The effects of surgical factors on postoperative astigmatism in patients enrolled in the Infant Aphakia Treatment Study (IATS)

Purpose To evaluate the effect of surgical factors on postoperative astigmatism in infants undergoing cataract extraction with or without intraocular lens (IOL) implantation. Methods The Infant Aphakia Treatment Study is a multicenter clinical trial in which 114 infants with unilateral congenital cataracts were randomized to undergo cataract extraction with IOL placement or contact lens aphakic correction. Surgical videos were reviewed with regard to incision type and location, whether the incision was extended, the number of sutures placed, and technique of closure. Corneal astigmatism was measured using a handheld keratometer prior to surgery and at 1 year of age. Results Corneal astigmatism decreased from a mean of 1.92 D at baseline to 1.62 D at age 1 year in the contact lens group but remained almost unchanged from 2.00 D to 2.09 D in the IOL group ( P = 0.023). There was no statistical difference between the amount of corneal astigmatism with regard to incision type ( P = 0.214) and no increase in astigmatism with extension of the incision to facilitate IOL placement ( P = 0.849) at 1 year. The number of sutures and technique of closure did not influence the amount of astigmatism at 1 year. Conclusions At the age of 1 year following cataract extraction in infants, contact lens correction and the lack of IOL placement are associated with a significant decrease in postoperative corneal astigmatism compared to IOL placement. No other surgical factors considered in this study had a statistically significant effect on corneal astigmatism.