The ASP group exhibited mean CCT , 756.7 m preoperatively and 914.8 m postoperatively ( p < 0.001 ) ; mean ET , 102.1 m preoperatively and 245.2 m postoperatively ( p < 0.001 ) ; and mean ST , 654.6 m preoperatively and 681.5 m postoperatively ( p < 0.999 ) .