Eyeworld

38 Dismantling barriers: Clinical pearls and practical guidance to implement laser-assisted cataract surgery by Robert Weinstock, MD Femtosecond laser as a cornerstone to improving refractive outcomes the anterior and posterior surface of the cornea, driving the laser treat- ment. When we look at the femtosec- ond laser incisions under the slit lamp, it is amazing how clean and perfect they are, and they are exactly where we program the laser to place them. The arcuate incisions can be opened in the operating room or 3 weeks later at the slit lamp based on the manifest refraction. The vast majority of patients have no epithe- lial defects. In contrast, when we rely on manual methods, reproducibility may be decreased, and it is more difficult to place incisions at the correct optical zone because the human hand is subject to error. see how precise lasers are compared with manual methods, gaining a strong sense of confidence in cor- recting low amounts of astigmatism. Weighing manual vs. laser incisions When we create incisions with the laser, many barriers disappear. It is more accurate, incisions are repro- ducible, and it is precise. An increasing body of litera- ture shows the value of reducing astigmatism with the femtosecond laser (Figure 1). It is one of the best features of laser-assisted cataract sur- gery (LACS), providing patients with better uncorrected visual acuity after cataract surgery. Femtosecond laser imaging takes multiple readings to precisely find M ost innovative cataract surgeons recognize that cataract surgery has become refractive surgery, and astigma- tism correction is an important part of this procedure. Astigmatism can be corrected easily at the time of cataract surgery. However, data from the 2015 ASCRS Clinical Survey show that a good portion of cataract surgeons are not performing astigmatic corrections for low amounts of astigmatism— steps that are easy to integrate into practice, especially with the femto- second laser. Astigmatism correction Toric intraocular lenses (IOLs) provide an excellent solution for patients with more than 2 or 3 D of astigmatism, but most patients have less than 1 D of astigmatism, which can be corrected with limbal relax- ing incisions (LRIs). If we do not correct it, the patient will not have 20/20 vision after cataract surgery. The 2015 ASCRS Clinical Survey revealed that 42% of respondents do not think arcuate refractive incisions created with a laser are better than conventional incisions. However, when we make arcuate incisions we New-generation femtosecond laser systems integrate imaging and automated planning, registration to avoid errors related to cyclotorsion or head tilt, and software to drive incisions. Conclusion LACS provides automation, registra- tion, and improved learning curves compared with manual methods. It can be applied to the vast majority of patients who are not candidates for toric IOLs because they have low amounts of cylinder. It is much easier and more precise than using manual LRIs. Dr. Weinstock is in private practice, Eye Institute of West Florida, Largo. Robert Weinstock, MD the anterior and posterior surface of see how precise lasers are compared New-generation femtosecond Figure 1. A growing body of literature addresses femtosecond arcuate incisions. This list includes 2015 publications alone. • Femtosecond laser-assisted arcuate keratotomy versus toric IOL implantation for correcting astigmatism • Yoo A, et al. J Refract Surg. 2015;31:574– 578. • Safety and efficacy of femtosecond laser- assisted arcuate keratotomy to treat irregular astigmatism after penetrating keratoplasty • Fadlallah A, et al. J Cataract Refract Surg. 2015;41:1168–1175. • Femtosecond laser-assisted intrastromal relaxing incisions after penetrating keratoplasty: effect of incision depth • Wetterstrand O, et al. J Refract Surg. 2015;31:474–479. • Femtosecond-assisted arcuate keratotomy for the correction of postkeratoplasty astigmatism: vector analysis and accuracy of laser incisions • Loriaut P, et al. Cornea. 2015;34:1063–1066. • Clinical utility of femtosecond laser-assisted astigmatic keratotomy after cataract surgery • Nejima R, et al. Jpn J Ophthalmol. 2015;59:209–215. • Vector analysis of corneal astigmatism after combined femtosecond-assisted phacoemulsification and arcuate keratotomy • Chan TC, et al. Am J Ophthalmol. 2015;160:250–255.e2. by Tal Raviv, MD Ten femtosecond laser phaco pearls W hen adopting la- ser-assisted cataract surgery (LACS), the following pearls can help surgeons achieve optimum surgical outcomes. 1. Capsulotomy: Center the capsu- lotomy on the lens, not the pupil. To improve 360-degree capsule- intraocular lens (IOL) overlap for better refractive stability, surgeons should center the capsulotomy on the crystalline lens, which is possible with optical coherence tomography imaging guidance. 2. Capsulotomy: Be mindful of capsulotomy edge gas bubbles. During capsulotomy removal, sur- geons should be mindful of possible micro-attachments. Separating a mi- cro-adherent femtosecond laser-cre- ated capsulotomy is straightforward Tal Raviv, MD and similar to tearing perforated paper—it doesn't require "folding over," as with a traditional capsulor- hexis tear. 3. Hydrodissection: Release trapped gas. Before, during, or after hydrodis- section, the surgeon should depress the nucleus to decompress trapped gas created by the femtosecond laser during lens softening. The gas creates a pneumo-dissection, after which the lens moves readily. 4. Hydrodissection: Tent and wiggle the cannula tip to ensure cortical cleavage. To ensure good cortical separation, lift the capsulotomy edge and wiggle the cannula tip from side to side while injecting balanced salt solution to hydrodissect the lens be- tween the capsule and cortex. (The pneumo-dissection typically occurs between cortex and epinucleus.) 5. Fragmentation: Customize the fragmentation pattern to the lens density. With LACS we can customize frag- mentation to different lens densities (Figure 1). To increase the softening continued on page 39

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