[Optical quality after 2.2mm microincisional cataract surgery with bimanual I/A in 154 eyes]

A prospective study to analyze the effects of 2.2mm microincisional coaxial phacoemulsification with bimanual irrigation/aspiration on the optical quality of the cornea and whole eye.

We compare two groups. Group A: 102 consecutive eyes undergoing this three-incision procedure and implanted with an Alcon® SN60WF IQ aspheric intraocular lens. Astigmatism, corneal and total asphericity, as well as H/B ratio were measured by OPD scann II, Nidek®, Japan, preoperatively (Day 0), 15 days postoperatively (Day 15) and 1 month postoperatively (M1). Group B: 52 eyes with corneal astigmatism greater than 1.25D, undergoing the same procedure but implanted with a Toric IOL (Alcon® Toric IQ SN6AT), followed in the same manner but with additional follow-up at 1 year.

Corneal surgically induced astigmatism (SIA) was essentially neutral: 0.065D ± 0.86 at Day 30 in group A, and 0.06D ± 0.34 at 1 month and -0.008D ± 0.4 at 12 months in group B. Corneal topographic astigmatism underwent a mean axis shift of 29.95° ± 27.6 in group A compared to 5.3° ± 3.7 in Group B, and remained stable at 1 year. Corneal asphericity did not change significantly between Day 0 and 30 in either group. H/B ratio increased significantly in both groups, with a gain of 22 % to 24 % after surgery.

This three-incision procedure does not degrade the optical quality of the cornea. Postoperative shift in the axis of astigmatism is only an issue in cases of low or asymmetric astigmatism and must be kept in mind for low-power toric IOL implantation.