Analysis of corneal astigmatism after Laser in Situ Keratomileusis(LASIK)for compound myopic astigma-tism

Objective To investigate the 1 month to 6 months astigmatism of cornea after Laser in Situ Keratomileusis(LASIK)for compound myopic astigmatism. Methods A total of 65 patients(126 eyes)of compound myopic astigmatism were treated with laser in situ keratomileusis(LASIK).Preoperative and 1,3 and 6 months postoperative corneal topography were performed.The patients were divided into two groups by different diopter of cylindrical power:astigmatism of cornea in two groups were compared.Analysis the change of corneal astigmatism in different zone and different time by t test. Results Astigmatism decreased significantly in 3mm zone but partly uncorrected after LASIK,regression equation for uncorrected astigmatism in 3mm zone(D)=1 196*non-corneal astigmatism factor+1 117;Astigmatism lig ly increased in 5mm、7mm zones and recovered in 3～6 months postoperative.Astigmatism axis in 3mm、5mm、7mm zones were of no statistical significant different from preoperative to 6 months postoperative. Conclusions Decrease of astigmatism was shown significantly in 3mm zone after surgery and partly uncorrected astigmatism was significantly correlative with non corneal astigmatism factor.Astigmatism increase lig ly in 5mm、7mm zones in 1 months postoperative and recovered in 3～6 months postoperative.Astigmatism axis of corneal in different zones were stable from preoperative to 6 months postoperative.