AIM:To study the changes of tear film and ocular surface after the coaxial incision 2.5mm and 3.0mm in the phacoemulsification.

METHODS: Seventy patients(92 eyes)from February 2015 to February 2016 in our hospital were enrolled. The patients were randomly divided into two groups. Thirty-four patients(46 eyes)in Group A: coaxial 2.5mm incision phacoemulsification cataract extraction and intraocular lens(IOL)implantation. Thirty-six patients(46 eyes)in Group B: the conventional coaxial 3.0mm small incision phacoemulsification cataract extraction and IOL implantation. The break up time(BUT), Schirmer's Ⅰ test(SⅠt)and lid-parallel conjunctival folds(LIPCOF)were assessed preoperatively and postoperatively.

RESULTS: At 1wk, 1 and 3mo postoperatively, the BUT in two groups decreased after operations, and the BUT of Group B was significantly lower than those of Group A, the differences were statistically significant(t=3.089, 4.497, 4.322; all P<0.05). The SⅠt in two groups increased after operations, the SⅠt of Group B was significantly higher than those of Group A and the differences were statistically significant(t=-6.286, -3.992, -3.278; all P<0.05). The LIPCOF score in two groups increased after operations, the LIPCOF score of Group B was significantly higher than those of Group A and the differences were statistically significant(t=-6.552, -5.131, -3.652; all P<0.05). At 6mo postoperatively, compared with the preoperative data, the BUT, SⅠt and LIPCOF score in Group A showed no statistically significant differences(t=0.646, 0.551, 0.165; P>0.05). The BUT, SⅠt and LIPCOF score in Group B showed statistically significant differences(t=-4.059, 3.629, 4.211; all P<0.05).

CONCLUSION: Ocular surface has less damage and tear film has little influence at early stage after the coaxial 2.5mm incision phacoemulsmcation, compared with the conventional coaxial 3.0mm incision phacoemulsification surgery.