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Pinguecula
A pinguecula is a common type of conjunctival stromal degeneration in the eye. It appears as an elevated yellow-white plaque in the bulbar conjunctiva near the limbus. Calcification may also be seen occasionally. Etiology The exact etiology is unknown, but it may be associated with aging and excessive exposure to UV light. Signs and symptoms It is seen as a yellow-white deposit on the conjunctiva adjacent to the limbus (the junction between the cornea and sclera). (It is to be distinguished clinically from a pterygium, which is a wedge shaped area of fibrosis that may grow onto the cornea.) A pinguecula usually does not cause any symptoms. It is most common in tropical climates and there is a direct correlation with UV exposure. Histologically, there is degeneration of the collagen fibers of the conjunctival stroma with thinning of the overlying epithelium and occasionally calcification. Actinic exposure of the thin conjunctival tissue is thought to cause fibroblasts to pro ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pterygium (conjunctiva)
A pterygium of the eye (: ''pterygia'' or ''pterygiums'', also called surfer's eye) is a pinkish, roughly triangular tissue growth of the conjunctiva onto the cornea of the eye. It typically starts on the cornea near the nose. It may slowly grow but rarely grows so large that it covers the pupil and impairs vision. Often both eyes are involved. The cause is unclear. It appears to be partly related to long term exposure to UV light and dust. Genetic factors also appear to be involved. It is a benign growth. Other conditions that can look similar include a pinguecula, tumor, or Terrien's marginal corneal degeneration. Prevention may include wearing sunglasses and a hat if in an area with strong sunlight. Among those with the condition, an eye lubricant can help with symptoms. Surgical removal is typically only recommended if the ability to see is affected. Following surgery a pterygium may recur in around half of cases. The frequency of the condition varies from 1% to 33% in ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Peripheral Light Focusing
Peripheral Light Focusing (PLF) can be described as the focusing of Solar Ultraviolet Radiation (SUVR) at the nasal limbus of the cornea. SUVR incident at the temporal limbus passes across the corneal dome and focuses at the nasal limbus. The limbal region is a stem cell In multicellular organisms, stem cells are undifferentiated or partially differentiated cells that can change into various types of cells and proliferate indefinitely to produce more of the same stem cell. They are the earliest type of cell ... rich tissue. Ocular conditions such as pinguecula and pterygium may occur due to the result of this increased exposure to SUVR in limal area, but it is not the only cause of pterygium formation. References Eye {{eye-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ultraviolet
Ultraviolet radiation, also known as simply UV, is electromagnetic radiation of wavelengths of 10–400 nanometers, shorter than that of visible light, but longer than X-rays. UV radiation is present in sunlight and constitutes about 10% of the total electromagnetic radiation output from the Sun. It is also produced by electric arcs, Cherenkov radiation, and specialized lights, such as mercury-vapor lamps, tanning lamps, and black lights. The photons of ultraviolet have greater energy than those of visible light, from about 3.1 to 12 electron volts, around the minimum energy required to ionize atoms. Although long-wavelength ultraviolet is not considered an ionizing radiation because its photons lack sufficient energy, it can induce chemical reactions and cause many substances to glow or fluoresce. Many practical applications, including chemical and biological effects, are derived from the way that UV radiation can interact with organic molecules. The ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Human Eye
The human eye is a sensory organ in the visual system that reacts to light, visible light allowing eyesight. Other functions include maintaining the circadian rhythm, and Balance (ability), keeping balance. The eye can be considered as a living optics, optical device. It is approximately spherical in shape, with its outer layers, such as the outermost, white part of the eye (the sclera) and one of its inner layers (the pigmented choroid) keeping the eye essentially stray light, light tight except on the eye's optic axis. In order, along the optic axis, the optical components consist of a first lens (the cornea, cornea—the clear part of the eye) that accounts for most of the optical power of the eye and accomplishes most of the Focus (optics), focusing of light from the outside world; then an aperture (the pupil) in a Diaphragm (optics), diaphragm (the Iris (anatomy), iris—the coloured part of the eye) that controls the amount of light entering the interior of the eye; then an ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Eye Care Professional
An eye care professional is an individual who provides a service related to the eyes or vision. It is any healthcare worker involved in eye care, from one with a small amount of post-secondary training to practitioners with a doctoral level of education. Types Ophthalmologist Ophthalmology ( /ˌɒfθælˈmɒlədʒi/ ''OFF-thal-MOL-ə-jee'') is a surgical subspecialty within medicine that handles the diagnosis and treatment of eye disorders. Ophthalmologists are physicians (M.D./D.O/have a doctorate in medicine) that undergo subspecialty training in medical and surgical eye care. To become an ophthalmologist the provider must first become a physician. To become a physician, after college they must go through 4 years of medical and surgical training where they are extensively educated in treating all parts of the human anatomy, including the eye. Their training includes, but is not limited to, coursework (classroom, clinical, and community experiences) that covers science, the lat ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Laser Photocoagulation
Laser coagulation or laser photocoagulation surgery is used to treat a number of eye diseases and has become widely used in recent decades. During the procedure, a laser is used to finely cauterize ocular blood vessels to attempt to bring about various therapeutic benefits. The procedure is used mostly to close blood vessels in the eye, in certain kinds of diabetic retinopathy; it is no longer used in age-related macular degeneration in favor of anti-VEGF drugs. Medical uses Diabetic retinopathy The American Academy of Ophthalmology practice guidelines recommend laser coagulation for people who have both mild to moderate nonproliferative diabetic retinopathy (NPDR) and clinically significant macular edema outside the fovea; treatment with anti-VEGF drugs is better than laser coagulation for clinically significant macular edema in the fovea. For people with severe NPDR and no macular edema, the AAO recommends laser photocoagulation for the whole retina; when there is macular ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Topical Steroid
Topical steroids are the topical forms of corticosteroids. Topical steroids are the most commonly prescribed topical medications for the treatment of rash and eczema. Topical steroids have anti-inflammatory properties and are classified based on their skin vasoconstrictive abilities. There are numerous topical steroid products. All the preparations in each class have the same anti-inflammatory properties but essentially differ in base and price. Side effects may occur from sudden discontinuation and prolonged, continuous use can lead to skin thinning. Intermittent use of topical steroids for atopic dermatitis is safe and does not cause skin thinning. Medical uses Weaker topical steroids are utilized for thin- skinned and sensitive areas, especially areas under occlusion, such as the armpit, groin, buttock crease, and breast folds. Weaker steroids are used on the face, eyelids, diaper area, perianal skin, and intertrigo of the groin or body folds. Moderate steroids are used fo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Contact Lens
Contact lenses, or simply contacts, are thin lenses placed directly on the surface of the eyes. Contact lenses are ocular prosthetic devices used by over 150 million people worldwide, and they can be worn to correct vision or for cosmetic or therapeutic reasons. In 2010, the worldwide market for contact lenses was estimated at $6.1 billion, while the US soft lens market was estimated at $2.1 billion.Nichols, Jason J., et a"ANNUAL REPORT: Contact Lenses 2010" January 2011. Multiple analysts estimated that the global market for contact lenses would reach $11.7 billion by 2015. the average age of contact lens wearers globally was 31 years old, and two-thirds of wearers were female.Morgan, Philip B., et al"International Contact Lens Prescribing in 2010" ''Contact Lens Spectrum''. October 2011. People choose to wear contact lenses for many reasons. Aesthetics and cosmetics are main motivating factors for people who want to avoid wearing glasses or to change the appearance or ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cosmesis
Cosmesis is the preservation, restoration, or bestowing of bodily beauty.'' Dorland's Medical Dictionary''. 25th ed. Philadelphia: W.B. Saunders Co.; 1995 In the medical context, it usually refers to the surgical correction of a disfiguring defect, or the cosmetic improvements made by a surgeon following incisions. Its use is generally limited to the additional, usually minor, steps that the surgeon (who is generally operating for noncosmetic indications) takes to improve the aesthetic appearance of the scars associated with the operation. Typical actions include removal of damaged tissue, mitigation of tension on the wound, and/or using fine (thin) sutures to close the outer layer of skin. Cosmetic surgery is the portion of plastic surgery that concerns itself with the elective improvement of cosmesis. Prosthetic limbs The practice of cosmesis, the creation of lifelike limbs made from silicone or PVC, has grown in popularity. Such prosthetics, such as artificial hands, can n ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Artificial Tears
Artificial tears are lubricating eye drops used to relieve dryness and irritation of the ocular surface. Dry eye syndrome ( keratoconjunctivitis sicca) is a common ocular surface disorder and is characterized by disruption of the tear film and increased inflammation. The tear film coats the surface of the eye and is composed of 3 layers: an aqueous, lipid, and mucous layer. The aqueous layer consists of a mixture of electrolytes, enzymes, antibodies, antimicrobial proteins, and other compounds. The lipid layer consists of fatty compounds that are responsible for decreasing evaporation of the tear film. The mucous layer contains mucins, gelatinous glycoproteins, which allow for an even distribution of the tear film over the corneal surface and decreased friction during blinking. Artificial tears are used to supplement a patient's naturally-produced tears and increase eye lubrication by mimicking characteristics of the tear film. Artificial tears can be supplemented with ot ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Malignancy
Malignancy () is the tendency of a medical condition to become progressively worse; the term is most familiar as a characterization of cancer. A ''malignant'' tumor contrasts with a non-cancerous ''benign'' tumor in that a malignancy is not self-limited in its growth, is capable of invading into adjacent tissues, and may be capable of spreading to distant tissues. A benign tumor has none of those properties, but may still be harmful to health. The term benign in more general medical use characterizes a condition or growth that is not cancerous, i.e. does not spread to other parts of the body or invade nearby tissue. Sometimes the term is used to suggest that a condition is not dangerous or serious. Malignancy in cancers is characterized by anaplasia, invasiveness, and metastasis. Malignant tumors are also characterized by genome instability, so that cancers, as assessed by whole genome sequencing, frequently have between 10,000 and 100,000 mutations in their entire genomes. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
