The comprehensive control of astigmatism during and following intraocular lens implantation

The operating corneoloscope and Terry operative keratometer were used respectively in 29 and 34 eyes during the intraocular lens implantation to measure the corneal astigmatism qualitatively or quantitatively, so that the tension of incision closure could be adjusted. The surgically induced astigmatism in qualitative group two weeks after the operation was 3.5 +/- 1.70 D and that in quantitative group was 2.56 +/- 1.60 D. There were 55.17% and 38.24% of the eyes with over 2.00 D corneal astigmatism in qualitative and quantitative group two months after the surgery. The astigmatism of both groups at the early stage after the operation was significantly lower than that of the control group (p < 0.05). Argon laser, Nd:YAG laser or razor-blade were used to cut 1 to 3 limbal sutures in 64 eyes with over with-the-rule astigmatism 2.25 D at the early stage (2 months) after the operation. One hour after suture cutting, the with-the-rule corneal astigmatism reduced significantly with an average of 2.61 D. The astigmatism continued to reduce and stabilized one month after the suture cutting. The arcuate keratotomy was performed in 21 eyes, of which the postoperative astigmatism was over 2.25 D (with the average of 3.34 D) more than 6 months after IOL implantation. The mean astigmatism was 0.82 and 1.18 D one day and 6 months after the keratotomy respectively. The uncorrected visual acuity improved significantly after the keratotomy. These results indicate that applying corneoloscope or Terry keratometer to adjust the tension of incision closure during operations, selected suture cutting at the early postoperative stage, and performing arcuate keratotomy at the late postoperative stage be the effective methods to reduce surgically induced corneal astigmatism.