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Meibum
Meibomian glands (also called tarsal glands, palpebral glands, and tarsoconjunctival glands) are sebaceous glands along the rims of the eyelid inside the tarsal plate. They produce meibum, an oily substance that prevents evaporation of the eye's tear film. Meibum prevents tears from spilling onto the cheek, traps them between the oiled edge and the eyeball, and makes the closed lids airtight. There are about 25 such glands on the upper eyelid, and 20 on the lower eyelid. Dysfunctional meibomian glands is believed to be the most often cause of dry eyes. They are also the cause of posterior blepharitis. History The glands were mentioned by Galen in 200 AD and were described in more detail by Heinrich Meibom (1638–1700), a German physician, in his work ''De Vasis Palpebrarum Novis Epistola'' in 1666. This work included a drawing with the basic characteristics of the glands. Anatomy Although the upper lid have greater number and volume of meibomian glands than the lower li ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Meibomian Gland Dysfunction
Meibomian gland dysfunction (also known as MGD) is a chronic disease of the meibomian glands, which is commonly characterized by obstruction of the end of the duct that delivers the secretion produced by the glands (called meibum) to the eye surface, which prevents the glandular secretion to reach the ocular surface. The dysfunction could be that the amount of secretion produced may be abnormal (either too little or too much meibum produced). Dysfunction could also be related to the quality of the meibum produced. MGD may result in evaporative dry eye, blepharitis, chalazion, unsealed lid during sleep, and meibomian gland atrophy. MGD causes the glands to be obstructed by thick, cloudy-to-yellow, more opaque and viscous-like, oily and waxy secretions, a change from the glands' normal clear secretions.Peter Bex, Reza Dana, Linda Mcloon, Jerry Niederkorn (2011)''Ocular Periphery and Disorders''/ref> Besides leading to dry eyes, the obstructions can be degraded by bacterial lipase ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sebaceous Gland
A sebaceous gland is a microscopic exocrine gland in the skin that opens into a hair follicle to secrete an oily or waxy matter, called sebum, which lubricates the hair and skin of mammals. In humans, sebaceous glands occur in the greatest number on the face and scalp, but also on all parts of the skin except the palms of the hands and soles of the feet. In the eyelids, meibomian glands, also called tarsal glands, are a type of sebaceous gland that secrete a special type of sebum into tears. Surrounding the female nipple, areolar glands are specialized sebaceous glands for lubricating the nipple. Fordyce spots are benign, visible, sebaceous glands found usually on the lips, gums and inner cheeks, and genitals. Structure Location Sebaceous glands are found throughout all areas of the skin, except the palms of the hands and soles of the feet. There are two types of sebaceous glands, those connected to hair follicles and those that exist independently. Sebaceous glands ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Blepharitis
Blepharitis is one of the most common ocular conditions characterized by inflammation, scaling, reddening, and crusting of the eyelid. This condition may also cause swelling, burning, itching, or a grainy sensation when introducing foreign objects or substances to the eye. Although blepharitis by itself is not sight-threatening, it can lead to permanent alterations of the eyelid margin. The primary cause is bacteria and inflammation from congested meibomian oil glands at the base of each eyelash. Other conditions may give rise to blepharitis, whether they be infectious or noninfectious, including, but not limited to, bacterial infections or allergies. Different variations of blepharitis can be classified as seborrheic, staphylococcal, mixed, posterior or meibomitis, or parasitic. In a survey of US ophthalmologists and optometrists, 37% to 47% of patients seen by those surveyed had signs of blepharitis, which can affect all ages and ethnic groups. One single-center study of 90 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sebum
A sebaceous gland is a microscopic exocrine gland in the skin that opens into a hair follicle to secrete an oily or waxy matter, called sebum, which lubricates the hair and skin of mammals. In humans, sebaceous glands occur in the greatest number on the face and scalp, but also on all parts of the skin except the palms of the hands and soles of the feet. In the eyelids, meibomian glands, also called tarsal glands, are a type of sebaceous gland that secrete a special type of sebum into tears. Surrounding the female nipple, areolar glands are specialized sebaceous glands for lubricating the nipple. Fordyce spots are benign, visible, sebaceous glands found usually on the lips, gums and inner cheeks, and genitals. Structure Location Sebaceous glands are found throughout all areas of the skin, except the palms of the hands and soles of the feet. There are two types of sebaceous glands, those connected to hair follicles and those that exist independently. Sebaceous glands ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Fatty Acid
In chemistry, particularly in biochemistry, a fatty acid is a carboxylic acid with an aliphatic chain, which is either saturated or unsaturated. Most naturally occurring fatty acids have an unbranched chain of an even number of carbon atoms, from 4 to 28. Fatty acids are a major component of the lipids (up to 70% by weight) in some species such as microalgae but in some other organisms are not found in their standalone form, but instead exist as three main classes of esters: triglycerides, phospholipids, and cholesteryl esters. In any of these forms, fatty acids are both important dietary sources of fuel for animals and important structural components for cells. History The concept of fatty acid (''acide gras'') was introduced in 1813 by Michel Eugène Chevreul, though he initially used some variant terms: ''graisse acide'' and ''acide huileux'' ("acid fat" and "oily acid"). Types of fatty acids Fatty acids are classified in many ways: by length, by saturation vs unsa ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Thygeson's Superficial Punctate Keratopathy
Thygeson's superficial punctate keratopathy (TSPK) is a disease of the eyes. The causes of TSPK are not currently known, but details of the disease were first published in the Journal of the American Medical Association in 1950 by renowned American ophthalmologist Phillips Thygeson (1903–2002), after whom it is named. Symptoms and signs A patient with TSPK may complain of blurred vision, dry eyes, a sensation of having a foreign body stuck in the eye, photophobia (sensitivity to bright light), burning sensations and watery eyes. On inspection with a slit lamp, tiny lumps can be found on the cornea of the eye. These lumps can be more easily seen after applying fluorescein or rose Bengal dye eye-drops. The lumps appear to be randomly positioned on the cornea and they may appear and disappear over a period of time (with or without treatment). TSPK may affect one or both eyes. When both eyes are affected, the tiny lumps found on the cornea may differ in number between eyes. The s ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Dry Eye Disease
Dry eye syndrome (DES), also known as keratoconjunctivitis sicca (KCS), is the condition of having dry eyes. Other associated symptoms include irritation, redness, discharge, and easily fatigued eyes. Blurred vision may also occur. Symptoms range from mild and occasional to severe and continuous. Scarring of the cornea may occur in untreated cases. Dry eye occurs when either the eye does not produce enough tears or when the tears evaporate too quickly. This can result from contact lens use, meibomian gland dysfunction, pregnancy, Sjögren syndrome, vitamin A deficiency, omega-3 fatty acid deficiency, LASIK surgery, and certain medications such as antihistamines, some blood pressure medication, hormone replacement therapy, and antidepressants. Chronic conjunctivitis such as from tobacco smoke exposure or infection may also lead to the condition. Diagnosis is mostly based on the symptoms, though a number of other tests may be used. Treatment depends on the underlying cause. Art ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Demodex Brevis
''Demodex brevis'' is one of the two species of face mite that inhabit humans (the other being ''Demodex folliculorum''). They are very similar to ''Demodex folliculorum'', with just a few differences. They are usually found in the sebaceous glands of the human body. The same way that ''D. folliculorum'' reproduces in the follicles, ''D. brevis'' reproduces in the sebaceous glands. Under normal conditions they are not harmful, and are considered to be commensals (the mite benefits but there is no harm or benefit to the host) rather than parasites (where the host is harmed) or mutualistic organisms (where the host is benefitted). During a severe infestation, though, there may be adverse effects on the host, such as demodicosis Demodicosis , also called Demodex folliculitis in humans and demodectic mange () or red mange in animals, is caused by a sensitivity to and overpopulation of '' Demodex spp.'' as the host's immune system is unable to keep the mites under control. .... ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Warm Compresses
A warm compress is a method of applying heat to the body. Heating sources can include warm water, microwaveable pads, wheat packs and electrical or chemical pads. Some unorthodox methods can include warmed potatoes, uncooked rice, and hard-boiled eggs. The most common warm compress is a warm, wet washcloth. Uses Warm compresses are a common non-pharmacological therapy used in the treatment of things such as sports injuries, dental pain, post-operative wound healing, and ophthalmic conditions. They are believed to improve blood flow, increase oxygenation in tissues and help manage inflammation. For eye problems Warm compresses are commonly used for the treatment of certain ocular conditions such as: * dry eyes * pinkeye (conjunctivitis) * stye or chalazion * swollen eyelids (blepharitis Blepharitis is one of the most common ocular conditions characterized by inflammation, scaling, reddening, and crusting of the eyelid. This condition may also cause swelling, burning, it ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lifitegrast
Lifitegrast, sold under the brand name Xiidra (), is a medication for the treatment of signs and symptoms of dry eye, a syndrome called keratoconjunctivitis sicca. Lifitegrast reduces inflammation by inhibiting inflammatory cell binding. It is often used in conjunction with ciclosporin (Ikervis, Restasis, or Cequa) for dry eye treatment including meibomian gland dysfunction and inflammatory dry eye. Adverse effects Common side effects in clinical trials were eye irritation, discomfort, blurred vision, and dysgeusia (a distortion of the sense of taste). Pharmacology Lifitegrast is supplied as an eye drop. Mechanism of action Lifitegrast inhibits an integrin, lymphocyte function-associated antigen 1 (LFA-1), from binding to intercellular adhesion molecule 1 (ICAM-1). This mechanism down-regulates inflammation mediated by T lymphocytes. History Lifitegrast was initially designed and developed by SARcode Bioscience which was acquired by Shire in 2013, which submitted a new drug ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Restasis
Ciclosporin, also spelled cyclosporine and cyclosporin, is a calcineurin inhibitor, used as an immunosuppressant medication. It is a natural product. It is taken orally or intravenously for rheumatoid arthritis, psoriasis, Crohn's disease, nephrotic syndrome, and in organ transplants to prevent rejection. It is also used as eye drops for keratoconjunctivitis sicca (dry eyes). Common side effects include high blood pressure, headache, kidney problems, increased hair growth, and vomiting. Other severe side effects include an increased risk of infection, liver problems, and an increased risk of lymphoma. Blood levels of the medication should be checked to decrease the risk of side effects. Use during pregnancy may result in preterm birth; however, ciclosporin does not appear to cause birth defects. Ciclosporin is believed to work by decreasing the function of lymphocytes. It does this by forming a complex with cyclophilin to block the phosphatase activity of calcineurin, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
