Femtosecond Laser Pretreatment Research Articles

Long-term impact of low-energy femtosecond laser and manual cataract surgery on macular layer thickness: A prospective randomized study.

To evaluate change in retinal layers 18 months after femtosecond laser-assisted cataract surgery (LCS) and manual cataract surgery (MCS) in a representative age-related cataract population using artificial intelligence (AI)-based automated retinal layer segmentation. This was a prospective, randomized and intraindividual-controlled study including 60 patients at the Medical University of Vienna, Austria. Bilateral same-day LCS and MCS were performed in a randomized sequence. To provide insight into the development of cystoid macular oedema (CME), retinal layer thickness was measured pre-operatively and up to 18 months post-operatively in the central 1 mm, 3 mm and 6 mm. Fifty-six patients completed all follow-up visits. LCS compared to MCS did not impact any of the investigated retinal layers at any follow-up visit (p > 0.05). For the central 1 mm, a significant increase in total retinal thickness (TRT) was seen after 1 week followed by an elevated plateau thereafter. For the 3 mm and 6 mm, TRT increased only after 3 weeks and 6 weeks and decreased again until 18 months. TRT remained significantly increased compared to pre-operative thickness (p < 0.001). Visual acuity remained unaffected by the macular thickening and no case of CME was observed. Inner nuclear layer (INL) and outer nuclear layer (ONL) were the main causative layers for the total TRT increase. Photoreceptors (PR) declined 1 week after surgery but regained pre-operative values 18 months after surgery. Low-energy femtosecond laser pre-treatment did not influence thickness of the retinal layers in any topographic zone compared to manual high fluidic phacoemulsification. TRT did not return to pre-operative values 18 months after surgery. The causative layers for subclinical development of CME were successfully identified.

Surgical time and efficacy of illuminated chopper-assisted cataract surgery involving miosis after femtosecond laser pretreatment.

To evaluate the efficacy of the illuminated chopper-assisted cataract surgery in terms of shortening the surgical time in eyes with miosis after femtosecond laser pretreatment. As retrospective study, three hundred thirty-six eyes of 336 consecutive patients who underwent the femtosecond laser and illuminated chopper-assisted cataract surgery were included. Cases with pupil less than 6 mm after femtosecond laser pretreatment were included in the miosis group. Pupil diameter, surgical time, and improved efficacy (100/surgical time×pupil size) were compared between eyes with and without miosis. Of 336 eyes, 20 were included in the miosis group (6.0%). Pupil diameter was smaller in eyes with miosis than in those without miosis (5.23 ± 0.38 mm vs 7.35 ± 0.64 mm, p < 0.001); however, surgical time was not different (6.86 ± 0.73 min vs 6.60 ± 1.27 min, p = 0.071) between the two groups. Mechanical pupil dilations were not needed in any cases. As a result, improved efficacy was calculated to be higher in patients with miosis (2.83 vs 2.14, p < 0.001). In terms of surgical time and improved efficacy, using the illuminated chopper simplified cataract surgery involving miosis after femtosecond laser pretreatment. The use of an illuminated chopper is expected to be a good solution for femtosecond laser-assisted cataract surgeries.

Comparison of the effects of femtosecond and nanosecond laser tailoring on the bonding performance of the heterojunction between PEEK/CFRP and Al–Li alloy

In this paper, an ultrafast femtosecond laser was used to tailor the surface of the PEEK/CFRP (carbon fiber reinforced plastics with polyether ether ketone as resin matrix), using a nanosecond laser as a contrast. By analyzing the effect of femtosecond and nanosecond laser tailoring on the surface morphology, surface chemical composition and wettability of PEEK/CFRP, the internal reasons for the improved of bonding performance of heterojunction between PEEK/CFRP and Al–Li alloy by laser pretreatment were explored. As a result, the shear strength increased considerably from 4.9 MPa to 16.1 MPa and 29.5 MPa after nanosecond laser and femtosecond laser pretreatment, respectively. Finally, the fracture surface and failure modes of heterojunction bonded joints were compared, and the different mechanisms of femtosecond and nanosecond laser tailoring PEEK/CFRP surface were explained. Femtosecond laser tailoring is a competitive process for improving the bonding properties of the heterojunction between PEEK/CFRP and Al–Li alloys because of its productivity, controllability and lack of pollution.

Improving polishing efficiency of RB-SiC through femtosecond laser pretreatment

It is a great technical challenge to precisely and efficiently polish RB-SiC substrates due to their two-phase structure and extreme hardness, especially for large-optics fabrication. Here, a simple laser pretreatment process is demonstrated for improving the polishing efficiency using femtosecond laser to modify the RB-SiC surface pre-coated with silicon powder. Material characterization and finite-element analyses reveal that the pre-coated surface is oxidized under femtosecond laser irradiation. As oxidation gradually penetrates deeper into the interface, the modified layer forms a bonding with the RB-SiC substrate. By optimizing laser scanning parameters to adjust the oxidation depth, a high-quality modified layer with stronger adhesion strength can be obtained. The approach is capable of delivering a modified layer that is easier to polish and tightly bonded to the RB-SiC substrate with an adhesion strength of 55.46 N. Thanks to the femtosecond laser modification, the surface roughness of the pretreated RB-SiC can be reduced to Sq 4.5 nm in just a few hours of polishing, which increases polishing efficiency over 3 times compared with direct abrasive polishing. Low requirements for substrate surface profile and simple operation make this laser pretreatment approach possible to be applied to more complex RB-SiC surfaces and significantly improve polishing efficiency.

Prostaglandin Release After Low-Energy Femtosecond Laser-Assisted Cataract Surgery Without Anti-Inflammatory Drug Premedication

To compare prostaglandin E2 (PGE-2) levels in the aqueous and pupil diameter in patients undergoing low-pulse energy femtosecond laser-assisted cataract surgery (LCS) without non-steroidal anti-inflammatory (NSAID) pretreatment with either fragmentation or capsulotomy performed first. Prospective, randomized, fellow-eye controlled comparison. This study was undertaken at the Department of Ophthalmology, Medical University of Vienna. The population consisted of 140 eyes of 70 patients with bilateral age-related cataract. Bilateral same-day LCS with either anterior capsulotomy before lens fragmentation (Caps-First) in one eye or vice versa (Frag-First) in a random sequence were performed. Aqueous was tapped 5 minutes after LCS and PGE-2 concentration was analyzed. Pupil diameters were recorded immediately before and after femtosecond laser pretreatment. The main outcome measure was PGE-2 concentrations in picograms/milliliter and pupil diameter in millimeters. Mean PGE-2 concentrations were 42.0 ± 63.7 pg/mL in the Caps-First group versus 71.8 ± 160.7 pg/mL with the Frag-First group (P=.186). Mean pupil diameters before and after pretreatment were 7.6 ± 0.8 mm and 7.6 ± 0.8 mm, respectively (P=.871). Mean PGE-2 concentrations and pupil diameters did not show any significant difference between time points or groups. Low-energy femtosecond laser pretreatment did not increase PGE-2 levels in the absence of NSAID pretreatment. This was independent of whether capsulotomy or fragmentation was performed first. Moreover, no pupillary miosis was observed.

In situ synthesis of NiO@Ni micro/nanostructures as supercapacitor electrodes based on femtosecond laser adjusted electrochemical anodization

Nickel oxide is a p–type transition metal oxide with excellent electrochemical performance, which is widely used in the application of supercapacitors. We introduce an approach of femtosecond laser ablation combined with electrochemical anodization for NiO nanostructures grow in situ on nickel sheet for supercapacitors electrodes. By controlling the processing conditions of femtosecond laser, various patterns covered the surface of nickel sheet, which promoted uniform NiO growth in situ on nickel sheet. Specific capacitance of the supercapacitor electrode fabricated using femtosecond laser pretreatment was superior to that of the NiO/Ni electrode prepared by electrochemical anodization alone at the current density of 1 mA cm−2. In addition, the capacitance retention of the NiO/Ni electrode for 1500 cycles was approximately 100%, and this electrode exhibited excellent conductivity according to electrochemical impedance spectroscopy measurements. According to these results, femtosecond laser enhanced electrochemical anodization was a promising approach for the fabrication of supercapacitors electrodes.

Femtosecond laser-assisted big bubble for deep anterior lamellar keratoplasty.

To assess the utility of a femtosecond laser-assisted stromal channel to assist the creation of a big bubble (BB) for deep anterior lamellar keratoplasty (DALK) surgery in cadaveric corneas. L V Prasad Eye Institute, Hyderabad, India. Experimental study. An attempt to create a BB was made on 10 donor pairs of human cadaveric corneoscleral tissues. The 20 corneas were split into 2 groups: Group A underwent femtosecond laser pretreatment and Group B had conventional manual deep lamellar technique. Laser pretreatment was performed using the VisuMax femtosecond laser system to create a stromal channel using the intracorneal ring segment treatment module for direct insertion of the 27-gauge air cannula for pneumodissection at a predetermined depth. Of the 20 corneas studied, type 1 BB was achieved in 9 of 10 corneas in Group A and in 7 of 10 corneas in Group B. One cornea from Group A had a combined type 1 and 2 BB, whereas no BB was achieved in 1 cornea. Creation of an intrastromal channel using a femtosecond laser at a predetermined depth seemed to be a promising option to increase the chances of achieving a BB when compared with the conventional air injection technique of BB DALK.

Intraindividual comparison of cytokine and prostaglandin levels with and without low-energy, high-frequency femtosecond laser cataract pretreatment after single-dose topical NSAID application.

To investigate interleukin (IL)-1β, IL-6, and total prostaglandin (PG) levels in the anterior chamber in patients undergoing low pulse energy femtosecond laser-assisted cataract surgery. Forty patients undergoing immediate sequential cataract surgery received randomized low-energy femtosecond laser pretreatment in 1 eye and conventional phacoemulsification in the other. Aqueous humor was collected precisely 5 minutes after femtosecond laser pretreatment and before conventional phacoemulsification from all 80 eyes. IL-1β, IL-6, and total PG (including PGE1, PGE2; PGF1a, PGF2a) levels were analyzed using enzyme-linked immunoassay kits. One drop of ketorolac 0.5% was administered 30 minutes preoperatively. Mean concentrations of IL-1β, IL-6, and total PG were 0.87, 0.67, and 32.19 pg/mL in the femto group compared with 0.10 (P = .36), 0.78 (P = .79), and 19.66 pg/mL (P < .05) in the nonfemto group. Levels of IL-1β and IL-6 were not statistically significantly different when compared between groups. There was a small but statistically significant increase of PG levels in the femto group. There were no statistically significant correlations between levels of 1β, IL-6, or total PG and suction time or lens density (P > .05). Low pulse energy femtosecond laser pretreatment did not trigger any additional IL and only a small but statistically significant increase of PG release in the anterior chamber after a single-dose of topical nonsteroidal antiinflammatory drug administered 30 minutes before the start of cataract surgery. The findings indicated that the minor inflammatory reaction was due to the lower pulse energy concept applied by the femtosecond laser.

Dual-functional CuxO/Cu electrodes for supercapacitors and non-enzymatic glucose sensors fabricated by femtosecond laser enhanced thermal oxidation

A facile approach is proposed to fabricate porous CuxO nanostructures on copper foil. By conducting femtosecond laser ablation and thermal oxidation, in-situ CuxO nanostructures growth was induced on the copper foil. These structures act as active and sensitive materials for supercapacitor and glucose sensor electrodes. By controlling the laser fluences and scan rates, various morphologies were obtained. The specific capacitance of the porous CuxO/Cu electrode reached 156.72 mF cm−2 at the current density of 1 mA cm−2, which was larger than that obtained without femtosecond laser ablation, and it was maintained at 83% as the current density increased to 12 mA cm−2. Through femtosecond laser pretreatment, micro/nanostructures were patterned on copper foil surface, enhancing the surface specific area for redox reaction. In addition, the sidewalls of the patterned structures offered nucleation sites of the diffused Cu ion and promoted the growth of copper oxide nanowires. Moreover, the non-enzymatic glucose sensors of the porous CuxO/Cu electrode had two linear ranges of 0.01–0.2 mM and 0.5–1.6 mM with the sensitivities of 1212.016 and 852.798 μA mM−1, respectively. These results indicate that the porous CuxO nanostructures and nanowires prepared using this facile method have potential applications in supercapacitor and enzyme-less glucose sensor electrodes.

Cytokines, chemokines, and flare in the anterior chamber after femtosecond laser–assisted cataract surgery

To analyze anterior chamber inflammation after pretreatment with a femtosecond laser platform during cataract surgery and compare the results with those of the manual procedure. Eye Clinic, Department of Surgery and Translational Medicine, University of Florence, Italy. Prospective case series. Aqueous humor was collected after femtosecond laser pretreatment (femtosecond group) and at the beginning of routine cataract surgery before the primary incision was created (control group). The levels of 14 cytokines and chemokines were measured using a multiplex array system. Surgical parameters (suction time, laser time, effective phacoemulsification time [EPT]) were recorded. Anterior chamber flare was measured bylaser photometry preoperatively and 1day and 7days postoperatively. Each group comprised 20 eyes. The EPT was significantly lower in the femtosecond group than in the control group. In the femtosecond group, the concentrations of IL (interleukin)-6, IL-8, IL-10, IL-12, vascular endothelial growth factor, and interferon-γ were significantly higher than in the control group. Flare in the anterior chamber measured with flare-cell meter was not significantly different between groups at any timepoint. No correlation was found between cytokine concentrations and age in either group and between cytokine levels and suction or laser time and postoperative flare in the femtosecond group. Also, no correlation was found between postoperative aqueous flare and EPT in either group. Despite the rise of proinflammatory cytokines in the aqueous humor after femtosecond laser pretreatment, the anterior chamber flare after cataract surgery was similar to that in controls. This might be a result of the lower EPT required after pretreatment.

Fabrication of coated tool with femtosecond laser pretreatment and its cutting performance in dry machining SLM-produced stainless steel

Selective Laser Melting (SLM) technique applied to the stainless steel has been developing rapidly in the biomedical and aerospace industries. However, a post-machining is still needed to efficiently improve the surface finish and dimensional precision of the SLM-produced stainless steel parts. Dry machining (machining without the using of cutting fluid) is attracting interest around the world, which can reach green manufacturing without water pollution, residue on the swarf, and danger to health. In this work, to achieve the green finishing machining of SLM-produced AISI 316 L stainless steel, the hard coated tools with a nanotextured substrate were designed, and the key preparation methods of this developed tools were presented. First, a periodic nano-ripple structure (nanotexture) was induced by femtosecond laser scanning on the WC/Co substrate tool with different processing parameters, then TiAlN film was deposited on the nanotextured substrate surface using the cathode arc-evaporation technique without employing any interlayer. The surface micro-topography and mechanical property of the nanotextured TiAlN coated surface were studied. Machining tests without cutting fluid were performed on the SLM-produced stainless steel using the developed tool, and the cutting tool without laser pretreatment was also employed for the comparison. The obtained results demonstrate that, the TiAlN coatings adhesiveness is significantly enhanced by the femtosecond laser-induced periodic structure on the WC/Co substrate, and the critical load of the TiAlN coatings is increased from 57 to 73 N. The improved machining performances of nanotextured tools in drying cutting SLM 316 L stainless steel are achieved, resulting in a decrease of 10–20% in cutting forces, a decrease of 10–15% in cutting temperature and a high surface quality of the machined workpieces at the high cutting speed. The possible mechanisms for the effects of femtosecond laser pretreatment are discussed.

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/AimTo 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).MethodsThis is an intraindividual...

Effect of Lens Fragmentation Patterns on Phacoemulsification Parameters and Postoperative Inflammation in Femtosecond Laser-Assisted Cataract Surgery

ABSTRACTPurpose: To evaluate intraoperative and postoperative outcomes with “chop” or “matrix” lens fragmentation patterns in femtosecond laser-assisted cataract surgery.Methods: Prospective comparative study of 66 eyes with grade III–IV nuclear sclerosis was conducted at an apex tertiary care ophthalmic center. Cases were randomly allocated to undergo femtosecond laser pretreatment using matrix pattern (group I; n = 33) or chop pattern (group II; n = 33) of lens fragmentation (LenSx laser platform), followed by phacoemulsification. The primary outcome measures were intraoperative phacoemulsification parameters and postoperative anterior chamber (AC) flare. Secondary outcome measures were intraoperative complications, postoperative central macular thickness, visual acuity, and endothelial cell counts. Follow-up was performed on postoperative day (POD) 1 and 30.Results: Phacoemulsification parameters including cumulative dissipated energy (p = 0.008), ultrasonic time (p = 0.001), aspiration time (p < 0.001), and total duration (p = 0.001) were significantly less in group I. The AC flare was 9.8 ± 4.6 in group I and 15.4 ± 6.0 in group II (p < 0.001) on POD 1, and the difference persisted at 1 month. A highly significant positive correlation was observed between the total duration of phacoemulsification and AC flare (p < 0.001). No case developed cystoid macular edema. The postoperative specular counts were significantly less in group II on POD 1 (p = 0.036) and POD 30 (p = 0.02). There was no difference in visual acuity between the two groups, and intraoperative complications were not observed in any case.Conclusion: A decrease in phacoemulsification time and energy is observed after femtosecond laser pretreatment with the matrix pattern of lens fragmentation as compared to the chop pattern. The endothelial cell loss and postoperative inflammation is significantly less with the matrix pattern, and the inflammation correlates with the duration of phacoemulsification.

Intraoperative outcomes and safety of femtosecond laser-assisted cataract surgery: Canadian perspective

ObjectiveTo report the intraoperative surgical outcomes and safety of femtosecond laser–assisted cataract surgery (FLACS) during surgeon learning curve and compare those outcomes with those of conventional phacoemulsification in a Canadian public hospital setting. DesignRetrospective chart review. ParticipantsFLACS and phacoemulsification patients at Brandon Regional Health Centre, Brandon, Manitoba, Canada. MethodsIntraoperative surgical outcomes and safety (rates of intraoperative complications and phacoemulsification parameters) were compared among 3 groups: the first consecutive 197 cases using femtosecond laser (FSL) pretreatment to ultrasound phacoemulsification in cataract surgery (group 1; early FLACS), the second consecutive 165 cases using FSL (group 2; later FLACS), and 80 consecutive conventional cataract surgery cases (group 3; conventional phaco). ResultsThere was a statistically significant difference for phacoemulsification parameters (actual phaco time [APT], effective phaco time [EPT], and ultrasound average) among the 3 groups (all p-values < 0.05). The mean phacoemulsification parameters (APT and EPT) for the early FLACS and the conventional phaco groups were significantly longer than those for the later FLACS group (p < 0.05). The mean FSL time for the early FLACS group was significantly longer than that for the later FLACS group. There was no statistical difference among the rates of intraoperative complications (suction breaks, capsular tags, FSL-induced miosis, posterior capsular tears, and anterior vitrectomy) for the 3 groups. ConclusionsDuring the learning curve, the intraoperative outcomes and safety of FLACS are comparable to the conventional phacoemulsification technique. After the learning curve, FLACS is significantly superior to conventional surgery in all measured phacoemulsification parameters.

Effects of topical ketorolac tromethamine 0.45% on intraoperative miosis and prostaglandin E2 release during femtosecond laser–assisted cataract surgery

To determine the effects of topical 0.45% ketorolac tromethamineon intraoperative miosis and prostaglandin E2 (PGE2) release during femtosecond laser-assisted cataract surgery. Seoul St. Mary's Hospital, Seoul, Korea. Prospective case series. The study comprised the following 3 groups: conventional cataract surgery without topical NSAIDs (conventional group); femtosecond laser-assisted cataract surgery with preoperative topical ketorolac tromethamine 0.45% (femtosecond NSAID group), and femtosecond laser-assisted cataract surgery without topical NSAIDs (femtosecond no-NSAID group). To measure the aqueous humor PGE2 concentration, a 100μL aqueous humor sample was collected from the anterior chamber after femtosecond laser pretreatment. The PGE2 concentration was measured using an enzyme immunoassay. Topical ketorolac tromethamine 0.45% led to a significant reduction in intraoperative miosis in the femtosecond NSAID group compared with the femtosecond no-NSAID group (P<.001). Absolute and relative reductions in pupil area in the femtosecond NSAID group were significantly lower than in the femtosecond no-NSAID group (P=.019 and P=.007, respectively). The mean aqueous humor PGE2 concentrations were 893.60 pg/mL ± 843.10 (SD) in the conventional group, 1911.43±1178.63 pg/mL in the femtosecond NSAID group, and 743.63±927.46 pg/mL in the femtosecond no-NSAID group (P<.001, conventional versus femtosecond NSAID and femtosecond NSAID versus femtosecond no NSAID; P>.05, conventional versus femtosecond NSAID). Preoperative topical ketorolac tromethamine 0.45% reduced miosis induced by femtosecond laser pretreatment and inhibitedaqueous humor PGE2 elevation.

Topical 0.1% Bromfenac Sodium for Intraoperative Miosis Prevention and Prostaglandin E2 Inhibition in Femtosecond Laser-Assisted Cataract Surgery.

The purpose of this study was to evaluate the effect of topical 0.1% bromfenac sodium, a nonsteroidal anti-inflammatory drug (NSAID), on intraoperative pupil dilation maintenance and prostaglandin E2 (PGE2) inhibition during femtosecond laser-assisted cataract surgery. Sixty patients (30 each in study and control groups) were included in this study. The patients received 0.1% bromfenac ophthalmic solution or control placebo twice a day for 3 days before surgery. Pupil size was measured at the initiation of femtosecond laser pretreatment and phacoemulsification. Aqueous humor was collected at the beginning of routine cataract surgery. PGE2 levels were measured with an enzyme-linked immunoassay. Laser flare photometry was measured preoperatively and at 1 day postoperatively. Compared with untreated patients, the change in pupil size and postoperative day 1 aqueous flare were significantly reduced throughout the operation in the patients treated with 0.1% bromfenac (P < 0.001). Mean PGE2 concentrations were also significantly decreased by treatment with 0.1% bromfenac (P < 0.001). The reduction of the pupil area and postoperative day 1 aqueous flare were significantly correlated with PGE2 levels (P < 0.001). NSAID treatment, when administered before femtosecond laser-assisted cataract surgery, was effective in maintaining intraoperative pupil dilation, preventing miosis, and reducing PGE2 levels.

Resident surgeon efficiency in femtosecond laser-assisted cataract surgery.

PurposeComparison of resident surgeon performance efficiencies in femtosecond laser-assisted cataract surgery (FLACS) versus conventional phacoemulsification.Patients and methodsA retrospective cohort study was conducted on consecutive patients undergoing phacoemulsification cataract surgery performed by senior ophthalmology residents under the supervision of 1 attending physician during a 9-month period in a large Veterans Affairs medical center. Medical records were reviewed for demographic information, preoperative nucleus grade, femtosecond laser pretreatment, operative procedure times, total operating room times, and surgical complications. Review of digital video records provided quantitative interval measurements of core steps of the procedures, including completion of incisions, anterior capsulotomy, nucleus removal, cortical removal, and intraocular lens implantation.ResultsTotal room time, operation time, and corneal incision completion time were found to be significantly longer in the femtosecond laser group versus the traditional phacoemulsification group (each P<0.05). Mean duration for manual completion of anterior capsulotomy was shorter in the laser group (P<0.001). There were no statistically significant differences in the individual steps of nucleus removal, cortical removal, or intraocular lens placement. Surgical complication rates were not significantly different between the groups.ConclusionIn early cases, resident completion of femtosecond cataract surgery is generally less efficient when trainees have more experience with traditional phacoemulsification. FLACS was found to have a significant advantage in completion of capsulotomy, but subsequent surgical steps were not shorter or longer. Resident learning curve for the FLACS technology may partially explain the disparities of performance. Educators should be cognizant of a potential for lower procedural efficiency when introducing FLACS into resident training.

Differences in energy expenditure for conventional and femtosecond-assisted cataract surgery using 2 different phacoemulsification systems

To compare the mean cumulative dissipated energy (CDE) in patients having femtosecond laser-assisted or conventional phacoemulsification cataract surgery using 2 different phacoemulsification platforms. Bascom Palmer Eye Institute, Miami, Florida, USA. Prospective comparative nonrandomized clinical study. Consecutive patients were scheduled to have femtosecond laser-assisted cataract surgery with the Lensx laser or conventional phacoemulsification using an active-fluidics torsional platform (Centurion) or torsional platform (Infiniti). The mean CDE and cataract grade were recorded. The study comprised 570 eyes (570 patients). There was no statistically significant difference in mean age (P=.41, femtosecond group; P=.33, conventional group) or cataract grade (P=.78 and P=.45, respectively) between the active-fluidics and gravity-fluidics platforms. In femtosecond cases (145 eyes), the mean CDE (percent-seconds) was 5.18±4.58 (SD) with active fluidics and 7.00±6.85 with gravity fluidics; in conventional cases (425 eyes), the mean CDE was 7.77±6.97 and 11.43±9.12, respectively. In both femtosecond cases and conventional cases, the CDE was lower with the active-fluidics platform than with the gravity-fluidics platform (P=.029, femtosecond group; P<.001 conventional group). With both fluidics platforms, the mean CDE was significantly lower in the femtosecond group than in the conventional group (both P<.001). The active-fluidics phacoemulsification platform achieved lower CDE values than the gravity-fluidics platform for conventional cataract extraction. Femtosecond laser pretreatment with the active-fluidics platform further reduced CDE.

Femtosecond laser combined with non-chopping rotation phacoemulsification technique for soft-nucleus cataract surgery: a prospective study.

Soft-lens cataract surgeries are becoming increasingly common for cataract surgeons and chopping the soft nucleus using conventional techniques is problematic. We introduced a femtosecond laser combined with a non-chopping rotation phacoemulsification technique for soft-nucleus cataract surgery and evaluated the safety and efficacy of using this technique. Sixty-six patients with soft-nucleus cataracts ranging from grade 1~3 were divided into 3 groups based on nuclear staging. Those groups were further divided into three subgroups: femtosecond laser pretreatment combined with a non-chopping rotation phacoemulsification technique (subgroup 1), conventional manual cataract surgery with a non-chopping rotation technique (subgroup 2) and conventional manual cataract surgery with a quick-chop technique (subgroup 3).Patients were followed up at 1, 7, and 30 days after surgery. There was an 84.6% and a 63.34% reduction in ultrasound time and cumulative dissipated energy, respectively, between the subgroup 1 and the subgroup 3; and this was associated with a 36.1% and 29.7% reduction in endothelial cell loss and aqueous flare. There were no adverse events at the follow-up times. With its reduced ultrasound energy, endothelial cell loss and aqueous flare, the femtosecond laser pretreatment combined with a non-chopping rotation technique was more efficient than conventional manual cataract surgery for soft-nucleus cataracts.

Cystoid macular edema after femtosecond laser–assisted versus phacoemulsification cataract surgery

To evaluate the incidence of postoperative clinical cystoid macular edema (CME) associated with femtosecond laser-assisted cataract surgery (Catalys laser system) versus phacoemulsification cataract surgery. Launceston Eye Institute, Launceston, Tasmania, Australia. Nonrandomized, single-surgeon, prospective, comparative cohort case series. Patients who had femtosecond laser-assisted cataract surgery and phacoemulsification cataract surgery between March 2012 and July 2014 were included in the study. The femtosecond laser-assisted cataract surgery group had anterior capsulotomy, lens fragmentation, with or without corneal incisions via femtosecond laser pretreatment. Standard phacoemulsification surgery and foldable acrylic intraocular lens insertion proceeded in all cases. All patients received topical nonsteroidal drops commencing 2 days preoperatively and continuing for 4 weeks postoperatively. The incidence of postoperative clinical CME (confirmed by optical coherence tomography) and comparison between groups were measured. The main outcome measure was the clinical CME rates. Of the eyes, 833 had femtosecond laser-assisted cataract surgery amd 458 had standard phacoemulsification cataract surgery. Both groups had similar baseline parameters. There were 7 cases of postoperative CME (0.8%) in the femtosecond laser-assisted cataract surgery group compared to 1 case (0.2%) in the phacoemulsification cataract surgery group, highlighting a trend toward greater cystoid macular edema in the femtosecond laser-assisted cataract surgery group. This correlated with a change in laser treatment speed (due to a software upgrade), suggesting that retinal safety thresholds need further careful analysis. Increased CME might be a subthreshold retinal injury safety signal after femtosecond laser pretreatment and warrants further study. There are no financial or conflicts of interest for any author.