Study: Laser Cataract Surgery Shows Slight Advantage Over Conventional Approach

BETHESDA, MD – August 21: Opthamologist Dr. Daniel Pluznik uses a LensX state-of-the-art laser to perform part one of a two-step cataract surgery on Milford Best, 82 at Palisades Eye Surgery Center in Bethesda, MD on August 21, 2012. Cataracts are the most common surgery performed in Medicare and is the most common cause of blindness in the world. Pluznik performs about 350 of these surgeries a year, sometimes 12-15 a day at a length of 15 minutes each. (Photo by Linda Davidson / The Washington Post via Getty Images)
Research identified many similarities in safety and efficacy of laser and conventional cataract surgeries.

A comparison of femtosecond laser-assisted cataract surgery (FLACS) and conventional cataract surgery (CCS) revealed that both methods were safe and effective, with no difference in midterm visual acuity; however, FLACS did show some advantages, particularly in certain surgical endpoints and corneal properties, according to findings published in the Journal of Cataract & Refractive Surgery.

The authors of this meta-analysis systematically searched for studies comparing FLACS and CCS. 

Out of 73 studies reviewed (48 observational studies and 25 randomized controlled trials [RCTs]), a total of 12,769 participant eyes were treated with FLACS and 12,274 were treated with CCS.

No significant difference in uncorrected distance visual acuity (UDVA) was found at 1 week (WMD -0.04; 95% CI, -0.12 to 0.03; P =.28) or the final visit (WMD -0.04; 95% CI, -0.11 to 0.03; P =.3). Corrected distance visual acuity (CDVA) was also comparable at both 1 week (WMD -0.03; 95% CI, -0.06 to 0.00; P =.07) and at 6 months or more (P =.12). At midterm, the differences in UDVA (WMD -0.02; 95% CI, -0.04 to -0.00; P =.04) and CDVA (WMD -0.01; 95% CI, -0.02 to 0.00; P =.005) were better after FLACS. The RCT subgroup analyses showed better UDVA after 6 months or more with FLACS, as well as CDVA at 1 week and at 6 months or more.

With regard to surgical endpoints, FLACS showed significantly shorter total phacoemulsification time (WMD -10.36; 95% CI, -14.49 to -6.22; P <.001) and effective phacoemulsification time (EPT) (WMD -1.88; 95% CI, -2.21 to -1.55; P <.001). Cumulative dissipated energy (CDE) was also less in the FLACS group (WMD -1.95; 95% CI, -2.48 to -1.42; P <.001). Circularity of the capsulotomy also improved with FLACS (WMD 0.04; 95% CI, 0.02-0.06; P <.001).

Out of the 8022 FLACS-treated eyes, there were 78 (0.97%) events of anterior capsular rupture, compared with 16 (0.20%) in 7951 CCS-treated eyes (OR 4.80; 95% CI, 2.86-8.05; P <.001). No significant difference was found between FLACS and CCS in posterior capsular ruptures (OR 1.53; 95% CI, 0.88-2.66; P =.13). No significant difference was seen in anterior capsule ruptures in the RCTs (OR 1.54; 95% CI, 0.54-4.36; P =.42). Although no posterior capsule ruptures occurred in FLACS compared with 7 in CCS (0.63%), this was not statistically significant (OR 0.12; 95% CI; 0.01-0.98; P =.05). No significant differences were seen in incidence of postoperative complications between groups. Incidence of central corneal edema were also comparable.

After manual cataract surgery, central corneal thickness (CCT) was significantly higher at 1 day (WMD -16.49; 95% CI, -22.78 to -10.20; P <.001) and 1 to 3 months (WMD -9.33; 95% CI, -15.64 to -3.02; P =.004), but this difference decreased over time (WMD -4.53; 95% CI, -11.88 to 2.83; P =.23). Endothelial cell loss (ECL) was significantly less after FLACS at 3 to 6 weeks (WMD -2.58; 95% CI, -4.18 to -0.97; P =.002) and 3 months (WMD -4.83; 95% CI, -6.94 to -2.73; P <.001), but the differences were not significant at 1 week or 6 months.

Among the RCTs, all but 1 trial was of medium-to-high quality, and industry funding was reported in 3 observational studies and 2 RCTs. Heterogeneity was displayed in UDVA, CDVA, EPT, circularity, CCT, and ECL. These results are limited by the necessity of comparing studies that used different lasers, which created an imbalanced comparison. Also, with too few published RCTs, the safety results were underpowered.

Study investigators conclude that although both procedures are safe and effective, FLACS has certain advantages. Furthermore complications with the laser technique “are likely to reduce further with increased surgical skills. Less requirement of ultrasound energy leads to less injury to corneal tissues, which is especially important in the long term. Critical stages in CCS can be facilitated using the laser. Standardization of surgical steps and higher precision are beneficial to both the surgeon and the patient, especially for patients with low endothelial cell density or dense cataract. Solving logistical problems and improving cost effectiveness is desirable. Further development and improvements using the relatively young laser technique can be expected. Large studies comparing different settings of more current and advanced systems are necessary.”

Disclosure: Several study authors declared affiliations with the pharmaceutical industry. Please see the original reference for a full list of authors’ disclosures.


Kolb CM, Shajari M, Mathys L, et al. Comparison of femtosecond laser-assisted cataract surgery and conventional cataract surgery: a meta-analysis and systematic reviewJ Cataract Refract Surg. 2020;46(8):1075-1085.