A prospective, controlled study of a 9/0 elastic polypropylene suture for cataract surgery: refractive results and complications.

A prospective, randomised study was performed on 52 patients undergoing routine limbal extracapsular cataract surgery to compare the effect of 10/0 nylon and 9/0 elastic polypropylene sutures on post-operative astigmatism. Both the magnitude and the axis of the astigmatism were measured by keratometry and refraction pre-operatively and at regular intervals for 3 months post-operatively. Both groups showed an increase in the magnitude of astigmatism immediately post-operatively. The polypropylene group showed a more rapid decrease in astigmatism over the first 7 days and subsequent stabilisation, although the only significant (p < 0.05) difference in astigmatism between the two groups was at 1 week post-operatively. Both groups showed 'with-the-rule' astigmatism immediately post-operatively, although more of the polypropylene group developed 'against-the-rule' astigmatism by the end of the study. Despite an early reduction in post-operative astigmatism in the polypropylene group, early spectacle prescribing would not be recommended because of the shift in the axis of astigmatism. In addition, the polypropylene group had a 4 times greater incidence of iris prolapse compared with the nylon group.