέρας, ''horn''. Structure The cornea has myelinated, unmyelinated nerve endings sensitive to touch, temperature and chemicals; a to ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Iron
Iron is a chemical element; it has symbol Fe () and atomic number 26. It is a metal that belongs to the first transition series and group 8 of the periodic table. It is, by mass, the most common element on Earth, forming much of Earth's outer and inner core. It is the fourth most abundant element in the Earth's crust, being mainly deposited by meteorites in its metallic state. Extracting usable metal from iron ores requires kilns or furnaces capable of reaching , about 500 °C (900 °F) higher than that required to smelt copper. Humans started to master that process in Eurasia during the 2nd millennium BC and the use of iron tools and weapons began to displace copper alloys – in some regions, only around 1200 BC. That event is considered the transition from the Bronze Age to the Iron Age. In the modern world, iron alloys, such as steel, stainless steel, cast iron and special steels, are by far the most common industrial metals, due to their mechan ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hemosiderin
Hemosiderin image of a kidney viewed under a microscope. The brown areas represent hemosiderin Hemosiderin or haemosiderin is an iron-storage complex that is composed of partially digested ferritin and lysosomes. The breakdown of heme gives rise to biliverdin and iron. The body then traps the released iron and stores it as hemosiderin in tissues. Hemosiderin is also generated from the abnormal metabolic pathway of ferritin. It is only found within cells (as opposed to circulating in blood) and appears to be a complex of ferritin, denatured ferritin and other material. The iron within deposits of hemosiderin is very poorly available to supply iron when needed. Hemosiderin can be identified histologically with '' Perls' Prussian blue stain''; iron in hemosiderin turns blue to black when exposed to potassium ferrocyanide. In normal animals, hemosiderin deposits are small and commonly inapparent without special stains. Excessive accumulation of hemosiderin is usually detected with ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Slit Lamp
In ophthalmology and optometry, a slit lamp is an instrument consisting of a high-intensity light source that can be focused to shine a thin sheet of light into the eye. It is used in conjunction with a biomicroscope. The lamp facilitates an examination of the anterior segment and posterior segment of the human eye, which includes the eyelid, sclera, conjunctiva, iris (anatomy), iris, natural crystalline lens, and cornea. The binocular slit-lamp examination provides a stereoscopic magnified view of the eye structures in detail, enabling anatomical diagnoses to be made for a variety of eye conditions. A second, hand-held lens is used to examine the retina. History Two conflicting trends emerged in the development of the slit lamp. One trend originated from clinical research and aimed to apply the increasingly complex and advanced technology of the time. [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bruno Fleischer
Bruno Otto Fleischer (2 May 1874 – 26 March 1965) was a German ophthalmologist. Kayser–Fleischer rings and Fleischer ring Fleischer rings are pigmented rings in the peripheral cornea, resulting from iron deposition in basal epithelial cells, in the form of hemosiderin. They are usually yellowish to dark-brown, and may be complete or broken. The rings are best seen us ...s are named for him. References Further reading * German ophthalmologists 1965 deaths 1874 births Eye color {{germany-med-bio-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Keratoconus
Keratoconus is an eye disorder in which the cornea, the transparent front part of the eye, gradually thins and bulges outward into a cone shape. This causes distorted vision, including blurry vision, double vision, increased nearsightedness, irregular astigmatism, and light sensitivity, which can reduce Quality of life (healthcare), quality of life. Both eyes are usually affected. The cause is not fully understood but likely involves a combination of heredity, genetic, environmental, and hormonal factors. Having a parent, sibling, or child with keratoconus increases risk significantly. Environmental risk factors include frequent eye rubbing and atopy, allergies. Diagnosis is typically made with corneal topography, which maps the shape of the cornea and reveals characteristic changes. In early stages, vision is often corrected with glasses or soft contact lenses. As the condition progresses, rigid or scleral contact lenses may be needed. In 2016, the FDA approved corneal col ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Kayser–Fleischer Ring
Kayser–Fleischer rings (KF rings) are dark rings that appear to encircle the cornea of the human eye, eye. They are due to copper deposition in the Descemet's membrane as a result of particular liver diseases. They are named after Germany, German ophthalmologists Bernhard Kayser and Bruno Fleischer who first described them in 1902 and 1903. Initially thought to be due to the accumulation of silver, they were first demonstrated to contain copper in 1934. Presentation The rings, which consist of copper deposits where the cornea meets the sclera, in Descemet's membrane, first appear as a crescent at the top of the cornea. Eventually, a second crescent forms below, at the "six o'clock position", and ultimately completely encircles the cornea. Associations Kayser–Fleischer rings are a sign of Wilson's disease, which involves abnormal copper handling by the liver resulting in copper accumulation in the body and is characterised by abnormalities of the basal ganglia of the brain, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Copper
Copper is a chemical element; it has symbol Cu (from Latin ) and atomic number 29. It is a soft, malleable, and ductile metal with very high thermal and electrical conductivity. A freshly exposed surface of pure copper has a pinkish-orange color. Copper is used as a conductor of heat and electricity, as a building material, and as a constituent of various metal alloys, such as sterling silver used in jewelry, cupronickel used to make marine hardware and coins, and constantan used in strain gauges and thermocouples for temperature measurement. Copper is one of the few metals that can occur in nature in a directly usable, unalloyed metallic form. This means that copper is a native metal. This led to very early human use in several regions, from . Thousands of years later, it was the first metal to be smelted from sulfide ores, ; the first metal to be cast into a shape in a mold, ; and the first metal to be purposely alloyed with another metal, tin, to create bronze, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Wilson's Disease
Wilson's disease (also called hepatolenticular degeneration) is a genetic disorder characterized by the excess build-up of copper in the body. Symptoms are typically related to the brain and liver. Liver-related symptoms include vomiting, weakness, fluid build-up in the abdomen, swelling of the legs, yellowish skin, and itchiness. Brain-related symptoms include tremors, muscle stiffness, trouble in speaking, personality changes, anxiety, and psychosis. Wilson's disease is caused by a mutation in the Wilson disease protein (''ATP7B'') gene. This protein transports excess copper into bile, where it is excreted in waste products. The condition is autosomal recessive; for people to be affected, they must inherit a mutated copy of the gene from both parents. Diagnosis may be difficult and often involves a combination of blood tests, urine tests, and a liver biopsy. Genetic testing may be used to screen family members of those affected. Wilson's disease is typically tre ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Limbal Ring
A limbal ring is a dark ring around the iris of the eye, where the sclera meets the cornea. It is a dark-colored manifestation of the corneal limbus resulting from optical properties of the region. The appearance and visibility of the limbal ring can be negatively affected by a variety of medical conditions concerning the peripheral cornea. It has been suggested that limbal ring thickness may correlate with health or youthfulness and may contribute to facial attractiveness. The thickness of the limbal ring varies by pupil dilation: When the pupil is larger, the limbal ring narrows. Some contact lenses are colored to simulate limbal rings. Youth, health, and attractiveness Both health and youth are positively correlated with a prominent limbal ring. For instance, a darker limbal ring tends to be found more attractive than the absence of a limbal ring, suggesting that both sexes "use the limbal ring as a probabilistic indicator of reproductive fitness". Furthermore, limbal rin ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Eye Diseases
This is a partial list of human eye diseases and disorders. The World Health Organization (WHO) publishes a classification of known diseases and injuries, the International Statistical Classification of Diseases and Related Health Problems, or ICD-10. This list uses that classification. H00-H06 Disorders of eyelid, lacrimal system and orbit * (H02.1) Ectropion * (H02.2) Lagophthalmos * (H02.3) Blepharochalasis * (H02.4) Ptosis (eyelid), Ptosis * (H02.5) Stye, an acne type infection of the sebaceous glands on or near the eyelid. * (H02.6) Xanthelasma of eyelid * (H03.0*) Parasitic infestation of eyelid in diseases classified elsewhere ** Dermatitis of eyelid due to Demodex species ( B88.0+ ) ** Parasitic infestation of eyelid in: *** leishmaniasis ( B55.-+ ) *** loiasis ( B74.3+ ) *** onchocerciasis ( B73+ ) *** phthiriasis ( B85.3+ ) * (H03.1*) Involvement of eyelid in other infectious diseases classified elsewhere ** Involvement of eyelid in: *** herpesviral (herpes simplex) ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
