Comparing conventional limbal relaxing incisions, femtosecond laser

July 1, 2014

Intraoperative aberrometry readings can be useful in reducing astigmatism when used with either conventional diamond blade limbal relaxing incisions and femtosecond laser arcuate incisions. In a study of 50 eyes, no statistically significant difference was found between two groups of patients in postoperative mean residual astigmatism.

 

Take Home

Intraoperative aberrometry readings can be useful in reducing astigmatism when used with either conventional diamond blade limbal relaxing incisions and femtosecond laser arcuate incisions. In a study of 50 eyes, no statistically significant difference was found between two groups of patients in postoperative mean residual astigmatism.

 

 

By Nancy Groves; Reviewed by Robert J. Weinstock, MD

St. Petersburg, FL-No statistically significant difference was found in mean residual astigmatism in a small study comparing conventional diamond blade limbal relaxing incisions (LRIs) and femtosecond laser arcuate incisional surgery. Intraoperative aberrometry (ORA system, WaveTec) was used to guide treatment decisions in both groups of patients, and this contributed to the similar outcomes, said Robert J. Weinstock, MD, who performed all the surgeries.

“In my opinion, the ORA intraoperative aberrometry readings greatly assisted both groups in providing excellent outcomes in astigmatism reduction,” said Dr. Weinstock, private practice in St. Petersburg, FL. “Decisions made in the operating room by using the intraoperative aberrometry to gather data enabled us in both groups to treat the astigmatism optimally.”

 

Understanding the study

In a group of 50 astigmatic eyes undergoing cataract surgery, 25 received conventional LRIs, while the other 25 had femtosecond laser arcuate incisions created with a Victus laser system (Bausch + Lomb).

Preoperatively, there was no statistically significant difference in the mean keratometric astigmatism between the conventional group (1.11 D ± 0.53 D) and the laser group (1.06 D ± 0.26 D). Postoperatively, mean residual refractive astigmatism was 0.44 D ± 0.46 D in the conventional group and 0.21 D ± 0.28 D in the laser group (p < 0.03).

The decision of how much astigmatism to treat and how many incisions to make can be guided by intraoperative aberrometry, or based on preoperative astigmatism measurements from topography, Dr. Weinstock said, and his goal was to compare the two different methods. In the group who received conventional, bladed LRIs, he created the incisions after obtaining aberrometry readings. In the laser group, aberrometry was used to guide incremental opening of the arcuate incisions.

“The results were interesting in that they showed a slight improvement in astigmatism reduction in the femtosecond laser group compared to the diamond blade group when we looked at the one-month residual astigmatism based on manifest refraction,” he explained. “However, the difference between the two groups was not statistically significant.”

 

He added that if ORA had not been used in both groups, the laser group probably would have come out farther ahead of the diamond blade group.

“More studies will have to be done to determine if that truly is the case,” Dr Weinstock said. “It’s good news for the patients that we have two viable techniques to reduce astigmatism, and when you add intraoperative aberrometry into the mix, and use that as well to help guide your decision making, it’s a further technology and tool to allow surgeons to deliver better refractive outcomes.”

 

Robert J. Weinstock, MD

P: 727-581-8706

E: rjweinstock@yahoo.com

Dr. Weinstock is a consultant for WaveTec and Bausch +Lomb.