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Corneal Ulcers
Corneal ulcer, often resulting from keratitis is an inflammatory or, more seriously, infective condition of the cornea involving disruption of its epithelial layer with involvement of the corneal stroma. It is a common condition in humans particularly in the tropics and in farming. In developing countries, children afflicted by vitamin A deficiency are at high risk for corneal ulcer and may become blind in both eyes persisting throughout life. In ophthalmology, a corneal ulcer usually refers to having an infection, while the term corneal abrasion refers more to a scratch injury. Types Superficial and deep corneal ulcers Corneal ulcers are a common human eye disease. They are caused by trauma, particularly with vegetable matter, as well as chemical injury, contact lenses and infections. Other eye conditions can cause corneal ulcers, such as entropion, distichiasis, corneal dystrophy, and keratoconjunctivitis sicca (dry eye). Many micro-organisms cause infective corneal ulcer. A ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bacterial Keratitis
Keratitis is a condition in which the eye's cornea, the clear dome on the front surface of the eye, becomes inflamed. The condition is often marked by moderate to intense pain and usually involves any of the following symptoms: pain, impaired eyesight, photophobia (light sensitivity), red eye and a 'gritty' sensation. Diagnosis of infectious keratitis is usually made clinically based on the signs and symptoms as well as eye examination, but corneal scrapings may be obtained and evaluated using microbiological culture or other testing to identify the causative pathogen. Classification (by chronicity) Acute * Acute epithelial keratitis * Nummular keratitis * Interstitial keratitis * Disciform keratitis Chronic * Neurotrophic keratitis * Mucous plaque keratitis Classification (infective) Viral The most common causes of viral keratitis include herpes simplex virus (HSV) and varicella zoster virus (VZV), which cause herpes simplex keratitis and herpes zoster keratitis ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Enterococci
''Enterococcus'' is a large genus of lactic acid bacteria of the phylum Bacillota. Enterococci are Gram-positive cocci that often occur in pairs (diplococci) or short chains, and are difficult to distinguish from streptococci on physical characteristics alone. Two species are common commensal organisms in the intestines of humans: '' E. faecalis'' (90–95%) and '' E. faecium'' (5–10%). Rare clusters of infections occur with other species, including '' E. durans'' , ''E. casseliflavus'', '' E. gallinarum'', and ''E. raffinosus''. Physiology and classification Enterococci are facultative anaerobic organisms, i.e., they are capable of cellular respiration in both oxygen-rich and oxygen-poor environments. Though they are not capable of forming spores, enterococci are tolerant of a wide range of environmental conditions: extreme temperature (10–45 °C), pH (4.6–9.9), and high sodium chloride concentrations. ''E. faecium'' and ''E. faecalis'' can be differentiated bas ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Adenovirus
Adenoviruses (members of the family ''Adenoviridae'') are medium-sized (90–100 nm), nonenveloped (without an outer lipid bilayer) viruses with an icosahedral nucleocapsid containing a double-stranded DNA genome. Their name derives from their initial isolation from human adenoids in 1953. They have a broad range of vertebrate hosts; in humans, more than 50 distinct adenoviral serotypes have been found to cause a wide range of illnesses, from mild respiratory infections in young children (the common cold) to life-threatening multi-organ disease in people with a weakened immune system. Virology Classification This family contains the following genera: * '' Aviadenovirus'' * '' Barthadenovirus'' * '' Ichtadenovirus'' * ''Mastadenovirus'' (including all human adenoviruses) * '' Siadenovirus'' * '' Testadenovirus'' Diversity In humans, currently there are 88 human adenoviruses (HAdVs) in seven species (Human adenovirus A to G): * A: 12, 18, 31 * B: 3, 7, 11, 14, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Herpes Zoster
Shingles, also known as herpes zoster or zona, is a viral disease characterized by a painful skin rash with blisters in a localized area. Typically the rash occurs in a single, wide mark either on the left or right side of the body or face. Two to four days before the rash occurs there may be tingling or local pain in the area. Other common symptoms are fever, headache, and tiredness. The rash usually heals within two to four weeks, but some people develop ongoing nerve pain which can last for months or years, a condition called postherpetic neuralgia (PHN). In those with poor immune function the rash may occur widely. If the rash involves the eye, vision loss may occur. Shingles is caused by the varicella zoster virus (VZV) that also causes chickenpox. In the case of chickenpox, also called varicella, the initial infection with the virus typically occurs during childhood or adolescence. Once the chickenpox has resolved, the virus can remain dormant (inactive) in human n ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Herpes Simplex
Herpes simplex, often known simply as herpes, is a viral disease, viral infection caused by the herpes simplex virus. Herpes infections are categorized by the area of the body that is infected. The two major types of herpes are Cold sore, oral herpes and genital herpes, though Herpes simplex#Types of herpes, other forms also exist. Oral herpes involves the face or mouth. It may result in small blisters in groups, often called cold sores or fever blisters, or may just cause a sore throat. Genital herpes involves the genitalia. It may have minimal symptoms or form blisters that break open and result in small ulcers. These typically heal over two to four weeks. Tingling or shooting pains may occur before the blisters appear. Herpes cycles between periods of active disease followed by periods without symptoms. The first episode is often more severe and may be associated with fever, muscle pains, swollen lymph nodes and headaches. Over time, episodes of active disease decrease in ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hypopyon
Hypopyon is a medical condition involving Inflammation#Cellular component, inflammatory cells in the anterior chamber of the human eye, eye. It is an exudate rich in white blood cells, seen in the anterior chamber, usually accompanied by redness of the conjunctiva and the underlying episclera. It is a sign of inflammation of the anterior uvea and iris (anatomy), iris, i.e. iritis, which is a form of uveitis, anterior uveitis. The exudate settles at the dependent aspect of the eye due to gravity. It can be sterile (in bacterial corneal ulcer) or not sterile (fungal corneal ulcer). Differential diagnosis Hypopyon can be present in a corneal ulcer. It can occur as a result of Behçet's disease, endophthalmitis, panuveitis/panophthalmitis, or adverse reactions to some drugs (such as rifabutin). Hypopyon is also known as ''sterile pus'' because it occurs due to the release of toxins and not by the actual invasion of pathogens. The toxins secreted by the pathogens mediate the outpouri ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
