الفهرس 
INTRODUCTIONOnly 14 pages are availabe for public view
 |  | from | 94 |  |  |
| | | from | 94 | | |
Abstract
In correction of hypermetropia using LASIK surgery, an excimer laser is used to increase corneal refractive power by removing a ring of tissue in the midperipheral zone of the corneal stroma. The hyperopic ablation algorithm steepens the corneal profile compared to the preoperative pro¬file. Hyperopic laser-assisted in situ keratomileusis (LASIK) has been shown to induce higher- order aberrations (HOA) at a rate that is higher per corrected diopter than a similar group of myopic eyes. Higher order aberrations are a relatively small component, comprising about 10% of the eye’s total aberrations. Higher order aberrations increase with age and mirror symmetry exists between the right and the left eyes. There are numerous higher-order aberrations, of which only spherical aberration, coma and trefoil are of clinical interest. The induction of HOA will lead to distorted images, and leading to patients’ complaints of halos, glare and poor quality of vision even with visual acuity of 20/25 or 20/20, postoperatively. However, reduction in visual qual¬ity represents one of the limits to the amount of hyperopic refractive correction. The magnitude of hyperopic ablations is only up to +6 or +7 D.The hyperopic ablation shifts positive spherical aberra¬tion first towards zero before inducing a negative spherical aberration that would af¬fect the patients’ vision.This study was conducted on 30 eyes of 15 patients with hyperopic refractive error (between+1 to +6 diopters) with and without astigmatic error up to 4 diopters. Patients age ranging from 18 to 48 years. Preoperative uncorrected visual acuity testing (UCVA), best corrected visual acuity (BCVA) manifest refraction, cycloplegic refraction, attempted refraction (equal manifest refraction plus tow third the difference between manifest and cycloplegic refraction) and pentacam were done. Postoperative UCVA, BCVA and Manifest refraction were done at 1 month and 3 months post operatively. Pentacam and questionnaire were done at the third month visit after surgery to evaluate corneal higher order aberrations after hyperopic LASIK and their correlation to patient satisfaction. First, we measured the changes in high order aberration (coma, trefoil, and spherical aberrations) after hyperopic LASIK. Then, we tried to find a correlation between these changes and the scores of a specially designed questionnaire measuring patient satisfaction after the procedure.In our study, questionnaire was administered at the third month visit after surgery. The questions were designed to evaluate corneal higher order aberrations after hyperopic LASIK and their correlation to patient satisfaction we found that that when the negativity of spherical aberration increased the postoperative glare, ghosting, light sensitivity worsen postoperatively. 93.3% of patients satisfied with hyperopic lasik and 6.7% not satisfied. Patient satisfaction was not affected by mean change of horizontal and vertical coma or trefoil, but when the negativity of spherical aberration increased postoperatively the patient was not satisfied. We also found that 80% of patients will recommend LASIK to their frinds and family and 20% was be neutral