Eyeworld

EW RESIDENTS 60 July 2016 by David Patterson, MD, and the residents of the Mayo Clinic Department of Ophthalmology S ince the inception of femtosecond laser-assisted cataract surgery (FLACS) in 2009 by Nagy et al., 1 the field of ophthalmology has seen an increase in the pro- portion of FLACS cases; however, much remains to be investigated regarding the potential risks and benefits of FLACS compared to manual phacoemulsification (MP). The femtosecond laser, initially used to create LASIK flaps circa 2001, was adapted for use in cataract surgery with the hope of providing more accurate corneal wounds, capsu- lotomies, and keratotomies, and to assist with lens fragmentation, ideally making cataract surgery even safer than it has been since the ad- vancement of phacoemulsification. Potential benefits of FLACS include decreased phacoemulsification ener- gy, 2 more accurate astigmatic kera- totomies, less endothelial cell loss, 3 precise corneal incisions 4 and seam- less, perfectly sized capsulotomies. 5 Potential disadvantages of FLACS in- clude a weaker capsulotomy, 6 more expense, 7 increased anterior cham- ber prostaglandin levels, 8 capsular block, 9 and a steep initial learning curve with higher early complica- tion rates. 10 FLACS also entails in- creased intraoperative manipulation and time due to the transition of the patient from the laser interface to the operating microscope. Further limitations of FLACS can be encoun- tered as a result of physical patient characteristics (i.e., large body hab- itus or prominent brow) or ocular pathology (white cataracts, corneal opacification/scarring, small pupils, presence of a bleb or tube, or severe glaucoma). 11 In a large prospective cohort trial, Abell et al. showed simi- lar rates of posterior capsular rupture and dropped nuclei with FLACS and MP, yet FLACS had a statistically significant increased rate of anterior capsular tears compared to MP. 12 A recent comparative cohort study by Ewe et al. did not find a clinically meaningful visual outcome benefit for FLACS over MP. 13 Despite a mul- titude of studies, no study has prov- en FLACS to be superior to MP with respect to clinical outcomes, and MP remains a very safe procedure, with greater than 95% of cases having no intraoperative complications. 12 In the article "Comparison of vitreous loss rates between manual phacoemulsification cataract surgery and femtosecond laser-assisted cat- aract surgery," published in the July 2016 issue of the Journal of Cataract & Refractive Surgery, Scott et al. found a statistically significant decrease in vitreous loss rates during cataract surgeries using FLACS compared to MP. This single-center (Mercy Health System, Springfield, Missouri), retrospective case series evaluated a total of 7,155 cataract surgeries performed between 2010 and 2014. In this unique community-based practice, 4 surgeons performed 3,784 cases from 2010–2012 using solely MP techniques, followed by 3,371 consecutive FLACS cases from 2013–2014 after the entire surgery center switched from MP to FLACS on March 4, 2013. The only MP cat- aract surgeries performed after this date resulted from physical limita- tions that would inhibit positioning of a patient under the laser, docking of the laser on the eye, or complete corneal opacification, which was only a factor in 2% of the cases from 2013–2014. One surgeon was excluded from the study due to that surgeon starting after FLACS had already been implemented, and thus there was no MP data to compare to the FLACS data for that surgeon. Exclusionary criteria included a preoperative planned vitrectomy, traumatic cataract, combination procedures, and cases requiring iris hooks or iris ring devices. However, the study did analyze the data with and without the exclusionary crite- ria. The group identified cases of vit- reous loss during the study period by reviewing all operative summaries, CPT coding, self-reported incidents of vitreous loss, and vitrectomy set use. The 2 groups were similar with respect to pre- and postoperative drops, aside from the MP receiving lidocaine gel vs. the FLACS group Review of "Comparison of vitreous loss rates between manual phacoemulsification cataract surgery and femtosecond laser-assisted cataract surgery" Andrew Barkmeier, MD, residency program director, Department of Ophthalmology, Mayo Clinic Does using the femtosecond laser reduce the rate of vitreous loss? I asked the Mayo Clinic residents to review this month's JCRS paper that studied this key question in a private practice setting. –David F. Chang, MD, EyeWorld journal club editor continued on page 62 Mayo Clinic residents. Back row, from left: Michael Choi, MD, Steven Maxfield, MD, Gavin Roddy, MD, PhD, David Patterson, MD, and Harish Raja, MD. Front row, from left: Nitika Arora, MD, Andrea Tooley, MD, Saba Alniemi, MD, Elizabeth Atchison, MD, Saranya Balasubramaniam, MD, Lauren Dalvin, MD, and Margaret Reynolds, MD Source: Mayo Clinic

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