EyeWorld India March 2018 Issue

March 2018 EWAP FEATURE 25 said. “Vitrectomized eyes simply do not allow adequate anterior chamber shallowing for those of us who use external tapping tech- niques.” He added that if you ask experienced DMEK surgeons, they will tell you that some of their most stressful and extended DMEK experiences were on vitrectomized patients. “I am hopeful that this may change in the future with the emergence and ongoing validation of pull-through DMEK techniques that allow direct control of the graft,” he said. “Until then, DSAEK is a great procedure in these eyes in my opinion.” How to manage the bubble Dr. Lee makes an inferior iridecto- my prior to tissue insertion. “I use 100% air fill once the DMEK tissue is centered and keep the patient flat for an hour in the recovery room, then check in the YAG laser room at the slit lamp and make sure the air clears the iridectomy,” he said. If it does, the patient is discharged. If it does not, he will release a small amount of air at the lamp and let the patient sit flat for 30 more minutes and recheck prior to discharge. Dr. Veldman typically cre- ates an iridectomy using a scratch down technique, which he subse- quently enlarges with intraocular micro-scissors, including removal of a small piece of peripheral iris tissue. “A good peripheral inferior iridectomy allows me to place a large, approximately 90% fill of 20% concentration SF6 gas,” he said. “With an adequate bubble in place, I use my finger to apply pressure to the sclera, with result- ant elevation of the intraocular pressure for a few 20–30 second cy- cles. I will typically have patients position for about 45 minutes, after which they sit up until I can check the adequacy and aqueous clear- ance of the iridectomy.” If there is not an inferior fluid meniscus that is contiguous with the iridectomy, Dr. Veldman will burp the smallest possible amount of gas from the inferior paracentesis and recheck the patient in 5 minutes, at which point there is typically a visible meniscus. Dr. Suh uses 20% SF6 and fills up to a large bubble size. She uses the anterior vitrectomy unit to make the inferior iridectomy. “But make sure that when the patient is sitting up and facing forward, there is clearance of the inferior iridectomy,” she said. EWAP References 1. Veldman PB, Dye PK, Holiman JD, Mayko ZM, Sáles CS, Straiko MD, Stoeger CG, Terry MA. Stamp- ing an S on DMEK donor tissue to prevent upside-down grafts: Laboratory validation and detailed preparation technique description. Cornea . 2015;34(9):1175–8. 2. Veldman PB, Dye PK, Holiman JD, Mayko ZM, Sáles CS, Straiko MD, Galloway JD, Terry MA. The S-stamp in descemet mem- brane endothelial keratoplasty safely eliminates upside-down graft implantation. Ophthalmol. 2016;123(1):161–4. Editors’ note: The physicians have no financial interests related to their comments. Contact information Lee: wblee@mac.com Suh: lhs2118@cumc.columbia.edu Veldman: peterbveldman@gmail.com Hill-RBF Method The Hill-RBF Method is a complete new approach for IOL power selection. RBF stands for Radial Basis activati- on Function. The calculation is driven by an advanced, self-validating method using pattern recognition based on artificial intelligence and sophisticated data interpo- lation. EyeSuite IOL The Hill-RBF Method is included exclusively in the latest EyeSuite software. In addition to the new calculator, Eye- Suite provides state of the art IOL calculation formulae such as Olsen, Barrett’s Universal II, True K and Toric Cal- culator. Up to 12 formulae are eligible in a user-friendly interface to match any surgeons demandings. www.haag-streit.com LENSTAR LS 900 Improving outcomes ADV_Hill-RBF_EyeWorldAsia_25-07-2017.indd 1 26.07.2017 13:50:23