The Importance of Good PR

I advocate pneumatic retinopexy (PR) for the treatment of retinal detachment, and have done so for nearly 30 years. I presented the results of a multicenter clinical trial comparing PR to scleral buckling at the 1988 AAO congress, and even today, I still think that for many patients with retinal detachment, PR has the best chance of restoring pre-detachment vision.

Buckle up?

In 1989, I participated in one of the largest clinical studies of PR ever performed – a multicenter, randomized, prospective trial that compared the outcomes of PR and scleral buckling in 198 patients (1). Patients were carefully selected for inclusion in the trial: they had to have retinal break(s) no greater than one clock hour in size, that were within the superior two thirds of the fundus, and only patients without significant proliferative vitreoretinopathy were enrolled. What we found was that the single-operation success rates with PR and scleral buckling were 73 percent and 82 percent, respectively, which additional laser or cryopexy increased to 81 and 84 percent, respectively. It is important to note that VA continued to improve by about 10 percent between six months and two years after the procedure, likely caused by restoration of the normal macular architecture. Indeed, in patients who had preoperative detachment of the retina, 20/50 or better vision was achieved after 2 years in 89 percent of eyes that received PR, and only 67 percent that underwent scleral buckling.

Now, the surgeons who participated in this trial were all fellowship trained and had prior experience of both PR and scleral buckling, yet the results differed significantly between the centers – the scleral buckle and PR success rates varied from 57 to 100 and 43 to 83 percent, respectively (1). When we examined our results more closely, what we found was that you can’t separate the surgeon from the surgery. Case selection, the surgeon’s ability to find all the breaks, surgical technique and correct postoperative positioning all factor into the outcome. So what did we find were key to successful PR? And what happens to eyes with failed PR?

Defining success

In the trial, 99 percent of detached retinas were ultimately reattached. I decided to take a more contemporary look at failed pneumatics, so I reviewed 43 consecutive primary detachments that I repaired with PR since September 2012, where I had at least one year of follow-up. One third were pseudophakic, and in one third the macula had detached preoperatively. PR successfully attached 81 percent of eyes with a single procedure, and final attachment was 100 percent. One eye developed proliferative vitreoretinopathy. Macula attachment did not influence single operation success, and neither did phakic status – which means that pseudophakia is not a contraindication to performing PR.

To attach the eight failed cases, 11 procedures were needed. In the one PVR case, silicon oil was inserted and later removed. Overall, 86 percent of all eyes attained 20/40 or better acuity, and all failed eyes attained 20/40 or better acuity. So at one year, even eyes which failed the first PR ultimately did well.

Cutting the wrong costs?

Hypothetically, if we compare the cost of performing 43 vitrectomies with a 90 percent success rate, with the cost of performing PR with an 81 percent success rate, PR (including reoperations) is less than half the cost of vitrectomy – and a failed PR does not disadvantage the eye when it comes to ultimate anatomic attachment or visual recovery. Unfortunately, the Centers for Medicare & Medicaid Services (CMS) in the US has defined single operation success as the primary quality measure for retinal detachment repair.

My colleagues and I have shown that single operation success does not necessarily equate to best vision or least cost, and hope that CMS will reconsider this erroneous definition of quality, and reconsider recent cuts to PR, which encourage more expensive, OR-based procedures. If surgeons are ever compensated based on their outcomes and cost, I suspect PR will become very popular.

Paul Tornambe is Director of the San Diego Retina Research Foundation and founder of Retina Consultants San Diego, California, USA.