September 2020

ASCRS NEWS

EyeWorld Journal Club
Review of “Outcomes of resident-performed laser-assisted vs. traditional phacoemulsification”


by Rachel Anderson, MD, and Jeffrey Goshe, MD


Jeffrey Goshe, MD
Residency program director
Cole Eye Institute
Cleveland Clinic
Cleveland, Ohio



Rachel Anderson, MD
Resident
Cole Eye Institute
Cleveland Clinic

FLACS has always held the potential to help inexperienced surgeons by automating key surgical steps. I invited the Cleveland Clinic residents to review this randomized, prospective comparison trial that appears in the September issue of JCRS.

—David F. Chang, MD
EyeWorld Journal Club Editor

A decade has passed since the U.S. FDA’s approval of femtosecond laser-assisted cataract surgery (FLACS),1 but questions remain as to whether the technology provides sufficient benefits to patients and ophthalmologists to justify its cost. FLACS attempts to standardize and automate several of the key steps of cataract surgery, including corneal wound creation, capsulorhexis, and lens fragmentation. In the hands of experienced surgeons, FLACS has demonstrated a benefit in process measures such as phacoemulsification time and total energy use as compared to conventional phacoemulsification cataract surgery (CPS).2,3,4,5 However, these theoretical advantages have failed to translate to a measurable benefit with regard to complication rates and refractive outcomes.6 Here we review the first prospective randomized trial comparing process measures and outcomes of FLACS versus CPS performed by ophthalmology residents, “Outcomes of resident-performed laser-assisted vs. traditional phacoemulsification” by Hansen et al.
This study included post-graduate year-3 and -4 ophthalmology residents operating at a single site (Parkland Memorial Hospital System in Dallas, Texas) within a single residency program (University of Texas Southwestern Medical Center). All cataract surgeries by this group between October 2015 and June 2017 were eligible for the study, which ultimately enrolled 135 eyes of 96 subjects. Eyes were randomly assigned to FLACS or CPS, and subjects were offered premium IOLs as appropriate, though lens subgroups were not analyzed separately. Eyes were excluded from consideration if they had prior ocular surgery, posterior polar cataract, phacodonesis, white or advanced cataract, anatomic conditions that precluded laser docking, pupil dilation <6 mm, or potential postoperative visual acuity worse than 20/30.
The authors found no difference between the groups in the majority of measured variables. Specifically, there were no significant differences with regard to best corrected visual acuity (BCVA); cumulative dissipated energy; intraocular balanced salt solution irrigation fluid usage; postoperative endothelial cell density; endothelial cell loss after surgery; total intraoperative time (of note, for the FLACS group, this did not include time at the femtosecond laser prior to entering the operating room); duration of hydrodissection/hydrodelineation, nuclear disassembly, or wound sealing. Several operative steps did vary significantly in duration between the two groups; wound creation, cortical cleanup, and IOL implantation were faster in the CPS group, and median time for capsulorhexis was faster in the FLACS group.
The small size of the study rendered it underpowered to detect statistically significant differences in safety between groups, but complications included one case of posterior capsule rent with vitreous prolapse per group; one case of posterior capsule rent without vitreous prolapse in the CPS group; and two cases of anterior capsule tears without vitreous prolapse in the CPS group. Postoperative cystoid macular edema was observed in one patient in the FLACS group.
This study provides a useful contribution to the growing body of work on FLACS, especially with regard to its usage by novice surgeons still in training. Still, a number of limitations merit discussion. As the study is limited to a single site within a single training program and a small sample of resident surgeons, the findings may not be generalizable. The use of exclusion criteria based on predicted case complexity may also limit the application of these findings to a broader patient population, including those cases in which FLACS is theorized to benefit most. As described in the introduction of the paper, the authors cite research that suggests that FLACS may be of particular benefit to patients with challenging problems such as shallow anterior chambers, subluxated lenses, and mature or posterior polar cataracts,7,8 yet these patients were excluded.
Perhaps the most significant limitation is the drastic gap in experience of FLACS versus CPS among residents and supervising ophthalmologists. Prior to participation in the study, each resident had participated as the assistant or primary surgeon in an average of 201 CPS cases; the mean number of FLACS cases was 12. While specific data were not provided on the teaching surgeons’ level of experience, it is highly likely that their experience was similarly lopsided, given that CPS has been the predominant method of cataract extraction for decades and that FLACS is relatively newer and has not been as widely adopted.
It is possible the relative lack of FLACS experience, as opposed to a factor intrinsic to the technique itself, is behind the absence of benefit in terms of efficiencies of time, energy, and irrigation fluid usage. The authors highlight an example scenario in which dearth of experience may be a driving factor: In FLACS cases, wound creation time was longer than in CPS cases due to difficulty with identification of the plane of laser incision. In addition, the surgical step of cortical removal in FLACS is made more difficult by the laser cuts into the anterior cortex, which render it difficult to engage the edge of the cortex. Skills such as these are likely to be experience-related and operator-dependent. In contrast to this paper, prior work demonstrated a significant decrease in phacoemulsification energy use in FLACS compared to CPS in both experienced and resident surgeons.4,9,10 However, there is a learning curve for FLACS even among experienced surgeons; the lack of experience among residents in this study may account for the discrepancy with the findings of other work.11,12,13 This may also be reflected by the residents’ perceptions of each surgical technique, in which 72% of residents reported feeling comfortable with independently performing CPS, while only 39% felt similarly comfortable with FLACS.
Subjects completed questionnaires to assess whether their experience of surgery differed depending on the surgical technique to which their eye(s) were randomized. In the full study cohort, there was no significant difference in satisfaction or level of intraoperative comfort between the groups. However, among patients whose eyes were randomized to opposite techniques, the statistically significant majority preferred FLACS. Since masking of surgical technique did not occur, this finding may have been due to patient bias. That is, patients who experienced both techniques may have perceived FLACS to be a more cutting edge, high value, and precise innovation, thus assigning the technique greater value. Future studies that seek to assess patient experience may benefit from docking the laser for a sham procedure in the CPS group or devising an alternative means of masking.
Overall, this study suggests that while FLACS has compelling theoretical benefits (phacoemulsification energy reduction, standardization of difficult surgical steps, shorter operative time), these benefits are inconsistently demonstrated in the hands of residents, and even when present, do not translate to a meaningful or measurable clinical benefit. However, the lack of experience in FLACS relative to CPS among residents in this study represents a major caveat, as it precludes the possibility of an apples-to-apples comparison of the two techniques. In the absence of a clear efficacy benefit, an argument in favor of FLACS could hinge on improved safety, though this study was underpowered to detect a difference in safety outcomes and failed to demonstrate a difference in many surrogate safety outcomes (e.g., total intraoperative time). Ultimately, this paper adds to the body of work that continues to call into question the feasibility of widespread adoption of FLACS in routine cataract surgery in the increasingly cost-conscious environment of U.S. healthcare.

Contact

Goshe
: GOSHEJ@ccf.org

References

1. He L, et al. Femtosecond laser-assisted cataract surgery. Curr Opin Ophthalmol. 2011;22:43–52.
2. Abell RG, et al. Femtosecond laser-assisted cataract surgery compared with conventional cataract surgery. Clin Exp Ophthalmol. 2013;41:455–462.
3. Reddy KP, et al. Effectiveness and safety of femtosecond laser-assisted lens fragmentation and anterior capsulotomy versus the manual technique in cataract surgery. J Cataract Refract Surg. 2013;39:1297–1306.
4. Abell RG, et al. Toward zero effective phacoemulsification time using femtosecond laser pretreatment. Ophthalmology. 2013;120:942–948.
5. Fan W, et al. Femtosecond laser-assisted cataract surgery in Fuchs endothelial corneal dystrophy: long-term outcomes. J Cataract Refract Surg. 2018;44:864–870.
6. Popovic M, et al. Efficacy and safety of femtosecond laser-assisted cataract surgery compared with manual cataract surgery: a meta-analysis of 14567 eyes. Ophthalmology. 2016;123:2113–2126.
7. Vasavada AR, et al. Femtodelineation to enhance safety in posterior polar cataracts. J Cataract Refract Surg. 2015;41:702–707.
8. Conrad-Hengerer I, et al. Femtosecond laser-assisted cataract surgery in intumescent white cataracts. J Cataract Refract Surg. 2014;40:44–50.
9. Brunin G, et al. Outcomes of femtosecond laser-assisted cataract surgery performed by surgeons-in-training. Graefes Arch Clin Exp Ophthalmol. 2017;255:805–809.
10. Hou JH, et al. Safety of femtosecond laser-assisted cataract surgery performed by surgeons in training. J Refract Surg. 2015;31:69–70.
11. Bali SJ, et al. Early experience with the femtosecond laser for cataract surgery. Ophthalmology. 2012;119:891–899.
12. Sutton G, et al. Femtosecond cataract surgery: transitioning to laser cataract. Curr Opin Ophthalmol. 2013;24:3–8.
13. Roberts TV, et al. Surgical outcomes and safety of femtosecond laser cataract surgery: a prospective study of 1500 consecutive cases. Ophthalmology. 2013;120:227–233.

Outcomes of resident-performed laser-assisted vs. traditional phacoemulsification

Brock Hansen, MD, Preston Blomquist, MD, Peter Ririe, MD, Severin Pouly, MD, Chan Nguyen MD, W. Matthew Petroll, PhD, and James McCulley, MD

J Cataract Refract Surg. 2020;46(9):1282–1286.
• Purpose: To compare the effectiveness of femtosecond laser-assisted cataract surgery (FLACS) and conventional phacoemulsification cataract surgery (CPS) by resident surgeons.
• Setting: Parkland Memorial Health and Hospital System, Dallas, Texas.
• Design: Prospective randomized study.
• Methods: All surgeries to be performed by PGY-3 and 4 residents from October 2015 through June 2017 were eligible for inclusion. Patients were required to complete a postop day 1, week 1, month 1, and month 3 visit. Specular microscopy was performed preoperatively and postoperatively. Surgeries were filmed and each step timed and compared. Surgeon and patient surveys were filled out postoperatively.
• Results: Of the 135 eyes of 96 subjects enrolled in the study, 64 eyes received FLACS and 71 eyes received CPS. There was no significant difference in best corrected visual acuity (BCVA), either preoperatively or at the postop day 1, week 1, month 1, or month 3 visits (P= 0.469, 0.539, 0.701, 0.777, and 0.777, respectively). Cumulated dissipated energy and irrigation fluid usage were not different between FLACS and CPS (P-values 0.521 and 0.368), nor was there a difference in the reduction of endothelial cell counts after surgery (P=0.881). Wound creation (P=0.014), cortical cleanup (P=0.009), and IOL implantation (P=0.031) were faster in the CPS group. Survey results indicated that the overall patient experience was similar for FLACS and CPS.
• Conclusion: This first prospective randomized trial evaluating resident-performed FLACS shows that, in resident hands, FLACS provides similar results to CPS with regard to visual acuity, endothelial cell loss, operative time

Review of “Outcomes of resident-performed laser-assisted vs. traditional phacoemulsification” Review of “Outcomes of resident-performed laser-assisted vs. traditional phacoemulsification”
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