Optical coherence tomography and 3-dimensional confocal structured imaging system-guided femtosecond laser capsulotomy versus manual continuous curvilinear capsulorhexis

Comparing the efficacy and safety between femtosecond laser-assisted cataract surgery and conventional phacoemulsification cataract surgery: systematic review and meta-analysis

OBJECTIVE

To investigate the efficacy and safety of femtosecond laser-assisted cataract surgery (FLACS) compared with conventional phacoemulsification cataract surgery (CPCS).

METHODS

Randomized controlled trials (RCTs) were systematically searched in PubMed, Embase, Cochrane Library, ClinicalTrials.gov, CNKI, and Wanfang. Main outcomes were visual acuity, capsulotomy parameters, effective lens position, and complications. Secondary outcomes included refractive outcomes, intraoperative parameters, and corneal parameters.

RESULTS

In total, 41 RCTs involving 9310 eyes were included. There was a statistically significant difference in favour of FLACS over CPCS for uncorrected distance visual acuity at 12 months (mean difference [MD] -0.03; 95% CI -0.05 to -0.01); corrected distance visual acuity at 1 week (MD -0.05; 95% CI -0.07 to -0.02) and 12 months (MD -0.02; 95% CI -0.04 to -0.00); area of capsulotomy at 1 month (MD 4.04 mm2; 95% CI 3.45-4.64) and 6 months (MD 5.02 mm2; 95% CI 3.28-6.77); and intraocular lens centroid-pupil centroid distance at 1 week (MD -0.06 mm; 95% CI -0.08 to -0.05), 1 month (MD -0.07 mm; 95% CI -0.09 to -0.06), and 6 months (MD -0.06 mm; 95% CI -0.07 to -0.04). With regard to surgical complications, FLACS was less than CPCS for the incidence of decentred IOL (odds ratio 0.06; 95% CI 0.01-0.24). However, FLACS did not increase the incidence of other intraoperative or postoperative complications except subconjunctival hemorrhage.

CONCLUSIONS

Both FLACS and CPCS are effective and safe. FLACS achieves better visual outcomes in the early postoperative period and long-term follow-up, accompanied by more accurate capsulotomy and more optimized effective lens position than CPCS. However, no difference of visual outcomes was found after middle-term follow-up.

Pupil versus 1st Purkinje capsulotomy centration with femtosecond laser: Long term outcomes with a sinusoidal trifocal lens

PURPOSE

To assess the role of femtosecond laser-assisted capsulotomy centration in the long-term intraocular positioning of a multifocal intraocular lens.

DESIGN

Prospective comparative study.

METHODS

A total of 60 eyes of 30 patients underwent femtosecond laser-assisted Refractive Lens Exchange (RLE). For every patient, capsulotomy centration was randomly performed according to pupil centre (PC) in one eye and first Purkinje reflex (FPR) in the other. The intraocular lens (IOL) positioning, visual acuities, spherical equivalent, internal aberrometry and quality of vision were assessed and compared at 3 years' follow-up between groups (PC and FPR).

RESULTS

Intraocular lens positioning showed a statistically significant difference between groups, with a closer centration to the visual axis in the FPR patients (p < 0.001). Internal aberrometry showed higher values in the PC capsulotomy centration group (p < 0.01).

CONCLUSIONS

FPR centered capsulotomy is associated to a closer centration of the IOL to the visual axis.

Femtosecond laser-assisted cataract surgery versus conventional phacoemulsification: A meta-analysis of randomized controlled trials

PURPOSE

The main purpose of our study is to compare the adverse events occurrence, complications, and postoperative outcomes of Femtosecond Laser-Assisted Cataract Surgery (FLACS) versus conventional phacoemulsification surgery (CPS) in adult patients undergoing cataract surgery.

METHODS

We conducted our research using PubMed, Scopus, and MEDLINE through EBSCOhost from 2012 to July 2022 with English and Spanish language restriction, including only Randomized Controlled Trials (RCTs). The PRISMA guidelines were observed for data abstraction, including a random-effects model for each outcome.

RESULTS

We analyzed 4844 eyes from 23 RCTs with some low risk of bias according to RoB 2 tool. We found statistically significant differences between the FLACS and CPS groups for the mean absolute error (MD = -0.12, 95% CI:-0.22-[-0.02], p = 0.01), the circularity of capsulorhexis (MD = 0.04, 95% CI: 0.04-0.05, p ≤ 0.00001), IOL centration (D = -0.07, 95% CI:-0.09-[-0.05], p ≤ 0.00001), CDE count (MD = -1.75, 95% CI: -2.75-[-0.74], p = 0.0006), mean phacoemulsification time (MD = -12.90, 95% CI:-20.89-[-4.92], p = 0.002), EPT (MD = -0.93, 95% CI: -1.68-[-0.019], p = 0.01) and endothelial cell density loss ((MD = -0.6, 95% CI: -1-[-0.19], p = 0.004). Also, the safety analysis showed a lower incidence of posterior capsule tear (PCT) in the FLACS group (OR =0.29, 95% CI: 0.09-1, p = 0.05).

CONCLUSIONS

Our results suggest that FLACS might be helpful for patients with relatively dense cataracts and low preoperative endothelial cell values.

Modified Technique of Setting Capsulotomy Thickness in Reducing Capsulotomy-Related Complications During Femtosecond Laser-Assisted Cataract Surgery: A Prospective, Comparative Cohort Study

INTRODUCTION

Although uncommon, incomplete capsulotomy, anterior capsule tags and anterior capsule tears are still encountered during femtosecond laser-assisted cataract surgery (FLACS), resulting in surgical complications. This highlights the need to improve femtosecond laser-assisted capsulotomy technique to reduce capsulotomy-related complications. Therefore, the purpose of this study was to investigate the efficacy of a newly developed, modified technique of setting capsulotomy irradiation thickness in lowering the incidence of capsulotomy-related complications in FLACS.

METHODS

This open-label prospective, comparative cohort study included 440 eyes (220 patients) treated with FLACS using the LenSx laser system (Alcon Laboratories, Inc. Fort Worth, TX, USA). Varying capsulotomy irradiation thicknesses were applied in each eye of the same patient. In Group 1, capsulotomy irradiation thickness was set between the upper edge of the highest point of the anterior capsule and the lower edge of the lowest point of the anterior capsule (modified technique). In Group 2, this was set between the center of the highest point of the anterior capsule and the center of the lowest part of the anterior capsule (conventional technique). Incidence rates of incomplete capsulotomy, anterior capsule tags and tears, and posterior capsule tears were compared.

RESULTS

Preoperative baseline characteristics showed no significant differences. Mean total of the irradiation thicknesses was 877.1 ± 81.9 µm in Group 1 and 808.9 ± 80.0 in Group 2, with a statistically significant difference (P < 0.001). Incidences of incomplete capsulotomy were 1.8% and 7.7%, anterior capsule tags were 2.3% and 8.6%, and anterior capsule tears were 0% and 3.2% in Groups 1 and 2, respectively. These differences were statistically significant (P = 0.006, 0.005, and 0.015, respectively). No posterior capsule tears were reported in either group.

CONCLUSION

The modified technique for capsulotomy in FLACS may significantly reduce the occurrence of capsulotomy-related complications, maximizing the benefits of FLACS.

Laser-assisted cataract surgery versus standard ultrasound phacoemulsification cataract surgery

BACKGROUND

Cataract is the leading cause of blindness in the world and, as such, cataract surgery is one of the most commonly performed operations globally. Surgical techniques have changed dramatically over the past half century with associated improvements in outcomes and safety. Femtosecond lasers can be used to perform the key steps in cataract surgery, such as corneal incisions, lens capsulotomy and fragmentation. The potential advantage of femtosecond laser-assisted cataract surgery (FLACS) is greater precision and reproducibility of these steps compared to manual techniques. The disadvantages are the costs associated with FLACS technology.

OBJECTIVES

To compare the effectiveness and safety of FLACS with standard ultrasound phacoemulsification cataract surgery (PCS) by gathering evidence from randomised controlled trials (RCTs).

SEARCH METHODS

We searched the Cochrane Central Register of Controlled Trials (CENTRAL; which contains the Cochrane Eyes and Vision Trials Register; 2022, Issue 5); Ovid MEDLINE; Ovid Embase; LILACS; the ISRCTN registry; ClinicalTrials.gov; the WHO ICTRP and the US Food and Drug Administration (FDA) website. We did not use any date or language restrictions in the electronic searches for trials. We last searched the electronic databases on 10 May 2022.

SELECTION CRITERIA

We included RCTs where FLACS was compared to PCS.

DATA COLLECTION AND ANALYSIS

Three review authors independently screened the search results, assessed risk of bias and extracted data using the standard methodological procedures expected by Cochrane. The primary outcome for this review was intraoperative complications in the operated eye, namely anterior capsule, and posterior capsule tears. The secondary outcomes included corrected distance visual acuity (CDVA), quality of vision (as measured by any validated patient-reported outcome measure (PROM)), postoperative cystoid macular oedema complications, endothelial cell loss and cost-effectiveness. We assessed the certainty of the evidence using GRADE.

MAIN RESULTS

We included 42 RCTs conducted in Europe, North America, South America and Asia, which enrolled a total of 7298 eyes of 5831 adult participants. Overall, the studies were at unclear or high risk of bias. In 16 studies the authors reported financial links with the manufacturer of the laser platform evaluated in their studies. Thirteen of the studies were within-person (paired-eye) studies with one eye allocated to one procedure and the other eye allocated to the other procedure. These studies were reported ignoring the paired nature of the data. There was low-certainty evidence of little or no difference in the odds of developing anterior capsular tears when comparing FLACS and PCS (Peto odds ratio (OR) 0.83, 95% confidence interval (CI) 0.40 to 1.72; 5835 eyes, 27 studies) There was one fewer anterior capsule tear per 1000 operations in the FLACS group compared with the PCS group (95% CI 4 fewer to 3 more).  There was low-certainty evidence of lower odds of developing posterior capsular tears with FLACS compared to PCS (Peto OR 0.50, 95% CI 0.25 to 1.00; 5767 eyes, 26 studies). There were four fewer posterior capsule tears per 1000 operations in the FLACS group compared with the PCS group (95% CI 6 fewer to same).  There was moderate-certainty evidence of a very small advantage for the FLACS arm with regard to CDVA at six months or more follow-up, (mean difference (MD) -0.01 logMAR, 95% CI -0.02 to 0.00; 1323 eyes, 7 studies). This difference is equivalent to 1 logMAR letter between groups and is not thought to be clinically important. From the three studies (1205 participants) reporting a variety of PROMs (Cat-PROMS, EQ-5D, EQ-SD-3L, Catquest9-SF and patient survey) up to three months following surgery, there was moderate-certainty evidence of little or no difference in the various parameters between the two treatment arms. There was low-certainty evidence of little or no difference in the odds of developing cystoid macular oedema when comparing FLACS and PCS (Peto OR 0.84, 95% CI 0.56 to 1.28; 4441 eyes, 18 studies). There were three fewer cystoid macular oedema cases per 1000 operations in the FLACS group compared with the PCS group (95% CI 10 fewer to 6 more).  In one study the incremental cost-effectiveness ratio (ICER) (cost difference divided by quality-adjusted life year (QALY) difference) was GBP £167,620 when comparing FLACS to PCS. In another study, the ICER was EUR €10,703 saved per additional patient who had treatment success with PCS compared to FLACS. Duration ranged from three minutes in favour of FLACS to eight minutes in favour of PCS (I2 = 100%, 11 studies) (low-certainty evidence).  There was low-certainty evidence of little or no important difference in endothelial cell loss when comparing FLACS with PCS (MD 12 cells per mm2 in favour of FLACS, 95% CI -40 to 64; 1512 eyes, 10 studies).  AUTHORS' CONCLUSIONS: This review of 42 studies provides evidence that there is probably little or no difference between FLACS and PCS in terms of intraoperative and postoperative complications, postoperative visual acuity and quality of life. Evidence from two studies suggests that FLACS may be the less cost-effective option. Many of the included studies only investigated very specific outcome measures such as effective phacoemulsification time, endothelial cell count change or aqueous flare, rather than those directly related to patient outcomes. Standardised reporting of complications and visual and refractive outcomes for cataract surgery would facilitate future synthesis, and guidance on this has been recently published.

Comparison of femtosecond laser-assisted cataract surgery and conventional phacoemulsification on corneal impact: A meta-analysis and systematic review

This meta-analysis aims to compare corneal injuries and function after femtosecond laser-assisted cataract surgery (FLACS) and conventional phacoemulsification surgery (CPS). A comprehensive literature search of PubMed, EMBASE, and the Cochrane Controlled Trials Register was conducted to identify randomized controlled trials (RCT) and high-quality prospective comparative cohort studies comparing FLACS with CPS. Endothelial cell loss percentage (ECL%), central corneal thickness (CCT), endothelial cell density (ECD), endothelial cell loss (ECL), percentage of the hexagonal cell (6A), and coefficient of variance (CoV) were used as an indicator of corneal injury and function. Totally 42 trials (23 RCTs and 19 prospective cohort studies), including 3916 eyes, underwent FLACS, and a total of 3736 eyes underwent CPS. ECL% is significantly lower in the FLACS group at 1-3 days (P = 0.005), 1 week (P = 0.004), 1 month (P<0.0001), 3 months (P = 0.001), and 6 months (P = 0.004) after surgery compared to CPS. ECD and ECL appeared no statistically significant difference between the two groups, except for the significant reduction of ECD at 3 months in the CPS group (P = 0.002). CCT was significantly lower in the FLACS group at 1 week (P = 0.05) and 1 month (P = 0.002) early postoperatively. While at 1-3 days (P = 0.50), 3 months (P = 0.18), and 6 months (P = 0.11), there was no difference between the FLACS group and the CPS group. No significant difference was found in the percentage of hexagonal cells and the coefficient of variance. FLACS, compared with CPS, reduces corneal injury in the early postoperative period. Corneal edema recovered faster in the FLACS group in the early postoperative period. In addition, FLACS may be a better option for patients with corneal dysfunction.

Pupil Status with Low-Energy Femtosecond Laser-Assisted Cataract Surgery versus Conventional Phacoemulsification: An Intraindividual Comparative Study

Purpose

To compare the pupil changes in low-energy femtosecond laser-assisted cataract surgery (FLACS) with conventional phacoemulsification (CP) intraindividually.

Patients and Methods

A retrospective review of registered surgical data from patients that undergone uncomplicated cataract surgery in a single centre, with randomly assigned femtosecond laser-assisted cataract surgery (FLACS) to one eye and conventional phacoemulsification (CP) to the other, was performed. The recorded pupil images were evaluated at pre and post laser treatment (after suction release) and at several surgical timepoints for both techniques (FLACS and CP). Pupil areas were calculated and compared in the same eye undergone FLACS (pre vs post laser treatment), between eyes (CP vs FLACS) in the same patient and between groups. Subgroups were built regarding age and ocular comorbidity.

Results

This study involved a total of 164 eyes of 82 patients (55 female, 27 male). No statistical differences regarding the total duration of surgery (p=0.805) between FLACS and CP. Pupil measurements between pre and post laser treatment in the FLACS group showed no statistically significant differences (p=0.107). The mean change in pupil area from the beginning until the end of surgery (total variation) was 6.59±2.08 mm² in the FLACS group and 6.67±2.13 mm² in the CP group, associated to less narrowing of pupil area with FLACS, although not statistically significant (p=0.080). Comorbidity group analysis revealed less, but not significant, pupil narrowing with the FLACS technique (p=0.071). No statistically significant differences between FLACS and CP concerning age subgroups were registered.

Conclusion

This study shows no significant pupil changes, namely myosis, after low-energy FLACS pre-treatment. Comparison between techniques showed less pupil variation in FLACS as compared to CP, more markedly in eyes with comorbidities (particularly with shallow anterior chamber), although non-statistically significant.

Multiple linear regression model for improving accuracy of capsulorhexis size calculation in femtosecond laser-assisted cataract surgery for adults: a retrospective single-center study

BACKGROUND

Differences between programmed capsulorhexis diameter and actual resulting capsulorhexis diameter (ARCD) are commonly encountered in femtosecond laser-assisted cataract surgery (FLACS). The purpose of this study was to identify the preoperative ophthalmic variables influencing capsulorhexis diameter index (CDI) in FLACS for adults and create a multiple linear regression model for obtaining a more accurate capsulorhexis diameter.

METHODS

This retrospective study involved sixty-seven eyes of 44 patients who received FLACS and intraocular lens implantation. The ARCD was measured using anterior segment swept-source optical coherence tomography (CASIA 2). Keratometry (K1, K2 and average K), anterior chamber depth (ACD), lens thickness (LT), anterior chamber width (ACW), white-to-white (WTW), curvature radius of anterior lens capsule (Front R) and axial length (AL) were all measured preoperatively. Based on the derived data, LT/ACW, LT/AL, LT/ACD and LT/ACW/Front R were calculated. The ratio of the programmed capsulorhexis diameter and ARCD was defined as the CDI. Correlation analysis was conducted to examine the relationship between preoperative variables listed above and the CDI. Multiple linear regression analysis was applied to select the most influential preoperative variables on CDI.

RESULTS

ACD, LT, ACW, Front R, AL, LT/ACW, LT/AL, LT/ACD, and LT/ACW/Front R showed significant correlation with CDI. Front R and LT/ACW/Front R were selected as constants in the multiple linear regression model using stepwise variable selection. The following equation represents the multiple linear regression model: CDI = 1.306-4.516 × LT/ACW/FrontR-0.011 × Front R, when P < 0.0001, adjusted R-squared = 0.919, variance inflation factor = 8.389, and Durbin-Watson ratio = 1.846. Predicted postoperative capsulorhexis diameter (PPCD) equation was created based on CDI equation as follows: PPCD = programmed capsulorhexis diameter × 1.306-4.516 × LT/ACW/FrontR-0.011 × Front R.

CONCLUSION

Front R and LT/ACW/Front R were found to be the most significant influencing factors of capsulorhexis size. CDI and PPCD calculation equations presented in this study may be useful in setting up more accurate programmed capsulorhexis diameter for FLACS in adults, resulting in a precise ARCD.

Comparison of ultrasound energy consumption between low-energy femtosecond laser-assisted cataract surgery and conventional phacoemulsification cataract surgery in patients with different cataract densities

PURPOSE

Femtosecond laser-assisted cataract surgery (FLACS)'s effect on reducing ultrasound energy, accumulated with cumulative dispersed energy (CDE) units, still remains controversial. This study aims to evaluate the effect of low-energy FLACS on CDE with that of conventional phacoemulsification surgery (CPS) in different cataract densities from multiple surgeons.

METHODS

It was a retrospective case-control study. Total 629 eyes receiving either low-energy FLACS (performed with Ziemer LDV Z8 platform) or CPS were divided into two groups according to preoperative grading of Lens Opacity Classification System III (LOCSIII): milder and harder cataract group. The mean CDE were compared in different cataract densities and surgeons. A linear regression analysis was performed to evaluate the effect of using low-energy FLACS on CDE in harder cataract cases.

RESULTS

We found overall CDE had no significant difference between two surgeries. However, low-energy FLACS led to a significantly lower CDE in patients with harder cataracts than CPS (18.47 ± 4.32 vs. 12.96 ± 2.34; p < 0.001). Similar results were observed in the three surgeon subgroups and in linear regression analysis and no significant difference of the effect accounting for surgeons. Moreover, low-energy FLACS results in a reduction of energy consumption comparing to CPS and has endothelial sparring effect in patients with harder cataracts.

CONCLUSIONS

The reduced energy consumption was observed by using low-energy FLACS irrespective of surgeons' experience or the approaches adopted in patients with harder cataracts. Therefore, we can have more confidence to suggest this innovative platform to the patients in such cases.

Clinical outcomes of femtosecond laser-assisted cataract surgery versus conventional phacoemulsification: A retrospective study in a tertiary eye care center in South India

Purpose

To compare the clinical outcomes of femtosecond laser-assisted cataract surgery (FLACS) versus conventional phacoemulsification (CP) in terms of refractive outcomes, cumulative dissipated energy, and intraoperative complications.

Methods

In this retrospective study performed in a tertiary care ophthalmic hospital, we reviewed 2124 eyes that underwent FLACS or CP. Uncorrected distance visual acuity (UDVA), corrected distance visual acuity (CDVA), cumulative dissipated energy (CDE), and intraoperative complications were analyzed in the study.

Results

Out of 2124 eyes, 873 underwent FLACS and 1251 underwent CP. The postoperative mean UCVA after one month was 0.05 ± 0.11 logMAR and 0.14 ± 0.23 logMAR for FLACS and CP, respectively (P < 0.00001). Mean CDVA one month post operation was 0.02 ± 0.07 logMAR and 0.06 ± 0.19 logMAR for FLACS and CP, respectively (P < 0.0001). The CDE for the FLACS group was 6.17 ± 3.86 (P < 0.00001) and it was 9.74 ± 6.02 for the CP group. The intraoperative complication for the FLACS group was 1.60% and the CP group was 2.39% (P < 0.00001).

Conclusion

The visual outcomes were better in FLACS compared to CP. The CDE was lower for the FLACS group and FLACS had significantly less intraoperative complications.

Comparison of the actual diameter of capsulotomy and predicted diameter of capsulotomy after femtosecond laser-assisted capsulotomy

PURPOSE

To compare the consistency between the actual diameter of capsulotomy (ADC) and the predicted diameter of capsulotomy (PDC) in femtosecond laser-assisted cataract surgery (FLACS) and analyze the factors that influence the deviation of the diameter of capsulotomy (DDC) between the actual and predicted.

SETTING

Aier Eye Hospital of Wuhan University, China.

DESIGN

Retrospective observational case series.

METHODS

Patients who underwent FLACS from March 2020 to March 2021 were reviewed. The ADC in FLACS was measured and compared with the PDC. The effects of age, sex, and biometrics on DDC were analyzed.

RESULTS

412 eyes of 336 patients were included. The mean age was 53.0 ± 0.91 years (range 3 to 91 years). When the PDC was set to 4.50 mm, the results showed that the ADC was 5.21 ± 0.21 mm with a significant difference between them ( P &amp;lt; .05). However, when the PDC was set to 5.2 mm, the ADC was 5.10 ± 0.38 mm without a significant difference between them ( P &amp;gt; .05). No correlation ( P &amp;gt; .05) was found between the DDC and the axial length, the DDC and the anterior chamber depth (ACD), and the DDC and the mean keratometry (Km), but a negative correlation was found between the DDC and the lens thickness (LT) ( r = -0.21; P &amp;lt; .05) and the DDC with age ( r = -0.70; P &amp;lt; .05). Using curvilinear regression analysis, a development of an age-depending correction formula was predicted: ADC = PDC + 1.23 - 0.30 ln (x) (x = age ≥3) ( R2 = 0.65; F = 752.39; P = .00).

CONCLUSIONS

The consistency of the ADC and PDC was influenced by age and LT. For patients aged 40 years or younger, the younger the patient, the wider the DDC; for patients older than 40 years, the DDC was small. The thicker the LT, the smaller the DDC.

Intraoperative Anterior Segment Optical Coherence Tomography in the Management of Cataract Surgery: State of the Art

Background: The introduction of non-invasive diagnostic tools in ophthalmology has significantly reshaped current clinical practice in different settings. Recently, different anterior segment (AS) intraoperative optical coherence tomography (i-OCT) systems have been employed for different interventional procedures including cataract surgery. Materials and Methods: A review on the use of AS i-OCT in the management of cataract surgery, following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines (PRISMA). The level of evidence according to the Oxford Centre for Evidence-Based Medicine (OCEM) 2011 guidelines, and the quality of evidence according to the Grading of Recommendations Assessment, Development and Evaluation (GRADE) system were assessed for all included articles. Results: Out of 6302 articles initially extracted, 6302 abstracts were identified for screening and 32 of these met the inclusion/exclusion criteria for full-text review; 19 articles were excluded. Conclusions: The use of AS i-OCT in cataract surgery, even if only a few studies have a high level or grade of evidence, may represent a useful tool for novel surgeons approaching phacoemulsification but also for expert ones for teaching purposes and to plan and manage complicated cases.

A Counter Prechop Technique Using a Modified Universal Prechopper in Combination with or without Using a Universal Chopper

Purpose

To introduce an alternative prechop technique without or with the use of a modified universal chopper (AE-2591, HI Kim chopper, ASICO, Inc. USA).

Methods

Patients who underwent cataract surgery using the phaco-chop technique and the modified prechop technique have been grouped and reviewed retrospectively. Endothelial cell count (ECC) and central corneal thickness (CCT) measured 7 days pre-operatively, and 1 month and 3 months post-operatively, were compared between the two groups. In modified prechop technique, a narrow 1.7 mm neck prechopper (AE-4298, HI Kim-Inamura chopper, ASICO, Inc., USA) was used with universal chopper (AE-2591, HI Kim chopper, ASICO, Inc., USA) as an additional device for grade 4 and above cataracts or without it for grade 2 to 3 cataracts. Details of the surgical technique is further described in the Method section.

Results

A total of 104 eyes in the modified prechop group and 97 eyes in the phaco-chop group were enrolled in the study. Pre-operative nuclear opacity, ECC, and CCT as well as post-operative ECC (absolute value and the loss) and CCT (absolute value and the change) throughout the follow-up between the two groups did not show statistically significant differences.

Conclusion

Counter prechop technique using the modified prechopper and universal chopper is a safe, easy, and versatile surgical technique that can be applied broadly in a wide range of cases with various complexities, including LOCS lll N1 to N6 nuclei, hypermature cataracts, small pupils, and fragile suspensory zonular ligaments, with post-operative result not inferior to that of the conventional technique.

Study on the enlargement index of femtosecond laser-assisted capsulorhexis in 2-6-year-old patients with congenital cataract

Background

To identify the capsule enlargement index after femtosecond laser-assisted anterior capsulorhexis in 2–6-year-old children who underwent congenital cataract surgery.

Methods

In this prospective case series study, femtosecond laser-assisted anterior capsulorhexis was performed in patients with congenital cataract, aged 2–6 years. The actual achieved capsulorhexis diameters were measured with Digimizer version 4.2.6. Correlation coefficient (r) and multiple linear regression analysis were used to evaluate the variables that could potentially influence anterior capsulorhexis enlargement index (E).

Results

This prospective study enrolled 28 eyes of 22 patients with congenital cataract. The mean age of the patients at surgery was 4.67 years ±1.54 (standard deviation [SD]). “E” of the 28 cases was 1.211 ± 0.039 (SD). Correlation analysis showed that “E” correlated significantly with the anterior chamber depth (ACD) (r = − 0.469, p = 0.021) and axial length (AL) (r = 0.452, p = 0.027). The following formula was developed by using multivariable linear regression analysis: Predicted E = 1.177–0.052 × ACD + 0.009 × AL, R² = 0.346 (F = 4.396, p = 0.046).

Conclusions

The anterior capsulorhexis enlargement index and its calculation formula could help to set up an accurate programmed capsulorhexis diameter for femtosecond laser-assisted congenital cataract surgery in children aged 2–6 years. Thus, an appropriate actual capsulorhexis diameter could be achieved.

Thermal Profile of Pulse Precision Capsulotomy: In vivo and in vitro Infrared Thermography Study

Purpose

This study aimed to elucidate the thermal safety of precision pulse capsulotomy (PPC) via in vivo and in vitro evaluation of the thermal profile using infrared thermography.

Methods

This prospective observational study enrolled 15 eyes from 15 participants who underwent cataract surgery using the Zepto PPC. All patients underwent temperature measurements of the incision site and the entire cornea using an infrared thermographer during the capsulotomy procedure. To accurately analyze the temperature change of the Zepto PPC, infrared thermography was performed with the Zepto handpiece while exposed to air and then in porcine eyes. Moreover, in each case, the difference in temperature change according to the use of an ophthalmic viscosurgical device (OVD) was also checked to determine the temperature buffering effect.

Results

In the clinical evaluations, the mean temperature elevation around the corneal incision and time duration from baseline to peak temperature during the Zepto capsulotomy were 4.0 ± 1.9℃ and 4.43 ± 1.26 s, respectively, with a mean peak temperature of 32.6 ± 2.0℃. The mean peak temperature and rise time of the naïve Zepto nitinol ring, as measured from the bottom side, were 109.0 ± 22.9℃ and 43.40 ± 11.06 s in the experimental procedures, respectively. In the porcine eyes, the mean elevation of temperature and rise time of the Zepto nitinol ring were 6.2 ± 1.6℃ and 11.67 ± 2.08 s with the use of OVDs, and 10.5 ± 3.3℃ and 14.00 ± 3.61 s without OVDs, respectively.

Conclusions

Zepto PPC has the potential to generate extremely high thermal energy, according to an in vitro study. However, the temperature rise of the Zepto capsulotomy can be minimized by using OVDs.

Clinical outcomes and complications between FLACS and conventional phacoemulsification cataract surgery: a PRISMA-compliant Meta-analysis of 25 randomized controlled trials

AIM

To update and investigate the clinical outcomes and complications between femtosecond laser-assisted cataract surgery (FLACS) and conventional phacoemulsification cataract surgery (CPCS).

METHODS

A Meta-analysis was performed using databases, including Pubmed, Embase, and the Cochrane library. At least one of the clinical outcomes and/or complications data in each included randomized controlled trials (RCT) was reported. The quality of the RCT was assessed with the Cochrane risk assessments tool.

RESULTS

Overall, 25 RCTs including 3781 eyes were included. No statistically significant difference detected between FLACS and CPCS in terms of corrected distant visual acuity (CDVA), uncorrected distant visual acuity (UDVA), and central corneal thickness (CCT) at the long-term follow up, although FLACS showed better CDVA at 1wk postoperatively, and less increase in CCT at 1d and 1wk. FLACS had better postoperative endothelial cell count (ECC) at 1 and 4-6wk, while there was no significantly difference between FLACS and CPCS at 1d, 3 and 6mo [weighted mean difference (WMD): 51.54, 95% confidence interval (CI): -5.46 to 108.54, P=0.08; WMD: 48.52, 95%CI: -17.54 to 114.58, P=0.15; WMD: 12.17, 95%CI: -48.61 to 72.94, P=0.69, respectively]. Postoperative endothelial cell loss (ECL) of the FLACS was significantly lower than that of the CPCS at 1, 4-6wk, and 3mo (P=0.02, 0.008, 0.03, respectively). However, there was no significant difference between two groups at 6mo (WMD: -30.36, 95%CI: -78.84 to 18.12, P=0.22). No significant difference was discovered with respect to the macular edema [odds ratio (OR): 0.93, 95%CI: 0.42 to 2.05, P=0.85], capsular complication excluding posterior capsular tears (OR: 0.79, 95%CI: 0.42 to 1.50, P=0.47) and intraocular pressure change (OR: 0.82, 95%CI: 0.39 to 1.72, P=0.60). However, posterior capsular tears were more common in CPCS group (OR: 0.12, 95%CI: 0.01 to 0.98, P=0.05). The effective phacoemulsification times were significantly lower in the FLACS group compared to the CPCS group (WMD: -0.78, 95%CI: -1.23 to -0.34, P=0.0006).

CONCLUSION

No statistically significant difference is discovered between FLACS and CPCS in clinical outcomes at the long-term follow up. However, higher rate of posterior capsular tears is detected in patients receiving CPCS.

Comparison of cumulative dispersed energy between conventional phacoemulsification and femtosecond laser-assisted cataract surgery with two different lens fragmentation patterns

The purpose of the study is to compare the total ultrasound power used between eyes undergoing different lens fragmentation patterns of femtosecond laser-assisted cataract surgery (FLACS) and conventional phacoemulsification surgery (CPS). A total of 506 patient eyes underwent preoperative grading of lens opacity using the Lens Opacity Classification System III (LOCSIII). The eyes were divided into two subgroups: subgroup 1 had a LOCSIII grade of 1-3, and subgroup 2 had a LOCSIII grade of 4-6. The eyes underwent FLACS (LenSx) for clear corneal wound, capsulotomy, and lens fragmentation. Either a grid pattern or radial pattern was used for lens fragmentation. The eyes received one of the following three treatments: (1) CPS without femtosecond laser assistant, (2) FLACS with a grid pattern (FGP) lens fragment, or (3) FLACS with a quadrant pattern (FQP) lens fragment. The mean cumulative dispersed energy (CDE) for each subgroup and treatment was evaluated. The mean CDE was lower in the two FLACS groups (1.21±1.91 in FGP and 1.22±1.92 in FQP) than that in the CPG group (2.67±2.84). In subgroup 1, CDE was higher in the CPG group (1.54±1.18) as compared with the FLACS groups (0.16±0.31 in FGP and 0.74±1.17 in FQP; P<0.001). In subgroup 2, CDE was higher in the CPG (6.47±3.46) as compared with the FLACS groups (2.74±2.21 in FGP and 5.34±2.17 in FQP; P<0.001). CDE was lower in the two FLACS groups than that in the CPS group, and CDE was the lowest with FGP in both subgroups 1 and 2.

Femtosecond Laser-assisted Lens Surgery with Low-energy Pulse versus Conventional Phacoemulsification for Presbyopia Correction: An Intraindividual Study

Background:

Lens surgery with multifocal IOL implantation for presbyopia correction is performed by femtosecond laser-assisted lens surgery or conventional phacoemulsification.

Objective:

To compare the clinical results of femtosecond laser-assisted with low-energy pulse conventional phacoemulsification lens surgery for presbyopia correction intraindividually.

Methods:

Charts from patients who underwent Refractive Lens Exchange (RLE) for presbyopia correction in a single center, with Femtosecond Laser-Assisted Lens Surgery (FLALS) in one eye and Conventional Phacoemulsification (CP) in the other, were retrospectively reviewed. All eyes had the same multifocal Intraocular Lens (IOL) implanted. The clinical outcomes and the results of the level of satisfaction questionnaire were compared between the two groups according to the technique employed (FLALS vs. CP) for a period of up to four years. Stability, efficacy and safety indices were also assessed.

Results:

This study comprised a total of 56 eyes of 28 patients randomly assigned FLALS in one eye and CP in the other. No statistically significant difference was observed between the two techniques regarding postoperative visual acuities, duration of surgical procedure, efficacy or safety indexes (p>0.05). Refraction was stable in all FLALS eyes, whereas a change occurred in 2 eyes (7.1%) operated with CP upon 6 months postoperatively, but without statistical significance (p˃0.05). Satisfaction was slightly better with FLALS but not statistically significant (p=0.134). No immediate myosis or other adverse events after the femtosecond laser were registered.

Conclusion:

The parameters assessed showed no significant differences between the two techniques, in spite of a difference of refraction stability upon 6 months postoperatively.

A Comparison of Refractive Accuracy Between Conventional and Femtosecond Laser Cataract Surgery Techniques Using Modern IOL Formulas

PURPOSE

To compare the refractive outcome prediction accuracy between conventional (CCS) and femtosecond laser assisted (FLACS) cataract surgery techniques using optimized lens constants for modern intraocular lens (IOL) formulas.

PATIENTS AND METHODS

Our retrospective, comparative, interventional case series, compared data from 196 eyes undergoing CCS and 456 eyes undergoing FLACS with Acrysof IOL (Alcon laboratories, Inc) implantation. After optimizing IOL constants, the predicted refractive outcome was calculated for all formulas for each case. This was compared to the actual refractive outcome to provide the prediction error. The performance of CCS and FLACS was compared by the absolute prediction error and percentage of eyes within 0.25D, 0.5D and 1.0D of anticipated refractive outcome.

RESULTS

There was no statistically significant difference in median absolute error between the CCS and LACS groups for the Kane (0.256, 0.236; p=0.389), SRK T (0.298, 0.302, p=0.910), Holladay (0.312, 0.275; p=0.090), Hoffer Q (0.314, 0.289; p=0.330), Haigis (0.309, 0.258; p=0.177), Barrett Universal 2(0.250, 0.250; p=0.866), Holladay 2 (0.250, 0.258; p=0.860) and Olsen (0.260, 0.255; p=0.570) formulas. Similarly, there was no consistent difference between the two techniques for percentage of patients within 0.25, 0.50 and 1.0D of predicted refractive outcome for each formula.

CONCLUSION

There was no difference in refractive outcome prediction accuracy between the CCS and FLACS techniques.

Femtosecond laser-assisted cataract surgery in shallow anterior chamber cases

PURPOSE

To assess the effectiveness, safety and predictability of femtosecond laser-assisted cataract surgery (FLACS) in eyes with shallow anterior chamber (AC).

METHODS

This is a prospective consecutive clinical study. All eyes presented an anterior chamber depth (ACD) ≤ 2.1 mm and were submitted to FLACS with monofocal intraocular lens (mIOL) or trifocal intraocular lens (tIOL) implantation. Uncorrected distance visual acuity (VA) and corrected distance VA values were used to assess efficacy and safety of the surgery. Refraction, intraocular pressure (IOP), endothelial cell density (ECD) and ACD were evaluated before and 6 months post-surgery.

RESULTS

Phacoemulsification was carried out successfully in all eyes, without intra- or postoperative complications. Efficacy and safety indexes were 0.96 and 1.26 for the mIOL group, and 0.87 and 1.01 for the tIOL group, respectively. The mean postoperative spherical equivalent was - 0.06 ± 0.28D and - 0.14 ± 0.38D for the mIOL and tIOL groups, respectively. The ECD varied from 2470 ± 483 to 2009 ± 538 cells/mm² (p < 0.05) and from 2443 ± 319 to 2245 ± 628 cells/mm² (p = 0.06) for the mIOL and tIOL groups, respectively. IOP significantly decreased (p < 0.05) after the surgery from 14.34 to 12.85 mmHg for the mIOL group and from 14.37 to 11.91 mmHg for the tIOL group, with a general reduction of medical hypotensive treatment in both groups (85% of cases required ≤ number of medications). ACD changed significantly (p < 0.05) from 1.96 ± 0.15 mm to 3.75 ± 0.30 mm after the surgery in the mIOL group and from 1.94 ± 0.15 mm to 3.23 ± 0.21 mm for the tIOL group.

CONCLUSION

FLACS with implantation of either mIOL or tIOL may provide good efficacy, safety and predictability in eyes with shallow AC.

Evaluation of femtosecond laser-assisted cataract surgery after 10 years of clinical application

INTRODUCTION

Femtosecond laser-assisted cataract surgery (FLACS) has been considered a technological advance in modern cataract surgery. After years of experience, it has been observed that clinical outcomes had more complications than expected at the beginning. The aim of this study is to compare the benefits and disadvantages of the FLACS technique with conventional cataract surgery.

METHOD

The PubMed and Web of Science platforms were used to search for scientific literature.

RESULTS

The FLACS has currently improved the surgical technique in terms of the shorter ultrasound time used and the lower loss of endothelial cells. Likewise, the centration of capsulotomy and the correction of astigmatism with arcuate incisions have also been improved. As disadvantages, are the high cost of the laser, the intraoperative capsular complications, the induction of intraoperative myosis, and the learning curve of the technique.

CONCLUSIONS

The FLACS technique is considered beneficial for specific cases, such as patients with scheduled premium surgery, or with low endothelial cell count. However, it is believed that given the technological cost it is not a cost effective technique for most standard cases in our daily clinical practice.

A randomised controlled trial comparing femtosecond laser-assisted cataract surgery versus conventional phacoemulsification surgery: 12-month results

AIMS

To report 12-month outcomes of randomised controlled trial comparing conventional phacoemulsification surgery (CPS) with femtosecond laser-assisted cataract surgery (FLACS).

METHODS

This was a single-centre, prospective single-masked randomised case-controlled trial. Four hundred patients were randomised to CPS or FLACS with the LenSx platform (Alcon Laboratories Inc.). Visual acuity, refraction, central corneal thickness, endothelial cell loss (ECL), adverse events and quality of life outcomes, using EuroQOL 5-dimensions (EQ-5D-3 L) and cataract surgery patient-reported outcome measures (PROMs) questionnaires (Cat-PROM5), were recorded.

RESULTS

Two hundred and thirty four patients (58.5%) attended 12-month follow-up (116 FLACS, 118 CPS). Mean LogMAR unaided distance visual acuity) (±SD) was 0.12 (0.18) with FLACS and 0.13 (0.19) with CPS (p=0.68; 95% Confidence Interval [CI]-0.06,0.04). Mean spherical equivalent (SE) refraction was -0.1±0.6 diopters (D) with FLACS and -0.2±0.6 D with CPS (p=0.44; 95% CI -0.09, 0.21). Mean corrected distance visual acuity (±SD) was -0.01 (0.1) with FLACS and 0(0.1) with CPS (p=0.45; 95% CI -0.04,0.02). Two patients per group underwent YAG laser capsulotomy for posterior capsular opacification (p=1). Mean ECL (per mm²±SD) was 301±320 with FLACS and 228±303 with CPS (p=0.07; 95% CI -7.26, 153.26). Mean Cat-PROM scores (±SD) were -5.5 (2.6) with FLACS and -5.8 (2.5) with CPS (p=0.3; 95% CI 0.31,1.01). EQ5-3DL mean index score (±SD) was 0.92 (0.13) with FLACS and 0.89 (0.14) with CPS (p=0.1; 95% CI -0.1, 0.01). Vector analysis comparing manual limbal relaxing incisions (LRIs) and intrastromal femtosecond laser-assisted astigmatic keratotomies (iFAKs) showed a greater correction index (p=0.02; 95% CI 0.06 to 0.60) and smaller difference vector (p=0.046; 95% CI -0.54, -0.01) with iFAK.

CONCLUSIONS

There were no differences in vision, refraction, adverse postoperative events or PROMs between FLACS and CPS groups at 12 months. iFAKs may provide more effective astigmatic correction compared to LRIs, 12 months postoperatively.

The benefits and drawbacks of femtosecond laser-assisted cataract surgery

INTRODUCTION

Since the introduction, femtosecond laser-assisted cataract surgery was believed to revolutionize cataract surgery. However, the judgment of clinical benefit was found to be far more complex than initially might have been thought. The aim of this review was to analyze the benefits and drawbacks of femtosecond laser-assisted cataract surgery compared with traditional phacoemulsification cataract surgery.

METHODS

PubMed and the Web of Science were used to search the medical literature. The following keywords were searched in various combinations: femtosecond laser, femtosecond laser-assisted cataract surgery, phacoemulsification cataract surgery, FLACS.

RESULTS

The benefits of femtosecond laser-assisted cataract surgery include lower cumulated phacoemulsification time and endothelial cell loss, perfect centration of the capsulotomy, and opportunity to perform precise femtosecond-assisted arcuate keratotomy incisions. The major disadvantages of femtosecond laser-assisted cataract surgery are high cost of the laser and the disposables for surgery, femtosecond laser-assisted cataract surgery-specific intraoperative capsular complications, as well as the risk of intraoperative miosis and the learning curve.

CONCLUSION

Femtosecond laser-assisted cataract surgery seems to be beneficial in some groups of patients, that is, with low baseline endothelial cell count, or those planning to receive multifocal intraocular lens. Nevertheless, having considered that the advantages of femtosecond laser-assisted cataract surgery might not be clear in every routine case, it cannot be considered as cost-effective.

Comparison of real-world treatment outcomes of femtosecond laser-assisted cataract surgery and phacoemulsification cataract surgery: A retrospective, observational study from an outpatient clinic in France

PURPOSE

This study compared real-world safety and efficacy outcomes of cataract surgery performed with LenSx femtosecond laser-assisted cataract surgery or manual phacoemulsification cataract surgery procedures.

METHODS

A retrospective observational study used data from anonymised electronic medical records to compare mean cumulative dissipated energy, the proportion of eyes reaching emmetropia, mean change in best-corrected distance visual acuity and the proportion of eyes with post-surgical complications, including corneal oedema and posterior capsule opacification. Results were adjusted for multiple comparisons for primary and secondary objectives.

RESULTS

Data from 811 phacoemulsification cataract surgery and 496 femtosecond laser-assisted cataract surgery procedures were analysed. Mean cumulative dissipated energy was significantly lower for femtosecond laser-assisted cataract surgery (6.5 percent-seconds) than for phacoemulsification cataract surgery (14.3 percent-seconds; p < 0.0001) procedures. More femtosecond laser-assisted cataract surgery (81.2%) procedures achieved emmetropia (⩽ 0.5 dioptre) than did phacoemulsification cataract surgery (73.5%) procedures, although this difference was not statistically significant. Mean change in best-corrected distance visual acuity and the proportion of eyes with corneal oedema, posterior capsule opacification or other complications were not significantly different between cohorts when adjusted for multiple comparisons.

CONCLUSIONS

In this single-centre, single-surgeon retrospective electronic medical record database study using divide and conquer technique, femtosecond laser-assisted cataract surgery was associated with significantly lower cumulative dissipated energy when compared to manual phacoemulsification cataract surgery. This supports the hypothesis that femtosecond laser-assisted cataract surgery involves less mechanical trauma, which might lead to more consistent refractive and safety outcomes than manual phacoemulsification cataract surgery, though such outcomes were found to be comparable in this study.

Femtosecond laser-assisted cataract surgery: A review

PURPOSE

Review scientific literature concerning femtosecond laser-assisted cataract surgery.

METHODS

Following databases were searched: CENTRAL (Cochrane Eyes and Vision Trials Register; Cochrane Library: Issue 2 of 12, June 2019), Ovid MEDLINE^® without Revisions (1996 to June 2019), Ovid MEDLINE^® (1946 to June 2019), Ovid MEDLINE^® Daily Update June 2019, MEDLINE and MEDLINE Non-Indexed Items, Embase (1980-2019), Embase (1974 to June 2019), Ovid MEDLINE^® and Epub Ahead of Print, in-Process & Other Non-Indexed Citations and Daily (1946 to June 2019), Web of Science (all years), the metaRegister of Controlled Trials ( www.controlled-trials.com ), ClinicalTrials.gov ( www.clinicaltrial.gov ) and World Health Organization International Clinical Trials Registry Platform ( www.who.int/ictrp/search/en ). Search terms/keywords included 'Femtosecond laser' combined with 'cataract', 'cataract surgery'.

RESULTS

Based on quality of their methodology and their originality, 121 articles were reviewed, including randomised controlled trials, cohort studies, case-controlled studies, case series, case reports and laboratory studies. Each step of the femtosecond laser-assisted cataract surgery procedure (corneal incisions, arcuate keratotomies, capsulotomy and lens fragmentation) has been discussed with relevance to published outcomes, as well as complication rates of femtosecond laser-assisted cataract surgery, and what we can learn from the larger studies/meta-analyses and the economics of femtosecond laser-assisted cataract surgery within different healthcare settings.

CONCLUSION

Studies suggest that the current clinical outcomes of femtosecond laser-assisted cataract surgery are not different to conventional phacoemulsification surgery and it is not cost effective when compared with conventional phacoemulsification surgery. In its current technological form, it is a useful surgical tool in specific complex cataract scenarios, but its usage has not been shown to translate into better clinical outcomes.

Precision pulse capsulotomy: Initial clinical experience in simple and challenging cataract surgery cases

PURPOSE

To evaluate precision pulse capsulotomy (PPC) in simple and challenging cataract surgery cases.

SETTING

Clínica Quesada, San Salvador, El Salvador.

DESIGN

Prospective case series.

METHODS

This single-center prospective study assessed cataract surgeries with anterior capsulotomy performed using a PPC device through a 2.2 mm corneal incision in the presence of an ophthalmic viscosurgical device. This was followed by phacoemulsification and intraocular lens implantation. Outcomes included capsulotomy appearance and diameter, surgical complications, and postoperative visual acuity.

RESULTS

The study comprised 38 eyes. All cases resulted in 360-degree complete, round capsulotomies averaging 5.5 mm in diameter with intracapsular IOL fixation. No PPC-related complications were observed intraoperatively or on follow-up at 3 to 8 months. The PPC was useful in challenging cases with corneal opacities that obscured the capsulotomy path or with poorly dilated pupils. Precision pulse capsulotomy occurs instantaneously everywhere along the capsulotomy path, which allowed safe release of subcapsular pressure in intumescent cataracts with consistent creation of a round, appropriately sized capsulotomy. The PPC edge quality was shown in a case with 6 clock hours of zonular dialysis in which iris hooks held the capsulotomy edge for over 45 minutes for removal of a 4+ cataract.

CONCLUSIONS

Precision pulse capsulotomy had a short learning curve and was integrated seamlessly into the surgical routine. The combination of suction with ultrafast capsulotomy provided capsulotomy roundness, sizing, safety, and edge quality that significantly facilitated difficult cases. The ease of use, consistency, and efficiency of PPC capsulotomy might support its use under many practice scenarios.

Intraindividual comparison between femtosecond laser-assisted and conventional cataract surgery

PURPOSE

To compare the safety and efficacy between femtosecond laser-assisted cataract surgery using the Victus laser system and conventional cataract surgery.

SETTING

Department of Ophthalmology, Kepler University Hospital, Linz, Austria.

DESIGN

Prospective randomized case series.

METHODS

Both eyes of patients with age-related cataract were randomized to conventional cataract surgery or femtosecond laser-assisted cataract surgery, both with intraocular lens (IOL) implantation. Postoperative follow-up was at 1 day, 1 week, 1 month, 3 months, and 6 months and comprised corrected distance visual acuity, endothelial cell density (ECD), central corneal thickness (CCT), and central retinal thickness. The main outcomes were intraoperative and postoperative complications and the effective phacoemulsification time (EPT). Intraocular lens and capsulotomy centration were evaluated using retroillumination slitlamp photography.

RESULTS

The study enrolled 50 patients. No intraoperative complications occurred in either group. The ECD, CCT, and central retinal thickness were similar between the groups at all follow-up examinations (P > .05). The EPT was not statistically significantly different between the groups (P = .22). The IOL centration was similar between the groups (P = .93).

CONCLUSION

Femtosecond laser-assisted and conventional cataract surgery using the mentioned system were equally safe and effective.

Morphologic features and surgically induced astigmatism of femtosecond laser versus manual clear corneal incisions

PURPOSE

To compare the morphologic features and surgically induced astigmatism (SIA) between laser and manual clear corneal incisions (CCIs) after femtosecond laser-assisted cataract surgery.

SETTING

Eye Center, 2nd Affiliated Hospital, Medical College of Zhejiang University, Hangzhou, China.

DESIGN

Prospective case series.

METHODS

Patients had femtosecond laser-assisted cataract surgery with a CCI created with the laser or manually after random allocation. The corrected distance visual acuity, corneal topography, and anterior segment optical coherence tomography were assessed at the 1-day, 1-week, 1-month, and 3-month follow-ups.

RESULTS

The laser CCI group comprised 45 eyes and the manual CCI group, 48 eyes. The SIA was significantly lower in the manual CCI group than the laser CCI group at all visits (P < .05). At the 1-day and 1-week follow-ups, the mean CCI thickness was significantly smaller in the manual CCI group (P < .05). In the laser CCI group, the perpendicular linear distance between the external wound opening and the corneal vertex central line was statistically shorter than in the manual CCI group (P < .05). At 3 months, the SIA was correlated with the perpendicular linear distance with a Pearson correlation coefficient of -0.341 (P = .001).

CONCLUSIONS

Femtosecond laser-created CCIs for cataract surgery caused more SIA than manually created CCIs, which could have resulted from inaccurate or uncertain corneal incision positioning of the femtosecond machine. Manual creation of CCIs is recommended in femtosecond laser-assisted cataract surgery until the locating system for the femtosecond laser incision is updated.

Intereye comparison of femtosecond laser-assisted cataract surgery capsulotomy and manual capsulorhexis edge strength

PURPOSE

To compare the breaking force required to tear the explanted capsule after femtosecond laser-assisted cataract surgery in the worse eye and manual cataract surgery in the contralateral eye.

SETTING

Personaleyes, Sydney, Australia.

DESIGN

Prospective nonrandomized case study.

METHOD

Patients with bilateral cataract had femtosecond laser-assisted cataract surgery with the Lensx laser in the eye with worse vision and manual cataract surgery in the contralateral eye. Each explanted capsule was stretched mechanically, and the breaking force and strain in grams (g) were compared. When a large contralateral difference in capsule strength was found, scanning electron microscopy (SEM) was applied to determine whether morphologic imperfections were present in a case with a weak capsule.

RESULTS

Paired samples of 78 eyes of 39 patients were tested. The mean breaking force was not significantly different between manual capsulorhexes (2.3 g ± 2.0 [SD]) and femtosecond laser capsulotomies (2.0 ± 2.2 g, P = .52). The breaking strain for the manual samples (33.8% ± 18.3%) and for the femtosecond laser samples (34.6% ± 18.6%) were also not significantly different (P = .81). In 5 patients, in the femtosecond group, the capsules required considerably less force to break than the capsules in the manual group. However, the SEM images of these samples did not show specific laser imperfections.

CONCLUSION

In paired human eyes, the capsulotomies created by a femtosecond laser with a contact lens interface were as strong as manual capsulorhexes.

Performance of femtosecond laser-assisted cataract surgery in Chinese patients with cataract: a prospective, multicenter, registry study

BACKGROUND

This study aimed to investigate the completion rate, visual performance, and adverse outcomes of femtosecond laser-assisted cataract surgery (FLACS) in Chinese patients.

METHODS

This is a prospective, single-arm, multicenter registry study of 19 cataract surgery clinics in China. Chinese patients with cataract who underwent FLACS using the Alcon LenSx® laser system in single eye (n = 1140) or both eyes (n = 201) were enrolled and data were collected between March 2015 and August 2016. Clinical characteristics were recorded before surgery, and on postoperative days 1, 7, and 30. For surgery on both eyes, the second eye was included in the analysis only if it was operated within 30 days after the first eye surgery. The primary outcome was the completion rate of circular anterior capsulotomy. Secondary outcomes for lens fragmentation, corneal incision, and intraocular lens (IOL) implantation included best corrected distance visual acuity (BCDVA) and completion rates. Adverse events (AEs) were recorded.

RESULTS

The completion rates of circular anterior capsulotomy, lens fragmentation, corneal incision, and IOL implantation were 98.6% (95% CI: 97.8-99.1%), 99.5% (95% CI: 99.1-99.8%), 97.6% (95% CI: 96.7-98.3%), and 100% (95% CI: 99.8-100%), respectively. BCDVA preoperatively and at postoperative day 30 were 1.134 ± 0.831 logMAR and 0.158 ± 0.291 logMAR, respectively. The proportion of eyes with BCDVA of 20/20 or better was 1.6% at baseline and 41.3% at postoperative day 30. AE incidence was 0.32%, with posterior capsule rupture present in 0.19% of eyes.

CONCLUSION

FLACS using the LenSx® laser system can achieve satisfactory results in a real-world setting.

Comparison of refractive predictability and endothelial cell loss in femtosecond laser-assisted cataract surgery and conventional phaco surgery: prospective randomised trial with 6 months of follow-up

Objective

Femtosecond laser-assisted cataract surgery (FLACS) decreases the use of energy and provides a more precise capsulorhexis compared with conventional phaco surgery (CPS). The purpose of this study was to examine if the lower energy use in FLACS caused less endothelial cell loss compared with CPS and if there was a difference in refractive predictability between CPS and FLACS.

Methods and analysis

This was a randomised controlled study of 96 patients with a 6-month follow-up comparing one eye surgery by FLACS and the contralateral eye operated by CPS (divide and conquer technique). Both eyes had intraocular aspheric lenses implanted. Uncorrected distance visual acuity, corrected distance visual acuity (CDVA), central corneal endothelial cell count and hexagonality (non-contact endothelial cell microscope) were assessed preoperatively at 40 and at 180 days postoperatively.

Results

The mean phaco energies were 6.55 (95% CI 5.43 to 7.66) and 9.77 (95% CI 8.55 to 10.95) U/S (p<0.0001) by FLACS and CPS, respectively. At day 40, the mean endothelial cell loss (ECL) was 344 cells/mm² (95% CI 245 to 443) by FLACS (12.89%) and 497 cells/mm² (95% CI 380 to 614) by CPS (18.19%) (p=0.027). At day 180, ECL was 362 cells/mm² (95% CI 275 to 450) in FLACS (13.56%) and 465 cells/mm² (95% CI 377 to 554) in CPS (17.03%) (p=0.036).

The mean absolute difference from the attempted refraction was 0.43 (95% CI 0.36 to 0.51) dioptres (D) at day 40 and 0.46 D (95% CI 0.39 to 0.53) at day 180 by FLACS compared with 0.43 D (95% CI 0.36 to 0.51) at day 40 (p=0.95) and 0.46 D (95% CI 0.37 to 0.52) at day 180 (p=0.91) with CPS.

Conclusion

ECL was significantly lower in FLACS compared with CPS at both day 40 and day 180. ECL was correlated to the energy used. We found no difference in refractive predictability or CDVA between the groups.

Parameters affecting anterior capsulotomy tear strength and distension

PURPOSE

To study the effects of anterior capsulotomy diameter and discontinuity on tear threshold load and distension for the technique of continuous curvilinear capsulorhexis (CCC).

SETTING

Singapore National Eye Centre, Singapore, and CapsuLaser Inc., Livermore, California, USA.

DESIGN

Two separate randomized pairwise cadaver eye preclinical studies.

METHODS

Capsulotomies were performed in 40 cadaver eyes of 20 donors using CCC. The pairwise comparisons were divided into 2 study groups: Study A: Continuous versus discontinuous capsulotomies; Study B: Capsulotomy diameter of 5.0 mm and smaller versus diameters of 5.2 mm and larger. A shoe-tree method was used to apply load to the capsulotomy rim, and the Instron tensile stress instrument measured threshold load and distension to initiate a capsular tear. Wilcoxon matched-pairs signed-rank tests were performed to assess statistical superiority.

RESULTS

In Study Group A, all pairs demonstrated that continuous capsulotomies were better than discontinuous capsulotomies for both the anterior tear threshold load and distension (P < .01). In Study Group B, 80% of the pairs demonstrated that diameters of 5.2 mm and larger were better than those of 5.0 mm and smaller diameter (P < .05).

CONCLUSIONS

Anterior capsulotomies behave as nonlinear elastic (elastomeric) systems when exposed to an external load and distension. This study demonstrated that continuous circular capsulotomies were more resistant to anterior tears than discontinuous capsulotomies. A point of irregularity or a defect in a capsulotomy rim has a high probability of being the tear initiation point. Furthermore, larger diameter capsulotomies were more resistant to anterior tears than smaller capsulotomies.

A randomized controlled trial comparing femtosecond laser-assisted cataract surgery versus conventional phacoemulsification surgery

PURPOSE

To compare the clinical results of conventional phacoemulsification surgery (CPS) with femtosecond laser-assisted cataract surgery.

SETTING

Guy's & St Thomas' NHS Foundation Trust, London, United Kingdom.

DESIGN

Single-center prospective randomized interventional case-controlled trial.

METHODS

Patients undergoing cataract surgery were randomized to receive either CPS or femtosecond laser-assisted cataract surgery. The surgery was performed with a femtosecond laser (Lensx), and all operations were performed with a gravity-fluidics torsional phacoemulsification machine (Infiniti). The visual acuity, refraction, central corneal thickness (CCT), central foveal thickness (CFT), endothelial cell loss, and rates of intraoperative and postoperative events were recorded. Quality of life outcomes were measured with the EuroQOL 5 dimensions questionnaire (EQ-5D) and patient-reported quality of vision was assessed with a cataract surgery patient-reported outcome measures questionnaire (Cat-PROM5).

RESULTS

The study comprised 400 eyes of 400 patients who had CPS (n = 200) or femtosecond laser-assisted cataract surgery (n = 200). Seven patients (3.5%) in the femtosecond laser-assisted group were not able to complete the treatment and received CPS. The mean uncorrected distance visual acuity (logarithm of the minimum angle of resolution [logMAR]) 0.15 ± 0.21 (SD) and 0.15 ± 0.19 logMAR after CPS and femtosecond laser-assisted surgery, respectively (P = 1.0); the pinhole-corrected visual acuity was 0.04 ± 0.12 and 0.04 ± 0.12, respectively (P = 1.0); the increase in CCT was 13 ± 19 μm and 15 ± 25 μm, respectively (P = .5); and the endothelial cell loss was 9.7 ± 13.7 % and 10.2% ± 13.7, respectively (P = .76). The manifest refraction spherical equivalent error was -0.14 ± 0.60 diopters (D) after CPS and -0.12 ± 0.60 D after femtosecond laser-assisted surgery (P = .74); the mean change in CFT was 9 ± 35 μm and 6 ± 35 μm, respectively (P = .55); and the rate of posterior capsule rupture was 3% and 0%, respectively (P = .03).

CONCLUSIONS

This study confirms the nonsignificant differences between 2 treatment modalities, notwithstanding a significant reduction in posterior capsule ruptures in the femtosecond laser-assisted surgery group.

Cataract refractive surgery: Innovative technology provides more choices for Canadian cataract patients

Historically, cataract surgery was aimed at removing the clouded lens of the eye and replacing it with an artificial lens; this provided clear vision to patients but without regard to their refractive error-their need for spectacles or contact lenses after surgery. Modern diagnostic and surgical instrumentation now makes it possible to address these refractive errors at the time of surgery, introducing a new paradigm-cataract refractive surgery. Although not medically necessary, many patients appreciate the chance to reduce or eliminate their need for spectacles after surgery, even if some personal cost is involved.

Precision pulse capsulotomy in phacoemulsification: Clinical experience in Indian eyes

Purpose:

To evaluate the surgical outcome of precision pulse capsulotomy (PPC) in phacoemulsification surgery.

Methods:

One hundred twenty-three eyes of 99 consecutive patients who underwent phacoemulsification with PPC through a 2.8 mm clear corneal incision were prospectively studied at a tertiary care centre. The size, shape of capsulotomy and intraoperative capsulotomy, and surgery-related complications were noted. Visual outcome, IOL stability, and signs of capsular opacification/contraction were evaluated at 3 and 6 months.

Results:

The mean age of patients was 49.5 ± 7.77 years. Complete, circular capsulotomy averaging 5.5 mm diameter was achieved in 117 of 123 eyes. In seven eyes, we experienced complications like capsulorhexis tear (n = 6) and inadvertent iris capture (n = 1). Probe malfunction occurred in six cases. Stable intracapsular intraocular lens (IOLs) fixation and centration was achieved in all eyes. None of the eyes had any significant posterior capsular opacification or capsular contraction at 3 and 6 months. In one eye anterior capsular opacification at the capsulotomy edge was noted at 6 months.

Conclusion:

PPC is a useful device for achieving a perfectly round capsulorrhexis. However, it has a learning curve and chances of skip areas in capsulorhexis, capsular tag, and its extension should be kept in mind. Special care should be taken in initial cases and while operating on eyes with poorly dilating pupil and mature cataracts.

[Morphological and clinical aspects of anterior capsulotomy in femtosecond laser-assisted cataract surgery]

The review covers morphological and clinical aspects of femtosecond laser-assisted anterior capsulotomy in cataract surgery. Literature data suggests that femtosecond laser-assisted capsulotomy is more accurate in size, shape, and centration than manual. Femtosecond laser-assisted anterior capsulotomy improves the accuracy of IOL positioning within the capsular bag.

Femtosecond laser-assisted cataract surgery, technology, outcome, future directions and modern applications

Since its introduction in 2009 femtosecond laser-assisted cataract surgery (FLACS) has promised to revolutionize cataract surgery. Despite its promise, the assessment of FLACS's perceived benefits has proven to be far more complicated than initially might have been thought. Most studies to date have not provided validation of FLACS technology as a clinically significant advancement on our current techniques. We review FLACS technology and outcomes including detailed analysis of safety, efficacy, cost effectiveness and future prospects using data from the literature and our own published clinical experience.

A Meta-Analysis Comparing Postoperative Complications and Outcomes of Femtosecond Laser-Assisted Cataract Surgery versus Conventional Phacoemulsification for Cataract

Objective. This meta-analysis aimed to compare the outcomes and postoperative complications between femtosecond laser-assisted cataract surgery (FLACS) and conventional phacoemulsification cataract surgery (CPCS). Methods. Bibliographic databases, including PubMed, Embase, and Cochrane library, were systematically searched for references on or before September 2015 regarding the outcomes and complications by FLACS or CPCS. Data on corneal endothelial cell loss, uncorrected distance visual acuity (UDVA), corrected distance visual acuity (CDVA), refractive outcomes, and postoperative complications were retrieved. Results. A total of 9 trials were included in this analysis. Refractive outcomes (MD = -0.21, 95% CI: -0.39~0.03, P = 0.02) were significantly improved after FLACS. Although corneal endothelial cell loss was not significantly reduced after FLACS, there was a trend towards lower corneal endothelial cell loss (mean difference (MD) = 197.82, 95% confidence interval (CI): 2.66~392.97, P = 0.05) after FLACS. There was no significant difference in UDVA (MD = -0.01, 95% CI: -0.13~0.10, P = 0.80) or CDVA (MD = -0.03, 95% CI: 0.07~0.00, P = 0.09) between the two surgeries. Elevated intraocular pressure and macular edema were most commonly developed complications after cataract surgery, and the incidence of these complications associated with the two surgeries was similar. Conclusion. Compared with CPCS, FLACS might achieve higher refractive stability and corneal endothelial cell count. Nevertheless, further study is needed to validate our findings.

Current and effective advantages of femto phacoemulsification

PURPOSE OF REVIEW

The purpose is to review the current and effective advantages of femtosecond laser-assisted cataract surgery (FLACS).

RECENT FINDINGS

FLACS has advantages over manual phacoemulsification in its precision, and predictability and may be especially advantageous in difficult situations such as shallow anterior chamber, subluxated cataracts, white cataracts, and so on. However, the femtosecond capsulorhexis may not be as strong as a manual rhexis. Laser-induced miosis is also a potential disadvantage.

SUMMARY

There may be increased surgeon confidence and patient satisfaction with FLACS and it may be friendlier to the internal structures of the eye. However, it is not superior to manual phacoemulsification in terms of primary outcomes such as visual and refractive outcomes or overall complications. Further refinements in technology may be needed to give it distinct advantages over manual phacoemulsification and to make it the norm in cataract surgery.

La chirurgie réfractive de la cataracte: des technologies novatrices élargissent les choix des patients canadiens

La chirurgie de la cataracte a toujours consisté à extraire le cristallin opacifié de l'œil pour le remplacer par une lentille artificielle. Cette intervention rend la vision du patient plus nette, sans pour autant corriger l'erreur de réfraction, c'est-à-dire la nécessité de porter des lunettes ou des lentilles cornéennes après l'opération. Les instruments diagnostiques et chirurgicaux modernes permettent désormais de corriger ces erreurs de réfraction au moment de l'opération, ce qui a fait émerger une nouvelle notion, celle de la chirurgie réfractive de la cataracte. Même si cette correction n'est pas nécessaire sur le plan médical, de nombreux patients se réjouissent de la possibilité de ne plus porter de lunettes ou d'en porter moins après l'opération, même s'ils doivent engager des frais.

Update and clinical utility of the LenSx femtosecond laser in cataract surgery

The introduction of femtosecond lasers to cataract surgery has been the major disruptive technology introduced into ophthalmic surgery in the last decade. Femtosecond laser cataract surgery (FLACS) integrates high-resolution anterior segment imaging with a femtosecond laser allowing key steps of cataract surgery to be performed with computer-guided laser accuracy, precision, and reproducibility. Since the introduction of FLACS, there have been significant advances in laser software and hardware as well as surgeon experience, with over 250 articles published in the peer-reviewed literature. This review examines the published evidence relating to the LenSx platform and discusses surgical techniques, indications, safety, and clinical results.

Efficacy and Safety of Femtosecond Laser-Assisted Cataract Surgery Compared with Manual Cataract Surgery: A Meta-Analysis of 14 567 Eyes

TOPIC

To investigate the efficacy and safety of femtosecond laser-assisted cataract surgery (FLACS) relative to manual cataract surgery (MCS).

CLINICAL RELEVANCE

It is unclear whether FLACS is more efficacious and safe relative to MCS.

METHODS

A literature search of MEDLINE, EMBASE, and Scopus from 2007 to March 2016 was conducted. Studies containing both FLACS and MCS arms that reported on relevant efficacy and/or safety parameters were included. Weighted mean differences (WMDs) and risk ratios (RRs) with 95% confidence intervals (CIs) were calculated.

RESULTS

From 2802 screened articles, 14 567 eyes from 15 randomized controlled trials and 22 observational cohort studies were included. For primary visual and refractive outcomes, no statistically significant difference was detected between FLACS and MCS in uncorrected distance visual acuity (WMD, -0.02; 95% CI, -0.04 to 0.01; P = 0.19), corrected distance visual acuity (WMD, -0.01; 95% CI, -0.02 to 0.01; P = 0.26), and mean absolute error (WMD, -0.02; 95% CI, -0.07 to 0.04; P = 0.57). In terms of secondary surgical end points, there was a statistically significant difference in favor of FLACS over MCS for effective phacoemulsification time (WMD, -3.03; 95% CI, -3.80 to -2.25; P < 0.001), capsulotomy circularity (WMD, 0.16; 95% CI, 0.11-0.21; P < 0.001), postoperative central corneal thickness (WMD, -6.37; 95% CI, -11.88 to -0.86; P = 0.02), and corneal endothelial cell reduction (WMD, -55.43; 95% CI, -95.18 to -15.69; P = 0.006). There was no statistically significant difference between FLACS and MCS for total surgery time (WMD, 1.25; 95% CI, -0.08 to 2.59; P = 0.07), capsulotomy circularity using a second formula (WMD, 0.05; 95% CI, -0.01 to 0.12; P = 0.10), and corneal endothelial cell count (WMD, 73.39; 95% CI, -6.28 to 153.07; P = 0.07). As well, there was a significantly higher concentration of prostaglandins after FLACS relative to MCS (WMD, 198.34; 95% CI, 129.99-266.69; P < 0.001). Analysis of safety parameters revealed that there were no statistically significant differences in the incidence of overall complications between FLACS and MCS (RR, 2.15; 95% CI, 0.74 to 6.23; P = 0.16); however, posterior capsular tears were significantly more common in FLACS versus MCS (RR, 3.73; 95% CI, 1.50-9.25; P = 0.005).

CONCLUSIONS

There were no statistically significant differences detected between FLACS and MCS in terms of patient-important visual and refractive outcomes and overall complications. Although FLACS did show a statistically significant difference for several secondary surgical outcomes, it was associated with higher prostaglandin concentrations and higher rates of posterior capsular tears.

Initial experience using a femtosecond laser cataract surgery system at a UK National Health Service cataract surgery day care centre

OBJECTIVES

To describe the initial outcomes following installation of a cataract surgery laser system.

SETTING

National Health Service cataract surgery day care unit in North London, UK.

PARTICIPANTS

158 eyes of 150 patients undergoing laser-assisted cataract surgery.

INTERVENTIONS

Laser cataract surgery using the AMO Catalys femtosecond laser platform.

PRIMARY OUTCOME MEASURE

intraoperative complications including anterior and posterior capsule tears.

SECONDARY OUTCOME MEASURES

docking to the laser platform, successful treatment delivery, postoperative visual acuities.

RESULTS

Mean case age was 67.7±10.8 years (range 29-88 years). Docking was successful in 94% (148/158 cases), and in 4% (6/148 cases) of these, the laser delivery was aborted part way during delivery due to patient movement. A total of 32 surgeons, of grades from junior trainee to consultant, performed the surgeries. Median case number per surgeon was 3 (range from 1-20). The anterior capsulotomy was complete in 99.3% of cases, there were no anterior capsule tears (0%). There were 3 cases with posterior capsule rupture requiring anterior vitrectomy, and 1 with zonular dialysis requiring anterior vitrectomy (4/148 eyes, 2.7%). These 4 cases were performed by trainee surgeons, and were either their first laser cataract surgery (2 surgeons) or their first and second laser cataract surgeries (1 surgeon).

CONCLUSIONS

Despite the learning curve, docking and laser delivery were successfully performed in almost all cases, and surgical complication rates and visual outcomes were similar to those expected based on national data. Complications were predominately confined to trainee surgeons, and with the exception of intraoperative pupil constriction appeared unrelated to the laser-performed steps.