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Trabeculoplasty
Trabeculoplasty is a laser treatment for glaucoma. It is done on an argon laser equipped slit lamp, using a Goldmann gonioscope lens mirror. Specifically, argon laser is used to improve drainage through the eye's trabecular meshwork, from which the aqueous humour drains. This helps reduce intraocular pressure caused by open-angle glaucoma. Research The LiGHT trial compared the effectiveness of eye drops and selective laser trabeculoplasty for open angle glaucoma. Both contributed to a similar quality of life but most people undergoing laser treatment were able to stop using eye drops. Laser trabeculoplasty was also shown to be more cost-effective.; See also * Laser surgery * Eye surgery * 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 all ... References Eye s ... [...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] |
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] |
Aqueous Humour
The aqueous humour is a transparent water-like fluid similar to plasma, but containing low protein concentrations. It is secreted from the ciliary body, a structure supporting the lens of the eyeball. It fills both the anterior and the posterior chambers of the eye, and is not to be confused with the vitreous humour, which is located in the space between the lens and the retina, also known as the posterior cavity or vitreous chamber. Blood cannot normally enter the eyeball. Structure Composition *Amino acids: transported by ciliary muscles *98% water *Electrolytes ( pH = 7.4 -one source gives 7.1) **Sodium = 142.09 **Potassium = 2.2 - 4.0 **Calcium = 1.8 **Magnesium = 1.1 **Chloride = 131.6 **HCO3- = 20.15 **Phosphate = 0.62 ** Osm = 304 *Ascorbic acid *Glutathione *Immunoglobulins Function *Maintains the intraocular pressure and inflates the globe of the eye. It is this hydrostatic pressure that keeps the eyeball in a roughly spherical shape and keeps the walls of the eyeball ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Intraocular Pressure
Intraocular pressure (IOP) is the fluid pressure inside the eye. Tonometry is the method eye care professionals use to determine this. IOP is an important aspect in the evaluation of patients at risk of glaucoma. Most tonometers are calibrated to measure pressure in millimeters of mercury ( mmHg). Physiology Intraocular pressure is determined by the production and drainage of aqueous humour by the ciliary body and its drainage via the trabecular meshwork and uveoscleral outflow. The reason for this is because the vitreous humour in the posterior segment has a relatively fixed volume and thus does not affect intraocular pressure regulation. An important quantitative relationship (Goldmann's equation) is as follows: :P_o = \frac + P_v Where: * P_o is the IOP in millimeters of mercury (mmHg) * F the rate of aqueous humour formation in microliters per minute (μL/min) * U the resorption of aqueous humour through the uveoscleral route (μL/min) * C is the facility of outflow in micr ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Laser Surgery
Laser surgery is a type of surgery that uses a laser (in contrast to using a scalpel) to cut tissue. Examples include the use of a laser scalpel in otherwise conventional surgery, and soft-tissue laser surgery, in which the laser beam vaporizes soft tissue with high water content. Laser surgery is commonly used on the eye. Techniques used include LASIK, which is used to correct near and far-sightedness in vision, and photorefractive keratectomy, a procedure which permanently reshapes the cornea using an excimer laser to remove a small amount of the human tissue. Types of surgical lasers include carbon dioxide, argon, Nd:YAG laser, and potassium titanyl phosphate, among others. Effects # Photochemistry, Photochemical effect: clinically referred to as photodynamic therapy. Photosensitizer (photophrin II) is administered which is taken up by the tumor tissue and later irradiated by laser light resulting in highly toxic substances with resultant necrosis of the tumor. Phot ... [...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] |
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] |
