No abstract

Background: Complaints of glare, halos, and disturbances of night vision after photorefractive keratectomy (PRK) probably result from changes in the corneal aberration structure induced by the laser ablation procedure. The purpose of this article is to characterize changes in the corneal aberration structure after PRK and to demonstrate the effect of pupil dilation on these changes. Methods: Videokeratographs obtained preoperatively (n = 112) and at 1 (n = 94), 3 (n = 103), 6 (n = 91), 12 (n = 60), 18 (n = 53), and 24 (n = 44) months postoperatively from 112 eyes of 89 patients who had undergone PRK for myopia were analyzed. The data were used to calculate the wavefront variance of the cornea for both small (3-mm) and large (7-mm) pupils.

Iron absorption measurements have been made in 131 individuals relating the absorption of nine different foods tagged biosynthetically with radioiron. Relatively low absorption, ranging from 1.7-7.9, was found with wheat, corn, black beans, lettuce and spinach. Higher values of from 15.6-20.3 were observed with soybeans, fish, veal and hemoglobin. When these values were related to the absorption of ferrous ascorbate determined simultaneously in each subject, food iron absorption could be predicted over the spectrum of normal to iron deficient states.