EyeWorld India September 2016 Issue

EWAP SECONDARY FEATURE 37 September 2016 check for unusual eye geometry. There is also a fixation check that is relevant for keratometry. When doing macular screening with swept-source OCT, it can provide good detection of macular holes and CME; however, the technology still has difficulties with geographic atrophy and epiretinal membranes. This is a valuable device to detect macular pathology, but conventional spectral domain OCT is necessary to refine the presumed diagnosis, Dr. Findl added. The most important impact of swept-source OCT for biometry is the more successful scans, he said. Swept-source OCT for biometry provides imaging of the entire eye, Dr. Findl said. It can screen for macular disease and can predict IOL tilt. In the future, the technology could potentially be used for the cornea back surface, to predict IOL position from the lens shape, and for ray tracing. Moving on to refractive outcomes and measurements, Dr. Findl focused on the use of both intraoperative aberrometry and intraoperative OCT measurements. Refractive outcomes after cataract surgery are within ±1 D of refractive error 91% of the time, he said, but this still means that 9% are outside of this range, which he said he doesn’t approve of. Additionally, in short eyes, refractive errors are more common. With intraoperative aberrometry, there is conflicting data in the literature concerning accuracy, he said. Additionally, intraoperative alterations of the cornea can cause errors, and this technology does not take the postoperative IOL position into account. Meanwhile, with intraoperative OCT measurements, there is significant reduction of the IOL prediction problem, Dr. Findl said. However, it’s also technologically demanding and not yet commercially available. Dr. Findl also discussed reducing astigmatism, highlighting the techniques that can be used for correction, such as toric IOLs, opposite clear corneal incisions (OCCI), and peripheral corneal relaxing incisions (PCRI). In conclusion, he said “swept- source OCT for biometry is a new and powerful tool.” Dr. Findl believes intraoperative measurements will be used in the future to refine power calculations. He also stressed, when using toric IOLs, the importance of using different devices to measure the cornea and marking preoperatively or using a tracking system. EWAP Editors’ note: Dr. Findl is a scientific advisor for Carl Zeiss Meditec (Jena, Germany). Contact information Findl: oliver@findl.at