EyeWorld Asia-Pacific September 2018 Issue

Both prostaglandins and beta blockers were found to be risk factors for developing postoperative CME. Source: Elizabeth Davis, MD cataract surgery, one of the side ef- fects could be elevated IOP, which would then lead to using these eye drops, Dr. Mikelberg explained. So it may have nothing to do with the IOP or glaucoma but instead could indicate that these patients had experienced complicated cataract surgery, Dr. Mikelberg said, adding that unfortunately, since the database doesn’t have a code for whether the surgery was complicated or not, investigators were unable to explore this. Yet another hypothesis is that it may be the preservative, as the two eye drops have the same preservative, BAK, in common, noted Dr. Mikelberg said, adding, however, he thinks this to be far less likely. He hopes that practitioners come away from the study with the realization that the use of a prostaglandin analog after cata- ract surgery is no riskier than a beta blocker. “The take-home message is that the use of a beta blocker or prostaglandin analog in the context of a patient who has had cataract surgery somewhat increases the risk of developing CME,” he said. “The risk seems to be equal whether you use a beta blocker or a prostaglandin analog.” Dr. Mikelberg pointed out that there is a caveat to the study. “The strength of this study is the 150 million patients in the database,” he said. “The strength of this enormous cohort is that you could pull out statistically significant results because of the sheer power of such a large database.” But the flip side is because of the sheer power, you could pull out things that while statistically significant, may not be clinically significant, he noted, adding that in this case they’re not recommending that patients undergo cataract surgery in any different way. In addition, these database studies are detect- ing significant associations but not causations. This could mean that the associa- tion between these medications and CME found here may not have anything to do with the prostaglandin analogs or the beta blockers themselves, Dr. Mikelberg noted, adding that a randomized trial would be needed to prove causation. If they had access to an- other database that stated whether the cataract surgery was compli- cated, it might also be possible to delve into this further. “That’s not coded, so I don’t see how we can do that,” Dr. Mikelberg concluded. EWAP Reference 1. Wendel C, et al. Association of postoperative topical prostaglan- din analog or beta-blocker use and incidence of pseudophakic cystoid macular edema. J Glau- coma. 2018;27:402–406. Editors’ note: Dr. Mikelberg has no financial interests related to his com- ments. Contact information Mikelberg: frederick.mikelberg@ubc.ca Post-cataract – from page 31 32 EWAP CATARACT/IOL September 2018