EyeWorld India March 2018 Issue

Review of ‘Femtosecond laser-assisted cataract surgeries (FLACS) reported to the European Registry of Quality Outcomes for by Robert Purgert, MD, PhD, and Jeffrey Goshe, MD Jeffrey Goshe, MD, residency program director, Cole Eye Institute, Cleveland Clinic Robert Purgert, MD, PhD, resident, Cole Eye Institute, Cleveland Clinic 30 EWAP CATARACT/IOL March 2018 F emtosecond laser-assisted cataract surgery (FLACS) was approved by the U.S. Food and Drug Administration in 2010. 1 FLACS uses laser technology to automate and standardize several key steps of phacoemulsification cataract surgery including corneal incision creation, capsulorhexis, and lens fragmentation. Though FLACS reduces phacoemulsification time 2 and provides theoretic benefits over manual phacoemulsification, complication rates and refractive outcomes for FLACS have been demonstrated to be equivalent to manual phacoemulsification techniques. 3 What is less un- derstood is the degree to which FLACS efficacy varies with base- line characteristics of operative eyes. This issue is examined in a cohort of FLACS patients with dif- fering baseline visual acuities by Lundström et al. in a study titled “Femtosecond laser-assisted cata- ract surgeries (FLACS) reported to the European Registry of Quality Outcomes for Cataract and Refrac- tive Surgery (EUREQUO): baseline characteristics, surgical procedure, and outcomes.” Eighteen cataract surgery clin- ics in 10 countries participated in the study. Patients were deemed candidates for FLACS according to each clinic’s routine practices. Pre- operative characteristics, surgical complications, and outcomes data for FLACS patients was reported to the European Registry of Quality Outcomes for Cataract and Refrac- tive Surgery (EUREQUO). Data was collected for 3,379 consecutive FLACS patients between 2013 and 2015. Preoperative characteristics for FLACS patients included: average age 64.4 years; gender 57.8% fe- male; ocular comorbidity in 19.1%. Intraoperatively, the femto- second laser was used primarily for combined capsulotomy and nucleus fragmentation (94.1%). The laser was used less frequently for corneal incision creation (33.9%) or corneal astigmatic cor- rection (8.6%). Traditional cataract surgical complications occurred in 0.7%. FLACS-specific surgical complications occurred in 2.2% and were most commonly related to the corneal incision. Postoperatively, refractive outcomes were favorable compared to manual phacoemulsification. 4 The mean postoperative CDVA was logMAR 0.04, with logMAR 0.3 or better achieved in 96.2% of cases. Spherical equivalent refractive error was within ±1.0 D of predic- tion in 91.8% of cases. Complica- tions were reported in 3.3% over an average follow-up period of 34 days. These included optic axis opacities (0.8%), central corneal edema (0.4%), and uncontrolled rise of intraocular pressure (0.1%). An insightful aspect of this report is the analysis conducted on patients stratified by preoperative visual acuity. Specifically, patients were divided into five groups by baseline visual acuity. Group 1 had acuity logMAR 0.0 or better and Group 5 had acuity logMAR 0.6 or worse, with other groups having acuities in between. Relative to patients with good baseline visual acuity, patients with poor base- line visual acuity had a number of distinguishing characteristics. Preoperatively, they had more ocular comorbidities. Intraop- eratively, they had more surgical complications and were more likely to receive monofocal lenses. Postoperatively, their refractive outcome was slightly worse than for patients with good baseline visual acuity, but they enjoyed a larger magnitude of visual im- provement and had an equivalent rate of complications. Overall, this paper supports prior reports demonstrating comparable refractive outcomes of FLACS and manual phacoemul- sification. It adds to the existing knowledge base by examining how FLACS efficacy varies with baseline visual acuity of operative eyes. This article highlights in multiple ways the important issue of patient selection in FLACS. This is poignantly illustrated by the authors’ finding that patients with the best preoperative visual acuity are at the highest risk of having worse visual acuity after surgery (5.9%), a finding also demon- strated in other cataract surgery cohorts. 5 The decision to proceed with cataract surgery should thus be weighed carefully in patients with very good preoperative visual acuity. In these situations, the surgery may be better classified as a refractive lens exchange rather than a cataract extraction, and this should be reflected in the counselling provided to patients on the risks and benefits of sur- gery. The fact that patients in this study were younger than earlier FLACS studies 6 suggests that the indications for FLACS, and per- haps cataract surgery in general, may indeed be moving toward what the authors describe as a “gray zone between refractive lens exchange and cataract extraction.” Of note, nearly 75% of the patients included in this study did not have enough preoperative visual