Femtosecond Laser-Assisted Cataract Surgery Versus Phacoemulsification Cataract Surgery (FACT): A Randomized Noninferiority Trial

Efficiency of venturi vs peristaltic-based phacoemulsification in femtosecond laser cataract surgery

PURPOSE

To compare the efficiency of peristaltic vs venturi vacuum platforms when applied to femtosecond-treated cataract.

SETTING

Outpatient Eye Center, Mercy Health System, Springfield, Missouri.

DESIGN

This is a prospective randomized controlled trial of 111 patients with moderate nuclear sclerosis scheduled for bilateral routine laser cataract surgery (LCS) ( ClinicalTrials.gov ; NCT03970525).

METHODS

Patients were randomized to receive surgery in 1 eye with a peristaltic system and the other with a venturi system. The vacuum and phacoemulsification power were the same for both systems. The primary outcomes were phacoemulsification energy (EFX), ultrasound time (UST), phacoemulsification in/out time (PIOT), surgery time (speculum in/out time), and endothelial cell count (ECC).

RESULTS

The type of vacuum/phacoemulsification system used during LCS had a significant impact on the 4 procedural outcomes. Specifically, EFX, UST, PIOT, and total microscope time (speculum in/out case time) were lower when the venturi system was used compared with the peristaltic system ( t (100) = -4.28, P < .001). The vacuum system used did not affect the uncorrected distance visual acuity, corrected distance visual acuity, or central cornea thickness. ECC decreased by 6.38% with venturi and 8.32% with peristaltic ( t (87) = 1.19, P = .235). There were no complications.

CONCLUSIONS

Venturi-based phacoemulsification was more efficient than peristaltic, based on energy and time, when used for removal of femtosecond-treated cataract.

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.

FABP3 promotes cell apoptosis and oxidative stress by regulating ferroptosis in lens epithelial cells

The purpose of this study is to investigate FABP3's biological function and potential mechanism in cataract. Treatment of H2O2 raised FABP3 expression. H2O2 decreased cell viability, enhanced apoptosis, promoted Bax and cleaved caspase-3 expression, inhibited Bcl-2 expression, enhanced the levels of IL-6, IL-1β, and TNF-α, raised MDA level, and decreased SOD and GSH levels in HLE-B3 cells. However, the effects of H2O2 on cell viability, apoptosis, inflammatory cytokines, and oxidative stress were reversed by FABP3 knockdown and aggravated by FABP3 overexpression. H2O2 increased the levels of lipid hydroperoxides and Fe2+, but reduced the expression of GPX4, SLC7A11, and Ferritin protein. Nevertheless, knockdown of FABP3 reversed the changes of lipid hydroperoxides, Fe2+, GPX4, SLC7A11, and Ferritin protein, and FABP3 overexpression caused the opposite results. In addition, the inhibition of FABP3 knockdown on cell apoptosis, inflammation, and oxidative stress was reversed by ferroptosis inducer (erastin), and the promotion of FABP3 overexpression on cell apoptosis, inflammation, and oxidative stress was reversed by ferroptosis inhibitor (Fer-1). Taken together, knockdown of FABP3 in lens epithelial cells treated with H2O2 restrained apoptosis, inflammation, and oxidative stress through regulating ferroptosis, suggesting that FABP3 might be a potential target for cataract treatment.

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.

Incidence and analysis of intraoperative complications in femtosecond laser-assisted cataract surgery: a large-scale cohort study to establish the learning curve

AIMS

To assess the safety of femtosecond laser-assisted cataract surgery (FLACS) based on surgical parameters and intraoperative complications analysis and to determine the length of the learning curve for FLACS.

METHODS

A prospective consecutive cohort study was conducted on Chinese patients who underwent either FLACS (3289 cases) or contemporaneous conventional phacoemulsification cataract surgery (2130 cases). The laser group was divided into four subgroups in chronological order. We recorded intraoperative complication incidences and compared with surgical parameters between groups. Subgroup analysis was conducted to explore the learning curve of FLACS.

RESULTS

The laser group had a 4.93% incidence of incomplete capsulotomies and a 1.22% incidence of anterior capsule tears. Subgroup analysis showed significant differences in 8 aspects between the first 250 cases (50 cases per surgeon) and the last 2539 cases, but only 2 aspects differed between the second 250 cases (50 cases per surgeon) and the last 2539 cases. There were no significant differences between the third 250 cases (50 cases per surgeon) and the last 2539 cases.

CONCLUSIONS

The intraoperative complications of FLACS were reported, and the learning curve is associated with a significant reduction in the incidence of intraoperative complications. The length of the basic learning curve of FLACS is 100 cases, and the length of the advanced learning curve was 150 cases. This study demonstrated that FLACS is characterised by a relatively straightforward and secure operative technique.

Comparison of low-energy FLACS and conventional cataract surgery: meta-analysis and systematic review

TOPIC

To systematically compare the effectiveness of conventional phacoemulsification surgery (CPS) and low-energy femtosecond laser-assisted cataract surgery (FLACS) in patients with cataract.

CLINICAL RELEVANCE

Cataract surgery is a common procedure, and comparing different techniques such as CPS and low-energy FLACS is crucial for optimizing patient outcomes.

METHODS

The PubMed, Web of Science, MEDLINE, EMBASE, and Cochrane library databases were searched for clinical trials. Outcomes of procedure time, effective phacoemulsification time, balanced salt solution usage, cumulative dissipated energy, mean change of corrected distance visual acuity, endothelial cells reduction, central corneal thickness (CCT), and aqueous cytokine level were evaluated. The effect measures were weighted mean differences with 95% CI. The protocol was registered at the Prospective Register for Systematic Reviews (registration number CRD42023420173).

RESULTS

11 studies were included in this meta-analysis, of which 1680 eyes were analyzed (637 eyes in the low-energy FLACS group and 1043 eyes in the CPS group). Low-energy FLACS demonstrated significantly fewer reductions in endothelial cell count at 6 months ( P < .001) compared with CPS. It also exhibited a shorter effective phacoemulsification time ( P < .001) and less balanced salt solution usage ( P < .001). However, there were no differences in cumulative dissipated energy, corrected distance visual acuity, CCT changes, or aqueous cytokine levels between the 2 groups.

CONCLUSIONS

Both low-energy FLACS and CPS are effective in treating cataracts, but low-energy FLACS may offer advantages such as reduced phacoemulsification time and less endothelial cell loss.

Comparative analysis of changes in retinal layer thickness following femtosecond laser-assisted cataract surgery and conventional cataract surgery

BACKGROUND

To investigate the influence of femtosecond laser-assisted cataract surgery (FLACS) on macula by examining changes in retinal layers after FLACS and to compare these changes with those after conventional cataract surgery (CCS).

METHODS

This study included 113 unrelated Korean patients with age-related cataract who underwent CCS or FLACS in Severance Hospital between September 2019 and July 2021. Optical coherence tomography was performed before and 1 month after surgery. The total retinal layer (TRL) was separated into the inner retinal layer (IRL) and outer retinal layer (ORL); moreover, the IRL was subdivided into the retinal nerve fiber layer, ganglion cell layer, inner plexiform layer, inner nuclear layer (INL), outer plexiform layer, and outer nuclear layer. We performed between-group comparisons of the postoperative thickness in each retinal layer and the postoperative differences in retinal thickness. The average retinal thickness of the four inner macular ring quadrants was used for comparative analysis.

RESULTS

Compared with the CCS group, the FLACS group exhibited a thicker ORL (P = 0.004) and a thinner INL (P = 0.007) after surgery. All retinal layer thickness values showed significant postoperative changes regardless of the type of surgery (P < 0.05). The postoperative increase in TRL and IRL thickness was significantly smaller in the FLACS group than in the CCS group (P = 0.027, P = 0.012).

CONCLUSIONS

The 1-month postoperative retinal changes were less pronounced in the FLACS group than in the CCS group.

Comparative study of FLACS vs conventional phacoemulsification for cataract patients with high myopia

PURPOSE

To compare the short-term changes in cornea, retina, and choroid of femtosecond laser-assisted cataract surgery (FLACS) with conventional phacoemulsification (CPS) in high myopia patients with cataract.

SETTING

Affiliated Hospital of Nantong University, Jiangsu Province, China.

DESIGN

Prospective single-center study.

METHODS

Demographics, ocular clinical features, ultrasound power, absolute phacoemulsification time, and effective phacoemulsification time were recorded for each patient. Endothelial cell density (ECD), central corneal thickness (CCT), corrected distance visual acuity (CDVA), intraocular pressure (IOP), center foveal thickness (CFT), subfoveal choroidal thickness (SFCT), and choroidal vascularity index (CVI) were evaluated preoperatively and at 1 week, 1 month, and 3 months postoperatively. Intraoperative parameters and intraoperative/postoperative complications were recorded.

RESULTS

97 eyes (46 eyes and 51 eyes in the FLACS and CPS groups, respectively) were included and analyzed. Effective phacoemulsification time was lower in the FLACS group compared with the CPS group ( P < .05). The increase in CCT was significantly lower in the FLACS group compared with the CPS group at 1 week and 1 month ( P < .05). CDVA and IOP were similar in both groups at the final visit ( P > .05). The ECD decreased was lower among CPS patients compared with FLACS patients. CFT, SFCT, and CVI increase in both groups but were increased more in the CPS group with high myopia patients. No serious complications occurred in either group.

CONCLUSIONS

FLACS is a more safety and effective in cataract patients with high myopia. It has advantages in effectively reducing EPT and promoting faster recovery of the cornea, macular, and choroidal thickness.

Intraoperative quantitative crystalline lens nuclear opacities analysis based on crystalline lenSx platform

PURPOSE

The main objective is to quantify the lens nuclear opacity using spectral-domain optical coherence tomography (SD-OCT) and to evaluate its association with Lens Opacities Classification System III (LOCS-III) system, lens thickness (LT), and surgical parameters. The secondary objective is to assess the diagnostic model performance for hard nuclear cataract.

METHODS

This study included 70 eyes of 57 adults with cataract, with 49 (70%) and 21 (30%) in training and validation cohort, respectively. Correlations of the average nuclear density (AND) /maximum nuclear density (MND) with LOCS-III scores, LT, and surgical parameters were analyzed. Univariate and multivariate logistic regression analysis, receiver operating characteristic curves and calibration curves were performed for the diagnostic of hard nuclear cataract.

RESULTS

The pre-operative uncorrected distance visual acuity (UDVA), intraocular pressure (IOP), mean axial length (AL), and LT were 1.20 ± 0.47 log MAR, 15.50 ± 2.87 mmHg, 27.34 ± 3.77 mm and 4.32 ± 0.45 mm, respectively. The average nuclear opalescence (NO) and nuclear colour (NC) scores were 3.61 ± 0.94 and 3.50 ± 0.91 (ranging from 1.00 to 6.90), respectively. The average AND and MND were 137.94 ± 17.01 and 230.01 ± 8.91, respectively. NC and NO scores both significantly correlated with the AND (rNC = 0.733, p = 0.000; rNO = 0.755, p = 0.000) and MND (rNC = 0.643, p = 0.000; rNO = 0.634, p = 0.000). In the training cohort, the area under the curve (AUC) of the model was 0.769 (P < 0.001, 95%CI 0.620-0.919), which had a good degree of differentiation (Fig. 2a). The calibration curve showed good agreement between predicted and actual probability.

CONCLUSION

The nuclear density measurement on SD-OCT images can serve as an objective and reliable indicator for quantifying nuclear density.

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.

Update on Femtosecond Laser-Assisted Cataract Surgery: A Review

The advent of femtosecond lasers has resulted in a new standard in cataract surgery, intended to overmatch the paradigm of conventional phacoemulsification. Femtosecond laser-assisted cataract surgery (FLACS) enables a higher level of reproducibility, precision, accuracy, and customization when performing several steps of cataract (or lens) surgery. Capsulotomy, corneal incisions, lens fragmentation, and arcuate incisions are the main procedures performed using FLACS. As the demand for better refractive outcomes and spectacle independence increases, the features of FLACS are highly relevant, especially when considering the implantation of premium intraocular lenses, such as toric, enhanced depth-of-focus, or multifocal lenses. The present article reviews the state of the art of femtosecond laser-assisted cataract (lens) surgery, contemplating the advantages and limitations of the two types of femtosecond laser pulses available (high and low energy) by evaluating their reported outcomes and complications.

The Royal College of Ophthalmologists' National Ophthalmology Database study of cataract surgery: report 16, influence of remuneration model on choice of intraocular lens in the UK

BACKGROUND/OBJECTIVES

Cataract surgery with intraocular lens (IOL) implantation is one of the most commonly performed surgeries worldwide. Within the UK, publicly funded cataract surgery is remunerated by two models: (1) "block contract" (BC), which commissions organisations to deliver whole service pathways without considering specific activity items; or (2) "payment by results" (PbR), which pays a tariff price for each procedure. This study aimed to examine the association between remuneration model and the cost and types of IOL used.

SUBJECTS/METHODS

Cataract operations recorded on the Royal College of Ophthalmologists' National Ophthalmology Database were included, with additional data collected for remuneration model from NHS England and cost of IOL from the NHS Spend Comparison Service.

RESULTS

We included 907,052 cataract operations from 87 centres. The majority of operations were performed in PbR centres (456 198, 50.3%), followed by BC centres (240 641, 26.5%) and mixed models centres (210 213, 23.2%). The mean price of hydrophobic (n = 7) and hydrophilic IOLs (n = 5) were £45.72 and £42.86, respectively. Hydrophobic IOLs were predominantly used (650 633, 71.7%) and were significantly more commonly used in centres remunerated by BC (96.5% vs. 3.5%) than those by PbR (65.7% vs. 34.3%) when compared to hydrophilic IOLs (p < 0.001).

CONCLUSIONS

This study demonstrated that the IOL choice may be perversely incentivised by the IOL cost and remuneration model. Although hydrophobic IOLs are more expensive at the point of surgery, their potential longer-term cost-effectiveness due to reduced requirement for YAG capsulotomy should be considered.

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.

Cost Utility and Value of Information Analysis of Femtosecond Laser-Assisted Cataract Surgery

Importance

The efficacy and safety of femtosecond laser-assisted cataract surgery is well documented. An important requirement for decision makers is the evaluation of the cost-effectiveness of femtosecond laser-assisted cataract surgery (FLACS) over a sufficiently long horizon. Evaluating the cost-effectiveness of this treatment was a preplanned secondary objective of the Economic Evaluation of Femtosecond Laser Assisted Cataract Surgery (FEMCAT) trial.

Objective

To estimate the cost utility of FLACS compared with phacoemulsification cataract surgery (PCS) on a 12-month time horizon.

Design, Setting, and Participants

This multicenter randomized clinical trial compared FLACS with PCS in parallel groups. All FLACS procedures were performed using the CATALYS precision system. Participants were recruited and treated in ambulatory surgery settings in 5 university-hospital centers in France. All consecutive patients eligible for a unilateral or bilateral cataract surgery 22 years or older with written informed consent were included. Data were collected from October 2013 to October 2018, and data were analyzed from January 2020 to June 2022.

Interventions

FLACS or PCS.

Main Outcomes and Measures

Utility was measured through the Health Utility Index questionnaire. Costs of cataract surgery were estimated by microcosting. All inpatient and outpatient costs were collected from the French National Health Data System.

Results

Of 870 randomized patients, 543 (62.4%) were female, and the mean (SD) age at surgery was 72.3 (8.6) years. A total of 440 patients were randomized to receive FLACS and 430 to receive PCS; the rate of bilateral surgery was 63.3% (551 of 870). The mean (SD) costs of cataract surgery were €1124.0 (€162.2; US $1235) for FLACS and €565.5 (€61.4; US $621) for PCS. The total mean (SD) cost of care at 12 months was €7085 (€6700; US $7787) in participants treated with FLACS and €6502 (€7323; US $7146) in participants treated with PCS. FLACS yielded a mean (SD) of 0.788 (0.009) quality-adjusted life-years (QALYs), and PCS yielded 0.792 (0.009) QALYs. The difference in mean costs was €545.9 (95% CI, -434.1 to 1525.8; US $600), and the difference in QALYs was -0.004 (95% CI, -0.028 to 0.021). The incremental cost-effectiveness ratio (ICER) was -€136 476 (US $150 000) per QALY. The cost-effectiveness probability of FLACS compared with PCS was 15.7% for a cost-effectiveness threshold of €30 000 (US $32 973) per QALY. At this threshold, the expected value of perfect information was €246 139 079 (US $270 530 231).

Conclusions and Relevance

The ICER of FLACS compared with PCS was not within the $50 000 to $100 000 per QALY range frequently cited as cost-effective. Additional research and development on FLACS is needed to improve its effectiveness and lower its price.

Trial Registration

ClinicalTrials.gov Identifier: NCT01982006.

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.

Prophylaxis of posterior capsule opacification through autophagy activation with indomethacin-eluting intraocular lens

Posterior capsule opacification (PCO) is the most common long-term postoperative complication of cataract surgery, leading to secondary vision loss. Optimized intraocular lens (IOL) structure and appropriate pharmacological intervention, which provides physical barriers and biological inhibition, respectively, can block the migration, proliferation, and epithelial-mesenchymal transition (EMT) of lens epithelial cells (LECs) for PCO prophylaxis. Herein, a novel indomethacin-eluting IOL (INDOM-IOL) with an optimized sharper edge and a sustained drug release behavior was developed for PCO prevention. Indomethacin (INDOM), an ophthalmic non-steroidal anti-inflammatory drug (NSAID) used for postoperative ocular inflammation, was demonstrated to not only be able to suppress cell migration and down-regulate the expression of cyclooxygenase-2 (COX-2) and EMT markers, including alpha-smooth muscle actin (α-SMA) and cyclin D1, but also promote the autophagy activation in LECs. Additionally, autophagy was also verified to be a potential therapeutic target for the down-regulation of EMT in LECs. The novel IOL, serving as a drug delivery platform, could carry an adjustable dose of hydrophobic indomethacin with sustained drug release ability for more than 28 days. In the rabbit PCO model, the indomethacin-eluting IOL showed excellent anti-inflammatory and anti-PCO effects. In summary, indomethacin is an effective pharmacological intervention in PCO prophylaxis, and the novel IOL we developed prevented PCO in vivo under its sustained indomethacin release property, which provided a promising approach for PCO prophylaxis in clinical application.

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.

Design and Conduct of Randomized Clinical Trials Evaluating Surgical Innovations in Ophthalmology: A Systematic Review

PURPOSE

Surgical innovations are necessary to improve patient care. After an initial exploratory phase, novel surgical technique should be compared with alternative options or standard care in randomized controlled trials (RCTs). However, surgical RCTs have unique methodological challenges. Our study sought to investigate key aspects of the design, conduct, and reporting of RCTs of novel surgeries.

DESIGN

Systematic review.

METHODS

The protocol was prospectively registered in PROSPERO (CRD42021253297). RCTs evaluating novel surgeries for cataract, vitreoretinal, glaucoma, and corneal diseases were included. Medline, EMBASE, Cochrane Library, and Clinicaltrials.gov were searched. The search period was January 1, 2016, to June 16, 2021.

RESULTS

A total of 52 ophthalmic surgery RCTs were identified in the fields of glaucoma (n = 12), vitreoretinal surgery (n = 5), cataract (n = 19), and cornea (n = 16). A description defining the surgeon's experience or level of expertise was reported in 30 RCTs (57%) and was presented in both control and intervention groups in 11 (21%). Specification of the number of cases performed in the particular surgical innovation being assessed prior to the trial was reported in 10 RCTs (19%) and an evaluation of quality of the surgical intervention in 7 (13%). Prospective trial registration was recorded in 12 RCTs (23%) and retrospective registration in 13 (25%); and there was no registration record in the remaining 28 (53%) studies.

CONCLUSIONS

Important aspects of the study design such as the surgical learning curve, surgeon's previous experience, quality assurance, and trial registration details were often missing in novel ophthalmic surgical procedures. The Idea, Development, Exploration, Assessment, Long-term follow-up (IDEAL) framework aims to improve the quality of study design.

Femtosecond Laser-Assisted Cataract Surgery versus Conventional Phacoemulsification Surgery: Clinical Outcomes with EDOF IOLs

In this study, we evaluate and compare the outcomes of conventional phacoemulsification cataract surgery (CPS) and femtosecond laser-assisted cataract surgery (FLACS) with the implantation of an extended depth of field (EDOF) intraocular lens (IOL). A prospective, consecutive cohort study was conducted. Patients were given the option to choose FLACS or CPS and were implanted with an EDOF IOL. Refractive data, visual acuity data, ocular aberration measured with a wavefront aberrometer, and optical quality measured with an optical quality analysis system II were collected at one month postoperatively. A total of 92 eyes of 64 patients were enrolled in this study; 35 eyes of 26 patients were treated with FLACS, whereas 57 eyes of 38 patients were treated with CPS. Uncorrected visual acuity at far, intermediate, and near distance and best-spectacle-corrected visual acuity were not statistically significantly different between the groups (all p > 0.05), nor were the mean cylinder and mean spherical equivalent refraction (both p > 0.05). The FLACS group had a lower ocular trefoil than the CPS group (p = 0.033), and there was no significant difference between the two groups considering other aberration parameters, whether ocular or internal (all p > 0.05). Optical-quality-related parameters showed also no significant difference between the two groups (all p > 0.05). In conclusion, there was no significant difference between FLACS and CPS with implantation of EDOF IOLs in postoperative ocular parameters, refractive outcomes, ocular aberration, optical quality, and aberration parameters, except a lower ocular trefoil in the FLACS group. In terms of these indicators, FLACS does not provide an additional clinical benefit for patients over CPS.

Big data in corneal diseases and cataract: Current applications and future directions

The accelerated growth in electronic health records (EHR), Internet-of-Things, mHealth, telemedicine, and artificial intelligence (AI) in the recent years have significantly fuelled the interest and development in big data research. Big data refer to complex datasets that are characterized by the attributes of "5 Vs"-variety, volume, velocity, veracity, and value. Big data analytics research has so far benefitted many fields of medicine, including ophthalmology. The availability of these big data not only allow for comprehensive and timely examinations of the epidemiology, trends, characteristics, outcomes, and prognostic factors of many diseases, but also enable the development of highly accurate AI algorithms in diagnosing a wide range of medical diseases as well as discovering new patterns or associations of diseases that are previously unknown to clinicians and researchers. Within the field of ophthalmology, there is a rapidly expanding pool of large clinical registries, epidemiological studies, omics studies, and biobanks through which big data can be accessed. National corneal transplant registries, genome-wide association studies, national cataract databases, and large ophthalmology-related EHR-based registries (e.g., AAO IRIS Registry) are some of the key resources. In this review, we aim to provide a succinct overview of the availability and clinical applicability of big data in ophthalmology, particularly from the perspective of corneal diseases and cataract, the synergistic potential of big data, AI technologies, internet of things, mHealth, and wearable smart devices, and the potential barriers for realizing the clinical and research potential of big data in this field.

Comparison of clinical outcomes between cystotome-assisted prechop phacoemulsification surgery and femtosecond laser-assisted cataract surgery for hard nucleus cataracts

BACKGROUND/OBJECTIVES

To compare the safety and efficacy of cystotome-assisted prechop phacoemulsification surgery (CAPPS) and femtosecond laser-assisted cataract surgery (FLACS) in patients with hard nucleus cataract.

SUBJECTS/METHODS

Ninety-six eyes of 64 patients with grade IV hard nucleus cataract were assigned to 1 of the 2 groups (49 CAPPS and 47 FLACS). Follow-up visits were performed at 1 day, 1 week, 1 month, 3 months, 6 months, and 1 year, and the outcome measures comprised ultrasound power, effective phacoemulsification time (EPT), corrected distance visual acuity (CDVA), endothelial cell density (ECD), corneal endothelium cell loss rate (ECL), central corneal thickness (CCT), and intraoperative and postoperative complications.

RESULTS

The ultrasound power and EPT were lower in the CAPPS group (p = 0.03 and <0.0001, respectively). Patients in both groups gained better CDVA postoperatively. The ECD value decreased at each follow-up visit and did not return to the preoperative level; FLACS resulted in greater endothelial cell loss compared to CAPPS. CCT increased immediately after the surgery and decreased thereafter. The mean CCT value returned to the preoperative level 3 months postoperatively in the CAPPS group, while in the FLACS group, CCT value took 6 months to return to the preoperative level. Miosis was more likely to occur in the FLACS group.

CONCLUSIONS

Due to its efficacy and cost-effectiveness, CAPPS is worth promoting and applying to clinical work in the future.

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.

Implantable collamer lens implantation (ICL) versus small incision lenticule extraction (SMILE) in low to moderate myopia: study protocol for a randomized, non-inferiority trial

BACKGROUND

Implantable collamer lens implantation (ICL) is a form of 'foldable' posterior chamber phakic intraocular lens refractive surgery that generally does not impair cornea and natural accommodation. The potential advantages of the ICL over keratorefractive laser procedures include less induction of higher-order aberrations (HOAs) and enhanced retinal image magnification. On the other hand, small incision lenticule extraction (SMILE), currently, one of the most popular refractive surgery procedures, also offers excellent visual outcomes, particularly for eyes with low to moderate amounts of myopia. The aim of this study is to evaluate whether ICL/TICL (toric ICL) is comparable to SMILE for low to moderate myopia in terms of refractive outcomes at 3 and 18 months post-operatively.

METHODS/DESIGN

This is a prospective randomized study. A total of 300 participants will be randomized into two groups, the ICL/TICL group and SMILE group. Eligible participants with spherical equivalent (SE) less than - 6.0 diopter (D) will be recruited. Following randomization, participants will be followed at 1, 3, 6, 12, and 18 months. The primary outcome is the refractive predictability at every postoperative point after surgery, which is the proportion of the number of eyes achieving a postoperative SE within ± 0.5 D and ± 1.0 D of the intended target. Secondary outcome parameters include visual acuity, refraction, adverse events, and quality of vision measurements.

DISCUSSION

This trial will provide information on whether ICL has comparable, if not superior, refractive outcomes compared to the established SMILE for low to moderate myopia, thus providing evidence for translation into clinical practice.

TRIAL REGISTRATION

Chinese clinical trial registry (ChiCTR) 2200055372. Registered on 08 January 2022.

Dry Eye Following Femtosecond Laser-Assisted Cataract Surgery: A Meta-Analysis

This study investigates the dry eye effect after femtosecond laser-assisted cataract surgery (FLACS) and also compares the risk of postoperative dry eye between FLACS and manual cataract surgery (MCS). We searched various databases between 1 January 2000 and 15 October 2022 and included peer-reviewed clinical studies in our review. Dry eye parameters were extracted at baseline and postoperative day one, week one, one month, and three months. Parameters included were the ocular surface discomfort index (OSDI), tear secretion (tear meniscus height, Schirmer's test), microscopic ocular surface damage (fluorescein staining), and tear stability (first and average tear breakup time). Additionally, the differences of each parameter at each time point were compared between FLACS and MCS. In total, six studies of 611 eyes were included. On postoperative day one, increased, pooled standardised mean differences (SMDs) were noted in the OSDI, tear secretion, tear film instability, and microscopic damage. During postoperative week one, dry eye worsened. Fortunately, dry eye achieved resolution afterwards and nearly returned to the baseline level at postoperative three months. When the parameters were compared between FLACS and MCS, those of FLACS had higher severities, but most were not statistically significant. Dry eye impact was approximately the same in FLACS and MCS at postoperative three months.

Large Hyphema following Femtosecond Laser-assisted Cataract Surgery (FLACS) and Trabectome Resulting in Endocapsular Hematoma

Aim

To report a large hyphema following femtosecond laser-assisted cataract surgery (FLACS) and trabectome resulting in endocapsular hematoma.

Background

Hyphema has previously been described following trabectome, however, no cases have been reported following FLACS or FLACS combined with microinvasive glaucoma surgery (MIGS). We report a case of a large hyphema following FLACS combined with MIGS that resulted in an endocapsular hematoma.

Case description

A 63-year-old myopic female with exfoliation glaucoma underwent FLACS with a trifocal intraocular lens implant and Trabectome in the right eye. Significant intraoperative bleeding ensued following the trabectome and was treated with viscoelastic tamponade, anterior chamber (AC) washout, and cautery. The patient developed a large hyphema with intraocular pressure (IOP) rise that was treated with multiple AC taps, paracentesis, and eye drops. The hyphema took approximately 1 month to completely clear, leaving an endocapsular hematoma. This was treated successfully with Neodymium:Yttrium-Aluminum-Garnet (Nd:YAG) laser posterior capsulotomy.

Conclusion

Hyphema may occur with angle-based MIGS in combination with FLACS and may cause endocapsular hematoma. An increase in episcleral venous pressure during the docking and suction phase of the laser may predispose to bleeding. Endocapsular hematoma is an uncommon finding after cataract surgery and may be treated with Nd:YAG posterior capsulotomy.

How to cite this article

Chang EL, Apostolopoulos N, Mir TA, et al. Large Hyphema following Femtosecond Laser-assisted Cataract Surgery (FLACS) and Trabectome Resulting in Endocapsular Hematoma. J Curr Glaucoma Pract 2022;16(3):195-198.

Femtosecond laser-assisted arcuate keratotomy for the management of corneal astigmatism in patients undergoing cataract surgery: Comparison with conventional cataract surgery

Purpose

To assess the effects of femtosecond laser arcuate keratotomy with femtosecond laser-assisted cataract surgery in the management of corneal astigmatism, compared with conventional phacoemulsification cataract surgery.

Design

Retrospective comparative interventional case series.

Methods

A total of 2,498 eyes of consecutive patients who presented with 3.00 diopters (D) or under of astigmatism were included. The patients were treated with conventional phacoemulsification cataract surgery (conventional group) and femtosecond laser arcuate keratotomy with femtosecond laser-assisted cataract surgery (femtosecond group).

Results

Surgically induced astigmatism (SIA) was higher in the femtosecond group than the conventional group (0.215, p < 0.001). Difference vector (DV) was lower in the femtosecond group (-0.136, p < 0.001). The cut-off value of the overcorrection in the femtosecond group was 0.752 D of target induced astigmatism (TIA). For patients with TIA 0.75 D or under, DV and the value of index of success (TIA into DV) were significantly higher in the femtosecond group (p = 0.022 and < 0.001). The overcorrection ratios were 48.8% in the conventional and 58.9% in the femtosecond group. (p < 0.001). For patients with TIA over 0.75 D, SIA and correction index (TIA into SIA) was higher in femtosecond group (0.310 and 0.250, p < 0.001 and < 0.001, respectively). Absolute angle of error was 20.612 ± 18.497 in the femtosecond group and higher than the conventional group (2.778, p = 0.010).

Conclusion

Femtosecond laser arcuate keratotomy in cataract surgery was effective in SIA between 0.75 to 3.00 D of corneal astigmatism. However, the overcorrection in the lower astigmatism and angle of error in the higher astigmatism were due to the postoperative corneal astigmatism not decreasing as much as SIA. Overcoming these challenges will lead to better management of corneal astigmatism.

Femtosecond Laser-assisted Cataract Surgery in Patients With Prior Glaucoma Surgery

PRCIS

Femtosecond laser-assisted cataract surgery (FLACS) is a safe procedure in glaucomatous eyes with prior glaucoma surgery, evidenced by stable intraocular pressure (IOP) and medication use, acceptable success rate, disease stability, and low complication rates at 1-year postoperative.

PURPOSE

The purpose of this study was to assess the 1-year efficacy and safety of FLACS in glaucomatous eyes with prior glaucoma surgery.

MATERIALS AND METHODS

Retrospective case series of all consecutive glaucomatous eyes with previous glaucoma surgery that underwent FLACS using the Catalys Precision Laser System with or without concomitant glaucoma surgery at a single ophthalmology center, between 2014 and 2020. Efficacy included change in IOP, glaucoma medication use, best-corrected visual acuity, and surgical success at 12 months postoperatively (POM12). Safety included structural and functional measures of disease stability and postoperative adverse events.

RESULTS

A total of 57 eyes with an average age of 62.6±8.1 years were included. At POM12, IOP decreased from 14.5±6.6 mmHg to 13.5±3.7 mm Hg (P=0.22) and glaucoma medication use decreased from 2.1±1.5 to 1.8±1.4 with a marginal significance (P=0.089). Best-corrected visual acuity improved significantly in both groups (P<0.001) and surgical success ranged between 74% and 90% according to the study's success criteria. Safety was favorable with disease stability evidenced by lack of deterioration in cup-to-disc ratio, visual field mean deviation, retinal nerve fiber layer thickness, and ganglion cell-inner plexiform layer thickness. One eye with prior history of trabeculectomy experienced transient bleb leak. Other adverse events were minor without sight-threatening sequelae.

CONCLUSIONS

The results of this study suggest that FLACS with or without concomitant glaucoma surgery could be a safe procedure in glaucomatous eyes-a population for which FLACS has been relatively contraindicated. Nonetheless, in those with preexisting filtering bleb, extra attention should be paid to the bleb area.

Ex-vivo study on the surface quality of corneal lenticule and stroma after low energy femtosecond laser lenticule extraction

This study aimed to assess the surface quality of cap, stroma and lenticular surfaces created using low-energy femtosecond laser lenticule extraction (Ziemer FEMTO LDV Z8). Twenty-four porcine eyes were divided into four groups (n = 6 each): two with optimal laser power (32%) with posterior curvature equivalent to a spherical correction of -2D and -5D, respectively and the other two with high power (64%) with spherical correction of -2D and -5D respectively. Samples were analysed using scanning electron microscopy (SEM). Surface morphology was evaluated using a standard scoring system; surface relief, surface regularity, extent and position of irregularities were graded by four independent clinicians. Eyes with 32% power and -2D correction had significantly less size of the irregular area than those with -5D; however, no significant difference was found between the two groups with 64% power. When comparing eyes with -2D correction, the size of the irregular area was lesser with 32% power. Surface relief was lesser with -5D correction with 32% power than 64% power. Low-energy femtosecond laser lenticule extraction (Ziemer FEMTO LDV Z8) produces good surface quality results. There is a tendency for smoother surface stromal quality with lower power settings than a higher power.

Safety of femtosecond laser-assisted cataract surgery versus conventional phacoemulsification for cataract: A meta-analysis and systematic review

Purpose

To compare the complications of femtosecond laser-assisted cataract surgery (FLACS) with those of conventional phacoemulsification surgery (CPS) for age-related cataracts.

Methods

PubMed, Cochrane Library, and EMBASE were systematically searched for studies comparing FLACS and CPS. Outcomes were operative complications, including the intraoperative capsule tear, postoperative corneal edema, macular edema, uncontrolled IOP, etc. The effect measures were weighted with odds ratios with 95% CIs.

Results

Nineteen RCTs and 18 cohort studies, including 24,806 eyes (11,375 of the FLACS group and 13,431 of the CPS group), were identified. There were no significant differences between the two groups in anterior capsule tear, corneal edema, macular edema, uncontrolled IOP, vitreous loss, posterior vitreous detachment, etc. Posterior capsule tear rate showed a significantly lower in RCT subgroups (P ​= ​0.04) and without differences in total (P ​= ​0.63). Significant differences were observed in the incidence of descemet membrane tear/trauma (P ​= ​0.02) and IFIS/iris trauma (P ​= ​0.04. Additionally, The FLACS specific complications showed a significantly higher rate of miosis (P ​< ​0.0001), corneal epithelial defect (P ​= ​0.001), corneal haze (P ​= ​0.002), and subconjunctival hemorrhage (P ​= ​0.01).

Conclusions

FLACS maintains the same safety compared with CPS in terms of all intraoperative and postoperative complications. Although FLACS did show a statistically significant difference for several FLACS specific complications, it would not influence the visual outcome and heal itself.

Femtosecond Laser-Assisted Cataract Surgery

PURPOSE

To evaluate refractive outcomes, safety, and cost-effectiveness of femtosecond laser-assisted cataract surgery (FLACS) compared with phacoemulsification cataract surgery (PCS).

METHODS

A PubMed search of FLACS was conducted in August 2020. A total of 727 abstracts were reviewed and 33 were selected for full-text review. Twelve articles met inclusion criteria and were included in this assessment. The panel methodologist assigned a level of evidence rating of I to all 12 studies.

RESULTS

No significant differences were found in mean uncorrected distance visual acuity, best-corrected distance visual acuity, or the percentage of eyes within ± 0.5 and ± 1 diopter of intended refractive target between FLACS and PCS. Intraoperative and postoperative complication rates were similar between the 2 groups, and most studies showed no difference in endothelial cell loss between FLACS and PCS at various time points between 1 and 6 months. In large randomized controlled studies in the United Kingdom and France, FLACS was less cost-effective than PCS.

CONCLUSIONS

Both FLACS and PCS have similar excellent safety and refractive outcomes. At this time, one technique is not superior to the other, but economic analyses performed in some populations have shown that FLACS is less cost-effective.

Biliverdin/Bilirubin Redox Pair Protects Lens Epithelial Cells against Oxidative Stress in Age-Related Cataract by Regulating NF-κB/iNOS and Nrf2/HO-1 Pathways

Age-related cataract (ARC) is the leading cause of vision impairment globally. It has been widely accepted that excessive reactive oxygen species (ROS) accumulation in lens epithelial cells (LECs) is a critical risk factor for ARC formation. Biliverdin (BV)/bilirubin (BR) redox pair is the active by-product of heme degradation with robust antioxidative stress and antiapoptotic effects. Thus, we purpose that BV and BR may have a therapeutic effect on ARC. In the present study, we determine the expression levels of enzymes regulating BV and BR generation in human lens anterior capsule samples. The therapeutic effect of BV/BR redox pair on ARC was assessed in hydrogen peroxide (H₂O₂)-damaged mouse LECs in vitro. The NF-κB/inducible nitric oxide synthase (iNOS) and nuclear factor erythroid 2-related factor 2 (Nrf2)/heme oxygenase-1 (HO-1) signaling pathways were evaluated to illustrate the molecular mechanism. The results revealed that the mRNA expressions of Nrf2, HO-1, and biliverdin reductase A (BVRA) were all decreased in human samples of age-related nuclear cataract. BV/BR redox pair pretreatment protected LECs against H₂O₂ damage by prohibiting NF-κB p65 nuclear trafficking, ameliorating iNOS expression, reducing intracellular and mitochondrial ROS levels, and restoring glutathione (GSH) and superoxide dismutase (SOD) levels. BV and BR pretreatment also regulated the expression of apoptotic molecules (Bax, Bcl-2, and cleaved caspase-3), thus decreasing the apoptosis of LECs. In addition, BV/BR pair promoted Nrf2 nuclear accumulation and HO-1 induction, whereas the knockdown of BVRA counteracted the effect of BV on activating Nrf2/HO-1 pathway and antiapoptosis. These findings implicated that BV/BR redox pair protects LECs against H₂O₂-induced apoptosis by regulating NF-κB/iNOS and Nrf2/HO-1 pathways. Moreover, BVRA is responsible for BV-mediated cytoprotection by reductive conversion of BV to BR. This trial is registered with ChiCTR2000036059.

Femtosecond laser-assisted cataract surgery after corneal refractive surgery

Cataract is the leading cause of blindness worldwide, and advanced cataract techniques such as femtosecond laser-assisted cataract surgery (FLACS) have been commercially available. Corneal refractive surgery (CRS) is one of the most popular surgeries for the correction of refractive errors. CRS changes the cornea not only anatomically but also pathophysiologically. However, there has been no clinical research analyzing the refractive and safety outcomes of FLACS after CRS. The aim of this retrospective chart review and comparative study is to evaluate the effect and safety of FLACS after CRS comparing with conventional PCS. Participants with a previous CRS history who underwent FLACS or conventional PCS were included in this study. The visual outcomes and the refractive outcomes including refractive, corneal, and ocular residual astigmatism were compared. The safety outcomes were then studied intraoperatively and postoperatively. A total of 102 patients with age-related cataract were enrolled. At 3 months postoperatively, UCVA, BCVA, and predictive error were not significantly different between the FLACS and conventional PCS groups. Reduction of refractive astigmatism was higher in FLACS. Postoperative ORA was significant lower in FLACS. Reduction of ORA was higher in FLACS. The intraoperative and postoperative complications were also not significantly different between the two groups. FLACS could effectively change refractive astigmatism and ORA; without more complications than conventional PCS. FLACS’ competitive edge in postoperative ORA may provide better visual quality than conventional PCS in patients with a previous history of CRS.

Risk factors for fluctuations in corneal endothelial cell density (Review)

The cornea is a transparent, avascular and abundantly innervated tissue through which light rays are transmitted to the retina. The innermost layer of the cornea, also known as the endothelium, consists of a single layer of polygonal endothelial cells that serve an important role in preserving corneal transparency and hydration. The average corneal endothelial cell density (ECD) is the highest at birth (~3,000 cells/mm²), which then decrease to ~2,500 cells/mm² at adulthood. These endothelial cells have limited regenerative potential and the minimum (critical) ECD required to maintain the pumping function of the endothelium is 400-500 cells/mm². ECD < the critical value can result in decreased corneal transparency, development of corneal edema and reduced visual acuity. The condition of the corneal endothelium can be influenced by a number of factors, including systemic diseases, such as diabetes or atherosclerosis, eye diseases, such as uveitis or dry eye disease (DED) and therapeutic ophthalmological interventions. The aim of the present article is to review the impact of the most common systemic disorders (pseudoexfoliation syndrome, diabetes mellitus, cardiovascular disease), eye diseases (DED, uveitis, glaucoma, intraocular lens dislocation) and widely performed ophthalmic interventions (cataract surgery, intraocular pressure-lowering surgeries) on corneal ECD.

Cataract: Advances in surgery and whether surgery remains the only treatment in future

Background

Cataract is the world's leading eye disease that causes blindness. The prevalence of cataract aged 40 years and older is approximately 11.8%-18.8%. Currently, surgery is the only way to treat cataracts.

Main Text

From early intracapsular cataract extraction to extracapsular cataract extraction, to current phacoemulsification cataract surgery, the incision ranges from 12 to 3 ​mm, and sometimes to even 1.8 ​mm or less, and the revolution in cataract surgery is ongoing. Cataract surgery has transformed from vision recovery to refractive surgery, leading to the era of refractive cataract surgery, and premium intraocular lenses (IOLs) such as toric IOLs, multifocal IOLs, and extended depth-of-focus IOLs are being increasingly used to meet the individual needs of patients. With its advantages of providing better visual acuity and causing fewer complications, phacoemulsification is currently the mainstream cataract surgery technique worldwide. However, patient expectations for the safety and accuracy of the operation are continually increasing. Femtosecond laser-assisted cataract surgery (FLACS) has entered the public's field of vision. FLACS is a combination of new laser technology and artificial intelligence to replace fine manual clear corneal incision, capsulorhexis, and nuclear pre-fragmentation, providing new alternative technologies for patients and ophthalmologists. As FLACS matures, it is being increasingly applied in complex cases; however, some think it is not cost-effective. Although more than 26 million cataract surgeries are performed each year, there is still a gap in the prevalence of cataracts, especially in developing countries. Although cataract surgery is a nearly ideal procedure and complications are manageable, both patients and doctors dream of using drugs to cure cataracts. Is surgery really the only way to treat cataracts in the future? It has been verified by animal experiments that lanosterol therapy in rabbits and dogs could make cataract severity alleviated and lens transparency partially recovered. Although there is still much to learn about cataract reversal, this groundbreaking work provided a new strategy for the prevention and treatment of cataracts.

Conclusions

Although cataract surgery is nearly ideal, it is still insufficient, we expect the prospects for cataract drugs to be bright.

Comparison of Femtosecond Laser-Assisted Cataract Surgery and Conventional Phacoemulsification on Endothelial Cell Density When Using Torsional Modality

Purpose

To compare the effects of femtosecond laser assisted cataract surgery (FLACS) and manual phacoemulsification on cumulative dissipated energy (CDE), torsional amplitude, and endothelial cell density (ECD).

Patients and Methods

This prospective, randomized study was conducted at Oka Eye Clinic (Fukuoka, Japan). Surgeries were performed using FLACS (with LenSx) or conventional technique in adults ≥20 years with grade 2–4 cataracts. Visits included preoperative, surgery day, and 5 postoperative visits (days 1, 4–10, 20–40, 60–120, and 150–210). Primary endpoint was CDE. Secondary endpoints included ECD percent change at day 150–210 versus preoperative visit and average torsional amplitude on surgery day. Exploratory endpoints included central corneal thickness and corrected distance visual acuity (CDVA). Superiority of FLACS to conventional technique was evaluated using t-tests based on a mixed model for repeated measures.

Results

Full analysis set included 53 eyes per group. Mean cataract grade was 2.92±0.58 in FLACS and 2.94±0.57 in conventional group. FLACS versus conventional method had significantly lower mean CDE (0.213±0.334 versus 1.718±0.898%-seconds, respectively; P<0.0001), demonstrating superiority of FLACS. Low endothelial cell loss (ECL) was achieved with both FLACS and conventional methods (1.5±5.6% and 2.7±5.2%; P=0.260). Torsional amplitude was significantly lower for FLACS versus conventional method (19.6±16.0% versus 31.1±6.6%; P<0.0001). Central corneal thickness was comparable for both methods at all visits except day 1; CDVA was comparable for both methods at all postoperative visits.

Conclusion

FLACS achieved significantly lower CDE compared with the conventional surgical method (P<0.0001). Low ECL was achieved with both FLACS (1.5%) and conventional (2.7%) methods.

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Study of the efficiency and workflow of femtosecond laser-assisted cataract surgery in a Spanish public hospital

BACKGROUND

To assess the time-efficiency of a designated operating room (OR) workflow in the introduction of femtosecond laser-assisted cataract surgery (FLACS, LenSx, Alcon®). The study was carried out in a public hospital a with high-volume of procedures.

METHODS

We performed this prospective, controlled, surgical intervention study in the ophthalmology department of a Spanish tertiary referral public hospital. A total of 167 eyes were enrolled, including 62 eyes undergoing conventional phacoemulsification surgery. In phase I, patients were assigned either to FLACS-I (n=63) or conventional phacoemulsification surgery (n=62). One surgeon operated the femtosecond laser, and another completed the procedure, while a third performed conventional phacoemulsification. In the second phase (FLACS-II), all the surgeries were FLACS (n=42). One surgeon performed the FLACS procedure, and two different surgeons completed the surgeries in separate ORs. Surgical and turnover times of all the patients were recorded.

RESULTS

Preparation time was statistically significantly lower in FLACS-I and FLACS-II (P<0.001), whereas the duration of the cataract procedure per se was higher in FLACS-II compared to conventional phacoemulsification (P=0.03). Phacoemulsification energy was higher in FLACS-II compared to FLACS-I (P=0.01), whereas laser-related surgical time was lower (P=0.001). Surgical complications and total surgical time showed no statistically significant differences between any of the three groups.

CONCLUSIONS

This study suggests a time-efficient and suitable workflow model for FLACS, considering the specific requirements and restrictions of a fully booked public hospital. Even so, we have shown that the FLACS procedure does not take longer than conventional phacoemulsification when following a detailed plan for OR workflow. In addition, our data reflect an improvement in FLACS surgical times with ongoing experience.

TRIAL REGISTRATION

NCT03931629 (retrospectively registered).

The Latest Evidence with Regards to Femtosecond Laser-Assisted Cataract Surgery and Its Use Post 2020

Femtosecond laser-assisted cataract surgery (FLACS) was introduced with the hope of making cataract surgery safer and making the refractive result more predictable. It is only in the last four years that level 1 prospective randomised controlled trials (RCT) using current technology have been published. These, along with a meta-analysis of recent studies have shown that there seems to be little long-term visual benefit when using FLACS with monofocal lenses. The promised decrease in ultrasound energy required to remove a cataract has not been consistently demonstrated. There is level one evidence that the rate of posterior capsular rupture is less with FLACS using modern software. The round capsulotomy may be of increasing importance with the uptake of toric, multifocal and extended depth of focus lenses where a predictable capsulotomy size and precise placement of the lens becomes more important.

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.

[Results of hybrid (femtosecond laser-assisted) phacoemulsification of hypermature cataract in patients with lens subluxation]

Studying the use of femtosecond laser in patients with complicated cataracts remains a topical issue in phaco surgery.

PURPOSE

To comparatively analyze the results of using hybrid (femtosecond laser-assisted) phacoemulsification in hypermature cataract in patients with lens subluxation.

MATERIAL AND METHODS

The study included 78 patients (78 eyes) with hypermature cataract in combination with lens subluxation of I-II degree. In the 1^st group (45 eyes) capsulorhexis was performed using a femtosecond laser. In the 2^nd group (33 eyes) manual capsulorhexis was performed.

RESULTS

On the first day after surgery, best corrected visual acuity of 0.8-1.0 was obtained in 57.8% of cases in the 1^st group and 33.3% in the 2^nd group. Transient corneal edema during the first 1-3 days was noted in 4.4% of cases in the 1^st group and in 15.2% - in the 2^nd group of patients. Pachymetry in the center of the cornea showed an increase in its thickness on the 1^st day after surgery from 0.564±0.027 mm to 0.591±0.033 mm in the 1^st group and from 0.561±0.023 mm to 0.637±0.043 mm (p<0.05) in the 2^nd group of patients. The loss of corneal endothelial cells amounted to 10.9±1.8% in the 1^st group and 17.4±2.9% in the 2^nd group (p<0.05). Macular edema with decreased visual acuity confirmed by OCT was detected in the 1^st group of patients in 2.2% of cases, in the 2^nd group - in 9.1% of cases. With a follow-up period of up to 3 years, IOL optics decentration by more than 1 mm was detected in 2.2% of cases in the 1^st group of patients and in 12.1% of cases in the 2^nd group.

CONCLUSION

Femtosecond laser-assisted capsulorhexis significantly improves the results of surgery in patients with hypermature cataract combined with lens subluxation.

Effects of Femtosecond Laser-Assisted Cataract Surgery on Macular and Choroidal Thickness in Diabetic Patients

Introduction

This study aimed to compare the short-term changes in retinal and choroid thickness in diabetic patients after femtosecond laser-assisted cataract surgery (FLACS) and phacoemulsification (PE) surgery.

Methods

A total of 47 eyes in the PE group and 44 eyes in the FLACS group were included. All patients underwent measurement of central macular thickness (CMT) and subfoveal choroidal thickness (SFCT) before and after surgery using optical coherence tomography (OCT).

Results

The effective phaco time (EPT) in the FLACS group was significantly reduced. The BCVA differed significantly between the two groups at 1 week and 1 month after surgery. The CMT in both groups increased at 1 week after the operation. It did not return to the preoperative level until month 12 in the PE group. In the FLACS group, the CMT began to decrease at month 3 and recovered to the preoperative level at month 12. The SFCT of the two groups increased at week 1; it began to decrease at month 6 in the PE group but did not recover to the preoperative level until month 12. The SFCT in the FLACS group recovered to preoperative levels at month 6. In the PE group, baseline CMT values predicted CMT change at week 1 and months 1, 3 and 12 after surgery. In the FLACS group, baseline CMT predicted CMT changes at week 1, month 1 and month 3. In the FLACS group, EPT predicted SFCT change at month 3.

Conclusion

FLACS is safe and effective in patients with no fundus change or mild diabetic retinopathy. It has advantages in effectively reducing EPT, achieving good vision earlier and promoting faster recovery of the retinal and choroidal thickness. Preoperative CMT is a significant predictor of CMT changes in the early period after FLACS.

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).

Clinical Results After Precision Pulse Capsulotomy

Purpose

To compare residual refractive error and complication rates between eyes undergoing a manual capsulotomy and those receiving a precision pulse capsulotomy using an automated device.

Patients and Methods

This study was a non-interventional two-arm retrospective chart review of clinical results after bilateral cataract surgery or refractive lens exchange (RLE) surgery with a monofocal toric intraocular lens (IOL) or a trifocal IOL where a manual capsulorhexis (Manual) or automated precision pulse capsulotomy (PPC) was performed.

Results

Exams from 243 eyes (122 PPC, 121 Manual) from 124 patients were reviewed; about 75% of which had a trifocal IOL implanted. There was no statistically significant difference in the MRSE with either IOL type, or overall. The overall percentage of eyes with residual refractive cylinder ≤ 0.50 D was significantly higher in the PPC group (89% vs. 79% in the manual group, p = 0.03), primarily driven by results with the toric IOL. Best corrected distance visual acuity was not statistically significantly different by group. Capsulotomy-related complications were lower in the PPC group relative to the manual group (4.1% vs. 6.6%), but this result was not statistically significant (p = 0.38).

Conclusion

Significantly more eyes had refractive cylinder ≤0.50 D in the PPC group. For all other measures, the automated PPC device produced clinical results equivalent to those achieved with a manual capsulorhexis.