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Issue link: https://daily.eyeworld.org/i/124056
February 2013 ASCRS•ASOA SYMPOSIUM & CONGRESS, SAN FRANCISCO2011 EW SHOW DAILY 35 Meeting Reporter The problem of leakage in well-constructed wounds by Enette Ngoei EyeWorld Contributing Writer W ith leaky wounds having a high risk of endophthalmitis, Michael B. Raizman, MD, Boston, and colleagues sought to simulate the propensity for clear corneal wound leaks caused by various patient manipulation such as eye rubbing, forced blinking, and light digital pressure. Speaking at a scientific paper session on intraocular surgery and phaco technology, Dr. Raizman said his study used a Calibrated Force Gauge (CFG) by Ocular Therapeutix Inc. (Bedford, Mass.) that can be used to quantitatively apply a known amount of force in increasing quantities. "We chose to set 1 oz of force as our maximal force. This was applied adjacent to the limbus, with increasing force in 0.25 oz steps," he said. In phase 1 of the study, Dr. Raizman and colleagues wanted to know how much the pressure rose with the CFG. They simulated IOP fluctuations caused by patient manipulation in 30 healthy volunteers not undergoing cataract surgery and measured their IOP three times at baseline and averaged it. Then, 1 oz of force was applied using the CFG 0.5 mm on the scleral side of the limbus for 2-3 seconds. The IOP was measured three times during application of force and averaged. It was found that the CFG with 1 oz of force on average created a mean IOP increase of about 26 mm Hg from baseline. With this information, Dr. Raizman and colleagues began phase 2 of the study. This included 30 patients with the clear corneal incision wounds closed with stromal hydration. The wounds were challenged using the CFG and examined for wound leakage. Approximately half of the wounds were created with a single plane incision and about half with a biplane incision. Dr. Raizman said he and colleagues were surprised at how frequently the well-constructed wounds leaked. "We know that patient manipulation can be detrimental to wound integrity, two-thirds of all wounds leaked with application of 1 oz of force or less and the majority of wounds leaked with less than 0.5 oz of force. If wounds leak under simulated patient manipulation, further steps may be warranted to protect the incision from potential fluid egress," Dr. Raizman concluded. Following in a similar vein, John A. Hovanesian, MD, Los Angeles, presented a paper that evaluated the leak rate among eyes that had self-sealing incisions as well as those that were closed with sutures. The study also used the CFG described earlier to apply 1 oz of force to unsutured stromal hydrated wounds and if they leaked upon CFG challenge, a suture was applied and the incision was challenged again to see if leakage was present, he said. Dr. Hovanesian said that from the results of his study: "It is fairly evident to us that stromal hydration alone is not adequate to prevent wound leaks, particularly wounds challenged after cataract surgery. Biplane incisions do fair better when challenged, and even sutured wounds leaked in a fairly surprisingly high number of cases of almost 25% of the cases in this study," he said. Dr. Hovanesian also mentioned that he is helping the FDA in evaluation of a polyethylene glycol (PEG) hydrogel sealant that is applied to the corneal wound at the end of surgery as a liquid that turns into a gel. It adheres firmly and complies with the shape and size of the wound and then hydrolyzes and sloughs off just a few days later. EW Editors' note: The physicians have financial interests with Ocular Therapeutix Inc. Run 4 Sight – April 21, 2013 More than 350 runners showed their support for the ASCRS Foundation's humanitarian work in Ethiopia by participating in the Foundation's Run for Sight 5K run or 1-mile walk Sunday morning. Participants ran a route through Golden Gate Park under perfectly clear skies in sunny 60-degree weather. "We want to thank our corporate sponsor, TearLab [San Diego], for their incredibly generous support, along with all the runners who took part in this fun event," said Richard L. Lindstrom, MD, Minneapolis.