Eyeworld

Supported by unrestricted educational grants from Alcon Laboratories, Bausch + Lomb, LENSAR, and Sightpath Medical 5 by Robert J. Weinstock, MD Deep impact a statistically significant reduction in effective phacoemulsification time by using fragmentation to remove the cataract. Surgeons can choose from an array of fragmentation patterns (Figure 2). For dense cataracts, I prefer a grid pattern, where I can chop the cataract, pretreating and softening it. We use much less ultrasound, and the case is quicker and easier. Clinical pearls When incorporating this technology into a practice, ond laser reduces the need for ultrasonic energy and facilitates nuclear disassembly. Endothelial cell damage is reduced because there is less heat and thermal damage compared with tradition- al (not femto) ultrasound-only cases. 1 Ultimately, I have noticed that there is less risk of posterior capsular tears due to excessive nuclear manipulation and time in the eye. Surgeons should research femtosecond lasers for them- selves. I have used 3 different laser platforms. All have shown nomograms based on manual diamond blade incisions and then customize them based on their own results. At the slit lamp the arcs and arc length are perfect, and optical coherence tomography shows how clean they are, with a consistent depth compared with manual in- cisions. Arcuate incisions created with the femtosecond laser open easily with a Sinskey hook or small cannula either intraoperatively or at the slit lamp postop. Two femtosecond laser man- ufacturers have released software and additional hardware for axis registration to avoid cyclotorsion errors. This feature, along with automated surgical planning software, allows surgeons using the Verion Image-Guided System and LENSAR Streamline to be even more precise in their cataract procedures. Lens fragmentation I have found that the femtosecond laser reduces phacoemulsification time and power (Figure 1). It soft- ens dense cataracts and pre-chops and pre-cracks the nucleus, so the surgeon can dismantle the nucleus more effectively. The femtosec- Femtosecond laser- assisted cataract surgery offers increased precision and advantages in lens fragmentation F emtosecond lasers are transforming cataract surgery, enabling surgeons to create laser arcuate incisions to correct astig- matism and perform laser frag- mentation of the lens to reduce ultrasonic energy. Arcuate incisions After using the femtosecond laser to create arcuate incisions, we quickly see how precise those incisions are compared with man- ual incisions. Most surgeons who perform refractive cataract surgery agree that we can correct up to 1.5 D of regular corneal astigmatism consistently with this laser. Eighty percent to 85% tends to be a commonly used corneal thickness depth, and an 8.5- to 9-mm optical zone is an ideal location when positioning these incisions. Many nomograms are available, including those of Skip Nichamin, MD, and Eric Donnenfeld, MD. (LRIcalculator. com provides additional informa- tion on manual limbal relaxing incisions.) Surgeons can start with Robert J. Weinstock, MD " After using the femtosecond laser to create arcuate incisions, we quickly see how precise those incisions are compared with manual incisions. " –Robert J. Weinstock, MD continued on page 7 Figure 1. Dr. Weinstock's first 200 femtosecond laser cataract surgeries required less phacoemulsification time and power compared with standard techniques. Absolute phaco time(s) Femto Standard Absolute phaco time (mean) 20 15 10 5 0 Average phaco power Femto Standard Average phaco power (mean) 10 8 6 4 2 0 P<0.001 P=0.403 12.7 16.2 8.0 8.50

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