A better understanding of pterygia.Pterygia are cloudy growths that creep out onto the front of the eye, block light, and lead to blindness if untreated. The condition occurs most often among outdoor workers and affects more than 10 percent of people who live in the tropics. Now, cell biologist Ted W. Reid of Texas Tech University in Lubbock has found that the disease arises when p53 genes in surface cells of the cornea mutate mu·tate intr. & tr.v. mu·tat·ed, mu·tat·ing, mu·tates To undergo or cause to undergo mutation. [Latin m in response to ultraviolet light. The mutated genes fail to regulate programmed cell death pro·grammed cell death n. See apoptosis. programmed cell death proposed system of cell death, often including poly(ADP)-ribosylation, ensures that a cell will not survive if it is so badly damaged that its recovery would harm the . Damaged cells that would normally be sloughed off migrate to the outer cornea, forming a pterygium pterygium /pte·ryg·i·um/ (te-rij´e-um) pl. ptery´gia [Gr.] a winglike structure, especially an abnormal triangular fold of membrane in the interpalpebral fissure, extending from the conjunctiva to the cornea. . Pterygia arise on the side of the eye nearer the nose because sunlight entering the eye from the other side is magnified 20 times by the cornea as it passes through. The nose blocks most of the light coming from the opposite direction. Pterygia can be removed surgically, but they tend to regrow Re`grow´ v. i. & t. 1. To grow again. The snail had power to regrow them all [horns, tongue, etc.] - A. B. Buckley. Verb 1. much more quickly than they grew originally. Reid says that to thwart regrowth Re`growth´ n. 1. The act of regrowing; a second or new growth. The regrowth of limbs which had been cut off. - A. B. Buckley. , surgeons should remove a larger margin of cells around the pterygium during the operation. People exposed to lots of sunlight should wear hats and sunglasses, he adds. |
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