EyeWorld is the official news magazine of the American Society of Cataract & Refractive Surgery.
Issue link: https://digital.eyeworld.org/i/146899
24 EW CATARACT July 2013 Pharmaceutical focus Putting cataract patients into the comfort zone by Maxine Lipner EyeWorld Senior Contributing Writer lidocaine and epinephrine—a mixture first devised by Alan Crandall, MD, Salt Lake City. Intraocular elixirs The latest anesthesia trends I t's a pivotal part of the cataract routine that requires a bit of a balancing act—determining just how to best keep patients comfortable during the procedure while minimizing potential risks. For many higher-volume practitioners in the U.S., the answer has been to use topical anesthetics to rapidly and safely perform cataract surgery, according to Lisa B. Arbisser, MD, adjunct associate professor, John A. Moran Eye Center, University of Utah, Salt Lake City, and in practice, Eye Surgeons Associates, Quad Cities, Iowa. However, some of the highest-volume cataract surgeons rely on regional peribulbar or retrobulbar injections for everyone, since it can be quicker, minimizing patient interaction as well as movement, but it requires a little more caution, Dr. Arbisser explained. Under a topical umbrella Dr. Arbisser prefers the topical approach in about 95% of her cases. She goes out of her way to allow even patients who can be difficult to communicate with to use the topical anesthesia, when possible. For example, for the profoundly deaf, Dr. Arbisser will arrange for signals, such as a touch on the shoulder or nose, to communicate with the patient. "After all, there are complications with needles around the eye, so we have to weigh our risks against our benefits," she said. James P. Gills, MD, professor of ophthalmology, University of South Florida, Tampa, likewise thinks there are many reasons to avoid needles when possible. "We use retrobulbar (injections), when indicated, but they are not without risk," Dr. Gills said. With injections there are myriad serious concerns. "Increased pressures, retrobulbar hemorrhage, and even blindness are potential, albeit rare, risks." In addition, there is a delay in visual recovery when injections are used. On the other hand, topical anesthesia has its own risks. One of the biggest problems can be sudden patient movement, Dr. Gills observed, noting that this is more than just an inconvenience and can potentially cause complications. One way to help stave off such movement is with the use of adjunctive intracameral lidocaine, an approach Dr. Gills pioneered. This takes away the sensation of pressure, which can sometimes be mistaken for pain, he explained. "The biggest problem occurs when patients become very anxious, and when they are anxious pressure is translated as pain," he said. "When you get patients in the operating room [who are] minimally sedated and they have a sensation of increased pressure, they think it's pain and jump, which may cause a complication." As part of his topical regimen, Dr. Gills uses Xylocaine (lidocaine, AstraZeneca, London) topical anesthetic with an antibiotic dilating solution and a nonsteroidal medication. "We give that to the patient approximately 45, 30, and 15 minutes prior to cataract surgery," he said. Dr. Arbisser also favors lidocaine gel for her topical regimen. She stressed that this first requires a drop of proparacaine to stave off pain from betadine instillation. The gel creates a barrier to the betadine, preventing it from doing its job. "You can't put the gel before the prep, and since the prep hurts you have to put some topical before that," Dr. Arbisser said. She also supplements this with unpreserved and preferably bisulfate-free intracameral In particularly complex cases, however, Dr. Arbisser relies on regional anesthesia. When considering this, she avoids those with disorganized orbits, patients on Coumadin (warfarin, Bristol-Myers Squibb, New York), as well as one-eyed individuals. Likewise, patients with posterior staphylomas are not good candidates, since this puts them at an approximately nine-fold increased risk of intraocular perforation. This is something most likely to occur in myopes, Dr. Arbisser noted. "Whoever is doing an injection needs to be well aware that it's a longer eye and be very sensitive about the angle that they use," she said. As part of her regional regimen, Dr. Arbisser gives a single peribulbar injection administered inferior, through the cul-de-sac only, of no more than 5 cc of a mixture of lidocaine 2% with epinephrine and hyaluronidase. The addition of the hyaluronidase helps the medication spread through the tissue planes in order to get full akinesia. There is some evidence that this reduces the toxicity of the lidocaine to the extraocular muscles since it spreads what otherwise would be a concentrated lump through the tissues, she explained. In addition to giving all patients IV-systemic sedation with a little versed and dilute alfentanil (Alfenta, Akorn, Lake Forest, Ill.), Dr. Arbisser relies on what she dubs "vocal local" to empower them. "What I always say at the beginning of the case is, 'You'll be aware of my presence, but you'll feel no pain. And if anything bothers you, just tell me and we'll do something about it right away.'" It is then important to follow through with that promise, she noted. When using peribulbar or retrobulbar techniques, Dr. Arbisser stressed the need to avoid multiple injections. "I virtually never supplement an injection because I think the risk is higher than the benefits," she said. Another possible option is use of sub-Tenon's injections, comcontinued on page 26