EyeWorld Asia-Pacific December 2016 Issue

December 2016 12 EWAP FEATURE In addition to using the highest cut rate possible, Dr. Arbisser uses a slow flow rate— peristaltic flow settings around 15 to 20, depending on whether a 20- or 23-gauge is used—and the lowest effective vacuum. Additionally, Dr. Arbisser maintains a normotensive eye by keeping the irrigation bottle moderately high. Vitrectomy approaches If a vitrectomy is needed, Dr. Berdahl will use either a limbal or pars plana incisions but pars plana is likely the preferred approach because anterior approaches pull the vitreous forward, while removing it from the back allows the vitreous to fall back. “But many surgeons don’t feel comfortable with the pars plana approach,” Dr. Berdahl said. “In a situation like this you want to feel comfortable.” Although he prefers the pars plana approach, one of its drawbacks includes the need to make a sclerotomy, which produces some risk of hemorrhage, Dr. Lee noted. Eyes with abnormal anatomy, such as very short eyes, may result in the pars plana not being in the normal location, and those would require a limbal paracentesis. In cases of copious vitreous prolapse, Dr. Arbisser said, a pars plana sclerotomy approach to anterior vitrectomy is most efficient and preferable. Alternatively, and theoretically most safely, a trocar system, which allows a transconjunctival sutureless entry, is best when the globe is closable or intact at the time of sclerotomy, as it requires pressure to insert, Dr. Arbisser said. Trocars have the advantage of allowing repeated entry without trauma to sclera or proximity to the scleral wall and choroid. It is least likely to result in vitreous traction associated with incarceration at the incision site. Lens placement Dr. Arbisser prefers placing a one-piece lens in the bag if she is able to change a capsular tear into a true continuous capsulorhexis. “If I cannot convert a tear to a capsulorhexis then I like to put a three-piece lens in the sulcus and optic capture through the anterior capsulorhexis,” Dr. Arbisser said. Dr. Lee’s first choice is to place a three-piece IOL in the sulcus with capture of the optic inside of the capsulorhexis. His second preferred lens approach is placing an entire three-piece IOL in the sulcus. Dr. Berdahl won’t use accommodating IOLs in such cases. However, if the rhexis is perfectly centered then it could be used to capture a multifocal IOL. “Unless you think you can put it in the capsular bag, then anterior optic capture it, I would be very disinclined to use a multifocal,” Dr. Berdahl said. EWAP Editors’ note: Drs. Arbisser, Lee, and Berdahl have no financial interests related to their comments. Contact information Arbisser: drlisa@arbisser.com Berdahl: johnberdahl@gmail.com Lee: bryan@bryanlee.pro cohesive viscoelastic behind it. As the cohesive agent dissipates, the surgeon can work where that agent used to be while the remaining dispersive OVD keeps the eye compartmentalized. “Then you need to decide whether or not there is vitreous prolapse that will require a vitrectomy, and what other problems you may need to deal with,” Dr. Arbisser said. In cases of zonular loss, a capsular tension ring may be needed. If it is a ruptured capsule, converting it to a capsulorhexis may work. However, if vitreous prolapse has occurred then the vitreous has to be removed first to avoid traction. “After the situation is stabilized, inspect to see what is happening, what is intact and what isn’t, plan and get the instrumentation you need,” Dr. Arbisser said. Triamcinolone use Dr. Arbisser recommends diluting triamcinolone 10-1 with balanced salt solution to minimize its dense, white ropey form that can obscure visualization. “It’s easy to think that there’s no vitreous in the anterior chamber and then once you visualize it with triamcinolone, you know where the enemy is and how to attack him,” said John Berdahl, MD , Sioux Falls, South Dakota. Additionally, the intraocular steroid helps corneal recovery and decreases corneal inflammation after a bigger-than-expected surgery, which helps with postop recovery. Dr. Arbisser has found triamcinolone most useful once a vitrectomy is done and most of the OVD has been removed. Then, surgeons can exchange the irrigation for the triamcinolone to see if they have truly reached the endpoint or not. “It is also critical to use it prior to implantation to avoid vitreous incarceration with the implant,” Dr. Arbisser said. “You always want to use it as the very last step to be certain you didn’t miss some vitreous strand before you close the eye.” Approach to vitreous To deal with vitreous, Dr. Berdahl’s machine settings include the highest cut rate available. “I have it cut first, then put it on I/A so I am putting less traction on the vitreous,” Dr. Berdahl said. Dr. Lee starts on irrigation- aspiration-cut mode with a low bottle height and the maximum cut rate. Once he compartmentalizes the eye with viscoelastic and performs an initial vitrectomy, if needed, he figures out how to remove the remaining cataract. “If there is a lot of nucleus left or if the lens is very hard, then manual removal may be best,” Dr. Lee said. Other approaches include phacoemulsification over an IOL scaffold or Sheets glide. If cortex is present, it can be removed manually with a dry technique or with a vitrector on irrigation- aspiration-cut or with bimanual I/A. Have a game plan - from page 8