AIM: To investigate the effect of endocapsular phacoemulsification cataract extraction and intraocular lens(IOL)implantation with a 1.8mm or 3.0mm clear corneal incision on total root mean square(RMS)value of the cornea, corneal astigmatism, spherical aberration, coma, trefoil and tear film.

METHODS:In a prospective study, 156 age-related patients(196 eyes)were randomly distributed into two groups. 1.8mm-group comprised 94 eyes that had a silicone IOL inserted through a 1.8mm sutureless clear corneal incision, while, 3.0mm-group comprised 102 eyes through a 3.0mm clear corneal incision. Postoperatively, the changes in the total RMS value of the cornea, corneal astigmatism, spherical aberration, coma, trefoil and tear film at 1wk, 1 and 3mo were determined respectively.

RESULTS: In both groups, postoperatively at 1wk,there were statistically significant differences(P<0.05)in the total RMS value of the cornea, corneal astigmatism, spherical aberration, coma, trefoil and tear film, while, there were statistically minimal differences(P<0.05)between 1.8mm-group and 3.0mm-group at 1mo, but were not statistically significantly different(P>0.05)between two groups at 3mo postoperative.

CONCLUSION:This study confirms that incision size has strong impact on the corneal higher-order aberrations, especially, 3.0mm incision caused significant differences in the total RMS value of cornea, corneal astigmatism, spherical aberration, coma, trefoil and tear film compared with 1.8mm micro-incision, therefore, micro-incision is very beneficial for clinical use in phacoemulsification.