 |
 |
 |
|
|||
|
|
|
|
|
Home | News | Links | How to Help | Contact Us | Search Patient Information: Glossary: Glossary of Terms
The eye's tears are composed of three layers: oil, water and mucus.
When tears lack the important components described above, or when too few tears are produced, the tear film can break down. This breakdown produces dry spots on the cornea, causing the symptoms associated with dry eye - a feeling of itchiness, grittiness, a burning sensation, and general discomfort. Click and ReadA-B-C-D-E-F-G-H-I-J-K-L-M-N-O-P-Q-R-S-T-U-V-W-X-Y-Z [Browse Terms] [Top] TONOMETER, APPLANATION TONOMETER
See, also, GLAUCOMA, GLAUCOMA AND UVEITIS A-B-C-D-E-F-G-H-I-J-K-L-M-N-O-P-Q-R-S-T-U-V-W-X-Y-Z [Browse Terms] [Top] The standard to determine the pressure inside the eye (intraocular pressure). The use of a device to measure the pressure in the eye. See, also, GLAUCOMA, GLAUCOMA AND UVEITIS A-B-C-D-E-F-G-H-I-J-K-L-M-N-O-P-Q-R-S-T-U-V-W-X-Y-Z [Browse Terms] [Top] Inflammation of the trabecular meshwork. A-B-C-D-E-F-G-H-I-J-K-L-M-N-O-P-Q-R-S-T-U-V-W-X-Y-Z [Browse Terms] [Top] 20/20 vision is a term used to express normal visual acuity (the clarity or sharpness of vision) measured at a distance of 20 feet. Someone with 20/20 vision can see clearly at 20 feet what should normally be seen at that distance. If a person has 20/100 vision, it means that they must be as close as 20 feet to see what a person with normal vision can see at 100 feet. 20/20 does not necessarily mean perfect vision. 20/20 vision only indicates the sharpness or clarity of vision at a distance. There are other important vision skills, including peripheral awareness or side vision, eye coordination, depth perception, focusing ability and color vision that contribute to your overall visual ability. Some people can see well at a distance, but are unable to bring nearer objects into focus. This condition can be caused by hyperopia (farsightedness) or presbyopia (loss of focusing ability). Others can see items that are close, but cannot see those far away. This condition may be caused by myopia (nearsightedness). A-B-C-D-E-F-G-H-I-J-K-L-M-N-O-P-Q-R-S-T-U-V-W-X-Y-Z [Browse Terms] [Top] TRABECULAR MESHWORK (truh-BEC-yoo-lur)
The trabecular meshwork is the spongy, mesh-like tissue surrounding the iris that allows the aqueous fluid (humor) to flow to Schlemm's canal then out of the eye through ocular veins. See, also, GLAUCOMA, GLAUCOMA AND UVEITIS A-B-C-D-E-F-G-H-I-J-K-L-M-N-O-P-Q-R-S-T-U-V-W-X-Y-Z [Browse Terms] [Top] TREATMENT ALGORITHM (ALGORITHM) A description of the steps recommended in the care of a particular disease. A "step-ladder" approach to intervention. Treatment guidelines are meant as general guidelines for physicians. A great deal of judgment and experience is required in applying such guidelines to the care of any particular individual patient. Treatment algorithms for ocular inflammatory disease have been developed by the Massachusetts Eye Research and Surgery Institution , in conjunction with the Ocular Immunology and Uveitis Foundation, in Boston. Click here to review these algorithms. A-B-C-D-E-F-G-H-I-J-K-L-M-N-O-P-Q-R-S-T-U-V-W-X-Y-Z [Browse Terms] [Top] UVEA, UVEAL TRACT (YOO-vee-uh)
Anteriorly, the iris controls the amount of light that reaches the retina, whereas the ciliary body is primarily responsible for aqueous humor production. The ciliary muscle changes the curvature of the lens through the fibers of the zonular ligament. This makes the lens thicker so the eye can focus on nearby objects and thinner so the eye can focus on distant objects. The choroid is the sole blood supply to the avascular outer part of the retina. The highly vascularized tissues of the choroid can be affected by systemic as well as local disease processes. In this diagram, the structures of the uvea are shown in red. A-B-C-D-E-F-G-H-I-J-K-L-M-N-O-P-Q-R-S-T-U-V-W-X-Y-Z [Browse Terms] [Top]
Inflammation of the uvea may occur as a consequence of diverse stimuli. These can be broadly classified according to the following mechanisms: traumatic, immunologic, infectious, and so-called masquerade. Uveitis may affect individuals of any age from infancy on. It also affects people from all parts of the world, and it is highly significant cause of blindness, accounting for 10-15% of all blindness in the United States. The average age (mean age) at presentation is approximately 40 years. Uveitis can affect people at virtually any age. Many patients in the pediatric age group, younger than 16 years, suffer devastating complications of uveitis. The peak age at onset of uveitis, in the third and fourth decades, magnifies the socioeconomic impact of uveitis on the individual and on the community. The incidence of uveitis in the United States is approximately 15 cases per 100,000 population per year, or a total of some 38,000 new cases per year. Anterior uveitis is the most common form of uveitis, followed by posterior or panuveitis, intermediate uveitis is the least common form but still comprises a significant number of cases (4% to 17% of all cases of uveitis). Facts about Uveitis:
The above-mentioned percentages and figures were obtained from a study of 1237 uveitis patients referred to the Uveitis and Immunology Service of the MEEI, Harvard Medical School, from 1982 to 1992. These figures were found to be similar to the results of other studies of tertiary referral centers from different parts of the world., especially those of developed countries. See, also, INFLAMMATION, IMMUNE SYSTEM, and AUTOIMMUNE DISEASE, OCULAR IMMUNOLOGIST, CELLS, FLARE, CLASSIFICATION OF UVEITIS, PEDIATRIC UVEITIS, JRA-ASSOCIATED UVEITIS, CELLS, and FLARE Click and ReadSELECT A HEALTH TOPIC: How to Find Medical Information OTHER LINKS OF INTEREST
A-B-C-D-E-F-G-H-I-J-K-L-M-N-O-P-Q-R-S-T-U-V-W-X-Y-Z [Browse Terms] [Top] UVEITIS SPECIALIST See, Ocular Immunologist Inflammation in the blood vessels. It may occur throughout the body. Click and ReadA-B-C-D-E-F-G-H-I-J-K-L-M-N-O-P-Q-R-S-T-U-V-W-X-Y-Z [Browse Terms] [Top] The ability to distinguish details and shapes of objects; also called central vision. A-B-C-D-E-F-G-H-I-J-K-L-M-N-O-P-Q-R-S-T-U-V-W-X-Y-Z [Browse Terms] [Top] The entire area that can be seen when the eye is forward, including peripheral vision. The ability to distinguish details and shapes of objects; also called central vision. A-B-C-D-E-F-G-H-I-J-K-L-M-N-O-P-Q-R-S-T-U-V-W-X-Y-Z [Browse Terms] [Top] VITRITIS (VIT-ree-itis)
See, also, CELLS, FLOATERS, INTERMEDIATE UVEITIS, and PARS PLANITIS. A-B-C-D-E-F-G-H-I-J-K-L-M-N-O-P-Q-R-S-T-U-V-W-X-Y-Z [Browse Terms] [Top] VITREOUS (VIT-ree-us)
Unlike the fluid in the front of the eye (aqueous fluid) which is continuously replenished, the gel in the vitreous chamber is stagnant. Therefore, if cells or other byproducts of inflammation get into the vitreous, they will remain there unless removed surgically (see floaters). If the vitreous pulls away from the retina, it is known as a vitreous detachment. As we age, the vitreous often liquefies and may collapse. This is more likely to occur, and occurs much earlier, in eyes that are nearsighted (myopia). It can also occurs after injuries to the eye or inflammation in the eye (uveitis). A-B-C-D-E-F-G-H-I-J-K-L-M-N-O-P-Q-R-S-T-U-V-W-X-Y-Z [Browse Terms] [Top] Vitrectomy is the surgical removal of the vitreous (transparent gel that fills the eye from the iris to the retina). Vitrectomy is a microsurgical procedure in which specialized instruments and techniques are used to repair retinal disorders and to treat intermediate uveitis. This is a major surgical procedure of the eye. A-B-C-D-E-F-G-H-I-J-K-L-M-N-O-P-Q-R-S-T-U-V-W-X-Y-Z [Browse Terms] [Top] VOGT-KOYANAGI-HARADA SYNDROME (VKH) Vogt-Koyanagi-Harada syndrome (VKH), formerly known as uveomenigitic syndrome, is a systemic disorder involving multiple organ systems, including the ocular, auditory, nervous, and integumentary systems. Severe bilateral panuveitis associated with exudative retinal detachment is the hallmark of ocular disease. The disease has worldwide distribution but has predilection for darkly pigmented races such as Asians, Hispanics, and Native Americans. In the United States, 44% in one series were blacks. VKH is uncommon in whites. It is a common cause of endogenous uveitis in Japan, constituting at least 8% of cases. This is also true for certain parts of Latin America, particularly Brazil. In the United States, it accounts for 1% to 4% of all uveitis referrals. Most patients are in the second to fifth decades of life at the onset of the disease. The inflammation is usually granulomatous. Although the exact etiology of VKH is unknown, the disease is thought to be a primarily inflammatory condition directed against melanin-containing cells or a common antigen expressed therein and shared by the skin, eye, meninges, and ear. Alternatively , some investigators have invoked a primary infectious etiology, and others postulate a microbe as initiating or triggering the autoimmune process. A-B-C-D-E-F-G-H-I-J-K-L-M-N-O-P-Q-R-S-T-U-V-W-X-Y-Z [Browse Terms] [Top] ZONULES (ZAHN-yoolz)
|
| Copyright © 1996-2008
C. Stephen Foster M.D. All Rights Reserved.
Disclaimer & Privacy Statement |
The function of tears is to bathe, lubricate, and nourish
the surface of the eye. Tears also contains antibodies that help protect
the eye from infection. Tears are produced by the 
The
uvea (from the Latin, uva or grape) is composed of 
The vitreous is the transparent, colorless, gelatinous mass
that fills the space between the 
The fibers (1) that hold the