OSN Europe: Is intraoperative refractive biometry a worthwhile investment for the cataract surgeon?

POINT

For the premium practice, it is a must-have

I believe that in a premium practice, intraoperative refractive biometry with the ORA system (Alcon) is a service we should be able to provide. There is no need and no time to use it routinely, but it is an extremely good tool in special cases, such as eyes that have previously undergone PRK or LASIK and in short or long eyes, in which accurate IOL power calculation is a challenge and no empiric formula can deliver what we want. It is equally useful in eyes implanted with phakic IOLs, in which measurements are difficult even with partial interferometry systems such as the Lenstar (Haag-Streit) and IOLMaster (Carl Zeiss Meditec), as well as in silicone oil-filled eyes or eyes with corneal irregularities. In pediatric cataract, it is a superb asset.

H. Burkhard Dick

There is a mistake some surgeons make when using the ORA, which is to hydrate and pressurize the eye with balanced salt solution. I initially did that and then realized it is better to homogeneously inject a viscous ophthalmic viscosurgical device because you do not hydrate the incision, can perfectly achieve the required IOP and have no fluid egress during measurement. This is one of the key points for good results and time optimization.

Indeed, some additional time is required when you do a procedure with the ORA. If you want to check on the changes induced by a refractive procedure such as arcuate incisions or correct the axis of a toric implant, you have to add about 5 minutes to your standard. It decreases your working space from the microscope to the eye, and you have to attach a sterile cover on the ORA at the microscope. You also need a second person, trained to stand on your side and use the touch screen. The ORA is a time investment and a money investment. But if you can improve predictability in the group of patients in which predictability is normally low, this investment is worth every cent.

Only very few people use ORA in Europe. In Germany, I was the first to adopt it, and the breakthrough for me was the VerifEye software and hardware upgrade, offering continuous, nonstop measurements that you can see on the screen. With the latest upgrade, the system is now much faster, versatile and specialty-driven.

H. Burkhard Dick, MD, PhD, is an OSN Europe Edition Board Member and chairman and head of the University Eye Clinic Bochum, Germany. Disclosure: Dick reports no relevant financial disclosures.

COUNTER

Reliability, cost-effectiveness have not been proven

Intraocular biometry is indeed a very interesting and attractive concept. A different issue is whether it solves problems or is reliable enough to be accepted or converted into standard practice.

The problem is that the condition of the eye post-cataract or refractive lensectomy is very diverse and influenced by many factors. The cornea is affected by the procedure in thickness and geometry. IOP plays an important role. The external influence of instruments such as the speculum and the eyelid configuration of the patient forced by local anesthesia are many times, indeed, an added variable to consider. The condition of the pupil is variable. The position of the lens and, consequently, the refractive results are not stable. They depend on the depth of the anterior chamber, which is affected by surgical maneuvers, by the quality of the surgery and by changes in the capsular bag that occur postoperatively in the immediate 24 hours and in the first 3 months. All of these variables make any measurement performed intraoperatively substantially unreliable.

Jorge L. Alio

The value of intraoperative biometry, and particularly the ORA, is at present doubtful. In my opinion, and from the experience I have had with it, it is not cost-effective, it is in most cases unreliable, and it only offers some value in the study of the astigmatism axis for the IOL. What we get is just the total information from the refraction of the eye, and issues such as the changes that happen in the anterior and posterior corneal surface are part of this measurement. How this matches with the toric IOL position is more than debatable. It might not be the final position of the eye, even though it might be orientative. Studies should correlate the intraoperative measurements with measurements performed postoperatively and at 1 and 3 months. Initial studies seem to be promising but are still too few and in small cohorts of patients to support evidence in favor of this technology.

Jorge L. Alió, MD, PhD, is an OSN Europe Edition Board Member and medical director, Vissum Corporation, Alicante, Spain. Disclosure: Alió reports no relevant financial disclosures.

Click here to read the Point/Counter published in Ocular Surgery News APAO Edition, July/August 2015.