Publication Exclusive: Intraoperative aberrometry measurements in cataract surgery spur debate

Welcome to CEDARS-ASPENS Debates, a monthly feature in Ocular Surgery News.

CEDARS (Cornea, External Disease, and Refractive Surgery Society) and ASPENS (American Society of Progressive Enterprising Surgeons) is a joint society of cornea, cataract and refractive surgery specialists, here to discuss some of the latest hot topics in ophthalmology.

Intraoperative aberrometry measurements have become much more utilized during cataract surgery in recent years for obvious reasons. Even when surgeons have access to this technology, there is still no consensus as to how to interpret the data. While many surgeons put all of their trust in these measurements, others may feel that the preoperative calculations are more reliable. This month, Dr. Tom Boland and I discuss the merits and pitfalls of using intraoperative aberrometry with routine cataract surgery. We hope you enjoy the discussion.

Kenneth A. Beckman, MD, FACS, OSN CEDARS-ASPENS Debates Editor

ORA technology provides improved surgical outcomes

Intraoperative aberrometry measurements in cataract surgery have become more prevalent in recent years, but I know that there are many surgeons still unsure of the role the technology can play in their practice. Its usefulness in post-refractive surgery eyes has been demonstrated without question, but what is its role in more typical eyes? The longer that I use the technology (ORA with VerifEye, Alcon), the more frequent my use, and the better my surgical outcomes have become.

We routinely do multiple measurements for IOL calculations, with each patient having axial length measured by immersion ultrasound, IOLMaster (Carl Zeiss Meditec) and/or Lenstar (Haag-Streit), and keratometry values measured in a variety of ways, from manual keratometry, autorefractor, Pentacam (Oculus), Orbscan (Bausch + Lomb), IOLMaster, Lenstar, Cassini (i-Optics) or other automated topographer. The resulting stew of numbers can be enough to make your head spin. In most cases, there is good correlation of data, but occasionally there is wide disagreement in measurement. In the absence of intraoperative aberrometry, how do you make your IOL choice? We all have our favorite instruments and favorite formulas, but eventually you have to make a choice; aberrometry can eliminate the confusion, and I routinely use it as a “tiebreaker” in these cases of conflicting data. This comes in handy especially with your more discriminating or “fussy” patients.

In dense cataracts, or eyes with significant posterior subcapsular cataract, it can be difficult or even impossible to capture measurements with optical biometry, and even ultrasound can be inaccurate if the cataract is dense enough to interfere with fixation. By utilizing aphakic intraoperative measurements, you can be sure of the precision and make a much more accurate IOL selection.

Premium IOLs are another area in which the ORA can be invaluable. Since adopting the use of this technology, our enhancement rate after multifocal or toric IOL placement has plummeted. With multifocal IOLs, if you are not reducing postoperative refractive error to less than 0.5 D on a regular basis, then you are going to have many disappointed patients and a higher than necessary enhancement rate. The use of intraoperative aberrometry can reliably get you to this level of refractive error. With toric IOLs, I now use the ORA on every case to verify the power of the IOL, as well as the cylinder power of the IOL, and then to verify the proper axis of placement. In many cases, this can completely alleviate the need for any preoperative marking of the eye because the intraoperative measurements are more reliable and can account for posterior corneal changes.

As femtosecond laser-assisted surgery becomes more prevalent, another area in which the ORA is helpful is with management of astigmatism-correcting incisions. I program the laser to make astigmatic keratotomy incisions, but I do not routinely open the incisions at the beginning of the case. At the completion of the case, once the IOL has been inserted and the eye has been pressurized, the real-time streaming refractive data from the VerifEye system can tell you how much residual astigmatism you have and help you determine if your incisions need to be opened or potentially extended. This adds almost no time to the procedure and can save you much chair time in the clinic later.

The bottom line is that as our technologies advance and patient expectations continue to rise, I find this to be an indispensable tool. Aside from the indications discussed above, I face an ever increasing number of post-refractive surgery patients presenting for cataract surgery and have seen my use of intraoperative measurements steadily climb to the point at which some weeks more than 50% of my cases involve the ORA. Going forward, I could not see myself going backward to the days when we did not use it. Once you try it, I am sure you will agree.

Click here to read the full publication exclusive, CEDARS Debate, published in Ocular Surgery News U.S. Edition, July 25, 2015.