Eyeworld

113 EW RETINA March 2016 by Karl Brasse, MD, Vreden, Germany, and I. Paul Singh, MD, Eye Centers of Racine & Kenosha, Wis. significant risk factors for detach- ment. Surgeons have performed thousands of YAG vitreolysis proce- dures and no studies have shown an increased risk for detachment in a standard, healthy eye. What's next? We agree with our retina colleagues that we need more peer-reviewed, randomized, masked studies to demonstrate efficacy of this proce- dure. Although we have seen highly satisfied patients in our offices, we need larger placebo-controlled studies. To this end, there are multiple ongoing studies looking at safety and efficacy with the newer tech- nologies mentioned. In fact, there is a study in the U.S. conducted by a large, well-known retina group that is gathering data and will likely be presenting data at the end of this year or early next year. In addition, Dr. Brasse is currently affiliated with 3 university centers in Europe that are in the process of organizing a controlled, prospective, multisite study on YAG vitreolysis. We eagerly await their findings as well as other studies worldwide. We encourage our retina colleagues to visit our practices and observe how the procedure is performed. We would also welcome a discussion on the impact of this procedure on a patient's daily life. Our goal is to help improve the quality of life for our patients. We want to again thank our retina colleagues for challenging this pro- cedure. It shows how much we care about our patients and our profes- sion. We do need to hold ourselves to the highest standards, and this dialogue ensures that we do. We look forward to more discussions in the future. EW References 1. Tsai WF, et al. Treatment of vitreous floaters with neodymium YAG laser. Br J Ophthalmol. 1993; 77:485–488. 2. Benhamou N, et al. Retinal detachment follow- ing YAG laser section of vitreous strands. Apropos of 3 cases. J Fr Ophthalmol. 1998; 21(7):495–500. Editors' note: Drs. Singh and Brasse have financial interests with Ellex. Contact information Brasse: brasse@augenarzt-vreden.de Singh: ipsingh@amazingeye.com Concerns about safety In the September 2015 article, when we stated that vitreolysis is a safe and effective treatment, we did not claim or infer that there are no ad- verse events. In our experience, YAG vitreolysis has a high safety profile, and this has been reported in the literature. 1 Out of the 800+ cases Dr. Singh has performed, he has not seen a single retinal detachment, tear, hole, or increase in macular edema. He has not seen a case of vitritis, iritis, or corneal edema. Of the 400+ cases Dr. Brasse has per- formed, he has seen only 1 retinal detachment, but that patient had preexisting comorbidities—a corneal transplant, cataracts, and retinal holes. For patients with healthy retinas and no other significant risk factors, we have not seen a detach- ment from this procedure yet. IOP spikes are a known risk in this procedure and we have seen them happen, but they are rare. Out of the 800+ cases Dr. Singh has performed, he has seen 4 significant spikes in IOP (a rate of 0.5%), and all 4 occurred in pseudophakic, post- YAG capsulotomy patients where the floaters were anteriorly positioned. We think that particles or gas af- fected the aqueous outflow in these patients. All of these IOP spikes were controlled with topical drops. Of the 400+ cases Dr. Brasse has performed, he has seen 3 significant pressure spikes, but these incidences occurred in patients with pigment dispersion syndrome or amyloido- sis who already had compromised outflow capabilities. We do not consider pressure spikes to be a problem with the pro- cedure; they may occur with almost any ocular procedure. We are aware some patients are not good candidates for this proce- dure, and therefore patient selection is an important consideration for maintaining a high degree of safety and efficacy. Our colleagues referenced a study of 3 cases of retinal detach- ment after YAG vitreolysis. 2 We would like to point out that all 3 patients presented in this study had preexisting conditions that predis- posed them to retinal detachments. In our practices, these are patients we would never choose to perform vitreolysis on because they had that the laser, aiming beam, and light source share the same axis. The studies that our retina colleagues quoted used lasers that fired only in the off-axis position and therefore could not visualize and treat a num- ber of symptomatic floaters. To avoid hitting the retina or the lens, surgeons need to be able to toggle back and forth between the off- and on-axis positions. In the on-axis position, the surgeon can see the floater in relation to the retina. If the floater is in focus and the ret- inal vessels are even partially in fo- cus, the surgeon should not fire the laser. If the retina is obscured while the floater in in focus, it is then safe to fire. Conversely, surgeons need to be able to see the floater in relation to the posterior capsule. To this end, we use the off-axis position to guide our visualization. This new optimized visualization allows for greater efficacy and a higher degree of safety than ever before. Another advancement in technology has been the delivery of energy. The laser we are using has a narrow Gaussian energy beam profile, which improves the efficien- cy of energy delivery. Most standard YAG lasers with typical OEM cavities produce a wider beam profile. The new narrow beam profile allows for the 50% air breakdown to be at 1.98 mJ, which is significantly lower than standard YAG lasers. For instance, the SuperQ laser (Ellex's previous OEM cavity laser) has an average 50% air breakdown of 3.43 mJ. For YAG lasers, the growth of plasma as a function of power is a LOG law phenomenon, and consequently the increase in size of plasma between 4 mJ and 12 mJ is only 40%. This is an important concept and is why we are able to use energy settings well above what was used in the past. It is also important to note that newer laser lenses have been created by multiple companies to aid in visualization during the procedure. Our retina colleagues expressed con- cern that we have financial interests with Ellex, the manufacturer of the laser. We want to be clear that we recommend the Ellex laser because it is the only laser on the market that provides these visualization capabilities. I n this issue of EyeWorld, mem- bers of the ASCRS Retina Clin- ical Committee discuss their disagreement with the article "Pearls for YAG vitreolysis of floaters." We truly appreciate our retina colleagues conveying their concerns about YAG vitreolysis. It is healthy to engage in this type of discussion because it helps ensure that we are all promoting safe and efficacious treatments for our patients. Here, we would like to address the Retina Clinical Committee's concerns about the safety and efficacy of this pro- cedure and offer a way to keep this dialogue moving forward. Modern vitreolysis is a different procedure We think there is a lack of under- standing and a misperception about the procedure we are promoting. This is not the same procedure as in past years. Earlier attempts at YAG vitreolysis were not always positive because the technology was not optimized for the procedure. In the case of vitreolysis, the technology and technique have changed, resulting in improved ef- ficacy and safety. Both the laser and lenses have been designed specifical- ly for this procedure. One significant technological advancement has been improved visualization. To perform this procedure, surgeons need to have adequate visualization between the lens and the retina. Previous YAG lasers could only fire in the "off-axis" position (slit lamp view and illumination tower at a different axis than the laser). This allowed us to visualize only 1–2 mm behind the posterior capsule. This is fine for YAG capsulotomies and laser peripheral iridotomies, but not for vitreolysis because most of the symptomatic floaters are located in the middle and posterior vitreous. Therefore, we end up missing a ma- jority of floaters using this off-axis position. The new optimized laser made by Ellex (Adelaide, Australia) offers coaxial illumination, which allows us to fire in the "on-axis" position because the mirror moves out of the way when the laser is fired. This allows the surgeon to treat floaters that we previously couldn't see using "off-axis" lasers. "On-axis" means Cataract surgeons respond to Retina Clinical Committee's concerns over YAG vitreolysis

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