Impact of a Corneal Pre-cut on Wound Architecture and Astigmatism in Cataract Surgery - a Pilot Study

Corneal wound architecture in cataract surgery has recently been assessed1-4 using optical coherence tomography. However, none of these studies observed the effect of the wound architecture on postoperative astigmatism. In a previous study performed at our center, cataract surgery using a 1.8 mm micro incision (MICS) was compared to a 2.5 mm standard incision (SICS) regarding wound architecture and surgically induced astigmatism. Wound size and wound architecture were assessed using a Time-Domain OCT intraand postoperatively. After implantation of the IOL the incisions were shown to be larger than planned.

This effect was shown to be more pronounced in the small incision group. Both epithelial and endothelial wound gaping at the end of surgery occurred more often in the MICS group. Furthermore, this study showed no effect of a 300 μm pre-cut on postoperative wound architecture and surgically induced astigmatism. Based on these findings we would like to perform another study using a high-resolution Spectral-Domain OCT, which allows for a three-dimensional depiction of wound architecture and a better understanding of the dynamic changes in wound structure during surgery. Furthermore a new high resolution OCT device will be available outside the operating theatre for postoperative measurements. Both devices are CE certified, will be used according to their indication and allow noncontact and therefore pain free measurements. As no significant impact of a 300μm pre-cut on wound architecture and astigmatism was shown in the predecessor study, we would like to evaluate the use of a 600μm pre-cut regarding wound architecture and surgically induced astigmatism as compared to a stab-incision (a corneal incision without a pre-cut). A dedicated wound architecture score will be used to evaluate wound configuration.

Postoperatively, OCT scans will be obtained, corneal curvature will be measured and subjective and objective refraction will be performed in order to measure the surgically-induced astigmatism.