Eyeworld

EW RETINA 118 September 2016 by Liz Hillman EyeWorld Staff Writer to confirm whether the IOL is where you want it," he said. A 2013 study published in Investigative Ophthalmology & Visual Science concluded that issues with IOL power calculations and posi- tioning could be reduced by taking intraoperative OCT measurements of the lens capsule. 10 Even more recently, a study published this year in the Journal of Cataract & Refrac- tive Surgery assessed the position of IOLs at the end of standard cataract surgery using spectral domain OCT, finding that contact between the IOL's central optic and the posterior capsule "rarely occurred." 11 Stephen Lane, MD, clinical pro- fessor of ophthalmology, University of Minnesota, Minneapolis, who was part of the panel commenting on Dr. Lisa's presentation, told EyeWorld he thinks intraoperative OCT has "the great potential of being able to provide information on where the lens is actually sitting in the eye," potentially improving the accuracy of the refractive result. "I think we're all pretty confi- dent that an IOL is not exactly in the same place we put it at the time of surgery, so how much does it move and does it move in a predict- able fashion forward or backward?" Dr. Lane said. Further research with this tech- nology could provide more infor- mation on whether there is an ideal place to put the IOL, and determine and identify any posterior stromal irregularities. 8 Dr. Ehlers said that with current technology there seems to be a clear place in lamellar keratoplas- ty procedures, particularly in eyes with extensive corneal edema and limited visualization of the anterior segment. In DALK, for example, intraop- erative OCT helps identify dissec- tion depth and optimize additional maneuvers. 9 Dr. Lisa said intraoperative OCT can help the surgeon better assess "localization of the endothelial side of the graft in every step," as well as identify Descemet's membrane remnants and any posterior stromal irregularities. "We can check interface and graft adherence, and in the case of compromised anterior chamber visu- alization—bullous keratopathy—we have more information," he said. "This may improve the adoption of DMEK surgery by flattening the learning curve. In DALK surgery it could help reduce the risk of perfora- tion and may improve reproducibili- ty of the big bubble procedure." Dr. Ehlers said intraoperative OCT could prove useful in complex IOL procedures as well. "Right now with the current technology, I think the most helpful application is in those more com- plex IOL procedures where the view is limited and you need to be able Justis Ehlers, MD, Cole Eye Institute, Cleveland Clinic, has been conducting research on intraoper- ative OCT for years, working with different systems in applications across ophthalmic surgery. "There are multiple areas of in- terest related to intraoperative OCT research. How can we optimize the surgeon feedback platform? What are the key procedures that bene- fit most from intraoperative OCT information? How do we optimize software systems for analysis? What is the impact of intraoperative OCT on long-term outcomes?" Dr. Ehlers said of some of the general areas of research for this technology. Dr. Ehlers wrote that previous research "demonstrated in a poten- tial significant percentage of cases that intraoperative OCT alters surgi- cal decision-making both in anterior and posterior segment surgery." 5,6 One study had 1-year results of a single center's multi-surgeon use of RESCAN 700 (Carl Zeiss Meditec, Jena, Germany). 7 Surgeons performed 91 anterior segment surgeries and 136 posterior segment cases using the RESCAN 700 sys- tem during surgery. According to the study, intraoperative OCT data altered the surgical decisions 38% of the time in lamellar keratoplasty procedures. In DMEK procedures, in- traoperative OCT can facilitate iden- tification of graft orientation, help visualize graft unfolding behavior, Data emerges but questions remain on benefit of this technology changing surgical outcomes O ptical coherence tomog- raphy (OCT) has already solidified its value to oph- thalmologists in the clinic, but it could be making its way into the operating room more often as well. While vitreoretinal surgeons have already seen the value of intraoperative OCT, there is grow- ing interest in its potential applica- tions in the anterior segment. "Much development has been focused on the retina, but recently investigations have been direct- ed toward the anterior segment," Carlos Lisa, MD, Fernández-Vega Ophthalmological Institute, Oviedo, Spain, said in a presentation at the 2016 ASCRS•ASOA Symposium & Congress. Over the last few years, several studies have been published about intraoperative OCT being used in the anterior chamber during canaloplasty 1 and lamellar kera- toplasty procedures. 2,3,4 But is the technology really leading surgeons to change their course of action in- traoperatively? And are those chang- es improving patient outcomes? While some data is emerging on that front, those questions have yet to be definitively answered. Value of intraoperative OCT in anterior segment surgeries DMEK surgery and graft orientation in previous failed penetrating keratoplasty Source: Carlos Lisa, MD

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