Eyeworld

EW CATARACT 20 January 2015 Pharmaceutical focus by Maxine Lipner EyeWorld Senior Contributing Writer product labeling includes instruc- tions not to add anything to the solution, but this has not stopped most. "We have all for years been 'doctoring our bottles' with additives that we think might be helpful," he said. Tightening regulations Issues can arise when federal and state regulatory bodies come by to review facilities, Dr. Lindstrom said. Enforcement has been somewhat random, with some facilities being shut down over this while others have not. Also confounding the issue, regulations may vary by state, with some requiring doctors to write prescriptions for medications added to the bottle for every patient to be fulfilled by a pharmacist. Others al- low doctors to mix in the additional medication and still others allow the nurses to handle this. "The penalties can be severe," Dr. Lindstrom said, adding that things currently seem to be tightening up. In addition, he finds regulators are cracking down on the practice of using one bottle of medication for more than one patient. "They're getting to the point where if you're going to dilate your patient preoperatively you have to throw that bottle of dilating drops away and use a new bottle (for the next case)," Dr. Lindstrom said. New addition A new treatment that is diluted in the balanced salt solution, Omidria (Omeros Corporation, Seattle), which contains phenyleph- rine (1%) to maintain mydriasis and ketorolac (0.3%) to prevent miosis and reduce postop pain, recently received FDA approval. Each 4 mL vial of Omidria is bisulfite and preservative-free. "Again, it is for 1 patient per ampule, but you don't have to write a prescription for each patient, and you don't have to have it done in the pharmacy because in the FDA clinical trials they had the nurses do it in the operating room and that's the way it's labeled," Dr. Lindstrom said. Dr. Kim said that the timing of Omidria's availability is opportune for another reason as well—a short- age of epinephrine. This is actually made for pediatric asthma patients with only a certain amount pro- duced yearly, he explained. "As cata- ract surgeons we've used it more and more, but they haven't increased the production for ophthalmic use," Dr. Kim said. "So we run into shortages on a fairly regular basis." He experienced a shortage at one of the ambulatory surgery cen- ters at which he operated that had temporarily severed ties with the compounding pharmacy that had been supplying this previously. "Most surgeons will put epi- nephrine in the bottle and/or inject it into the anterior chamber, but we didn't have either option," Dr. Kim said. "It shocked me to see how many of these pupils constricted during surgery." About 50% of his cases are done with the femtosecond laser, with the laser itself likely con- tributing to the pupil constriction in many of these patients. "You end up with a significantly smaller pupil and if you don't have epinephrine, you're going to have to mechani- cally dilate the pupil with a pupil expansion device," he said. Even a 1- or 2-mm decrease in pupil size can be clinically signif- icant, Dr. Kim said. "A 2.5-mm decrease in pupil size results in an approximately 30% reduction in the pupillary area, which corresponds to an approximately 50% reduction in the operative field," he said, adding that when there is a decrease in pu- pil size, complications usually arise. Dr. Lindstrom concurs. "As cataract surgeons what's giving us exposure is a well-dilated pupil," he said. "If exposure goes down, complications go up." He said that for the typical 10-minute cataract procedure with BSS alone the pupil comes down about 1 mm, and for a 20-minute procedure it comes down about 2 mm. With Omidria the data set shows pupillary dilation is nicely maintained and is slightly enhanced at the beginning of surgery, Dr. Lindstrom said. Likewise, Dr. Kim said in the clinical trial, 23% of pla- cebo patients had a pupil diameter less than 6 mm toward the end of the case compared to 4% of patients treated with Omidria, a result found to be statistically significant. Phenylephrine, the dilating agent in Omidria, might be supe- rior to epinephrine, Dr. Lindstrom thinks. Epinephrine makes the heart rate go up and can cause hyperten- sion, while phenylephrine does not. "For some of these older pa- tients, phenylephrine is safer," Dr. Lindstrom said. In addition, there is the nonste- roidal component, ketorolac, which helps to prevent miosis and reduce postoperative pain. "Prostaglandins Cataract's fluid balanced salt solution situation New solution in the mix I t is an integral part of cataract surgery: the use of balanced salt solution. It aids in everything from cooling the phacoemulsi- fication tip to providing volume to keep the anterior chamber formed during the procedure, according to Terry Kim, MD, professor of ophthalmology, Duke University Eye Center, Durham, N.C. The situation with balanced salt solution is any- thing but static. Here is the latest on tightening regulations and what is now available. One of the issues cataract surgeons in the U.S. are currently dealing with is a 2008 FDA ruling requiring practitioners to use only approved balanced salt solutions. Concerns about TASS with unregu- lated balanced salt solutions were at the center of this, said Francis Mah, MD, director of cornea and external disease, and co-director of refrac- tive surgery, Scripps Clinic, La Jolla, Calif. "The 'knockoffs' were asso- ciated with toxic anterior segment syndrome," Dr. Mah said. "I think eliminating a lot of these has helped to reduce TASS epidemics because at least some of them were associated with the balanced salt solution that was being manufactured by other manufacturers." Two staples in the area that have been FDA approved for some time are BSS (Alcon, Fort Worth, Texas) and BSS Plus (Alcon), Dr. Mah said, adding that practitioners often add a bit of epinephrine to the bottle to help keep the pupil dilated. This, however, is an off-label use of the product. Further, when bisul- fite-free epinephrine was no longer available, this became an issue, Dr. Mah said. "It turns out you can use the bisulfite as long as it's diluted and it doesn't seem to cause prob- lems to the endothelial cells, but again it's an issue of using it off-la- bel," he said. "Also, some physicians will use antibiotics in the BSS and BSS Plus." However, a lot of studies show these are of questionable benefit in BSS, Dr. Mah said. Richard L. Lindstrom, MD, ad- junct professor emeritus, University of Minnesota, Minneapolis, said that Balanced salt solution use is an integral part of the cataract removal process. Source: Richard L. Lindstrom, MD

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