Preliminary results promising for intraoperative wavefront measurement of LRI effect

Initial experience with intraoperative use of a wavefront analyzer (WaveTec Visions Systems) suggests that it may be a very useful tool for achieving increased accuracy and efficiency in astigmatism correction, said James E. McDonald II, MD.

The device has a very small footprint and attaches to the surgical microscope. Based on Talbot moiré interferometry, it provides real-time analysis of both low and high order aberrations with a resolution of < 0.1 D.

The technology is being evaluated in a multicenter study. Dr. McDonald presented results from a series of 29 patients who underwent cataract surgery with IOL placement and limbal relaxing incisions (LRIs). Wavefront measurements were obtained prior to the phaco incision, after IOL implantation, and after the LRIs. The evaluations added only 1 to 2 minutes to the OR time.

Patients were re-evaluated at 3, 6, and 13 weeks postoperatively, and the analyses showed very strong correlations between the real-time wavefront measurements and the postoperative manifest refractive change and corneal topography.

"In a retrospective review of 191 IOL implantation cases among six surgeons, we found less than 65% of eyes were within 0.5 D of targeted refraction and 1 out of 20 were off by as much 1.0 D. These types of outcomes create a challenge as we present premium lenses to our patients," said Dr. McDonald.

"We are very encouraged by our initial experience with this technology for intraoperative measurements because it suggests it may move us forward toward our goal of better postoperative outcomes."