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Macular Corneal Dystrophy
Macular corneal dystrophy, also known as Fehr corneal dystrophy, is a rare pathological condition affecting the stroma of cornea first described by Arthur Groenouw in 1890.Groenouw A. Knötchenförmige Hornhauttrübungen (noduli corneae). Arch Augenheilkunde. 1890;21:281–289. Signs are usually noticed in the first decade of life and progress afterwards, with opacities developing in the cornea and attacks of pain. This gradual opacification leads to visual impairment often requiring keratoplasty in the later decades of life. Epidemiology While Macular Corneal Dystrophy is found throughout the world, countries with the highest prevalence include Iceland, Saudi Arabia, India, and the United States. In Iceland, MCD accounts for almost one-third of all corneal grafts performed. Estimates from Claims Data in the United States place the prevalence of MCD at 9.7 per million, which represents less than 1% of corneal dystrophies. Pathophysiology Macular Corneal Dystrophy is an autoso ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Oskar Fehr
Oskar Fehr (9 October 1871 – 1 August 1959) was a German ophthalmologist. Among his medical specialties were swimming pool conjunctivitis, tumours of the eye, and retinal detachment. He was an internationally renowned eye surgeon. Life Fehr was born in Braunschweig to a Jewish family. He studied in Heidelberg, Berlin, and Kiel, receiving his doctorate at Heidelberg in 1897. From 1897 to 1906, he was assistant physician at the eye clinic of Julius Hirschberg (1843–1925) in Berlin. From 1907, he was head physician at the department of eye diseases at the Rudolf Virchow Hospital. He received the title of professor in 1919. Besides his work in the hospital, he had a large private practice in the western part of Berlin, close to the Tiergarten. In 1934, Fehr was forbidden to enter the clinic where he had worked for more than 25 years. He continued his private practice and operated in different nursing homes. When Jewish doctors were prohibited to treat gentiles in 1938, he was o ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Immunophenotyping
Immunophenotyping is a technique used to study the protein expressed by cells. This technique is commonly used in basic science research and laboratory diagnostic purpose. This can be done on tissue section (fresh or fixed tissue), cell suspension, etc. An example is the detection of tumor markers, such as in the diagnosis of leukemia. It involves the labelling of white blood cells with antibodies directed against surface proteins on their membrane. By choosing appropriate antibodies, the differentiation of leukemic cells can be accurately determined. The labelled cells are processed in a flow cytometer, a laser-based instrument capable of analyzing thousands of cells per second. The whole procedure can be performed on cells from the blood, bone marrow Bone marrow is a semi-solid biological tissue, tissue found within the Spongy bone, spongy (also known as cancellous) portions of bones. In birds and mammals, bone marrow is the primary site of new blood cell production (or h ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Gene Therapy
Gene therapy is Health technology, medical technology that aims to produce a therapeutic effect through the manipulation of gene expression or through altering the biological properties of living cells. The first attempt at modifying human DNA was performed in 1980, by Martin Cline, but the first successful nuclear gene transfer in humans, approved by the National Institutes of Health, was performed in May 1989. The first therapeutic use of gene transfer as well as the first direct insertion of human DNA into the nuclear genome was performed by French Anderson in a trial starting in September 1990. Between 1989 and December 2018, over 2,900 clinical trials were conducted, with more than half of them in Phases of clinical research, phase I. In 2003, Gendicine became the first gene therapy to receive regulatory approval. Since that time, further gene therapy drugs were approved, such as alipogene tiparvovec (2012), Strimvelis (2016), tisagenlecleucel (2017), voretigene neparvovec ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Photorefractive Keratectomy
Photorefractive keratectomy (PRK) and laser-assisted sub-epithelial keratectomy (or laser epithelial keratomileusis) (LASEK) are laser eye surgery procedures intended to correct a person's vision, reducing dependency on glasses or contact lenses. LASEK and PRK permanently change the shape of the anterior central cornea using an excimer laser to ablate (remove by vaporization) a small amount of tissue from the corneal stroma at the front of the eye, just under the corneal epithelium. The outer layer of the cornea is removed prior to the ablation. A computer system tracks the patient's eye position 60 to 4,000 times per second, depending on the specifications of the laser that is used. The computer system redirects laser pulses for precise laser placement. Most modern lasers will automatically center on the patient's visual axis and will pause if the eye moves out of range and then resume ablating at that point after the patient's eye is re-centered. The outer layer of the corne ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Corneal Transplantation
Corneal transplantation, also known as corneal grafting, is a surgical procedure where a damaged or diseased cornea is replaced by donated corneal tissue (the graft). When the entire cornea is replaced it is known as penetrating keratoplasty and when only part of the cornea is replaced it is known as lamellar keratoplasty. Keratoplasty simply means surgery to the cornea. The graft is taken from a recently deceased individual with no known diseases or other factors that may affect the chance of survival of the donated tissue or the health of the recipient. The cornea is the transparent front part of the eye that covers the iris, pupil and anterior chamber. The surgical procedure is performed by ophthalmologists, physicians who specialize in eyes, and is often done on an outpatient basis. Donors can be of any age, as is shown in the case of Janis Babson, who donated her eyes after dying at the age of 10. Corneal transplantation is performed when medicines, keratoconus conser ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Optical Coherence Tomography
Optical coherence tomography (OCT) is a high-resolution imaging technique with most of its applications in medicine and biology. OCT uses coherent near-infrared light to obtain micrometer-level depth resolved images of biological tissue or other scattering media. It uses interferometry techniques to detect the amplitude and time-of-flight of reflected light. OCT uses transverse sample scanning of the light beam to obtain two- and three-dimensional images. Short-coherence-length light can be obtained using a superluminescent diode (SLD) with a broad spectral bandwidth or a broadly tunable laser with narrow linewidth. The first demonstration of OCT imaging (in vitro) was published by a team from MIT and Harvard Medical School in a 1991 article in the journal ''Science (journal), Science''. The article introduced the term "OCT" to credit its derivation from optical coherence-domain reflectometry, in which the axial resolution is based on temporal coherence. The first demonstrat ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Confocal Microscopy
Confocal microscopy, most frequently confocal laser scanning microscopy (CLSM) or laser scanning confocal microscopy (LSCM), is an optical imaging technique for increasing optical resolution and contrast (vision), contrast of a micrograph by means of using a Spatial filter, spatial pinhole to block out-of-focus light in image formation. Capturing multiple two-dimensional images at different depths in a sample enables the reconstruction of three-dimensional structures (a process known as optical sectioning) within an object. This technique is used extensively in the scientific and industrial communities and typical applications are in life sciences, semiconductor inspection and materials science. Light travels through the sample under a conventional microscope as far into the specimen as it can penetrate, while a confocal microscope only focuses a smaller beam of light at one narrow depth level at a time. The CLSM achieves a controlled and highly limited depth of field. Basic c ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Alcian Blue Stain
Alcian blue () is any member of a family of polyvalent basic dyes, of which the Alcian blue 8G (also called Ingrain blue 1, and C.I. 74240, formerly called Alcian blue 8GX from the name of a batch of an ICI product) has been historically the most common and the most reliable member. It is used to stain acidic polysaccharides such as glycosaminoglycans in cartilages and other body structures, some types of mucopolysaccharides, sialylated glycocalyx of cells etc. For many of these targets it is one of the most widely used cationic dyes for both light and electron microscopy. Use of alcian blue has historically been a popular staining method in histology especially for light microscopy in paraffin embedded sections and in semithin resin sections. The tissue parts that specifically stain by this dye become blue to bluish-green after staining and are called "Alcianophilic" (comparable to "eosinophilic" or " sudanophilic"). Alcian blue staining can be combined with H&E staining, PAS ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Histopathology
Histopathology (compound of three Greek words: 'tissue', 'suffering', and '' -logia'' 'study of') is the microscopic examination of tissue in order to study the manifestations of disease. Specifically, in clinical medicine, histopathology refers to the examination of a biopsy or surgical specimen by a pathologist, after the specimen has been processed and histological sections have been placed onto glass slides. In contrast, cytopathology examines free cells or tissue micro-fragments (as "cell blocks "). Collection of tissues Histopathological examination of tissues starts with surgery, biopsy, or autopsy. The tissue is removed from the body or plant, and then, often following expert dissection in the fresh state, placed in a fixative which stabilizes the tissues to prevent decay. The most common fixative is 10% neutral buffered formalin (corresponding to 3.7% w/v formaldehyde in neutral buffered water, such as phosphate buffered saline). Preparation for h ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Photophobia
Photophobia is a medical symptom of abnormal intolerance to visual perception of light. As a medical symptom, photophobia is not a morbid fear or phobia, but an experience of discomfort or pain to the eyes due to light exposure or by presence of actual physical sensitivity of the eyes, though the term is sometimes additionally applied to abnormal or irrational fear of light, such as heliophobia. The term ''photophobia'' comes . Causes Patients may develop photophobia as a result of several different medical conditions, related to the human eye, eye, the nervous system, genetic, or other causes. Photophobia may manifest itself in an increased response to light starting at any step in the visual system, such as: * Too much light entering the eye. Too much light can enter the eye if it is damaged, such as with corneal abrasion and retinal damage, or if its pupil is unable to normally constrict (seen with damage to the oculomotor nerve). * Due to albinism, the lack of pigment in th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Macular Corneal Dystrophy Lamp Exam
A skin condition, also known as cutaneous condition, is any medical condition that affects the integumentary system—the organ system that encloses the body and includes skin, nails, and related muscle and glands. The major function of this system is as a barrier against the external environment. Conditions of the human integumentary system constitute a broad spectrum of diseases, also known as dermatoses, as well as many nonpathologic states (like, in certain circumstances, melanonychia and racquet nails). While only a small number of skin diseases account for most visits to the physician, thousands of skin conditions have been described. Classification of these conditions often presents many nosological challenges, since underlying causes and pathogenetics are often not known. Therefore, most current textbooks present a classification based on location (for example, conditions of the mucous membrane), morphology ( chronic blistering conditions), cause (skin conditions result ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Proteoglycan
Proteoglycans are proteins that are heavily glycosylated. The basic proteoglycan unit consists of a "core protein" with one or more covalently attached glycosaminoglycan (GAG) chain(s). The point of attachment is a serine (Ser) residue to which the glycosaminoglycan is joined through a tetrasaccharide bridge (e.g. chondroitin sulfate- GlcA- Gal-Gal- Xyl-PROTEIN). The Ser residue is generally in the sequence -Ser- Gly-X-Gly- (where X can be any amino acid residue but proline), although not every protein with this sequence has an attached glycosaminoglycan. The chains are long, linear carbohydrate polymers that are negatively charged under physiological conditions due to the occurrence of sulfate and uronic acid groups. Proteoglycans occur in connective tissue. Types Proteoglycans are categorized by their relative size (large and small) and the nature of their glycosaminoglycan chains. Types include: Certain members are considered members of the "small leucine-rich pr ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
