Eyeworld

127 March 2016 EW MEETING REPORTER "The final parameter that we can customize is flap shape," Dr. Majmudar said, questioning if a round flap is really ideal for LASIK. The cornea is not round, he said, it is an ellipse. The average corneal size is 11 mm by 12 mm, so it may be better to have an ellipsoid flap. An advantage of an elliptical flap is that the majority of patients who will be treated have with-the-rule (WTR) astigmatism (requiring an ellipti- cal ablation shape). He added that Swept-source OCT is very fast, Dr. Maeda said. It can cover up to 16 mm so you can capture the whole corneal image. With this machine, Dr. Maeda said he conducted a trend analysis of keratoconus progression, which can be useful for corneal crosslinking. Prediction of IOL po- sition can also be determined with swept-source OCT. Meanwhile, with spectral domain OCT, the corneal epitheli- um and stroma can be separated. This also can provide keratoconus detection and epithelium thickness profile regression. Dr. Maeda said that full field OCT is still in a prototype form, but the resolution seems much better with this tool. En face image can be obtained with full field OCT, he said, and this could be used for in vivo biopsy in the future. Using femto flap for optimized LASIK A session titled "Advances in Customized Refractive Treatments and Femtosecond Lasers in 2016" focused on using femtosecond laser technology with a number of other treatment options and discussed the advantages and disadvantages involved with each. Parag Majmudar, MD, Chica- go, highlighted "Femtoflap for an Optimized LASIK." It has been 20 years since LASIK became "main- stream," he said. Since that time, many changes have occurred. There has been a realization that ectasia is a major concern, there have been excimer laser technology advances from broad beam to flying spot to the current generation of lasers for faster and smoother ablations, and femtosecond technology has largely supplanted microkeratomes as the tool of choice. There are many advantages of being able to use the femtosecond laser, Dr. Majmudar said, including customizable flap parameters, like side cut angles, flap size, flap thick- ness, and flap shape. When using an acute angle side cut, there may be a higher incidence of flap slippage, he said, but femto- second lasers allow the surgeon to make a customized side cut angle. Additionally, flap size is im- portant, and femtosecond lasers can reproducibly create smaller diameter vs. larger diameter flaps. Smaller flaps may have less dry eye, but they could also result in higher order aberrations if not exactly centered. You can also use the femtosec- ond laser to control flap thickness. Variability of microkeratome flaps is well documented. With femto flap thickness, the standard deviation is much smaller, he said. round flaps may rotate once they are in place, which could result in striae, whereas elliptical flaps only fit one way. There are also fewer lamellae severed. At this point in time, how- ever, Dr. Majmudar indicated that he is still using round flaps. The "ultimate" use of femto, he said, is as a customized non-excimer vision correction tool. He detailed BARCELONA, SPAIN JUNE 16–19, 2018 | B A R C E L O N A | J U N E 1 6 – 1 9 | B A R C E L O N A | J U N E 1 6 – 1 9 SIGN UP FOR WOC2018 UPDATES! ICOPH.ORG/WOC PARTICIPATE in cutting-edge continuing education opportunities. NETWORK with more than 10,000 attendees from over 120 countries. VISIT more than 100 exhibiting companies. ATTEND hundreds of scientific sessions led by renowned experts. Host: Spanish Society of Ophthalmology Co-Hosts: European Society of Ophthalmology and Spanish Society of Implant-Refractive Ocular Surgery continued on page 128

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