Astigmatism after Cataract Surgery using Various Wound Sizes, Configurations, and Suture Techniques

ABSTRACT

We performed a retrospective review of three hundred and twelve consecutive patients who underwent phacoemulsification and posterior chamber lens implantation between January 1, 1990 and December 31, 1990. Patients were divided into three groups according to the wound size 3.5 - 4.0 mm(95 patients); 5.0 - 5.5mm(74 patients) and 6.5 - 7.0mm(143 patients). The patients in the 3.5 to 4.0mm did not receive suture and the patients in the 5.0 to 5.5mm wound size received one horizontal suture. The patients in the 6.5 to 7.0mm group were further evaluated by comparing those who received two horizontal sutures with those who received a running shoelace suture. At one day, one week, one month, and one year after surgery, astigmatic error was measured and a vector analysis calculation of diopters of mean induced keratometric astigmatism was performed. There was a statistically significant increase in astigmatism following 6.5 to 7.0mm incision as compared to 3.5 to 5.5mm incision at each time interval. There was no significant difference in astigmatism at any time period between the 5.0 to 5.5mm and 3.5 to 4.0mm incision groups. The longer the incision, the greater the postoperative against-the-rule astigmatic shift at the last follow up. Among those of 6.5 - 7.0 wound size, the shoelace suture technique induced greater with-the-rule astigmatic change than two horisontal sutures at postoperative day one but the difference did no longer persist at one year.