Intraoperative aberrometry may help deliver on posthyperopic LASIK expectations

November 15, 2015

Use of intraoperative aberrometry to select IOL power results in improved refractive outcomes in eyes that have a history of hyperopic LASIK, according to the results of a retrospective study reported by Dan B. Tran, MD.

By Cheryl Guttman Krader

Las Vegas-Use of intraoperative aberrometry to select IOL power results in improved refractive outcomes in eyes that have a history of hyperopic LASIK, according to the results of a retrospective study reported by Dan B. Tran, MD.

The study included data for 350 consecutive cases using the technology (ORA System with VerifEye Technology, Alcon Laboratories) performed by 84 surgeons from 77 different centers across the United States, said Dr. Tran at the 2015 meeting of the American Academy of Ophthalmology.

Mean absolute value of the prediction error (MAVPE) was calculated using data from the patient’s refraction measured at 1 month postoperatively and the predictions using the aberrometry-determined IOL power and that based on the surgeon’s preoperative determination.

 

The results showed that the MAVPE was significantly lower using intraoperative aberrometry compared with that calculated using preoperative biometry data (0.43 D versus 0.52 D; p = 0.003).

In addition, the proportion of cases with a refractive error ±0.5 D of predicted was improved significantly using intraoperative aberrometry compared with the conventional determination (71% versus 63%; p = 0.02).

“After standard cataract surgery, about 70% of eyes will be within 0.5 D of the refractive target,” said Dr. Tran, private practice, Orange County, CA. “However, it is more challenging to accurately calculate IOL powers in eyes with a history of keratorefractive surgery, and data show that less than half of these eyes will be within 0.5 D of refractive target.”

 

Postkeratorefractive surgery patients, however, come in demanding the quality of vision they had after LASIK, Dr. Tran added.

“This is the first large analysis to look at posthyperopic LASIK patients undergoing cataract surgery,” he said. “The proportion of eyes within 0.5 D of refractive target seems to be about the same as that achieved with conventional preoperative biometry calculations in eyes without a history of keratorefractive surgery and is similar to what has been reported using intraoperative aberrometry for IOL power determination in postmyopic LASIK eyes.”

All of the surgeons who contributed cases to the study were trained in the use of the intraoperative aberrometry system.

 

Eyes were included only if there was a preoperative IOL power available in the patient’s record and were excluded if they had pre-existing ocular disease or BCVA worse than 20/40 after surgery.  Although a variety of IOLs were represented in the series, all IOLs implanted were from a single IOL portfolio (AcrySof, Alcon Laboratories).

Dr. Tran concluded by reminding attendees that the results are from a retrospective study that included data from multiple surgeons who used various surgical techniques and different IOLs.

“A well-controlled prospective study is the next step that should be done,” he said.

Dr. Tran is a consultant to Alcon.