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Trabeculectomy
Trabeculectomy is a surgical procedure used in the treatment of glaucoma to relieve intraocular pressure by removing part of the human eye, eye's trabecular meshwork and adjacent structures. It is the most common glaucoma surgery performed and allows drainage of aqueous humor from within the eye to underneath the conjunctiva where it is absorbed. This outpatient procedure was most commonly performed under monitored anesthesia care using a retrobulbar block or peribulbar block or a combination of topical and subtenon (Tenon's capsule) anesthesia. Due to the higher risks associated with bulbar blocks, topical analgesia with mild sedation is becoming more common. Rarely general anesthesia will be used, in patients with an inability to cooperate during surgery. Procedure An initial pocket is created under the conjunctiva and Tenon's capsule and the wound bed is treated for several seconds to minutes with mitomycin C (MMC, 0.5–0.2 mg/ml) or 5-fluorouracil (5-FU, 50 mg/ml) ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Trabectome
The Trabectome is a surgical device that can be used for ab interno trabeculotomy, a minimally invasive glaucoma surgery for the surgical management of adult, juvenile and infantile glaucoma. The trabecular meshwork is a major site of resistance to aqueous humor outflow. As angle surgeries such as Trabectome follow the physiologic outflow pathway, the risk of complications is significantly lower than filtering surgeries. Hypotony with damage to the macula (hypotony maculopathy), can occur with pressures below 5 mmHg for instance after traditional trabeculectomy, because of the episcleral venous pressure limit. The Trabectome handpiece is inserted into the anterior chamber, its tip positioned into Schlemm's canal, and advanced to the left and to the right. Different from cautery, the tip generates plasma to molecularize the trabecular meshwork and remove it drag-free and with minimal thermal effect. Active irrigation of the trabectome surgery system helps to keep the anterior chambe ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Glaucoma
Glaucoma is a group of eye diseases that result in damage to the optic nerve (or retina) and cause vision loss. The most common type is open-angle (wide angle, chronic simple) glaucoma, in which the drainage angle for fluid within the eye remains open, with less common types including closed-angle (narrow angle, acute congestive) glaucoma and normal-tension glaucoma. Open-angle glaucoma develops slowly over time and there is no pain. Peripheral vision may begin to decrease, followed by central vision, resulting in blindness if not treated. Closed-angle glaucoma can present gradually or suddenly. The sudden presentation may involve severe eye pain, blurred vision, mid-dilated pupil, redness of the eye, and nausea. Vision loss from glaucoma, once it has occurred, is permanent. Eyes affected by glaucoma are referred to as being glaucomatous. Risk factors for glaucoma include increasing age, high pressure in the eye, a family history of glaucoma, and use of steroid medication. F ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Glaucoma Surgery
Glaucoma is a group of diseases affecting the optic nerve that results in vision loss and is frequently characterized by raised intraocular pressure (IOP). There are many glaucoma surgeries, and variations or combinations of those surgeries, that facilitate the escape of excess aqueous humor from the eye to lower intraocular pressure, and a few that lower IOP by decreasing the production of aqueous humor. Procedures that facilitate outflow of aqueous humor Laser trabeculoplasty A trabeculoplasty is a modification of the trabecular meshwork. Laser trabeculoplasty (LTP) is the application of a laser beam to burn areas of the trabecular meshwork, located near the base of the iris, to increase fluid outflow. LTP is used in the treatment of various open-angle glaucomas. The two types of laser trabeculoplasty are argon laser trabeculoplasty (ALT) and selective laser trabeculoplasty (SLT). As its name suggests, argon laser trabeculoplasty uses an argon laser to create tiny burns on the t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Glaucoma Valve
A glaucoma valve is a medical shunt used in the treatment of glaucoma to reduce the eye's intraocular pressure (IOP). Mechanism The device works by bypassing the trabecular meshwork and redirecting the outflow of aqueous humour through a small tube into an outlet chamber or bleb. The IOP generally decreases from around 33 to 10 mmHg by removing aqueous on average 2.75 microliters/min. Types The first glaucoma drainage implant was developed in 1966. Following on the success of the Molteno implant, several varieties of device have been developed from the original, the Baerveldt tube shunt, or the valved implants, such as the Ahmed glaucoma valve implant and the later generation pressure ridge Molteno implants. These are indicated for glaucoma patients not responding to maximal medical therapy, with previous failed guarded filtering surgery (trabeculectomy). The flow tube is inserted into the anterior chamber of the eye and the plate is implanted underneath the conjunctiva to all ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Peter Gordon Watson
Peter Gordon Watson (30 April 1930 – 31 January 2017) was a British ophthalmologist, professor and researcher better known as the inventor of surgical procedure trabeculectomy. With John Cairns, in the 1970s, Watson developed trabeculectomy, the most common form of surgery for glaucoma today. His 1977 textbook, ''The Sclera and Systemic Disorders'' (third edition published in 2012) is still considered the only comprehensive textbook on disease of the sclera. Biography Peter Gordon Watson was born on April 30, 1930, in Newport, Wales, United Kingdom, the son of Ralph and Renée née Smith. He studied and trained in ophthalmology at University College Hospital, London, Moorfields Eye Hospital, London and the Institute of Ophthalmology. Watson held several positions including president of the Academia Ophthalmology Internationalis, member of the International Council of Ophthalmology, Editor of ''Eye'' magazine, Founder and Chair of the Cambridge Eye Trust, and Deputy Hospitaller ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Eye Surgery
Eye surgery, also known as ophthalmic or ocular surgery, is surgery performed on the eye or its adnexa, by an ophthalmologist or sometimes, an optometrist. Eye surgery is synonymous with ophthalmology. The eye is a very fragile organ, and requires extreme care before, during, and after a surgical procedure to minimize or prevent further damage. An expert eye surgeon is responsible for selecting the appropriate surgical procedure for the patient, and for taking the necessary safety precautions. Mentions of eye surgery can be found in several ancient texts dating back as early as 1800 BC, with cataract treatment starting in the fifth century BC. Today it continues to be a widely practiced type of surgery, with various techniques having been developed for treating eye problems. Preparation and precautions Since the eye is heavily supplied by nerves, anesthesia is essential. Local anesthesia is most commonly used. Topical anesthesia using lidocaine topical gel is often used fo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Trabecular Meshwork
The trabecular meshwork is an area of tissue in the eye located around the base of the cornea, near the ciliary body, and is responsible for draining the aqueous humor from the eye via the anterior chamber (the chamber on the front of the eye covered by the cornea). The tissue is spongy and lined by trabeculocytes; it allows fluid to drain into a set of tubes called Schlemm's canal which is lined by endothelium with blood and lymphatic properties that allow aqueous humor to flow into the blood system. Structure The meshwork is divided up into three parts, with characteristically different ultrastructures: #''Inner uveal meshwork'' - Closest to the anterior chamber angle, contains thin cord-like trabeculae, orientated predominantly in a radial fashion, enclosing trabeculae spaces larger than the corneoscleral meshwork. #''Corneoscleral meshwork'' - Contains a large amount of elastin, arranged as a series of thin, flat, perforated sheets arranged in a laminar pattern; cons ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
5-fluorouracil
Fluorouracil (5-FU), sold under the brand name Adrucil among others, is a cytotoxic chemotherapy medication used to treat cancer. By intravenous injection it is used for treatment of colorectal cancer, oesophageal cancer, stomach cancer, pancreatic cancer, breast cancer, and cervical cancer. As a cream it is used for actinic keratosis, basal cell carcinoma, and skin warts. Side effects of use by injection are common. They may include inflammation of the mouth, loss of appetite, low blood cell counts, hair loss, and inflammation of the skin. When used as a cream, irritation at the site of application usually occurs. Use of either form in pregnancy may harm the baby. Fluorouracil is in the antimetabolite and pyrimidine analog families of medications. How it works is not entirely clear, but it is believed to involve blocking the action of thymidylate synthase and thus stopping the production of DNA. Fluorouracil was patented in 1956 and came into medical use in 1962. It is on ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hypotony
Ocular hypotony, or ocular hypotension, or shortly hypotony, is the medical condition in which intraocular pressure (IOP) of the eye is very low. Description Normal IOP ranges between 10–20 mm Hg. The eye is considered hypotonous if the IOP is ≤5 mm Hg (some sources say IOP less than 6.5 mmHg). Types Ocular hypotony is divided into statistical and clinical types. If intraocular pressure is low (less than 6.5 mm Hg) it is called statistical hypotony, and if the reduced IOP causes a decrease in vision, it is called clinical. Causes Hypotony may occur either due to decreased production of aqueous humor or due to increased outflow. Hypotony has many causes including post-surgical wound leak from the eye, chronic inflammation within the eye including iridocyclitis, hypoperfusion, tractional ciliary body detachment or retinal detachment. Eye inflammation, medications including anti glaucoma drugs, or proliferative vitreoretinopathy causes decreased production. Increased outflow or ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ciliary Body
The ciliary body is a part of the eye that includes the ciliary muscle, which controls the shape of the lens, and the ciliary epithelium, which produces the aqueous humor. The aqueous humor is produced in the non-pigmented portion of the ciliary body. The ciliary body is part of the uvea, the layer of tissue that delivers oxygen and nutrients to the eye tissues. The ciliary body joins the ora serrata of the choroid to the root of the iris.Cassin, B. and Solomon, S. ''Dictionary of Eye Terminology''. Gainesville, Florida: Triad Publishing Company, 1990. Structure The ciliary body is a ring-shaped thickening of tissue inside the eye that divides the posterior chamber from the vitreous body. It contains the ciliary muscle, vessels, and fibrous connective tissue. Folds on the inner ciliary epithelium are called ciliary processes, and these secrete aqueous humor into the posterior chamber. The aqueous humor then flows through the pupil into the anterior chamber. The ciliary bo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cochrane (organisation)
Cochrane (previously known as the Cochrane Collaboration) is a British international charitable organisation formed to organise medical research findings to facilitate evidence-based choices about health interventions involving health professionals, patients and policy makers. It includes 53 review groups that are based at research institutions worldwide. Cochrane has approximately 30,000 volunteer experts from around the world. The group conducts systematic reviews of health-care interventions and diagnostic tests and publishes them in the Cochrane Library. According to the Library, articles are available via one-click access, but some require paid subscription or registration before reading. A few reviews, in occupational health for example, incorporate results from non-randomised observational studies as well as controlled before–after (CBA) studies and interrupted time-series studies. History Cochrane, previously known as the Cochrane Collaboration, was founded in 1 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Endophthalmitis
Endophthalmitis is inflammation of the interior cavity of the eye, usually caused by infection. It is a possible complication of all intraocular surgeries, particularly cataract surgery, and can result in loss of vision or loss of the eye itself. Infection can be caused by bacteria or fungi, and is classified as exogenous (infection introduced by direct inoculation as in surgery or penetrating trauma), or endogenous (organisms carried by blood vessels to the eye from another site of infection). Other non-infectious causes include toxins, allergic reactions, and retained intraocular foreign bodies. Intravitreal injections are a rare cause, with an incidence rate usually less than .05%. Signs and symptoms There is usually a history of recent eye surgery or penetrating trauma to the eye. Symptoms include severe pain, vision loss, and intense redness of the conjunctiva. Hypopyon can be present and should be looked for on examination by a slit lamp. It can first present with the 'blac ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
