Toward zero effective phacoemulsification time using femtosecond laser pretreatment

Research progress on the impact of cataract surgery on corneal endothelial cells

Background

Cataracts are a common eye disease and a major cause of blindness in China and worldwide. In China, the incidence of cataracts among people over 60 years old is as high as 80%. Surgery is the primary treatment for various types of cataracts, but such invasive procedures can affect corneal endothelial cells to some extent.

Content

Cataract surgery can damage corneal endothelial cells, leading to complications such as corneal edema in mild cases. Severe damage can result in endothelial decompensation, necessitating secondary corneal endothelial transplantation. Preoperative thorough assessment of endothelial status, intraoperative endothelial protection measures, and postoperative active use of medications to prevent further damage to endothelial cells can reduce endothelial cell loss. Factors influencing endothelial cell status include whether the patient has related systemic diseases or ocular conditions, the hardness of the nucleus, the choice of surgical incision, the method of nuclear fragmentation, the type of viscoelastic agent used, the orientation of the phacoemulsification needle bevel, the duration and energy of ultrasound use, the choice of fluid control system, the use of protective auxiliary instruments, the application of intraocular lens scaffold technology, femtosecond laser assistance, and the use of certain medications.

Conclusions

Actively regulating the factors affecting corneal endothelial cells to reduce damage related to cataract surgery is crucial. This paper reviews the existing literature on various factors affecting corneal endothelial cells during cataract surgery and explores future developments and research directions.

Comparison of corneal endothelial cell loss in FLACS: impact on endothelial cells in different regions

PURPOSE

To compare changes in corneal endothelial parameters after femtosecond laser-assisted cataract surgery (FLACS) and conventional phacoemulsification surgery (CPS) in different corneal regions.

SETTING

Chang Gung Memorial Hospital, Linkou, Taiwan.

DESIGN

Single-center, retrospective.

METHODS

Before and 1, 3, and 6 months postoperatively, specular microscopy was performed to measure endothelial cell density (ECD), corneal thickness, hexagonal cell rate (Hex), and coefficient of variation (CoV). Position 1 referred to the central cornea, position 2 was nearest to the main wound, and position 3 was at the peripheral zone diagonal to the main wound.

RESULTS

This study analyzed 96 eyes in the FLACS group and 110 eyes in the CPS group. Preoperatively, position 1 had lower ECD and CoV and higher Hex compared with the peripheral regions. FLACS patients had a significantly less phacoemulsification time and cumulative dissipated energy. At 1 month, FLACS patients showed a significantly smaller increase in corneal thickness at positions 1 and 2. At 3 months, FLACS patients had lower endothelial cell loss (ECL) at positions 1 and 3. ECL remained lower in FLACS patients at 6 months. The highest ECL was observed at position 2 in both groups and was progressive up to 6 months.

CONCLUSIONS

After phacoemulsification, ECL varied in different corneal regions. At 3 months, the FLACS group exhibited significantly less ECL at the central cornea; however, the continued ECL at 6 months near the main wound suggested ongoing endothelial remodeling in the region.

Comparison of venturi and peristaltic based phacoemulsification efficiency in routine femtosecond laser cataract surgery

OBJECTIVE

To compare the efficiency of venturi and peristaltic pump phacoemulsification systems in patients undergoing routine laser cataract surgery.

DESIGN

Single center, nonrandomized clinical study.

PARTICIPANTS

The study compared consecutive eyes with moderate nuclear sclerosis undergoing routine laser cataract surgery at the Outpatient Eye Center, Mercy Health System, Springfield, MO, USA.

METHODS

Each surgery used the same femtosecond laser settings. Surgeries were performed with either a venturi or peristaltic vacuum system by a single surgeon (WJS). The EFX, percent power, ultrasound time (UST), the total time that the phaco tip was in the eye (phaco tip in/out time, PIOT), and the surgery time (speculum in/out time) were recorded. Exclusions and intraoperative complications were also analyzed.

RESULTS

995 eyes were included in the study. The EFX in the venturi eyes (1.7 ± 1.3; n = 521) compared to peristaltic eyes (2.1 ± 1.4; n = 474) was lower (p < 0.0001). Similarly, the UST in the eyes performed with the venturi system versus the peristaltic system was reduced (32.4 ± 22.3 s vs 40.7± 25.7 s; p < 0.0001). The PIOT in the venturi group compared to the peristaltic group was less (71.1 ± 31.1 sec vs 79.1 ± 36.1 s; p = 0.0002). The case time (speculum in/out time) was lower for the venturi eyes (307.2 ± 68.8 s vs. 311.6 ± 53.6 s; p = 0.268).

CONCLUSION

In eyes undergoing routine laser cataract surgery, the use of the venturi pump system was more efficient compared to the peristaltic pump system based on energy use and time, and there was no significant difference in complications.

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.

Changes in endothelial cell density after conventional phacoemulsification and FLACS in eyes with dense cataracts

PURPOSE

To compare the safety, effectiveness, and changes in endothelial cell density (ECD) after standard phacoemulsification and femtosecond laser-assisted cataract surgery (FLACS) in dense cataracts (Lens Opacities Classification System III grade 3.0 NO and above).

SETTING

Nethradhama Superspeciality Eye Hospital, Bangalore, India.

DESIGN

Prospective, randomized, comparative study.

METHOD

100 eyes of 100 patients were randomly assigned to either conventional phacoemulsification surgery (CPS) or FLACS (LENSAR Laser System) using predefined patterns of nuclear fragmentations. Measured outcomes included intraoperative phacoemulsification time, irrigation fluid volume, surgical time, and complication rates. ECD was evaluated at baseline, 2 weeks, and 6 months postoperatively.

RESULTS

The CPS group had significantly higher mean total phacoemulsification time (11.17 ± 6.5 seconds vs 8.03 ± 3.77 seconds), effective phacoemulsification time (6.14 ± 3.62 seconds vs 4.42 ± 2.07 seconds), and total surgical time (8.18 ± 2.36 minutes vs 7.11 ± 1.55 minutes) than the FLACS group ( P < .001). Volume of irrigation fluid was comparable between the 2 groups (CPS, 36.7 ± 12.18 mL; FLACS, 38.64 ± 13.73 mL ( P = .45). Mean corneal edema score and central corneal thickness values on postoperative day 1 were significantly higher for the CPS group. At 6 months, % ECD loss was significantly higher in the CPS group (16.08%) vs the FLACS group (12.8%) ( P < .001). 3 eyes in the CPS group had wound burns of varying severity.

CONCLUSIONS

FLACS with customized nuclear fragmentation patterns resulted in significantly less intraoperative phacoemulsification time, surgical time, and endothelial cell loss compared with conventional phacoemulsification when treating dense cataracts.

TRIAL REGISTRATION NUMBER

CTRI/2021/12/038887.

Femtosecond laser-assisted cataract surgery for complex cataracts - A review

Since its inception in 2009, femtosecond laser-assisted cataract surgery (FLACS) has become an alternative to conventional phacoemulsification cataract surgery (CPCS). Clinical studies were unable to demonstrate superior visual outcomes, but revealed reduced endothelial cell loss. More recently, the cost-effectiveness of FLACS over CPCS in routine cataract surgeries has been challenged. However, the unique abilities of FLACS to customize anterior capsulotomies precisely, soften and fragment the nucleus without capsular bag stress, and create corneal incisions may have special utility in complex cataract and less-common scenarios. In this article, we review the unique role of FLACS in complex cataract surgeries and how it could play a role to improve the safety and predictability of nonroutine cataract surgery.

Intraocular pressure changes before and after a femtosecond laser procedure for cataract surgery

This study aimed to evaluate the changes in intraocular pressure (IOP) before and after femtosecond laser capsulorhexis and lens fragmentation for cataract surgery. We measured the IOP before, immediately, 30 min, and 1 h after the laser procedure in 47 eyes of 47 patients who underwent the femtosecond laser procedure. The mean IOP was 17.51 ± 3.28 mmHg, 30.23 ± 6.70 mmHg, 17.96 ± 3.75 mmHg, and 21.77 ± 5.88 mmHg before, immediately after, 30 min after, and 1 h after the laser procedure, respectively. The mean IOP significantly increased immediately (adjusted P < 0.001) and 1 h (adjusted P = 0.001) after the laser procedure compared with the pre-laser IOP. The mean IOP at 30 min after the laser procedure was significantly lower than that immediately after the procedure (adjusted P < 0.001). However, the IOP 1 h after the laser procedure became higher than that 30 min after the laser procedure. Additionally, the IOP 1 h after the laser procedure was positively correlated with the baseline IOP and negatively correlated with the axial length. In conclusion, this study demonstrated that cataract surgery should be commenced within 30 min after the femtosecond laser procedure to ensure a safe cataract surgery that reduces the risk of increased intraocular pressure.

Narrative review after post-hoc trial analysis of factors that predict corneal endothelial cell loss after phacoemulsification: Tips for improving cataract surgery research

PURPOSE

Identifying pre/perioperative factors that predict corneal endothelial-cell loss (ECL) after phacoemulsification may reveal ways to reduce ECL. Our literature analysis showed that 37 studies have investigated one or several such factors but all have significant limitations. Therefore, the data of a large randomized controlled trial (PERCEPOLIS) were subjected to post-hoc multivariate analysis determining the ability of nine pre/perioperative variables to predict ECL.

METHODS

PERCEPOLIS was conducted in 2015-2016 to compare two phacoemulsification techniques (subluxation and divide-and-conquer) in terms of 3-month ECL. Non-inferiority between the techniques was found. In the present study, post-hoc univariate and multivariate analyses were conducted to determine associations between ECL and age, sex, cataract density, preoperative endothelial-cell density, phacoemulsification technique, effective phaco time (EPT), and 2-hour central-corneal thickness. The data are presented in the context of a narrative review of the literature.

RESULTS

Three-month data were available for 275 patients (94% of the randomized cohort; mean age, 74 years; 58% women). Mean LOCSIII cataract grade was 3.2. Mean EPT was 6 seconds. Mean ECL was 13%. Only an older age (beta = 0.2%, p = 0.049) and higher EPT (beta = 1.2%, p = 0.0002) predicted 3-month ECL. Cataract density was significant on univariate (p = 0.04) but not multivariate analysis. The other variables did not associate with ECL.

CONCLUSIONS

Older age may amplify ECL due to increased endothelial cell fragility. EPT may promote ECL via cataract density-dependent and -independent mechanisms that should be considered in future phacoemulsification research aiming to reduce ECL. Our literature analysis showed that the average ECL for relatively unselected consecutively-sampled cohorts is 12%.

Resident operative time as an independent predictor of early post-operative cataract surgery outcomes and supervising attending surgeon impact: a retrospective case series

BACKGROUND

The authors sought to determine if resident operative time in cataract extraction and intraocular lens insertion (CE/IOL) affects early visual outcomes and post-operative recovery. They further sought to investigate if attending surgeons can reduce resident operative time.

METHODS

This retrospective, chart-review, case series at single Veterans Affairs Hospital (VA Tennessee Valley Healthcare System) studied resident cataract surgeries between March 1, 2018 and March 31, 2020. Following power analysis, 420 eyes of 400 patients from all resident cataract surgeries were included. Eyes with attending as primary surgeon, laser-assisted cataract surgery, or concurrent secondary procedures were excluded. Linear mixed effect models were used to study the association between operative time and visual outcomes while adjusting for covariates including cumulative dissipated energy, preoperative factors, and intraoperative complications.

RESULTS

Longer operative time was statistically associated with worse post-operative-day 1 (POD1) pinhole visual acuity (PH-VA) adjusting for cumulative dissipated energy and other operative factors (p = 0.049). Although resident physicians were the primary surgeons, the operative times were different between the ten supervising attending surgeons in the study (p < 0.001).

CONCLUSION

The results suggest that increased resident operative time is a significant, independent risk factor for decreased POD1 PH-VA. Increased resident operative time is not associated with worsened long term visual outcomes. Attending surgeons may be able to reduce resident operative time, which is associated with improved early visual outcomes.

Application of Femtosecond Laser in Challenging Cataract Cases

Femtosecond laser can provide precise and customized incision of ocular tissue with excellent accuracy and predictability. Thus, femtosecond laser-assisted cataract surgery (FLACS) can theoretically enhance the safety and efficacy of cataract surgery by providing reproducible and reliable clear corneal incision, limbal relaxing incision, anterior capsulotomy, and lens fragmentation. However, thus far, the superiority of the anatomical and visual outcomes of FLACS over those of conventional cataract surgery have been unclear. Nevertheless, studies have indicated that FLACS can potentially be helpful in improving the safety of cataract surgery in challenging situations, such as zonular weakness, preexisting capsular tear, white cataract, shallow anterior chamber, and pediatric cataracts, which may contribute to enhanced visual and anatomical outcomes. In this review, we provide a summary of the application of femtosecond laser in general cataract cases. In addition, we introduce the application of FLACS in the abovementioned challenging situations and discuss the results of studies regarding the safety and outcome of FLACS in these challenging cases.

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.

FLACS vs conventional phacoemulsification by junior cataract surgeons: randomized trial

PURPOSE

To report intraoperative performance and postoperative outcomes of femtosecond laser-assisted cataract surgery (FLACS) and conventional phacoemulsification (PE) in the hands of junior surgeons.

SETTING

Iladevi Cataract & IOL Research Centre, Ahmedabad, Gujarat, India.

DESIGN

Prospective single-masked randomized controlled trial.

METHODS

320 eyes (320 patients) undergoing cataract surgery for uneventful cataracts in the hands of junior surgeons were randomized to Group 1-FLACS or Group 2-PE. Intraoperatively, cumulative dissipated energy (CDE) and fluid used were compared. Postoperatively, the following were compared: central corneal thickness (CCT) on day 1, 1 week, and 1 month; corneal clarity (day 1 and 1 week); anterior chamber inflammation (day 1 and 1 week); change in endothelial cell density (ECD) at 6 months postoperatively; and corrected distance visual acuity (CDVA) at 1 week and 1 month postoperatively.

RESULTS

157 and 158 patients in groups 1 and 2 analysed. Intraoperatively, CDE (5.41 ± 2.73 vs 8.83 ± 4.28 in Groups 1 and 2, P = .0001) and fluid used (79.33 ± 33.46 vs 101.82 ± 32.23 mL in Groups 1 and 2, P < .0001) were significantly lesser in Group 1. CCT was significantly higher in Group 2 on day 1 (550.96 ± 33.64 vs 587.70 ± 55.76 μm in Groups 1 and 2, P < .0001) and at 1 week postoperatively (527.94 ± 30.78 vs 545.11 ± 35.17 μm in Groups 1 and 2, P = .001). 72% of eyes had clear corneas on day 1 in Group 1 compared with 39% in Group 2 ( P = .01). Anterior chamber inflammation and CDVA were comparable. Change in ECD was significantly lower (9.3%) in Group 1 vs 12.7% in Group 2, P < .0001.

CONCLUSIONS

FLACS showed lower intraoperative CDE, fluid usage, lesser increase in CCT, better early postoperative corneal clarity, and lesser change in ECD at 6 months postoperatively in the hands of junior surgeons during standard cataract surgery.

Management of inflammation after the cataract surgery

PURPOSE OF REVIEW

To review most recent studies and clinical trials regarding pathogenesis, treatment, and prevention of inflammation after the cataract surgery.

RECENT FINDINGS

FLACS gave opportunity to evaluate inflammatory cytokines in the aqueous humour right after the laser procedure, which led to acknowledging the inflammation pathogenesis during the phacoemulsification. Although there is still a lack of evidence, which would prove the long-term benefit of NSAIDs, they are indicated and effective when risk factors for PCME are present. PREMED studies showed that combination of NSAID and steroids after the surgery for healthy subjects is cost-effective. The triamcinolone injection together with topical steroids and NSAIDs for diabetic patients after the cataract surgery was the most cost-effective in preventing PCME according to the PREMED. Dropless cataract surgery is another emerging topic: dexamethasone implants and suspensions look promising as we await more clinical trials with drug-loaded IOLs.

SUMMARY

Inflammation after the cataract surgery can be prevented, and these methods are one of the most essential topics with growing phacoemulsification rate. Topical NSAIDs are cost-effective not only for patients with risk factors for PCME but also for healthy subjects. New dropless techniques are being successfully introduced in the clinical practice.

Comparison of ultrasound phacoemulsification and FemtoMatrix® PhotoEmulsification® cataract surgery

Objective

To introduce a novel technology currently under final development before regulatory approvals for the furtherment of cataract surgery, using the FemtoMatrix^® laser system, and to demonstrate its safety and efficacy as compared to standard ultrasound phacoemulsification.

Methods

Thirty-three patients with bilateral cataracts were operated on with one eye undergoing PhotoEmulsification^® treatment on the FemtoMatrix^® device and the contralateral eye receiving the control procedure, i.e., standard ultrasound phacoemulsification treatment. The number of "zero-phaco" procedures (denoting that I/A alone was sufficient to aspirate the lens fragments and that no ultrasound energy was needed) was recorded and Effective Phaco Time (EPT) values were compared. The patient follow-up was 3 months.

Results

Thirty-three eyes from a population with a mean cataract grade of 2.6 were treated on the FemtoMatrix^®, of which 29 were "zero-phaco" (88%). All patients were operated on by a single surgeon who was a relative novice to the technology (63 patients treated prior to this study). Conversely, of the 33 fellow eyes who underwent standard ultrasound phacoemulsification, none were zero-phaco (0%) - all required varying degrees of ultrasound energy to make lens aspiration possible. The mean EPT was significantly lower in the PhotoEmulsification^® laser group (0.2 ± 0.8 s) than in the phaco group (1.3 ± 1.2 s) (p < 0.0001). The safety profiles of the two procedures were comparable, with no device-related adverse events noted.

Conclusion

FemtoMatrix^® is a promising femtosecond laser platform that, when compared to phacoemulsification, significantly decreases or eliminates EPT altogether. The system is used to perform PhotoEmulsification^®, making zero-phaco cataract procedures feasible including in high-grade cataracts (>3). It enables personalized treatment by automatically measuring and adapting the laser energy required to obtain the most efficient cutting of the crystalline lens. This new technology appears to be safe and effective in cataract surgery.

Femtosecond laser-assisted cataract surgery: Update and perspectives

Cataract surgery is among the most frequently performed surgical procedures worldwide and has a tremendous impact on patients' quality of life. Phacoemulsification (PCS) is accepted as a standard of care; its technique has continuously evolved and already achieved good anatomical, visual, and refractive outcomes. Lasers in ophthalmology are widely used in clinical practice, femtosecond lasers (FSLs) for corneal surgery in particular. It was natural to assess the usefulness of FSL in cataract surgery as this technology was within reach. Indeed, precise and reproducible cuttings provided by FSL platforms could improve standardization of care and limit the risk associated with the human element in surgery and provide a step toward robot-assisted surgery. After docking and planning the procedure, femtosecond lasers are used to perform corneal incisions, capsulorhexis, lens fragmentation, and arcuate incisions in an automated manner. A well-constructed corneal incision is primordial as it offers safety during the procedure, self-seals afterward, and influences the refractive outcome. Capsulorhexis size, centration, and resistance to shearing influence the surgery, intraocular lens (IOL) centration and stability, and posterior capsular opacification formation. Lens fragmentation is where most of the energy is delivered into the eye, and its amount influences endothelial cell damage and potential damage to other ocular structures. The arcuate incisions offer an additional opportunity to influence postoperative astigmatism. Femtosecond laser-assisted cataract surgery (FLACS) has been a topic of research in many studies and clinical trials that attempted to assess its potential benefits and cost-effectiveness over PCS and is the subject of this mini-review.

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.

Kataraktoperation beim Vorliegen einer Fuchs-Endotheldystrophie

Bei Betroffenen mit einer Fuchs-Endotheldystrophie beginnen die Probleme mit den Augen häufig in einem Alter, in dem sich auch schon erste Anzeichen einer Katarakt zeigen. Und umgekehrt findet man in der augenärztlichen Praxis immer wieder Patient*innen mit einer deutlichen Katarakt und einer Cornea guttata als Nebenbefund. In beiden Situationen stellt sich dann die Frage, ob zunächst nur eine posteriore lamelläre Keratoplastik (in Deutschland meist als DMEK) bzw. nur eine Kataraktoperation erfolgen oder ob gleich ein kombiniertes Vorgehen (sog. Triple-Operation) angestrebt werden sollte. Nur bei jungen Betroffenen mit einer fortgeschrittenen Fuchs-Endotheldystrophie ohne jeglichen Hinweis auf eine Katarakt und gut erhaltener Akkommodation kann, je nach individuellen Gegebenheiten, eine alleinige DMEK sinnvoll sein, in allen anderen Fällen erscheint eine Triple-Operation geeigneter. Dabei erscheint ein sequenzielles Vorgehen in diesen Situationen weniger angebracht, da sich in zahlreichen Studien zeigte, dass der Verlauf und die Ergebnisse nach einer Triple-Operation mit denen nach einem sequenziellen Vorgehen vergleichbar sind. Beim Vorliegen einer signifikanten Katarakt und einer Cornea guttata fällt die Entscheidung im Hinblick auf das operative Vorgehen deutlich schwerer. Hierbei gibt es unterschiedliche Aspekte in der Anamnese sowie den ophthalmologischen Untersuchungen (z. B. zentrale Hornhautdicke, Endothelzelldichte), die einem bei der Entscheidung helfen können. Soll dann zunächst nur eine Kataraktoperation erfolgen, sollten geeignete Maßnahmen ergriffen werden, um ein möglichst optimales Ergebnis trotz Vorliegen der Cornea guttata zu erreichen. Im folgenden Beitrag soll auf die wichtigsten prä-, peri- und postoperativen Aspekte im Hinblick auf die bestmögliche operative Versorgung von Betroffenen mit Fuchs-Endotheldystrophie und Katarakt eingegangen werden.

Outcomes of Femtosecond Laser-Assisted Cataract Surgery Compared to Conventional Phacoemulsification in Eyes with Pseudoexfoliation Syndrome

OBJECTIVE

To compare the outcomes including complications, in a large cohort of eyes with pseudoexfoliation syndrome that underwent Femtosecond Laser-Assisted Cataract Surgery (FLACS) versus conventional phacoemulsification.

DESIGN

Retrospective cohort study.

PARTICIPANTS

A total of 513 eyes from 366 patients with pseudoexfoliation syndrome that underwent cataract surgery between April 1, 2014, and December 31, 2018.

METHODS

Charts were reviewed for preoperative examination findings, intraoperative complications, and post-operative outcomes. Best-corrected visual acuity (BCVA) was measured by logMAR and compared between groups at one month and the final follow-up visit.

RESULTS

Of 513 eyes, 71 (13.8%) underwent FLACS, and 442 (86.2%) eyes underwent conventional cataract surgery. Between the two groups, there was no difference in the incidence of vitreous prolapse, capsular tear, pupillary expansion device usage, capsular tension support device usage, or postoperative cystoid macular edema (p > .05 for all). At the final visit, there was no significant difference in BCVA between FLACS and conventional phacoemulsification groups (mean logMAR 0.26 vs. 0.25, p = .87).

CONCLUSIONS

When comparing FLACS and conventional phacoemulsification in eyes with pseudoexfoliation syndrome, no difference was seen in the incidence of complications. BCVA was comparable between the two groups. Zonular weakness significantly increased the risk of complications in both groups.

Ultrasound energy consumption and macular changes with manual and femtolaser-assisted high-fluidics cataract surgery: a prospective randomized comparison

PURPOSE

The purpose of the study was to compare ultrasound (US) consumption and central macular thickness (CMT) and volume changes with manual and femtosecond laser (FSL)-assisted cataract nucleus workup.

METHODS

Sixty patients scheduled for immediate sequential bilateral surgery underwent a prospective randomized intraindividual comparison of nucleus sector fragmentation performed manually in one eye and with low-energy FSL assistance in the partner eye, followed by high-fluidics phacoaspiration with a maximum US power of 30%. Ultrasound (US) energy consumption and macular thickness and volume were compared as measured by intraoperative effective phacoemulsification time (EPT) and high-resolution spectral domain optical coherence tomography pre- and 1 week, 3 weeks and 6 weeks postoperatively. Results are presented as means ± SD or medians [min; max].

RESULTS

Fifty-two patients completed the full follow-up. For the manual and FSL-assisted groups, nuclear hardness was almost identical with a mean LOCS III grade of 2.44 ± 1.08 and 2.50 ± 1.00 (p = 0.371). Median EPT was 1.40 [0.2; 8.3] and 1.25 [0.2; 9.4] seconds. Median preoperative CMT was 276.50 [263.25; 289.75] µm and 276.00 [262.00; 290.00] µm. Median postoperative CMT was 278.00 [260.50; 288.00] versus 275.50 [264.00; 290.50] µm at 1 week, 279.50 [266.75; 292.25] versus 280.00 [266.50; 294.50] µm at 3 weeks and 280.50 [268.00, 293.75] versus 279.50 [264.75; 295.25] µm at 6 weeks. Differences in CMT and total macular volume between the groups were not statistically significant at any point in time.

CONCLUSION

Femtosecond laser (FSL) prefragmentation of the nucleus into six sectors did not reduce US energy consumption compared with manual splitting of the nucleus into four quadrants in this particular surgical setting. Sectorial FSL-prechopping with the low-energy FSL used had no additional impact on postoperative macular thickness and volume.

Illuminated Chop Using an Illuminated Chopper in Cataract Surgery: on the Way to Minimal-energy Phacoemulsification

Purpose: To minimize ultrasound power use and surgical phaco time in illuminated chop cataract surgery.Methods: The charts of patients who underwent senile cataract surgery by a single surgeon were reviewed retrospectively. A conventional intracameral endoilluminator was used in a Stop & Chop group (n = 45), while an illuminated chopper was used in an illuminated chop (I-Chop) group (n = 71). EFX, a unitless value that roughly correlates with ultrasound energy during phacoemulsification, surgical phaco time, and changes in endothelial cell count were compared between the two groups and the ratio of zero phacoemulsification in the I-Chop group was evaluated.Results: EFX of the Stop & Chop and I-Chop groups was 18.08 ± 16.15 and 0.82 ± 3.53, respectively (p = 0.001), while the surgical phaco time was 185.08 ± 41.42 and 162.04 ± 49.65 seconds (p = 0.01). However, the endothelial loss did not differ in the two groups (7.03 ± 7.89 vs. 7.13 ± 9.47%, p = 0.76). In the I-Chop group, 56 (86%) eyes had zero phaco energy and patients with EFX >1 (n = 6) had more severe nuclear sclerosis grading (2.90 ± 0.71 vs. 4.5 ± 1.0; p = 0.001).Conclusions: The I-Chop group had lower EFX and shorter surgical phaco time than the Stop & Chop group. Illuminated chop using an illuminated chopper is one way to attain minimal phacoemulsification.

Factors impacting cumulative dissipated energy levels and postoperative visual acuity outcome in cataract surgery

Purpose

To determine factors impacting cumulative dissipated energy (CDE) and postoperative best-corrected visual acuity (BCVA) in phacoemulsification.

Design

Review of 1102 cases at University of California, San Francisco (UCSF) and at Zhongshan Ophthalmic Center (ZOC), China.

Subjects

Patients who underwent cataract surgery at UCSF 03/2014–03/2019 and at ZOC 10/2018–05/2019.

Methods

Patient demographics, medical history, routine ocular examination, and surgical information, including disassembly method, complications, and surgeon training level were recorded. Univariable and multivariable regression models were used to determine factors associated with CDE and good postoperative BCVA (20/40 or better) at 1 month.

Outcome measures

CDE, postoperative BCVA.

Results

In multivariable analysis, patient age at time of surgery, diabetes, degree of nuclear sclerosis (NS), white-to-white corneal diameter, disassembly method, preoperative BCVA, surgeon training level, and surgical center were significantly associated with CDE. Log₁₀CDE increased by 0.20–0.31 for patient age ≥ 70 years, by 0.07 if the patient had diabetes, by 0.12–0.41 for NS grade ≥ 2, by 0.48 per 10 mm increase in white-to-white corneal diameter, by 0.34–0.47 for disassembly method other than non-stop chop, by 0.16 per unit increase in preoperative logMAR BCVA, and by > 0.09 when phacoemulsification was performed by residents early in their training. Log₁₀CDE was 0.33 higher at UCSF than ZOC. In multivariable analysis, worse baseline visual acuity and age above 90 years at time of surgery decreased the odds of good BCVA (OR = 0.26 per unit increase in preoperative logMAR BCVA; OR = 0.12 for age > 90); comorbid retinal issues decreased the odds of good postoperative BCVA (OR = 0.13–0.39); greater anterior chamber depth (ACD) or shorter axial length (AL), increased the odds of good postoperative outcome (OR = 2.64 per 1 mm increase ACD, OR = 0.84 per 1 mm increase AL).

Conclusions

Cataract grade determined by slit lamp exam and, for the first time, older patient age, were noted to be important predictors of high CDE. CDE was not a risk factor for postoperative BCVA measured at postoperative 1 month. When surgery was performed by trainees under supervision, lower training level was associated with higher CDE, but not with worse postoperative BCVA.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12886-021-02205-w.

Femto-assisted versus conventional phacoemulsification differently impact on choroid structure after surgery

PURPOSE

To report potential choroidal changes in eyes undergoing femtosecond laser cataract surgery (FLACS) and phacoemulsification surgery (PCS) by OCT.

METHODS

The patients were images by means Spectral Domain OCT imaging with EDI technology which may obtain OCT image. We exported a single EDI-OCT scan passing through the fovea and then it was imported into ImageJ program to perform a quantitative analysis.

MAIN OUTCOME MEASURES

The main outcome measures were: (i) sub foveal choroidal thickness (SFCT); (ii) the choroidal vascularity index (CVI); and (iii) central retinal thickness (CRT).

RESULTS

At postoperative 1 week, FLACS group showed an increased CRT (241.2 ± 31.6-245.5 ± 36.4 µm; p = 0.016). Likewise, CVI and SFCT exhibited a slight increase but no statistically differences were highlighted (p > 0.05). At the follow-up visit of 1 month, all OCT parameters did not display any significant difference (p > 0.05). At post-operative 1 week, the PCS group displayed a significant increase in CRT, SFCT, and CVI. On the contrary, at the follow-up visit of 1-month, all choroidal parameters were characterized by a no statistically significant reduction (p > 0.05).

CONCLUSIONS

Our study exhibited a significant increase in CT and CVI in eyes that underwent conventional cataract surgery. Femtosecond laser-assisted cataract extraction did not result in macular change due to less postoperative inflammation.

Refractive Outcomes in Fuchs' Endothelial Corneal Dystrophy: Conventional and Femtosecond Laser-Assisted Cataract Surgery

Purpose

To investigate the refractive outcomes of eyes with Fuchs’ endothelial corneal dystrophy (FECD) following phacoemulsification.

Methods

This is a retrospective chart review of patients with FECD who underwent phacoemulsification. Manifest refraction at the early postoperative period (1–6 weeks) and late postoperative period (3–12 months) was collected. The spherical equivalent (SE) and variance of SE from target in diopters (D) were analyzed.

Results

A total of 219 eyes from 175 FECD patients (73 FLACS, 146 conventional phacoemulsification) were included. In the early postoperative period, when comparing variance from intended target, 62% (n=126) had a SE variance of ≤0.5 D, 22% (n=44) >0.5 D and ≤1 D, and 17% (n=34) >1 D. In the late postoperative period, 62% (n=85) had a SE variance of ≤0.5 D, 19% (n=26) >0.5 D and ≤1 D, and 20% (n=27) >1 D. There was no difference in the variance of SE comparing FLACS versus conventional phacoemulsification in either the early postoperative period (p=0.78) or the late postoperative period (p=0.29).

Conclusion

Patients with mild-to-moderate FECD had favorable refractive outcomes with phacoemulsification. There was no difference in refractive outcomes in eyes with FECD between the group that underwent FLACS versus the group that underwent conventional phacoemulsification.

Femtosecond laser-assisted cataract surgery in eyes with shallow anterior chamber depth: comparison with conventional phacoemulsification

PURPOSE

To compare the postoperative outcomes between femtosecond laser-assisted cataract surgery (FLACS) and conventional phacoemulsification in eyes with shallow anterior chamber depth (ACD).

SETTING

Eye Clinic, NEUROFARBA Department, University of Florence, Italy.

DESIGN

Prospective case series.

METHODS

Forty eyes of 40 patients with senile cataract and true ACD less than 2.00 mm underwent FLACS (femto group, n = 20) or manual phacoemulsification (phacoemulsification group, n = 20). Preoperatively and 1 week and 1 month and 6 months postoperatively, central corneal thickness (CCT) and endothelial cell density were evaluated; basal epithelial cell (BEC) and Langerhans dendritic cell (LDC) densities and keratocyte activation were assessed using in vivo corneal confocal microscopy. Intraoperative parameters such as cumulative dissipated energy (CDE) and ultrasound (US) power were recorded.

RESULTS

Endothelial cell loss (ECL) was significantly lower in the femto group at all timepoints (P ≤ .001). In the phacoemulsification group, the CCT was significantly higher 1 week (P < .001) and 1 month (P < .001) postoperatively than preoperatively; conversely, in the femto group, it was higher only after 1 week (P < .001). BECs and LDCs significantly increased at 1 postoperative week (P < .001), returning to preoperative values after 1 month in both groups. Keratocyte activation remained significantly higher at 1 postoperative month only in the phacoemulsification group (P = .005). CDE and US power were lower in the femto group (P = .017 and P = .001, respectively); they were correlated with ECL (r = 0.662, P = .000; r = 0.389, P = .013).

CONCLUSIONS

In eyes with shallow ACD, FLACS was a safe and an effective technique, significantly reducing the postoperative ECL and corneal inflammation compared with conventional phacoemulsification.

Femtosecond laser-assisted cataract surgery compared with phacoemulsification cataract surgery: randomized noninferiority trial with 1-year outcomes

PURPOSE

To report the 1-year outcomes of a randomized trial comparing femtosecond laser-assisted cataract surgery (FLACS) and phacoemulsification cataract surgery (PCS).

SETTING

Moorfields Eye Hospital, New Cross Hospital, and Sussex Eye Hospital, United Kingdom.

DESIGN

Multicenter, randomized controlled noninferiority trial.

METHODS

Patients undergoing cataract surgery were randomized to FLACS or PCS. Postoperative assessments were masked. Outcomes included uncorrected distance visual acuity (UDVA), corrected distance visual acuity (CDVA), complications, corneal endothelial cell count, and patient-reported outcomes measures.

RESULTS

The study enrolled 785 participants. A total of 311 of 392 (79%) participants were allocated to FLACS and 292 of 393 (74%) participants were allocated to PCS attended follow-up at 1 year. Mean UDVA was 0.14 (SD = 0.22) for FLACS and 0.17 (0.25) for PCS with difference of -0.03 logarithm of the minimum angle of resolution (logMAR) (95%, -0.06 to 0.01, P = .17). Mean CDVA was 0.003 (0.18) for FLACS and 0.03 (0.23) for PCS with difference of -0.03 logMAR (95% CI, -0.06 to 0.01, P = .11); 75% of both FLACS (230/307) and PCS (218/290) cases were within ±0.5 diopters (D) refractive target, and 292 (95%) of 307 eyes of FLACS and 279 (96%) of 290 eyes of PCS groups were within ±1.0 D. There were no significant differences between arms for all other outcomes with the exception of binocular CDVA mean difference -0.02 (-0.05 to 0.002) logMAR (P = .036) favoring FLACS. Mean cost difference was £167.62 per patient greater for FLACS (95% iterations between -£14.12 and £341.67).

CONCLUSIONS

PCS is not inferior to FLACS regarding vision, patient-reported health, and safety outcomes after 1-year follow-up. A difference was found for binocular CDVA, which, although statistically significant, was not clinically important. FLACS was not cost-effective.

Why Use Ultrashort Pulses in Ophthalmology and Which Factors Affect Cut Quality

The power density of femtosecond lasers and exposure time to the tissue are crucial for a successful procedure in terms of safety and precision. The reduction of the pulse duration allows reducing the quantity of the energy to be delivered to the tissue for disruption with strongly diminished mechanical and thermal collateral damage. The cutting effect of ultra-short pulses is very precise, minimally traumatic, safe, and predictable. Future developments will lead to further energy reductions to achieve optical breakdowns. However, the pulse length cannot be shortened arbitrarily because below 100 fs nonlinear effects can change the process in an unfavorable way. Compared to manual-conventional cataract surgery, femtosecond laser-assisted cataract surgery (FLACS) shows many advantages in clinical application, especially with regard to precision and tissue protection. The femtosecond laser has become particularly important and has made the overall procedure safer when we deal with complex cataract cases such as subluxated lenses. We provide an overview of the evolution of femtosecond laser technology for use in refractive and cataract surgeries. This article describes the advantages of available laser platforms with ultrashort pulses and mainly focuses on the technical and physical backgrounds of ophthalmic surgery technologies.

Comparing corneal outcome between femtosecond laser-assisted cataract surgery and conventional phaco surgery in Fuchs' endothelial dystrophy patients: a randomized pilot study with 6mo follow up

AIM

To compare the corneal outcome in Fuchs' endothelial dystrophy (FED) patients between femtosecond laser-assisted cataract surgery (FLACS) and conventional phaco surgery (CPS).

METHODS

This was a randomized controlled study comparing one eye surgery by FLACS and the contralateral eye operated by CPS (stop and chop technique) in FED patients. Central corneal thickness, corneal light backscatter, corneal densitometry, and central corneal endothelial cell count and hexagonality (noncontact endothelial cell microscope), and corrected distance visual acuity (CDVA) were assessed preoperatively and at day 1, 40, and 180 postoperatively.

RESULTS

Totally 31 patients (16 women) were included. At day 40 postoperatively, the mean endothelial cell loss (ECL) was 23.67% by FLACS and 17.30% by CPS (P=0.53). At day 180 postoperatively, ECL was 25.58% in FLACS and 21.32% in CPS (P=0.69). Densitometry data in all layers and all annuli from anterior layer to posterior layer in annuli 0-2, 2-6, 6-10 and 10-12, total densitometry with all layers and all annuli was performed. A significant difference was found in 6-10 (posterior layer) at day 1 with -1.42 grayscale units (GSU; 95%CI: -2.66 to -0.19, P=0.02). In 10-12 (anterior layer, central layer and all layers) at day 40 were significant different with 7.7 (95%CI: 1.89 to 13.50, P=0.009), 3.97 (95%CI: 0.23 to 7.71, P=0.03), 4.73 GSU (95%CI: 0.71 to 8.75, P=0.02), respectively. In the remaining parameters we found no difference between the two groups (P>0.05). Three CPS eyes suffered from corneal decompensation.

CONCLUSION

There is no significant difference in corneal outcome between FLACS and CPS. Endothelial cell density and pentacam corneal outcome may be inadequate as outcome parameters in FED patients.

Intraocular Pressure Reduction after Femtolaser Assisted Cataract Surgery and Its Association with the Use of Ultrasound

Background and Objectives: To quantify the change in intraocular pressure (IOP) after phacoemulsification in patients having undergone femtolaser assisted cataract surgery (FLACS), and study the influence of the use of ultrasound on this change. Setting: Jules-Gonin Eye Hospital, University Department of Ophthalmology, Lausanne, Switzerland. Materials and Methods: Interventional study. Methods: All consecutive cases operated with FLACS and with complete data for the studied parameters were selected for inclusion in the study. Data had been prospectively collected and was analysed retrospectively. Linear regression was performed to explore the association of change in IOP with time of measure, ultrasound use, sex, age, and duration of surgery. Results: There was a mean decrease in intraocular pressure of 2.5 mmHg (CI 95% −3.6; −1.4, p < 0.001) postoperatively. No association between the change in intraocular pressure and ultrasound time or effective phaco time was observed when the data were analyzed one at a time or in a multiple linear regression model. There was no association with sex, age, nuclear density, presence of pseudoexfoliation, duration of surgery, and time of ocular pressure measurement. Eyes with preoperative IOP ≥ 21 mmHg had a more significant IOP reduction after surgery (p < 0.0001) as did eyes with an anterior chamber depth <2.5 mm (p = 0.01). Conclusion: There was a decrease in intraocular pressure six months after FLACS in our study similar to that in the published literature for standard phacoemulsification. The use of ultrasound may not influence the size of the decrease, whereas the preoperative IOP and anterior chamber depth do. FLACS may be as valuable as standard phacoemulsification for cases where IOP reduction is needed postoperatively.

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 Cataract Surgery in Soft and Hard Nuclear Cataracts: A Comparison of Effective Phacoemulsification Time

Purpose

To compare effective phacoemulsification time (EFX) in femtosecond laser-assisted cataract surgery (FLACS) versus traditional quick chop phacoemulsification (QCP) in senile nuclear cataracts with different densities focusing on soft and hard ones.

Patients and Methods

A prospective non-randomized comparative study was carried out in Al Watany Eye Hospital and Ain Shams University Hospital, Cairo, Egypt; 250 eyes with senile nuclear cataract (NC) were included and classified into two main groups, FLACS and QCP groups. Each of them was stratified according to nuclear density into three subgroups, subgroups I (Soft NC), II (Medium NC), and III (Hard NC). Sextans-softened fragmentation pattern was performed in the FLACS group. Total EFX utilized for nucleus disassembly and removal was recorded by the completion of each surgery.

Results

A total of 117 eyes were included in the FLACS group and 133 eyes in the QCP group. No significant difference in EFX was observed between the two groups (P = 0.228). Regarding subgroups, EFX showed no statistically significant difference between FLACS and QCP (P = 0.283) in soft NC. For hard NC, a trend to lower values of EFX in FLACS compared with QCP was found, but without statistically significant difference (P = 0.122). Only in medium NC were significantly lower values obtained in FLACS compared with QCP (P < 0.0001).

Conclusion

When compared with QCP technique, FLACS can be used for advantages aside from EFX reduction, including astigmatic keratotomies, accurate sizing, and centration of capsulotomies especially in hard and soft nuclear cataracts. Significant reduction of total EFX with FLACS is most prominent only in medium-density nuclear cataracts.

Comparison of Femtosecond Laser-Assisted and Ultrasound-Assisted Cataract Surgery with Focus on Endothelial Analysis

Femtosecond laser-assisted cataract surgery has the potential to make critical steps of cataract surgery easier and safer, and reduce endothelial cell loss, thus, improving postoperative outcomes. This study compared FLACS with the conventional method in terms of endothelial cells behavior, clinical outcomes, and capsulotomy precision.

METHODS

In a single-center, randomized controlled study, 130 patients with cataracta senilis received FLACS or conventional cataract surgery.

RESULTS

A significant endothelial cell loss was observed postoperatively, compared to the preoperative values in both groups. The endothelial cell counts was significantly better in the FLACS group in cataract grade 2 (p = 0.048) patients, compared to conventionally at 4 weeks. The effective phaco time was notably shorter in grade 2 of the FLACS group (p = 0.007) compared to the conventional. However, no statistically significant differences were found for the whole sample, including all cataract grades, due to the overall cataract density in the FLACS group being significantly higher (2.60 ± 0.58, p < 0.001) as compared to conventional methods (2.23 ± 0.42).

CONCLUSIONS

Low energy FLACS provides a better result compared to endothelial cell loss, size, and shape variations, as well as in effective phaco time within certain cataract grade subgroups. A complete comparison between two groups was not possible because of the higher cataract grade in the FLACS. FLACS displayed a positive effect on endothelial cell preservation and was proven to be much more precise.

Corneal higher-order aberrations after cataract surgery: Manual phacoemulsification versus femtosecond-laser assisted technique

Purpose:

To compare and evaluate corneal higher-order aberrations (c-HOA) between conventional manual phacoemulsification (Phaco), femtosecond laser-assisted cataract surgery (FLACS), and femtosecond laser-assisted cataract surgery with astigmatic keratotomy (FSAK).

Methods:

In this retrospective single center study, 53 healthy individuals with cataract (73 eyes) underwent phacoemulsification with implantation of an intraocular lens. Three groups were formed: group A, Phaco (n = 27 eyes of 21 patients); group B, FLACS (n = 25 eyes of 15 patients); group C, FSAK (n = 21 eyes of 17 patients). An iTrace aberrometer (Tracey Technologies, Houston, TX, USA) was used to perform aberrometry with a pupil scan size of 5.0 mm. We used ANOVA analysis and the paired sample t-test for statistical analysis.

Results:

There was no difference in total c-HOA between the groups prior to surgery (F(2,66) = 2.2, p = 0.128), but some evidence for a difference between the groups after surgery (F(2,65) = 3.87, p = 0.025). After surgery, total c-HOA increased in all groups, but the greatest increase occurred FSAK.

Conclusion:

Manual phacoemulsification and femtosecond laser-assisted cataract surgery seem to have less impact on corneal higher-order aberrations than the combination of femtosecond laser-assisted cataract surgery with astigmatic keratotomy.

Femtosecond-Laser Assisted Surgery of the Eye: Overview and Impact of the Low-Energy Concept

This article provides an overview of both established and innovative applications of femtosecond (fs)-laser-assisted surgical techniques in ophthalmology. Fs-laser technology is unique because it allows cutting tissue at very high precision inside the eye. Fs lasers are mainly used for surgery of the human cornea and lens. New areas of application in ophthalmology are on the horizon. The latest improvement is the high pulse frequency, low-energy concept; by enlarging the numerical aperture of the focusing optics, the pulse energy threshold for optical breakdown decreases, and cutting with practically no side effects is enabled.

Femtosecond laser-assisted cataract surgery compared with phacoemulsification: the FACT non-inferiority RCT

BACKGROUND

Cataract surgery is one of the most common operations. Femtosecond laser-assisted cataract surgery (FLACS) is a technique that automates a number of operative steps.

OBJECTIVES

To compare FLACS with phacoemulsification cataract surgery (PCS).

DESIGN

Multicentre, outcome-masked, randomised controlled non-inferiority trial.

SETTING

Three collaborating NHS hospitals.

PARTICIPANTS

A total of 785 patients with age-related cataract in one or both eyes were randomised between May 2015 and September 2017.

INTERVENTION

FLACS (n = 392 participants) or PCS (n = 393 participants).

MAIN OUTCOME MEASURES

The primary outcome was uncorrected distance visual acuity in the study eye after 3 months, expressed as the logarithm of the minimum angle of resolution (logMAR): 0.00 logMAR (or 6/6 if expressed in Snellen) is normal (good visual acuity). Secondary outcomes included corrected distance visual acuity, refractive outcomes (within 0.5 dioptre and 1.0 dioptre of target), safety and patient-reported outcome measures at 3 and 12 months, and resource use. All trial follow-ups were performed by optometrists who were masked to the trial intervention.

RESULTS

A total of 353 (90%) participants allocated to the FLACS arm and 317 (81%) participants allocated to the PCS arm attended follow-up at 3 months. The mean uncorrected distance visual acuity was similar in both treatment arms [0.13 logMAR, standard deviation 0.23 logMAR, for FLACS, vs. 0.14 logMAR, standard deviation 0.27 logMAR, for PCS, with a difference of -0.01 logMAR (95% confidence interval -0.05 to 0.03 logMAR; p = 0.63)]. The mean corrected distance visual acuity values were again similar in both treatment arms (-0.01 logMAR, standard deviation 0.19 logMAR FLACS vs. 0.01 logMAR, standard deviation 0.21 logMAR PCS; p = 0.34). There were two posterior capsule tears in the PCS arm. There were no significant differences between the treatment arms for any secondary outcome at 3 months. At 12 months, the mean uncorrected distance visual acuity was 0.14 logMAR (standard deviation 0.22 logMAR) for FLACS and 0.17 logMAR (standard deviation 0.25 logMAR) for PCS, with a difference between the treatment arms of -0.03 logMAR (95% confidence interval -0.06 to 0.01 logMAR; p = 0.17). The mean corrected distance visual acuity was 0.003 logMAR (standard deviation 0.18 logMAR) for FLACS and 0.03 logMAR (standard deviation 0.23 logMAR) for PCS, with a difference of -0.03 logMAR (95% confidence interval -0.06 to 0.01 logMAR; p = 0.11). There were no significant differences between the arms for any other outcomes, with the exception of the mean binocular corrected distance visual acuity with a difference of -0.02 logMAR (95% confidence interval -0.05 to 0.00 logMAR) (p = 0.036), which favoured FLACS. There were no significant differences between the arms for any health, social care or societal costs. For the economic evaluation, the mean cost difference was £167.62 per patient higher for FLACS (95% of iterations between -£14.12 and £341.67) than for PCS. The mean QALY difference (FLACS minus PCS) was 0.001 (95% of iterations between -0.011 and 0.015), which equates to an incremental cost-effectiveness ratio (cost difference divided by QALY difference) of £167,620.

LIMITATIONS

Although the measurement of outcomes was carried out by optometrists who were masked to the treatment arm, the participants were not masked.

CONCLUSIONS

The evidence suggests that FLACS is not inferior to PCS in terms of vision after 3 months' follow-up, and there were no significant differences in patient-reported health and safety outcomes after 12 months' follow-up. In addition, the statistically significant difference in binocular corrected distance visual acuity was not clinically significant. FLACS is not cost-effective.

FUTURE WORK

To explore the possible differences in vision in patients without ocular co-pathology.

TRIAL REGISTRATION

Current Controlled Trials ISRCTN77602616.

FUNDING

This project was funded by the National Institute for Health Research (NIHR) Health Technology Assessment programme and will be published in full in Health Technology Assessment; Vol. 25, No. 6. See the NIHR Journals Library website for further project information. Moorfields Eye Charity (grant references GR000233 and GR000449 for the endothelial cell counter and femtosecond laser used).

Evaluation of femtosecond laser-assisted anterior capsulotomy in the presence of ophthalmic viscoelastic devices (OVDs)

The introduction of femtosecond laser-assisted cataract surgery is an alternative approach to conventional cataract surgery. Our study aimed to determine the effectiveness of femtosecond laser-assisted capsulotomy in the presence of different ophthalmic viscoelastic devices (OVDs) in the anterior chamber. Fresh porcine eyes (n = 96) underwent LDV Z8-assisted anterior capsulotomy, either in the presence of an OVD (Viscoat, Provisc, Healon, Healon GV or HPMC) or without, using 90% and 150% energies respectively. Following that, the capsule circularity, tag’s arc-length, tag-length, tag-area and rupture strength (mN) of the residual capsular bag were evaluated. We found that increasing energy from 90 to 150% across the OVD sub-groups improved the studied capsulotomy parameters. Amongst the 90% energy sub-groups, the circularity and tag-parameters were worse with Viscoat and Healon GV, which have higher refractive index and viscosity compared to the aqueous humour. Using 150% energy, Healon GV showed a significantly worse total arc-length (p = 0.01), total tag-length (p = 0.03) and total tag-area (p = 0.05) compared to the control group. We concluded that; an OVD with a refractive index similar to aqueous humour and lower viscosity, such as Healon or Provisc, as well as a higher energy setting, are recommended, to enhance the efficacy of laser capsulotomy.

Cystoid Macular Edema Following Cataract Surgery with Low-Energy Femtosecond Laser versus Conventional Phacoemulsification

Purpose

To compare postoperative changes in central subfield macular thickness (CSMT) and prevalence of cystoid macular edema (CME) in patients undergoing cataract surgery with low-energy femtosecond laser versus standard phacoemulsification.

Design

This was a retrospective comparative real-world study.

Methods

Postoperative data of 252 eyes of 165 patients were collected: 138 eyes received low-energy femtosecond laser-assisted cataract surgery (FLACS) and 114 eyes underwent conventional phacoemulsification cataract surgery (CPCS). Postoperative changes in CSMT and prevalence of CME were compared between the two groups.

Results

There was a significant increase in mean CSMT from preoperative to postoperative values at 2.5 months in both the FLACS and CPCS group (p<0.001). Mean change (preoperation to 2.5 months postoperation) in CSMT was 6.2±11.5 µm in the FLACS group and 7.3±26.6 µm in the CPCS group, which was statistically significant but clinically not relevant. Comparison of mean changes in CSMT (preoperation to 2.5 months postoperation) between the FLACS and CPCS groups revealed no significant differences. The rate of pseudophakic CME (PCME) development was lower in the FLACS group (1.4%) than the CPCS group (4.4%; p=0.247). When using PREMED criteria to define clinically significant PCME, only 0.7% patients in the FLACS group and 1.8% in the CPCS group showed development of clinically significant PCME (p=0.586).

Conclusion

The mean change in CSMT and occurrence of postoperative CME was lower in the low-energy FLACS group than the standard-phacoemulsification group; however, the difference was not statistically significant.

Comparative evaluation of femtosecond laser-assisted cataract surgery and conventional phacoemulsification in eyes with a shallow anterior chamber

PURPOSE

To compare intraoperative performance and postoperative outcomes between femtosecond laser-assisted cataract surgery (FLACS) and conventional phacoemulsification in eyes with a shallow anterior chamber (AC).

SETTING

Iladevi Cataract & IOL Research Centre, India.

DESIGN

Prospective randomized masked clinical study.

METHODS

Patients undergoing cataract surgery with a shallow AC (<2.5 mm) were randomized to have FLACS (Group 1, n = 91) or conventional phacoemulsification (Group 2, n = 91). Patients were followed up at 1 day, 1 week, and at 1, 3, and 6 months. The primary outcome measure was central corneal thickness (CCT). The secondary outcome measures were corneal clarity, AC cells and flare, endothelial cell density (ECD), coefficient of variance, hexagonality, and uncorrected distance visual acuity (UDVA) at 1 week.

RESULTS

The study comprised 182 eyes (91 in each group) The cumulative dissipative energy was lower in the FLACS group (P < .05). The mean CCT was significantly lower with FLACS (540.40 μm + 49.40 [SD] vs 556 + 12.5 μm, P = .03) at 1 day and 1 week (535.5 + 44.3 μm vs 551 + 40.8 μm, P = .04), with fewer eyes having higher than grade 2 AC cells and flare with FLACS (85% vs 72%, P = .056) at 1 day and 1 week (15% vs 28%, P = .03). At 1 week, the UDVA was better with FLACS (0.089 ± 0.31 logarithm of the minimum angle of resolution [logMAR] vs 0.178 ± 0.65 logMAR, P = .042). At 6 months, the reduction in ECD was lower in the FLACS group; however, the difference was not statistically significant.

CONCLUSION

In eyes with shallow ACs, compared with conventional phacoemulsification, FLACS maintained clearer corneas, showed less increase in CCT, lower AC inflammation, and better UDVA in the early postoperative period.

Evaluation of the relation between Lens Opacities Classification System III grading and nuclear size by direct measurement

CONTEXT:

Although relation between Lens Opacities Classification System III (LOCS III) and nuclear density is established, no data are available about nuclear size at different LOCS III grades.

AIMS:

The aim of this study is to evaluate the relation between LOCS III grading of nuclear opacity obtained preoperatively and the size of the nucleus obtained during cataract surgery.

SETTINGS AND DESIGN:

This was a prospective observational study carried out in a hospital attached to medical college.

MATERIALS AND METHODS:

Patients who underwent manual small-incision cataract surgery or extra-large temporal tunnel cataract extraction and gave consent were included in this study. Institutional Ethics Committee clearance was taken for the study. Preoperative LOCS III grading was obtained at slit-lamp biomicroscope. Ocular dimensions were obtained by preoperative immersion biometry. The thickness and diameter of the nucleus obtained by extraction were measured up to 10 μ accuracy. Data were analyzed for the change in nuclear thickness, nuclear diameter, age, lens thickness, and anterior chamber depth in relation to the LOCS III grade of the nucleus.

STATISTICAL ANALYSIS USED:

Statistical analysis used in this study was one-way ANOVA, mean, and range.

RESULTS:

There was a significant increase (P < 0.05) in nuclear thickness, nuclear diameter, and age with increasing LOCS III grade of the nucleus. The change in nuclear size was linear between Grades 1 and 4. The nuclear size did not increase between Grades 4 and 5. It increased steeply from Grade 5 to Grade 6.9.

CONCLUSION:

LOCS III grading of the nucleus can be utilized for determining the nuclear thickness and diameter preoperatively. These data can be helpful in adjusting machine parameters during phacoemulsification.

Outcomes of resident-performed laser-assisted vs traditional phacoemulsification

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, USA.

DESIGN

Prospective randomized study.

METHODS

All surgeries to be performed by postgraduate year 3 and year 4 residents from October 2015 through June 2017 were eligible for inclusion. Patients were required to complete postoperative day 1, week 1, month 1, and month 3 visits. Specular microscopy was performed preoperatively and postoperatively. Surgeries were filmed, and each step was 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 corrected distance visual acuity (CDVA), either preoperatively or at the postoperative day 1, week 1, month 1, or month 3 visits (P = .469, .539, .701, .777, and .777, respectively). Cumulated dissipated energy and irrigation fluid usage were not different between FLACS and CPS (P = .521 and .368, respectively), nor was there a difference in the reduction of endothelial cell counts postoperatively (P = .881). Wound creation (P = .014), cortical cleanup (P = .009), and IOL implantation (P = .031) were faster in the CPS group. Survey results indicated that the overall patient experience was similar for FLACS and CPS.

CONCLUSIONS

This first prospective randomized trial evaluating resident-performed FLACS shows that, in resident hands, FLACS provides similar results to CPS regarding visual acuity, endothelial cell loss, operative time, patient satisfaction, and surgical complication rate.

Optimization of energy parameters during surgery of high-density cataract

The goal is to develop a combined technique for preliminary YAG laser fragmentation and Femto laser exposure on a CATALYS device and to evaluate its role in reducing the time and energy parameters of a surgery of high-density cataract. Material and methods. The study included 118 patients (118 eyes) with age-related cataracts of the 3rd and 4th degrees of lens nucleus density. In the main group, before phacoemulsification (PE) with a Femto laser support and IOL implantation, preliminary YAG laser phacofragmentation of the lens nucleus was performed. In the first control group, PE was performed with Femto laser support and IOL implantation. In the second control group PE with IOL implantation. Results. A 35% decrease in the energy of the Femto laser action at a 3rd degree of lens nucleus density was achieved, and 40% at the 4th degree, in comparison with the PE with the Femto laser support without preliminary YAG laser phacofragmentation, a 38% decrease in the cumulative ultrasound energy at 3rd degree of the lens nucleus density, and 42% at 4th degree compared with isolated ultrasonic cataract phacoemulsification. Conclusion. The proposed modification of the technique of combined YAG laser and Femto laser exposure allows achieving during cataract surgery a complete fragmentation of the lens nucleus of a high degree of density, helps minimizing the risk of complications and reaching quick postoperative rehabilitation of patients.

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.

Clinical and Surgical Outcomes of Femtosecond Laser-Assisted Cataract Surgery (FLACS) on Hard Cataracts in the Egyptian Population

Objective

To evaluate the clinical and surgical outcomes of femtosecond laser-assisted cataract surgery (FLACS) in hard cataract of Egyptian population.

Setting

ICare Center, Alexandria, Egypt.

Design

Retrospective observational.

Methods

The study included 50 FLACS cases of 40 patients who had cataract; NO4 NC4 or more according to Lens Opacities Classification System III (LOCS III), performed between October 2018 and May 2019. The cases underwent anterior capsulotomy, lens fragmentation, and corneal incisions with the femtosecond laser. Arcuate keratotomy was performed in selected cases. Phacoemulsification and implantation of an intraocular lens are then performed.

Results

Patients mean age was 63.06 ± 7.75 yr, mean femtosecond laser energy was 12.92 ± 0.72 mJ, mean docking time was 3.00 ± 0.83 min and overall mean laser treatment time was 92.00 ± 25.01 sec. Mean laser treatment time was lower in cases that did not get astigmatic keratectomy (87.7 ± 18.97 vs 89.47 ± 13.43 sec; p < 0.73). Attempted refraction was -0.09 ± 0.52 D and achieved 12 months postoperative manifest sphere equivalent refraction (SER) was -0.19 ± 1.11 D (r = 0.8 and P˂0.001). Mean error (ME) was -0.2 ± 1.11 (range: -2.5-1.5) while mean absolute error (MAE) was 0.97 ± 0.57 (range: 0-2.5). Eighty percent and 92% of cases had 1 month postoperative SER within 1.0 D and 1.5 D, respectively. One eye (2%) had incomplete capsulotomy, 7 eyes (14%) had incomplete corneal incision and lens fragmentation was complete in all cases except 1 eye (2%). Thirty-four eyes (68%) showed postdocking conjunctival ecchymosis and 35 eyes (70%) had intraoperative miosis.

Conclusion

FLACS has low complication rate with effective results. High cost of technology is still the main barrier against its popularity.

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.

[Energy load and state of corneal endothelium in hybrid (femtosecond laser-assisted) and torsional phacoemulsification]

Postoperative state of the corneal endothelium is the most important criterion for evaluating the safety of cataract phacoemulsification.

PURPOSE

To compare the intraoperative energy load and postoperative state of corneal endothelium in hybrid (femtosecond laser-assisted) and torsional phacoemulsification.

MATERIAL AND METHODS

The study analyzed surgical outcomes of 603 patients (714 eyes) divided into 3 groups: 225 patients (267 eyes) underwent modified femtosecond laser-assisted phacoemulsification (1st group), 237 patients (278 eyes) underwent standard femtosecond laser-assisted phacoemulsification (2nd group), and 141 patients (169 eyes) who underwent torsional phacoemulsification (3rd group). The follow-up period lasted up to 2 years.

RESULTS

In patients with grade II lens density (here and further - L. Buratto classification is used), effective ultrasound time was 0.56±0.11 s in the 1st group, 0.83±0.17 s in the 2nd group, and 2.78 ± 0.51 s in the 3rd group (p(1-2)<0.05; p(1-3)<0.05; p(2-3)<0.05). In patients with grade III lens density effective ultrasound time was 2.04±0.37 s in the 1st group, 2.97±0.53 s in the 2nd group, and 4.59±0.91 s in the 3rd group (p(1-2)<0.05; p(1-3)<0.05; p(2-3)<0.05). In patients with grade IV lens density, effective ultrasound time was 3.95±0.81 s in the 1st group, 5.11±1.03 s in the 2nd group, and 8.37±1.73 s in the 3rd group (p(1-2)<0.05; p(1-3)<0.05; p(2-3)<0.05). In patients with grade II lens density, loss of endothelial cells was 3.3±1.1% in the 1st group, 3.7±1.2% in the 2nd group, and 4.3±1.2% in the 3rd group (p(1-2)>0.05; p(1- 3)<0.05; p(2-3)<0.05). In patients with grade III lens density, loss of endothelial cells was 5.1±1.4% in the 1st group, 5.7±1.5% in the 2nd group, 7.2±1.7% in the 3rd group (p(1-2)>0.05; p(1-3)<0.05; p(2-3)<0.05). In patients with grade IV lens density, loss of endothelial cells was 8.9±2.1% in the 1st group, 10.1±2.3% in the 2nd group, and 13.3±2.5% in the 3rd group (p(1-2)>0.05; p(1-3)<0.05; p(2- -3)<0.05).

CONCLUSION

Both techniques of femtosecond laser-assisted phacoemulsification significantly reduce the effective ultrasound time (p<0.05) and the degree of corneal endothelial cells loss (p<0.05) compared with torsional phacoemulsification.

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.

Comparison of Perioperative Parameters in Femtosecond Laser-Assisted Cataract Surgery Using 3 Nuclear Fragmentation Patterns

PURPOSE

The purpose of this study was to compare the perioperative parameters of quadrant, sextant, and grid lens fragmentation patterns in femtosecond laser-assisted cataract surgery (FLACS).

DESIGN

Prospective randomized clinical trial.

METHODS

Setting: Eye Center of the Second Affiliated Hospital, School of Medicine, Zhejiang University, Hangzhou, China.

STUDY POPULATION

A total of 894 eyes in 661 patients with cataracts were enrolled. Intervention or observation procedures: the nuclear density was graded according to the Emery-Little classification. Patients received lens fragmentation using a quadrant, sextant, or grid pattern after random allocation. Evaluations included intraoperative parameters, complications, and postoperative outcomes.

MAIN OUTCOME MEASUREMENTS

effective phacoemulsification time (EPT), intraoperative complications, visual acuity and intraocular pressure at one day postoperatively, as well as endothelial cell density, endothelial cell loss, and central corneal thickness at 1 week postoperatively.

RESULTS

In grade 1 nuclei, the mean EPT in the grid group was the shortest compared to those in the quadrant (P = 0.011) and sextant (P = 0.001) groups. In grade 2 nuclei, all 3 patterns showed no significant differences in the mean EPT (P > 0.05). In grade 3 nuclei, the sextant group revealed shorter mean EPT than the grid (P = 0.017) and quadrant (P > 0.05) groups. In grades 4 and 5 nuclei, the quadrant pattern had the shortest mean EPT among all 3 patterns (P < 0.05). The grid pattern is associated with higher intraocular pressure in hard nuclei (grades 4 and 5) than the other 2 patterns (P < 0.05).

CONCLUSIONS

The grid and quadrant patterns allow for shorter EPT in soft (grade 1) and hard (grades 4 and 5) nuclei, respectively. All 3 patterns can be selected for treating grade 2 nuclei. The sextant pattern may be the best option when treating grade 3 nuclei. The grid pattern should be avoided in hard nuclei combined with glaucoma or glaucoma suspect.