| Excimer laser in situ keratomileusis is a new type of cornea refractive operation,It is less painful ,and curative effect is significant, it has been fond of more and more myopia patients and has got a satisfactory indication. But there are some correlated complication to effect patients, visual indication. recent years phthalmia-ter gradually aware that the change of ac-commodation is important in the postop effect. Althou-gh bulk patients,ocellanae naked visual acuity is really well after LASIK, but, some patients feel asthenopia when they work in a short distance.Even some of them has been effected in quality of life. So we should measure each regulating function seriously before operation. During the operation, we should think over syntheticly the practice working distance, amount of reserve and the demand of watching distance, design the operative project reasonably.Cornea as one of the important part of refective systerm, it has 3/4 refective ability of the whole eyes. The curvature of cornea, the thickness of cornea, and any change of the cornea all can effect the eye's refective ability, and effect the quality imaging on the retina consequently.The basic principle of cornea refective operation is changing the cornea ability by any way to change vergency of the light as getting across the cornea,making the parallel light to focalize on fovea centralis of retina after passing the refective systerm ,so to rectify refective error. LASIK operation will change the refective status, the adjustment and the aggregation. In order to get perfect visual effect, the actual and exact diopter examination before the operation plays an very impotant role to the effect of the operation.The study also found that after the operation the visual aculty of some patients were more than 1.0, but the result of the optometry were not perfect, some even were -4,25D. The reason may be after the operation the ability the adjustment abnormally increasing or the hyperkinesia of adjustment, the change of the size of the pupil, the unspherical change of the surface of the cornea and etc affct the aculty of the optometry. A-ccording to the error of computer optometry uni,we think about the problem of the measure of the tension of eyeball after the operation.Now, both in and out the country all consider that the the tension of eyeball will become low after the operation, and also get the correcting formula for caculating the tension of eyeball after the operation. the design of computer optometry uni is according to the sphere, but the cornea change to be unspherical after the operation. Then is there a problem about correcting count such as the tension of eyeball? It needs a lot of observation and study to get a exact reasonal and satisfying result.There are a lot of articles about the syndrome both in and after the operation and the change of the optic fuction, but there are less report about the effect to the adjustment, the aggregation of the eyes. So in this article,we observed the change of the refective status and adjustment both before and after the LASIK operation and also the ratio of AC and C, in order to study the change of the parameter after the LASIK operation and the relation of the each other.Objective: To find out the effect of laser in situ keratomileusis (LASIK) on eye accommodation and Refractive status.Methods: This is a prospective clinical study. one hundred and eighteen myopic patients (two hundred and thirty-six eyes) wh underwent myopic LASIK were in cluded in this study were divided into five groups (before-LASIK, one month after LASIK, three months after LASIK, six months after LASIK ,one year after LASIK). According to pre - operative refractive status, The subject wore correcting lens according to their refractive error. First, optometry by computer with TOPCON KP-8100 unit was performed; then, Mydrin-P was used to disperse pupil ,and optometry by computer with TOPCON KP-8100.Preoperatively and post operatively, uncorrected visual acuity (UCVA), best corrected visual acuity (BCVA), spherical equivalent (SE) , AC/A, and aberrations were detected on each patient.Results: 1. THE discrepancy of Sph degree is significant between large pupil and normal pupil before LASIK. (p<0.01), all Sph degree diminished after mydriasis. Astigmatism and axial direction is not significant (P>0.05). 2. The discrepancy of result of computer refraction between large pupil and normal pupil is significant in 1,3, 6,12 month after operation (P<0.01)。3. Visual acuity≥1.0after LASIK,But computer refraction is not well, all sph. degree diminished after mydriasis. 4. The chang of computer refraction, numerus between large pupil and normal pupil in 1,3,6,12 month after operation compare respectively the chang before operation, the discre-pancy of equipotent Sph degree is significant (p<0.01). 5. To compare the ratio of A/C 1month, 3month, 6month and 12 month after the operation separately, the result had notable discrepancy (p<0.01).Conclusion:1. mydriasis has a large effect to the sph.diopter, has little effect to astigmatism and axial direction.2. It shows that there is adjustment problem after the operation, we can't only use the result of the optometry at normal pupil as the standard to judge dioptric deinsufficience and excess.3. After the operation, the patients'visual acuity≥1.0, but the optometry shows negative. It become the ability the adjustment abnormally increasing or the hyperkinesia of adjustment in parts of the patients, and also have the relation with the optometry error and the different size of the pupil. So we can't use the visual acuity (≥1.0) as the standard to judge the refective status and the effect of the operation by rote.4. After the LASIK operation, the adjustment of the myopia eyes increased, the adjustment lag reduced, the adjustment were more exact, the quality of the imaging on the retina was improved. 5. The ratio of AC/A become lower after the LASIK operation.
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