EyeWorld is the official news magazine of the American Society of Cataract & Refractive Surgery.
Issue link: https://digital.eyeworld.org/i/276058
E W FEATURE 1 09 the laser treatment can cause miosis. When there are rare cases that an eye will not dilate, Jonathan H. Talamo, MD, associate clinical p rofessor of ophthalmology, Harvard Medical School, and medical direc- tor, Surgisite Boston, who works with the Catalys laser system (OptiMedica/Abbott Medical Optics, Santa Ana, Calif.), will use an oph- thalmic viscosurgical device and insert a Malyugin ring (this is an o ff-label use of the laser system). "Because the docking is so gentle, we can close up the incisions and redock the eye," he said. He finds he can treat a patient successfully if they dilate beyond 6 mm, but sur- geons new to femto-cataract laser use should aim for at least 7 mm of dilation, he recommended. The laser also requires some patient selection considerations— specifically, surgeons will want pa- tients who can fixate for a length of time, said Dr. Talamo. "It has to be someone who can lie still while you do a docking procedure and image them," he said. "If you give too much IV seda- tion, patients can get too drowsy and uncooperative, and that can cause problems with suction. It's a delicate balance with anesthesia," Dr. Weinstock said. Another challenge with the laser that Dr. Weinstock has found is with cortical cleanup. "When the laser creates the capsulotomy, it also cuts the cortex. This often creates a chal- lenge in hydrodissection and finding the tissue plane that's so easy to find with a manual capsulorhexis be- tween the cortex and the underside o f the anterior capsule." With a laser capsulotomy, surgeons must go under the capsule and grab the cor- tex with the I/A tip during cortical cleanup. However, Dr. Talamo has found cortical cleanup easier than with traditional cataract surgery. "The l aser leaves a predictable thickness in terms of the thin layer of cortex that's left behind. I use 500 µm of untreated tissue between the poste- rior capsule and at the back of the laser treatment. You typically don't have much of an epi-nucleus," he said. Dr. Talamo does find some strands of tissue occasionally but said that it's important to feel com- fortable going under the capsule to get the cortex. He prefers to use bimanual irrigation and aspiration to get the cortex. Dr. Weinstock said one surgical aspect he continues to do manually is wound creation. "If there's one part of the femto technology that's not fully mature, it's wound cre- ation. Trying to get that perfect lim- bal position and open it easily just hasn't happened in my experience," he said. "In my hands, the diamond blade is more efficient and precise." There's also some change to surgical flow that patients may not notice but surgeons will, Dr. Slade said. "It's fairly disruptive in that the patient goes from preop to the laser area and then the OR. For the sur- g eon, it's another sit down. It's also more chair time with the patient, which isn't necessarily bad. Using the laser takes the same amount of time as surgery, from 3 to 5 minutes at the laser to 3 to 5 minutes in surgery," he said. Accuracy and safety The femtosecond lasers are said to enhance accuracy and safety of the cataract procedure. When it comes to safety, surgeons must consider that term in both the clinical and r egulatory senses, said Dr. Slade. Although the regulatory definition of safety involves studies with thousands of patients, the surgeons quoted here shared their personal observations and experiences. "My impression is that it does add accuracy, precision, and in some cases, does have unique safety as- pects," Dr. Slade said. Those aspects include providing a more seamless surgery for patients with a white cataract, compromised zonules, or pseudoexfoliation. "Clinically, we see that the corneas are clearer and that there's a tighter spread of our spherical out- comes. We also have a better result with the laser arcuates than the manual arcuates that we did before," Dr. Slade said. Dr. Weinstock concurred with Dr. Slade's accuracy-related observa- tions. "The optical zone is more precise, and the depth is more exact than anything I can do with a dia- mond blade," he said. Because there is less nucleus manipulation and reduced phaco time and energy, Dr. Weinstock has found use of the laser helpful in patients with unhealthy corneas, in- cluding those with Fuchs' dystrophy. Dr. Lawless also feels confident using the laser in mild cases of Fuchs' dystrophy as well as with white cataracts. "The other time I find it of particular use is in poten- tial floppy iris syndrome where the incisions, capsulotomy, and nucleus divisions are performed before the eye is open," he said. "I still use in- tracameral adrenaline in these cases, but I have found that the laser ap- proach makes these cases more rou- tine." Analysis from Dr. Talamo's center has found that instead of reaching within a half diopter of the i ntended refractive goal in 70% of patients, his most recent results using the laser achieved that goal for 88% of patients. He believes that number will continue to increase. Surgical recovery also appears more seamless, said Dr. Trattler, who uses the LENSAR laser. "My patients see better at day one because there's l ess phaco energy used. There's faster visual recovery and less corneal edema," he said. Dr. Lawless said his anterior cap- sule tear rate with the laser is 0.1%, and the best he could ever achieve with manual surgery was 1%. He also finds that the use of intrastro- mal astigmatic incisions combined with on-axis surgery where indicated have helped him tighten his astig- matic results, especially in multifo- cal IOL patients with pre-existing corneal astigmatism of 1.1 D or less. Patient reaction Aside from the higher price tag asso- ciated with use of the laser, patients have reacted favorably to femto- assisted phaco, these physicians reported. "We present both options as vi- able ways of doing surgery. Without exception, patients wanting refrac- tive cataract surgery want the laser procedure," Dr. Talamo said. Not infrequently, patients going the non-premium IOL route elect for the laser as a strategy for astigma- tism correction as well. "Patients know about it, and they want it. They've heard about it from friends and family who have had the procedure," Dr. Trattler said. EW Editors' note: Drs. Lawless and Slade have financial interests with Alcon. Dr. Talamo has financial interests with OptiMedica/Abbott Medical Optics. Dr. Trattler has financial interests with LENSAR, Abbott Medical Optics, and Bausch + Lomb. Dr. Weinstock has financial interests with Bausch + Lomb. Contact information Lawless: Michael.lawless@visioneyeinstitute.com.au Slade: sgs@visiontexas.com Talamo: jtalamo@lasikofboston.com Trattler: wtrattler@gmail.com Weinstock: rjweinstock@yahoo.com February 2011 March 2014 Femtosecond phaco techniques Flap creation pearls O ne femto laser system that can be used for LASIK flap creation is the VICTUS, Dr. Weinstock said. "The docking system is similar to the IntraLase [Abbott Medical Optics]," he said. "The VICTUS is a very precise laser in terms of flap thickness, a customizable side cut, and flap diameter." The hinge can be placed where the surgeon prefers, he added. Dr. Weinstock recommended doing all flap cases together and all cataract cases together. "For me, the flow doesn't work well if I am bouncing back and forth between LASIK and cataract laser procedures," he said. The patients embrace the technology and seldom experience dis- comfort. "It's great that this device has multiple applications," he said. Although Dr. Slade isn't currently using the LenSx laser for flap cre- ation, he's done about 100 previously. "We did 100 eyes with no compli- cations and extremely good results," he said. Dr. Slade noted there was better standard deviation of thickness because of the image-guided lamellar cut. "Rather than the laser making a cut 150 µm across the surface, you can actually guide the cut to follow Descemet's membrane, so you have a lamellar cut with a plano bed," he said. 108-125 Feature_EW March 2014-DL2_Layout 1 3/6/14 3:59 PM Page 109