Femtosecond laser versus manual clear corneal incision in cataract surgery

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.

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

PURPOSE

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

DESIGN

Prospective comparative study.

METHODS

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

RESULTS

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

CONCLUSIONS

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

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.

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

PURPOSE

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

Clear corneal incision, an important step in modern cataract surgery: a review

A clear corneal incision (CCI) is the most commonly used entrance site in modern phacoemulsification cataract surgery. Despite some initial concerns about increased endophthalmitis rates through a self-sealing CCI, recent literature suggests that the risk of infection with proper wound construction and all other necessary precautions is minimal. The technique of creating a clear corneal incision has, with recent developments in corneal imaging, undergone critical appraisal leading to a better understanding of incision architecture. Many surgeons operate through smaller incisions, and they have a wide choice of surgical instruments to create their corneal incisions. The aim of this review is to discuss the history and the current status of clear corneal incision creation, the design and materials of surgical blades, and the current trends in manufacturing and sustainability. Although disposable instruments have some advantages and are very popular, recycling, if possible, and avoiding unnecessary plastic waste are important considerations. In any case, the step of CCI is a small one for the surgeon, but a big one for the eye. That is why it has to be done with the utmost precision and in-depth knowledge is important.

Safety and efficacy of cataract surgery performed with a low-energy femtosecond laser compared with conventional phacoemulsification in Chinese patients: a randomized clinical trial

BACKGROUND

To compare the safety and efficacy of femtosecond laser-assisted cataract surgery (FLACS) performed with the low-energy FEMTO LDV Z8 (Ziemer Ophthalmic Systems AG, Port, Switzerland) laser compared with conventional phacoemulsification (CP) in Chinese patients.

METHODS

This prospective, multicenter, interventional study included 126 patients who were randomized (1:1) to undergo either FLACS or CP followed by intraocular lens (IOL) implantation between January 2019 and April 2020. The primary endpoint included the comparison of the endothelial cell loss (ECL) between the two groups at 3 months. Secondary endpoints included the comparison of cumulative dissipated energy (CDE), change in central corneal thickness (CCT) from baseline, and postoperative uncorrected and corrected distance visual acuities (UDVA and CDVA) in the two groups.

RESULTS

At all postoperative time points, the FLACS group was found to be non-inferior to CP for the mean ECL (- 409.3 versus - 436.9 cells/mm² at 3 months) and mean CDE (4.1 versus 4.5 percent-seconds). The increase in CCT was significantly lower in the FLACS group compared with the CP group at Day 7 (4.9 versus 9.2 µm; P = 0.04); however, the difference was not statistically significant at 1 and 3 months. Postoperatively, mean UDVA and CDVA were comparable between the two groups. No intraoperative complications occurred.

CONCLUSIONS

Cataract surgery performed with a low-energy femtosecond laser was non-inferior to CP; however, the FLACS group had a statistically significantly lower increase in CCT at Day 7 compared with CP. Trial registration This trial is registered at ClinicalTrials.gov on May 15, 2019, with trial registration number: NCT03953053.

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.

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.

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

Purpose

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

Patients and Methods

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

Results

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

Conclusion

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

Functional Profile of a Customized Wound Parameter in Femtosecond Laser-Assisted Corneal Incision for Cataract Surgery

Purpose

To evaluate the performance of optimized parameters of femtosecond laser for cataract surgery corneal incisions regarding opening, patency and surgically induced astigmatism (SIA).

Patients and Methods

Patients scheduled for femtosecond laser-assisted cataract surgery between May 2018 and December 2018 were enrolled. Inclusion criteria were a healthy preoperative cornea and uneventful FLACS. Exclusion criteria were preoperative corneal astigmatism over 1.0 D, previous corneal trauma or pathologies. Clinical data were obtained from the electronic medical records. Surgical planning was based on Scheimpflug tomography images for keratometric data. At postoperative day 60, new keratometric evaluation was performed, obtained using the same device.

Results

101 eyes (61 patients) matched the criteria for SIA analysis. Overall mean SIA was 0.44 ± 0.33 D (0-1.55 D). Axis and size did not have any statistically significant effects on SIA. The overall centroid of the SIA was 0.11. For the opening analysis, was included 156 eyes (79 patients). Successful opening in 87.7% of cases (137 eyes). Temporal incisions had the highest success rate (98.36%).

Conclusion

These femtosecond laser parameters showed high opening rates with low opening times. These optimized parameters led to a low incidence of SIA and high predictability regardless of incision site and size. The association between incision opening and SIA was not statistically significant. There was, however, an association between incision opening success and site.

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.

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

PURPOSE

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

Femtosecond Laser-Assisted Ophthalmic Surgery: From Laser Fundamentals to Clinical Applications

Femtosecond laser (FSL) technology has created an evolution in ophthalmic surgery in the last few decades. With the advantage of high precision, accuracy, and safety, FSLs have helped surgeons overcome surgical limits in refractive surgery, corneal surgery, and cataract surgery. They also open new avenues in ophthalmic areas that are not yet explored. This review focuses on the fundamentals of FSLs, the advantages in interaction between FSLs and tissues, and typical clinical applications of FSLs in ophthalmology. With the rapid progress that has been made in the state of the art research on FSL technologies, their applications in ophthalmic surgery may soon undergo a booming development.

Comparison of wound architecture in implantable collamer lens surgery: Self-sealing single-plane opposite clear corneal incision versus main surgical incision

PURPOSE

Incision architecture can play an important role in corneal astigmatism management through peripheral corneal relaxing incisions. The aim of this study was to compare the incision architecture of single-plane opposite clear corneal incisions (OCCIs) and main surgical incisions (MSIs) in patients undergoing implantable collamer lens (ICL) surgery.

METHODS

A retrospective cross-sectional tomographic analysis of MSI and OCCI architectures was performed 6 months after ICL surgery. Image acquisition was performed using spectral-domain anterior segment optical coherence tomography.

RESULTS

A total of 31 OCCIs and 24 MSIs were evaluated. The mean incision angle was 42.83 ± 5.69 degrees for MSIs and 48.26 ± 6.07 degrees for OCCIs (p < 0.01), and the mean MSI and OCCI length was 1146.70 ± 150.48 µm and 976.68 ± 140.19 µm, respectively (p < 0.01). The mean increase in epithelium depth in the wound was 37.63 ± 11.91 µm in the MSI group and 47.64 ± 15.45 µm in the OCCI group (p = 0.02). Endothelial misalignment was observed in both types of incisions. However, the misalignment with MSI was greater than with OCCI, 106.67 ± 31.84 µm versus 83.75 ± 23.39 µm (p = 0.01), respectively.

CONCLUSION

Both types of incisions, OCCI and MSI, were shown to be safe with complete wound sealing and healing 6 months postoperatively. The MSIs performed in the temporal position were more angled and longer, with greater endothelial retraction and minor epithelial thickening in the wound area compared with astigmatic incisions without manipulation.

Endothelial Cell Loss, Cumulative Dissipated Energy, and Surgically Induced Astigmatism in Sutureless Scleral Tunnel Phaco-Assisted Cataract Extraction in Advanced Cataracts

Purpose

To evaluate sutureless scleral tunnel phaco-assisted cataract extraction in regards to the cumulative dissipated energy (CDE) used, the resulting endothelial cell loss (ECL), and the surgically induced astigmatism (SIA) in advanced cataracts.

Methods

A prospective interventional uncontrolled case series was performed. Patients with advanced cataracts according to the Lens Opacities Classification System III (LOCS III) had sutureless scleral tunnel phaco-assisted cataract extraction. They were followed up one week, one month, and 3 months postoperatively for SIA and ECL. The used CDE was recorded.

Results

The study included 198 eyes: 36 eyes (18.2%) with LOCS III grade nuclear opalescence (NO4) cataracts, 102 eyes (51.5%) with LOCS III grade NO5, and 60 eyes (30.3%) with LOCS III grade NO6. Three months postoperatively, the mean SIA was 0.94 ± 0.71D. The endothelial cell density (ECD) was reduced significantly to 2341.31 ± 471 cells/mm² (p=0.0001) with a mean ECL of 5.39%. The mean CDE and ECL% were 0.174 ± 0.46 U/S (2.07%), 0.859 ± 0.42 U/S (5.01%), and 2.306 ± 0.89 U/S (8.01%) in LOCS III grade NO4, NO5, and NO6, respectively. The overall mean CDE was 1.17 ± 0.99 U/S, which was significantly correlated with the ECL (p=0.0001).

Conclusion

Sutureless scleral tunnel phaco-assisted cataract extraction in advanced cataracts enabled reduction in CDE with good preservation of the ECD and acceptable SIA.

Moxifloxacin releasing intraocular implant based on a cross-linked hyaluronic acid membrane

Intraocular antibiotic delivery is an important technique to prevent bacterial infection after ophthalmic surgery, such as cataract surgery. Conventional drug delivery methods, such as antibiotic eye drops, have limitations for intraocular drug delivery due to the intrinsic barrier effect of the cornea. Therefore, frequent instillation of antibiotic eyedrops is necessary to reach a sufficient bactericidal concentration inside the eye. In this study, an intraocular implant, MXF-HA, that combines hyaluronic acid (HA) and moxifloxacin (MXF) was developed to increase the efficiency of intraocular drug delivery after surgery. MXF-HA is manufactured as a thin, transparent, yellow-tinted membrane. When inserted into the eye in a dry state, MXF-HA is naturally hydrated and settles in the eye, and the MXF contained therein is delivered by hydrolysis of the polymer over time. It was confirmed through in vivo experiments that MXF delivery was maintained in the anterior chamber of the eye at a concentration sufficient to inhibit Pseudomonas aeruginosa and Staphylococcus aureus for more than 5 days after implantation. These results suggest that MXF-HA can be utilized as a potential drug delivery method for the prevention and treatment of bacterial infections after ophthalmic surgery.

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

AIM

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

METHODS

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

RESULTS

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

CONCLUSION

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

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).

Optimization of femtosecond laser-constructed clear corneal wound sealability for cataract surgery

PURPOSE

To compare the sealability of femtosecond laser (FSL)-assisted corneal incisions (CIs) with that of triplanar manual (M)-CIs and to determine FSL wound parameters minimizing leakage.

SETTING

Private practice.

DESIGN

Phase IV, single-surgeon, retrospective cohort study.

METHODS

One eye per patient was included. Two groups defined by the main wound (FSL-CI or M-CI) were compared for leakage, inferred by placement of a suture at the end of surgery. Leakage in FSL-CIs was analyzed as a function of customizable wound parameters: anterior plane depth (APD), posterior plane depth (PPD), anterior side-cut angle (ASCA), and posterior side-cut angle (PSCA). The risk of leakage of FSL-CIs with optimal and nonoptimal parameters was further compared with that of M-CIs.

RESULTS

A total of 1100 eyes (757 [68.8%] FSL-CI; 343 [31.2%] M-CI) were included. Wound leakage occurred in 133 FSL-CI (17.6%) and 30 M-CI eyes (8.7%) (P < .001). FSL wound parameters associated with the lowest risk of leakage were 60% APD, 70% PPD, 120 degrees ASCA, and 70 degrees PSCA. FSL-CIs constructed with at least 3 optimal parameters (60% APD, 70% PPD, and 120 degrees ASCA) had a similar risk of leakage to M-CIs (odds ratio [OR], 1.1; 95% CI, 0.5-2.3). FSL-CIs with suboptimal parameters had twice the risk of leakage of M-CIs (OR, 2.0; 95% CI, 1.1-3.8).

CONCLUSIONS

Overall, FSL-CIs leaked more than M-CIs. However, FSL-CIs with optimized wound profiles had an equivalent risk of leakage to M-CIs. Wound parameter customization is an asset of FSL technology that allows optimization of FSL-CI sealability.

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.

Femtosecond Laser Assisted Cataract Surgery: A Review

Femtosecond laser assisted cataract surgery (FLACS) offers a level of precision, accuracy and customization that is not possible with manual phacoemulsification (MP). With the increase of patient expectations and premium intraocular lens utilization in the era of refractive cataract surgery, predictability and accuracy has become of utmost importance. FLACS has four main functions: creation of a consistently sized round capsulotomy, treatment of keratometric astigmatism with arcuate incisions, construction of clear corneal incisions, and fragmentation and/or softening of the lens. However, FLACS may have limitations due to suction loss, incomplete capsulotomy or poor pupillary dilation. Patient selection and surgeon experience is critical. This review article will focus on the various platforms available for FLACS, the steps in cataract surgery it can perform, and overall advantages and limitations of the technology.

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.

Challenges and strategies for the delivery of biologics to the cornea

Biologics, like peptides, proteins and nucleic acids, have proven to be promising drugs for the treatment of numerous diseases. However, besides the off label use of the monoclonal antibody bevacizumab for the treatment of corneal neovascularization, to date no other biologics for corneal diseases have reached the market. Indeed, delivering biologics in the eye remains a challenge, especially at the level of the cornea. While it appears to be a rather accessible tissue for the administration of drugs, the cornea in fact presents several anatomical barriers to delivery. In addition, also intracellular delivery barriers need to be overcome to achieve a promising therapeutic outcome with biologics. This review outlines efforts that have been reported to successfully deliver biologics into the cornea. Biochemical and physical methods for achieving delivery of biologics in the cornea are discussed, with a critical view on their efficacy in overcoming corneal barriers.

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

Background:

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

Objective:

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

Methods:

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

Results:

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

Conclusion:

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

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.

Effect of femtosecond laser-assisted steepest-meridian clear corneal incisions on preexisting corneal regular astigmatism at the time of cataract surgery

AIM

To investigate the clinical efficacy and safety of femtosecond laser-assisted steepest-meridian clear corneal incisions for correcting preexisting corneal astigmatism performed at the time of cataract surgery.

METHODS

This prospective case series study comprised consecutive age-related cataract patients with corneal regular astigmatism (range: +0.75 to +2.50 D) who had femtosecond laser-assisted steepest-meridian clear corneal incisions (single or paired). Corneal astigmatism was performed with the Pentacam preoperatively and 3mo postoperatively. Total corneal astigmatism and steepest-meridian measured in the 3-mm central zone were used to guide the location, size and number of clear corneal incision. The vector analysis of astigmatic change was performed using the Alpins method.

RESULTS

Totally 138 eyes of 138 patients were included. The mean preoperative corneal astigmatism was 1.31±0.41 D, and was significantly reduced to 0.69±0.34 D (equivalent to difference vector) after surgery (P<0.01). The surgically-induced astigmatism was 1.02±0.54 D. The correction index (ratio of target induced astigmatism and surgically-induced astigmatism: 0.72±0.36) as well as the magnitude of error (difference between surgically-induced astigmatism and target induced astigmatism: -0.29±0.51) represented a slight under correction. For angle of error, the arithmetic mean was 1.11±13.70, indicating no significant systematic alignment errors.

CONCLUSION

Femtosecond-assisted steepest-meridian clear corneal incision is a fast, customizable, adjustable, precise, and safe technique for the reduction of low to moderate corneal astigmatism during cataract surgery.

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

PURPOSE

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

A Novel Sequential Docking Technique: Use of Femtosecond Arcuate Keratotomy and Femtosecond Assisted Cataract Surgery Using a Pupil Expansion Ring on a Patient with Intraoperative Floppy Iris Syndrome

Purpose

The purpose of this study was to evaluate the efficacy of a novel double-docking technique, incorporating the use of femtosecond laser arcuate keratotomy (FSAK) in correcting low-degree astigmatism and Malyugin ring, in a patient with intraoperative floppy iris syndrome (IFIS).

Methods

A case report of a 72-year-old man with grade 4 cataract, low-degree astigmatism (<2D), and IFIS (pupil size <4 mm, intraoperatively) is presented. The patient underwent cataract surgery using a femtosecond laser to treat low-degree astigmatism because the patient requested for the use of a multifocal  intraocular lens (IOL). The first docking was performed to complete arcuate keratotomy, produce the mainparacentesis incisions, and create clear corneal incisions. Insertion of the Malyugin ring was performed after the first docking, whereas the second one was executed to complete continuous curvilinear capsulotomy and lens fragmentation. The patient's uncorrected visual acuity (UCVA) was measured pre- and post-operatively. The complications were evaluated post-operatively and 3 months later during the follow-up visit.

Results

The patient's UCVA for distance improved from 0.3 (6/12 Snellen equivalent) to 0 (6/6 Snellen equivalent) logMAR post-operatively. During the follow-up visit, the patient's uncorrected near visual acuity was at J2. His corneal astigmatism changed from -1.0 Diopter @177° pre-operative to -0.12 D @173° post-operative. No other intraoperative or post-operative complications were observed.

Conclusion

The double-docking technique, with the use of FSAK, and Malyugin ring produced successful surgical outcomes for the patient. The benefits of this technique allow surgeons to avoid changing the shape of the patient's cornea from the injection of the viscoelastic device into the anterior chamber, which could lower the femtosecond laser's precision and docking location.

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.

Astigmatic Outcomes of Single, Non-Paired Intrastromal Limbal Relaxing Incisions During Femtosecond Laser-Assisted Cataract Surgery Based on a Custom Nomogram

Purpose

To determine astigmatic changes of intrastromal limbal-relaxing incisions (LRIs) performed during femtosecond laser-assisted cataract surgery (FLACS).

Design

Retrospective case series.

Patients and Methods

Patients undergoing FLACS with adjunctive astigmatism management with intrastromal LRIs were included. All eyes had preoperative corneal cylinder (Kcyl) ≥0.20 D on ocular biometry. An intrastromal LRI nomogram of single, non-paired LRIs placed at the 9 mm optical zone was used. Keratometry was measured preoperatively, and postoperatively at 1 week, 1 month, and 3 months (POM3). Alpins astigmatism analysis was used to calculate target-induced astigmatism (TIA, equivalent to preoperative Kcyl), surgically induced astigmatism (SIA), difference vectors (DV), and correction indices (CI). Secondary analysis included multivariable binary logistic regression to determine clinical factors associated with corrections >125% (CI > 1.25).

Results

A total of 154 eyes (125 patients) were studied. Mean preoperative Kcyl was 0.87±0.42 D (SD), which did not significantly differ from POM3 Kcyl (0.87±0.51 D, p=0.470). Only the against-the-rule (ATR) subgroup demonstrated a small but significant reduction in Kcyl from preoperative (0.96±0.51D) to POM3 (0.89±0.55D, p=0.032). Sixteen eyes (10.4%) had Kcyl ≤0.5 D preoperatively, compared to 46 eyes (29.9%) at POM3 (p<0.0001). Mean SIA was 0.80±0.52 D. Mean DV was 0.85±0.47. Mean CI was 0.79. Fifty-one eyes (33%) had astigmatism correction >125%. On multivariable regression analysis, ATR astigmatism class (p=0.026) and lower arc lengths (30º) (p=0.005) were associated with correction >125%. Lower preoperative corneal astigmatism was inversely correlated with CI (p<0.001).

Conclusion

Although intrastromal LRIs can be conveniently performed during FLACS and appear safe, only patients with ATR astigmatism demonstrated a significant reduction in corneal astigmatism 3-months postoperatively under the current nomogram. Areas for future refinements to the nomogram were identified.

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

PURPOSE

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

SETTING

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

DESIGN

Prospective case series.

METHODS

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

RESULTS

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

CONCLUSIONS

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

Comparison of Surgically Induced Astigmatism and Corneal Morphological Features Between Femtosecond Laser and Manual Clear Corneal Incisions

PURPOSE

To assess corneal morphologic changes and surgically induced astigmatism (SIA) following clear corneal incisions (CCIs) created manually or with the Catalys femtosecond laser (Johnson & Johnson Vision, Santa Ana, CA).

METHODS

In this retrospective cohort analysis, patients undergoing femtosecond laser-assisted cataract surgery (FLACS) or manual cataract surgery between June and September 2018 from a single surgical center in Toronto, Canada, were considered for inclusion. Postoperative corneal astigmatism values were compared to preoperative astigmatism indices to determine the SIA at the postoperative 3-month (POM3) mark using the Alpins vector method. Secondary outcomes included postoperative corrected distance visual acuity (CDVA), central corneal thickness (CCT), and CCI morphology parameters.

RESULTS

Refractive outcomes from 104 eyes of 61 patients (54 eyes in the manual group and 50 eyes in the FLACS group) were included. There was no significant difference in POM3 SIA (manual: 0.45 ± 0.28 diopters [D], FLACS: 0.57 ± 0.46 D, P = .11); however, a significantly larger SIA was noted in the FLACS cohort at postoperative 1 week (P = .02) and 1 month (P = .04). FLACS led to a significantly smaller POM3 CCI thickness (P = .006), and CCI position was comparable between the two techniques (P = .44). There were no significant differences between groups in CDVA (P = .19), CCT thickness (P = .20), or phacoemulsification time (P = .59).

CONCLUSIONS

There was no significant difference in SIA between FLACS and manual cataract surgery at POM3. With a significantly smaller CCI thickness seen in FLACS cases, and a comparable CCI position, the reason for the increased SIA following laser CCIs in the early postoperative period was unclear. [J Refract Surg. 2019;35(12):796-802.].

[Femtosecond laser-assisted cataract surgery and conventional phacoemulsification cataract surgery in patients with lens subluxation]

PURPOSE

To analyze the results of femtosecond laser-assisted cataract surgery (FLACS) and conventional phacoemulsification cataract surgery (CPCS) in patients with 1-2 degree lens subluxation.

MATERIAL AND METHODS

The follow-up involved 86 patients (89 eyes). The 1^st group comprised 34 patients (35 eyes) that underwent FLACS; the 2^nd group included 52 patients (54 eyes) who underwent CPCS.

RESULTS

At day four of the follow-up central corneal thickness was significantly lower after FLACS (p_m-u=0.024), but the difference did not remain statistically reliable by 1.5 months after the surgery. At discharge day and 4 months after the surgery uncorrected visual acuity (UCVA) after FLACS reliably exceeded UCVA of the 2^nd group patients (p_m-u=0.00) with mean UCVA being 0.61±0.29 and 0.42±0.25 respectively. Internal higher order aberrations (HOA) in 5.0 mm zone in the 1^st group decreased by 4 times and amounted to 0.236±0.06 μm, in the 2^nd group increased by 4.1 times and was 4.606±8.16 μm; the difference between the groups was statistically significant (p_m-u<0.001). Mean endothelial cells density after FLACS was 2551.91±321.55 cells/mm², after CPCS - 2352.35±436.68 cells/mm² (p_m-u<0.005). Complications after FLACS included 2 cases (5.71%) of posterior capsular rupture and 1 case (2.8%) of post-op corneal edema; patients after CPCS had 6 (11.1%) and 12 (22.2%) complication cases respectively.

CONCLUSION

FLACS is the safer and more effective surgery choice for patients with 1-2 degree lens subluxation in comparison with CPCS; it decreases the risk of possible complications and provides faster postoperative rehabilitation.

Intra and post-operative complications observed with femtosecond laser-assisted cataract surgery versus conventional phacoemulsification surgery: a systematic review and meta-analysis

BACKGROUND

In this analysis, we aimed to systematically compare the complications which were associated with femtosecond laser-assisted cataract surgery (FLACS) versus the conventional phacoemulsification surgery (CPE).

METHODS

Commonly used search databases, specifically MEDLINE, Cochrane Central, EMBASE, and http://www.clinicaltrials.gov were carefully searched for English publications comparing FLACS versus CPE. The selected endpoints which were assessed included incomplete capsulotomy, anterior capsulotomy tag, anterior capsule tear, posterior capsule tear, injury to the descemet's membrane, zonular dialysis, vitreous loss, macular or corneal edema, and elevated intra-ocular pressure. Statistical analysis was carried out by the latest version of the RevMan software (version 5.3) and represented by risk ratios (RR) with 95% confidence intervals (CI).

RESULTS

A total number of 7156 participants were included. Three thousand five hundred and fifty four (3554) participants were assigned to the FLACS group. The risks for incomplete capsulotomy, anterior capsulotomy tag, and anterior capsular tear were significantly higher with FLACS (RR: 22.42, 95% CI: 4.53-110.82; P = 0.0001), (RR: 33.07, 95% CI: 6.53-167.56; P = 0.0001) and (RR: 4.74, 95% CI: 2.59-8.68; P = 0.00001) respectively. The risks for macular/corneal edema (RR: 2.05, 95% CI: 1.18-3.55; P = 0.01) and elevated intra-ocular pressure (RR: 3.24, 95% CI: 1.55-6.78; P = 0.002) were also significantly higher with FLACS. However, the risks for impaired descemet's membrane (RR: 0.95, 95% CI: 0.61-1.47; P = 0.80), zonular dialysis (RR: 0.40, 95% CI: 0.06-2.72; P = 0.35), vitreous loss (RR: 0.09, 95% CI: 0.01-1.63; P = 0.10) and posterior capsular tear (RR: 1.45, 95% CI: 0.23-9.16; P = 0.69) were not significantly different.

CONCLUSIONS

The current results showed that FLACS did not improve intra/post-operative complications in comparison to CPE. Further larger studies should confirm this hypothesis.

Intra and post-operative complications observed with femtosecond laser-assisted cataract surgery versus conventional phacoemulsification surgery: a systematic review and meta-analysis

BACKGROUND

In this analysis, we aimed to systematically compare the complications which were associated with femtosecond laser-assisted cataract surgery (FLACS) versus the conventional phacoemulsification surgery (CPE).

METHODS

Commonly used search databases, specifically MEDLINE, Cochrane Central, EMBASE, and http://www.clinicaltrials.gov were carefully searched for English publications comparing FLACS versus CPE. The selected endpoints which were assessed included incomplete capsulotomy, anterior capsulotomy tag, anterior capsule tear, posterior capsule tear, injury to the descemet's membrane, zonular dialysis, vitreous loss, macular or corneal edema, and elevated intra-ocular pressure. Statistical analysis was carried out by the latest version of the RevMan software (version 5.3) and represented by risk ratios (RR) with 95% confidence intervals (CI).

RESULTS

A total number of 7156 participants were included. Three thousand five hundred and fifty four (3554) participants were assigned to the FLACS group. The risks for incomplete capsulotomy, anterior capsulotomy tag, and anterior capsular tear were significantly higher with FLACS (RR: 22.42, 95% CI: 4.53-110.82; P = 0.0001), (RR: 33.07, 95% CI: 6.53-167.56; P = 0.0001) and (RR: 4.74, 95% CI: 2.59-8.68; P = 0.00001) respectively. The risks for macular/corneal edema (RR: 2.05, 95% CI: 1.18-3.55; P = 0.01) and elevated intra-ocular pressure (RR: 3.24, 95% CI: 1.55-6.78; P = 0.002) were also significantly higher with FLACS. However, the risks for impaired descemet's membrane (RR: 0.95, 95% CI: 0.61-1.47; P = 0.80), zonular dialysis (RR: 0.40, 95% CI: 0.06-2.72; P = 0.35), vitreous loss (RR: 0.09, 95% CI: 0.01-1.63; P = 0.10) and posterior capsular tear (RR: 1.45, 95% CI: 0.23-9.16; P = 0.69) were not significantly different.

CONCLUSIONS

The current results showed that FLACS did not improve intra/post-operative complications in comparison to CPE. Further larger studies should confirm this hypothesis.

Comparison of changes in corneal endothelial cell density and central corneal thickness between conventional and femtosecond laser-assisted cataract surgery: a randomised, controlled clinical trial

BACKGROUND/AIM

To identify changes in endothelial cell density (ECD) and central corneal thickness (CCT) in eyes undergoing femtosecond laser-assisted cataract surgery (FLACS) compared with conventional phacoemulsification surgery (CPS).

METHODS

This is an intraindividual randomised, controlled clinical trial. One eye was randomised to receive FLACS, while the contralateral eye of the same patient received CPS. The femtosecond laser pretreatment included creating main and side-port corneal incisions, capsulotomy and lens fragmentation. Non-contact endothelial cell microscopy and pachymetry were performed preoperatively and at postoperative day 1, week 1, month 1 and month 3.

RESULTS

A total of 134 paired eyes from 67 patients were included in the analysis. ECD was not significantly different between the two groups at either postoperative month 1 (2370±580 cells/mm² and 2467±564 cells/mm² in FLACS and CPS groups, respectively; p=0.18) or at postoperative month 3 (2374±527 cells/mm² and 2433±526 cells/mm² in FLACS and CPS groups, respectively; p=0.19). No significant difference was observed in the mean CCT values between the two groups over the follow-up period (p>0.05).

CONCLUSION

Postoperative corneal ECD and CCT were comparable between FLACS and CPS during the 3 months' follow-up period.

Risk-Adjusted CUSUM Analysis of the Learning Curve of Femtosecond Laser Assisted Cataract Surgery

Objectives: To determine the length of the learning curve of femtosecond laser-assisted cataract surgery (FLACS) by a risk-adjusted cumulative sum method. Materials and Methods: This was a retrospective review of the first 288 FLACS performed by three surgeons over a 12-month period. The learning curves were analyzed separately for each surgeon and as pooled data via risk-adjusted cumulative sum methods. Change-point analysis was performed to estimate the length of the learning curve. Results: Rates of complications were as follows: anterior capsular tear (ACT) (3.4%), posterior capsular rupture (PCR) (0.7%), vitreous loss (0.3%), iris trauma (0.7%), Descemet's membrane tear (0.3%). There was a strong confidence level (96%) that there was a stable performance in terms of PCR after case 16 for the pooled data. Surgeon 1 did not have any cases of PCR, surgeons 2 and 3 exhibited change points at case 5 and 16, respectively (confidence levels = 99%, 98%). There was a strong confidence level (99.8%) that there was stable performance in terms of ACT after case 14 for the pooled data, however the individual surgeons demonstrated individual change points at case 1 (surgeon 1, confidence 99%), case 14 (surgeon 2, confidence 99%), and case 49 (surgeon 3, confidence 96%). Conclusions: The results suggest that there is an increased risk of ACT and PCR in FLACS within a surgeon's first 14 and 16 operations, respectively. Measures should be adopted to minimize harm to patients during this phase. However, overall rates of complications were safe.

Architecture evaluation of the main clear corneal incisions in femtosecond laser-assisted cataract surgery by optical coherence tomography imaging

Purpose

To assess the stability and reliability of femtosecond laser-assisted cataract surgery (FLACS) incisions design and dimensions using anterior segment optical coherence tomography (AS-OCT) imaging.

Setting

Renato Ambrósio Ophthalmologic Study Center from Hospital Oftalmológico de Brasília, Brasília, Brazil.

Design

Prospective nonrandomized controlled case series.

Methods

Eyes undergoing FLACS with triplanar main temporal clear corneal incision (CCI) were evaluated at the end of the case. Eyes that required any incision hydration, surgical complications or lacked follow-up were excluded. The AS-OCT was performed after femtosecond delivery; at the end of the case; at 1 day and at 30 days after surgery. Data of pachymetry, endothelial and epithelial gaps, Descemet detachment and CCI architecture were compared.

Results

Eleven eyes from 11 patients completed follow-up. Corneal thickness was statistically different between after femtosecond delivery and the end of the case (P-value <0.05), but without difference compared to 30 days evaluation. There was an increase of Descemet detachments (P-value <0.05) and endothelial gaps (P-value =0.0133) at the end of the case compared to post-femtosecond delivery. As for the architecture of the CCI, significant difference was found between the parameters of entry angle and exit angle measured with AS-OCT and the programmed.

Conclusion

The AS-OCT was capable of visualizing changes in the cornea at the CCI. Despite the stress caused by manipulation, results indicated good stability of incision and reproducibility of tunnel length.

Synopsis

Difference of corneal thickness at the CCI between after femtosecond and after phacoemulsification measurements (P-value <0.05), with increase of endothelial gaps (P-value =0.0133) and Descemet detachments (P-value <0.05).

[Comparison of clinical and functional results of conventional and femtosecond laser-assisted cataract phacoemulsification]

PURPOSE

To perform a comparative analysis of ultrasound and hydrodynamic parameters, and the outcomes of femtosecond laser-assisted cataract surgery (FLACS) and conventional phacoemulsification cataract surgery (CPCS).

MATERIAL AND METHODS

This prospective cohort study included 246 eyes. The first group consisted of 138 patients who underwent FLACS, second group - 108 patients after CPCS.

RESULTS

Total ultrasound time was 95.36±47.93 and 113.3±97.71 seconds (p=0.04) in the 1^st and the 2^nd groups, respectively. The duration of torsional ultrasound was 84.72±50.03 seconds in 1^st group (p=0.04) and 113.3±97.71 seconds in the 2^nd group (p=0.04). Aspiration time was 208.3±95.86 seconds in the 1^st group (p=0.04) and 258.43±158.81 seconds in the 2nd group (p=0.04). On the 3-4^th day after the surgery, uncorrected distance visual acuity (UDVA) and corrected distance visual acuity (CDVA) were significantly better in the 1^st group - 0.62±0.21 (LogMAR 0.20±0.19) and 0.53±0.15 (LogMAR 0.30±0.21) (p=0.01), respectively, compared to the 2^nd group with UDVA of 0.75±0.18 (LogMAR 0.10±0.16) and CDVA of 0.69±0.19 (LogMAR 0.20±0.15) (p=0.04). Central corneal thickness (CCT) was 573.41±33.12 and 632.43±58.30 μm in the 1^st and 2^nd groups, respectively (p=0.020). At 1 month post-op there were no statistically significant differences in UDVA (p=0.17), CDVA (p=0.40) or CCT (p=0.50) between the groups.

CONCLUSION

Compared with CPCS, total ultrasound time (p=0.04), torsional ultrasound time (p=0.04) and aspiration time (p=0.04) were significantly lower in the FLACS group. CCT was significantly lower (p=0.02), while UDVA (p=0.04) and CDVA (p=0.01) were significantly higher in the FLACS group in the early post-operative period (3-4 days after surgery). There were no statistically significant differences in the parameters between the groups 1 month after the surgery.

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

PURPOSE

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

SETTING

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

DESIGN

Single-center prospective randomized interventional case-controlled trial.

METHODS

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

RESULTS

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

CONCLUSIONS

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

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

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

Femtosecond laser-assisted cataract surgery versus standard phacoemulsification cataract surgery: Study from the European Registry of Quality Outcomes for Cataract and Refractive Surgery

PURPOSE

To compare the visual, refractive, and adverse outcomes of femtosecond laser-assisted cataract surgery and conventional phacoemulsification cataract surgery.

SETTING

Cataract surgery clinics in 9 European countries and Australia (femtosecond-assisted) and 18 European countries and Australia (conventional).

DESIGN

Multicenter case-control study.

METHODS

Eyes having femtosecond laser-assisted cataract surgery were matched to eyes from the European Registry of Quality Outcomes for Cataract and Refractive Surgery phacoemulsification cataract surgery database for preoperative corrected distance visual acuity (CDVA), age, and preoperative risk factors. Intraoperative and postoperative complications, postoperative CDVA, and refractive outcome were compared. The follow-up was 7 to 60 days.

RESULTS

The study matched 2814 femtosecond-assisted cases to 4987 conventional phacoemulsification cases. Femtosecond-assisted surgery compared as follows to conventional phacoemulsification: posterior capsule complications, 0.7% versus 0.4%; postoperative logMAR CDVA, 0.05 (6/6^-3) versus 0.03 (6/6^-2); worse postoperative CDVA at follow-up (by 5 letters or more), 1.0% versus 0.4%; CDVA 0.3 (6/12) or better, 96.3% versus 97.1%; absolute biometry prediction error, 0.43 diopter (D) versus 0.40 D; within ±0.5 D of target, 72% versus 74.3%; and postoperative complications, 3.4% versus 2.3%.

CONCLUSIONS

Femtosecond laser-assisted cataract surgery did not yield better visual or refractive outcomes than conventional phacoemulsification cataract surgery. Intraoperative complications were similar and low in both groups. Postoperative complications were lower in conventional phacoemulsification cataract surgery.

FINANCIAL DISCLOSURE

None of the authors has a financial or proprietary interest in any material or method mentioned.

Differences in energy and corneal endothelium between femtosecond laser-assisted and conventional cataract surgeries: prospective, intraindividual, randomized controlled trial

AIM

To compare intraoperative phacoemulsification parameters and its effect on the corneal endothelium of eyes undergoing femtosecond laser-assisted cataract surgery (FLACS) versus conventional phacoemulsification (CP) cataract surgery.

METHODS

Two hundred eyes from one hundred patients were included in a prospective, non-blinded, randomized, controlled, intraindividual clinical study. One hundred eyes underwent FLACS while their one hundred fellow eyes underwent CP. All surgeries were performed using the Victus^® femtosecond laser platform and Infinity^® Vision System phacoemulsification machine. Primary outcome measure was endothelial cell density 6mo after surgery. Secondary outcome measures included central corneal thickness (CCT), average cell area, standard deviation, coefficient of variation and hexagonality before surgery and 6mo after surgery and endothelial cell density loss during this period were also evaluated. Intraoperative efficiency parameters [cumulative dissipated energy (CDE), total intraocular surgery time, total ultrasound time, total phacoemulsification time, total torsional energy time, total aspiration time, ultrasound energy, torsional amplitude and fluid required during surgery] were also collated.

RESULTS

Data from these patients was not considered for analysis. Data from 92 patients were analysed. Postoperative endothelial cell density (cells/mm²) between groups (2211.88±392.49 CP; 2246.31±403.48 FLACS) was not statistically significant (P=0.869). Total ultrasound time, torsional energy time, CDE and fluid requirements were significantly lower the FLACS group (P<0.05). Other parameters did not show statistically significant difference between FLACS and CP.

CONCLUSION

FLACS displays significant improvements in phacoemulsification parameters in comparison to CP. There are no significant differences in corneal endothelium measures between FLACS and CP.

Assessment of surgeon experience with femtosecond laser-assisted cataract surgery

PURPOSE

To evaluate the collective user experience with an image-guided femtosecond laser (FSL) for cataract surgery in a high-volume, multi-surgeon, ambulatory surgical center.

SUBJECTS AND METHODS

A detailed online survey was distributed to all surgeons in a single ambulatory surgical center who had performed cataract surgery using a FSL since its acquisition in December 2012. Information collected included the number of cases performed, typical surgical techniques and parameters, satisfaction with individual features of the laser (rated on a scale from 1=completely unsatisfied to 10=extremely satisfied) and commentary on ease of use and suggested improvements.

RESULTS

Seventeen of 30 surgeons (56.7%) completed the survey, representing a case volume of 1,967 eyes. Fourteen surgeons (82.4%) felt they required ≤10 cases with the FSL to operate with the same safety and control as in standard phacoemulsification surgery. Satisfaction was highest for capsulotomies, lens fragmentation, lens softening, arcuate incisions and the graphic user interface (mean scores 9.4, 8.7, 8.7, 7.2 and 8.9, respectively). Preferred capsulotomy diameter was 4.8-5.2 mm (64.7% of respondents). About half (52.9%) of respondents centered the capsulotomy on the pupil and the other 47.1% centered the capsulotomy using optical coherence tomography. Most respondents (81.3%) preferred transepithelial arcuate incisions compared to intrastromal incisions. Satisfaction was lowest with FSL-created, main, clear corneal incisions and paracenteses (mean scores 4.4 and 4.2, respectively).

CONCLUSION

Laser-assisted cataract surgery has a short learning curve and a high rate of user satisfaction. Further software and hardware development is warranted to improve user satisfaction with peripheral and clear corneal incisions.

Efficacy of 0.015% intracameral epinephrine for significant miosis induced by photodisruption during femtosecond laser-assisted cataract surgery

Despite the various advantages of femtosecond laser-assisted cataract surgery (FLACS), pupillary constriction during laser photodisruption is considered one of the most unfavorable events. This study aimed to investigate the efficacy of intracameral 0.015% epinephrine injection for miosis after laser pretreatment during FLACS.A total of 82 patients who underwent FLACS for age-related cataracts were investigated in this retrospective study. The epinephrine group included patients who received intracameral epinephrine injection for miosis after femtosecond laser pretreatment, while the no-epinephrine group included the patients who underwent FLACS without intracameral epinephrine due to minimal miosis. Quantitative pupil area measurements were performed through the analysis of captured images extracted from surgical videos of both femtosecond laser pretreatment and phacoemulsification.Laser photodisruption induced miosis in both groups, although the degree of miosis was greater in the epinephrine group (4.65 ± 0.87 mm) than in the no-epinephrine group (6.30 ± 0.65 mm; P < .001). The intracameral epinephrine injection significantly increased the pupil diameter from 4.65 ± 0.87 to 5.49 ± 0.76 mm (21.61 ± 22.68%; P < .001) and the pupil area from 70.28 ± 24.46 to 96.49 ± 25.24 mm (52.89 ± 63.54%; P < .001). After additional viscomydriasis, there was no difference between groups in pupil diameter (epinephrine vs no-epinephrine group; 6.10 ± 0.77 vs 6.39 ± 0.65 mm; P = .073).A single intracameral injection of 0.015% epinephrine provided immediate and appropriate redilation of pupil in patients with significant miosis after femtosecond laser photodisruption. Intracameral epinephrine is a simple and practical option for pupil redilation in case of miosis during FLACS.

Comparison of cumulative dispersed energy (CDE) in femtosecond laser-assisted cataract surgery (FLACS) and conventional phacoemulsification

PURPOSE

To compare the amount of phacoemulsification ultrasound energy used between eyes undergoing femtosecond laser-assisted cataract surgery (FLACS) and conventional phacoemulsification.

METHODS

One eye of consecutive patients undergoing routine non-complicated phacoemulsification from January 2014 to December of 2015 was included in the analysis. FLACS was performed using the Alcon LenSx. Linear regression was used for analysis with type of surgery (FLACS versus conventional phacoemulsification) as the exposure and cumulative dispersed energy (CDE) as the outcome variable. Age, surgeon, eye side, and eye sequence (first versus second eye) were covariates.

RESULTS

A total of 1159 surgeries met inclusion criteria. The average age of the cohort was 70.6 (SD 8.6) years, 590 cases (51%) were performed by surgeon 1, and 582 cases (50%) were right eyes. Overall, FLACS resulted in significantly lower CDE as compared to conventional phacoemulsification (β = 0.89, 95% CI 0.83, 0.95). When stratified by eye side and surgeon, FLACS performed on left eyes operated on by surgeon 1 resulted in lower CDE as compared to conventional phacoemulsification (β = 0.76, 95% CI 0.66, 0.87), but not for right eyes operated on by surgeon 1 (β = 0.92, 95% CI 0.79, 1.07) or for eyes operated on by surgeons 2 or 3.

CONCLUSIONS

The use of FLACS on the Alcon LenSx platform results in a small decrease in phacoemulsification energy as compared to conventional phacoemulsification in certain cases. Further study assessing optimal laser settings and surgical technique is necessary.

Comparison of Surgically Induced Astigmatism and Morphologic Features Resulting From Femtosecond Laser and Manual Clear Corneal Incisions for Cataract Surgery

PURPOSE

To compare the surgically induced astigmatism (SIA) vector, flattening effect, torque, and wound architecture following femtosecond laser and manual clear corneal incisions (CCIs).

METHODS

In a double-armed, randomized, prospective case series, cataract surgery was performed for 600 eyes using femtosecond laser (300 eyes) or manual (300 eyes) 2.4-mm CCIs in temporal or superior oblique locations. SIA, flattening effect, torque, and the summated vector mean for SIA were calculated. Correlation with individual features was established and incision morphology was investigated by anterior segment optical coherence tomography at 3 months of follow-up.

RESULTS

The SIA, flattening effect, and torque were lower in the femtosecond laser group for both incision locations, although the differences were not significant (all P > .05). The femtosecond laser group showed less dispersion of SIA magnitude and flattening effect. Temporal and superior oblique incisions resulted in flattening effect values of -0.11 and -0.21 diopters (D), respectively, in the femtosecond laser group and -0.13 and -0.34 D, respectively, in the manual group. Significant correlations with individual features were only found in the femtosecond laser group, with preoperative astigmatism being the only significant SIA predictor by multiple regression analysis (P = .003). Femtosecond laser CCIs showed less deviation from the intended length, wound enlargement, endothelial misalignment, and Descemet membrane detachments (all P < .037).

CONCLUSIONS

Femtosecond laser CCIs were more reproducible. Although SIAs were smaller in femtosecond laser CCIs than in manual CCIs for both temporal and superior oblique incisions, the difference was not statistically significant. Association with individual features is highly variable. [J Refract Surg. 2018;34(5):322-329.].