AIM: To evaluate the effect of 2.2mm micro-incision coaxial phacoemulsification on corneal astigmatism and surgically induced astigmatism(SIA).

METHODS: Fifty-six cataract patients(78 eyes)were randomized into two groups: 38 eyes in the 2.2mm incision group and 40 eyes in the 3.0mm group. Torsional phacoemulsification was followed. Corneal astigmatism, SIA and uncorrected distance visual acuity(UCVA)were assessed at 30 and 90 days after cataract surgery.

RESULTS:One month postoperatively, the corneal astigmatism of the 2.2mm group was 0.85±0.42D and the 3.0mm group was 1.18±0.37D. Three months postoperatively, the corneal astigmatism of the 2.2mm group was 0.74±0.40D and the 3.0mm group was 1.00±0.30D. One month and 3 months postoperatively, SIA of the 3.0mm group was greater than SIA of the 2.2mm group(P<0.05). In the 3.0mm group, mean SIA at 1 month was greater than SIA at 3 months(P<0.05), but SIA was similar. There was no statistical significance between the mean SIA between 1 month and 3 months. Postoperative UCVA was better in the 2.2mm group at both 1 month and 3 months postoperatively.

CONCLUSION: 2.2mm micro-incision coaxial phacoemulsification contributed to postoperative corneal astigmatism. When incision size was reduced, SIA was reduced, refractive stabilization was faster and UCVA was better.