摘要
AIM:To analyse the changes in magnitude and orientation of astigmatism after suture removal(SR)in keratoplasty eyes as measured by refraction,tomography,and aberrometry.METHODS:Twenty-six eyes of 25 patients after optical keratoplasty requiring SR to reduce the astigmatism during the follow-up period were prospectively included.Eyes with poor quality topography scans or if there were no sutures in the steepest semi meridian were excluded.Corrected distance visual acuity(CDVA),manifest refraction,corneal tomography and aberrometr y were per formed on all patients before and after SR.RESULTS:The mean age of the patients was 40.8±14.4 y.Penetrating keratoplasty was performed in 23 eyes(89%)and deep anterior lamellar keratoplasty was done in 3 eyes(11%).There was a statistically significant reduction in the magnitude of refractive,tomographic and aberrometry astigmatism after SR(P<0.001)at 2 h after suture removal.The mean net reduction of the astigmatism was greater as measured by corneal tomography compared to refractive astigmatism(P<0.05).There was no statistically significant change in refractive astigmatism between 2 h and 2 mo after SR(P=0.55).Vector calculations demonstrated a greater amount of undercorrection in the tomography group and the rotational error was more towards counterclockwise direction.Mean monocular log MAR CDVA improved from 0.57 D to 0.49 D after SR(P=0.002).CONCLUSION:The net reduction in the magnitude of astigmatism after SR is greater in the tomography and aberrometry groups.With one episode of SR,there is no difference in the aberration profile.