Research on shock wave driving technology of methane explosion.

In order to improve the driving ability of the explosion wave simulation equipment, reduce the erosion effect of condensed explosives on the explosion wave simulation equipment, improve the safety of the test process, and make better use of the meteorological detonation driving method, it is necessary to optimize the source of the shock wave load in the driving section. Based on the finite volume method of FLACS, a methane detonation driving model corresponding to the test is established to explore the feasibility of using methane as an explosion source to test the structure against explosion shock wave. A methane detonation drive test was carried out to verify the accuracy of the numerical model. Finally, an engineering model for attenuation of shock wave overpressure peak value in pipeline is established by dimensional analysis, and the model coefficient is determined by numerical simulation and test data. The results show that the blast pressure is the highest when the methane volume ratio reaches 9.5 vol% in the methane-air mixture. Simply increasing oxygen content has little effect on the peak overpressure and positive pressure duration of shock wave. In the pure oxygen environment, the detonation effect can be achieved when the volume ratio of methane to oxygen is 1:2, and the incident pressure of the shock wave is proportional to the volume of the gas cloud. When the gas cloud volume is constant, a reasonable selection of methane-oxygen mixture ratio can achieve a better detonation effect, which can effectively increase the peak overpressure of the shock wave in the test section. The research results can provide technical reference for the development of new explosion wave simulation equipment.

Refractive Astigmatism Outcomes of Femtosecond Laser-Assisted Arcuate Keratotomies Combined with Femtosecond Laser-Assisted Cataract Surgery: Two-Year Results.

PURPOSE: To evaluate the effectiveness and stability of refractive astigmatism reduction after penetrating femtosecond laser-assisted arcuate keratotomy performed at the time of femtosecond laser-assisted cataract surgery. METHODS: Non-randomized retrospective data analysis of all patients that underwent femtosecond laser-assisted cataract surgery with femtosecond laser-assisted arcuate keratotomy over a 4-year period with a non-toric monofocal intraocular lens (2017-2021) at a tertiary care academic center. Postoperative visual acuity, manifest refraction, and predicted residual refractive error were also recorded at 1 month, 3-6 months, 12-18 months, and 2 years postoperatively. Preoperative keratometric astigmatism was compared to postoperative refractive astigmatism using vector calculations and the ASCRS double-angle plot tool. RESULTS: This study comprised 266 eyes (179 patients) that met inclusion criteria. The mean preoperative keratometric astigmatism magnitude was 0.99 ± 0.53 D. At 1 month, 3-6 months, 12-18 months, and 2 years postoperatively, the mean refractive cylinder was 0.49 ± 0.45 D, 0.49 ± 0.45 D, 0.55 ± 0.54 D, and 0.52 ± 0.46 D, respectively. Horizontal against-the-rule astigmatism showed a higher tendency toward undercorrection than vertical with-the-rule astigmatism, which had a slightly higher tendency toward overcorrection. With-the-rule astigmatism had smaller difference vectors between target-induced astigmatism and surgically induced astigmatism. CONCLUSIONS: Femtosecond laser-assisted arcuate keratotomy performed at the time of femtosecond laser-assisted cataract surgery was an effective option for correcting low-to-moderate corneal astigmatism for up to 2 years.

FLACS (Femtosecond-Laser-Assisted Cataract Surgery) combined with pupiloplasty in iris-lens coloboma.

Purpose: To describe the use of FLACS (Femtosecond-Laser-Assisted Cataract Surgery) and pupiloplasty technique employed in a cataract surgery associated with iris-lens-zonule coloboma, as well as to report the advantages that FLACS can provide in this type of complicated surgery. Observations: During FLACS (Victus® - TECHNOLAS, Bausch and Lomb Incorporated, USA), after the docking procedure, the parameters of capsulotomy, fragmentation and incisions were manually adjusted. Iris retractors were anchored to the edge of the anterior lens capsule to provide stability to the bag during phacoemulsification maneuvers, and a capsular tension ring and intraocular lens (IOL) were implanted. Iris repair was approached using a modification of the slip-knot technique. For this purpose, a 10.0 Prolene on a straight needle was used and knotted extraocularly, over the conjunctiva. Finally, an anterior vitrectomy was performed as a precaution. Conclusions and importance: In spite of the existing controversy regarding FLACS technology compared to conventional surgery, it seems to be beneficial in complicated cases such as cataracts associated with iris and lens coloboma, since it allows the modification of different parameters that facilitate and ensure surgery safety. On the other hand, the iris repair technique described facilitates manipulation of the iris sutures. In addition, complementary techniques such as the use of a capsular tension ring and pupiloplasty help to center and stabilize the IOL, and to reduce the symptoms derived from iris coloboma, obtaining a better visual quality.

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.

Effects of femtosecond laser-assisted cataract surgery combined with intraocular lens implantation on postoperative deviation rate of multifocal intraocular lens and visual quality in cataract patients / 国际眼科杂志(Guoji Yanke Zazhi)

AIM: To explore the effects of femtosecond laser-assisted cataract surgery combined with intraocular lens implantation(FLACS-IOL)on postoperative deviation rate of multifocal intraocular lens(MIOL)and visual quality in cataract patients.METHODS: In the prospective study, 95 patients with cataract(108 eyes)who underwent MIOL implantation in the hospital between January 2021 and December 2022 were enrolled. According to different surgical methods, they were divided into FLACS group(51 cases, 56 eyes)and Phaco group(44 cases, 52 eyes). The operation time, incision diameter of anterior capsule, effective phaco time(EPT), cumulative dissipated energy(CDE), uncorrected distance visual acuity(UCDVA), best corrected distance visual acuity(BCDVA), eccentricity distance of IOL and deviation rate at 3 mo after surgery, total high order aberration(HOA), Trefoil and coma under 3 mm pupil were compared between the two groups.RESULTS: The operation time in the FLACS group was significantly shorter than that in the Phaco group, EPT and CDE were significantly lower than those in the Phaco group(all P&#x003C;0.05). There was no significant difference in incision diameter of anterior capsule between the two groups(P&#x003E;0.05). At 1 wk, 3 mo after surgery, UCDVA in the FLACS group was better than that in the Phaco group(all P&#x003C;0.05). There were significant difference in UCDVA at 1 wk, 3 mo after surgery or BCDVA at 3 mo after surgery between the two groups(P&#x003C;0.05). At 3 mo after surgery, eccentricity distance of IOL in the FLACS group was shorter than that in the Phaco group, and deviation rate was significantly lower than that in the Phaco group(all P&#x003C;0.05). Under pupil diameter of 3 mm, HOA, trefoil and coma of whole eyes were decreased in both groups at 3 mo after surgery(P&#x003C;0.05). At 3 mo after surgery, there were significant differences in HOA and trefoil of whole eyes between the FLACS group and Phaco group(P&#x003C;0.05), but there was no significant difference in coma at 3 mo after surgery(P&#x003E;0.05).CONCLUSION: FLACS-IOL can effectively reduce deviation rate of IOL and obtain better visual quality in cataract patients.

Combined Femtosecond Laser-Assisted Keratotomy and Cataract Surgery for Enhancing Refractive Outcomes. An Indonesian Case Study.

Purpose: We evaluate the reduction of corneal astigmatism and the improvement of visual outcomes of this surgical method in the Indonesian population. We also assess the accuracy and predictability of using femtosecond laser astigmatic keratotomy (FLAK) combined with cataract surgery. Patients and Methods: In a retrospective study, a total of 275 subjects (78 with against-the-rule (ATR) astigmatism, 178 with with-the-rule (WTR) astigmatism, and 19 with oblique (OBL) astigmatism) with preexisting corneal astigmatism ranging from 0.75D to 3.00D underwent FLAK. All subjects completed a 3-month follow-up. The femtosecond laser used for creating paired AK 2.2 mm, primary incision, and paracentesis incision was the FEMTO Z8 NEO from Ziemer Ophthalmic System, Switzerland. The surgical approach was guided by the "NAPA" nomogram. Results: The reduction in postoperative astigmatism was 56.90% for the WTR group, 49.46% for the ATR group, and 47.33% for the oblique group. A significant reduction in astigmatism was observed at the 1-week, 1-month, and 3-month follow-up intervals in both the WTR and ATR groups. The reduction in astigmatism was more favorable in cases of moderate astigmatism within the WTR group, as compared to the ATR and oblique groups. Postoperative astigmatism reduction was found to be more predictable in the right eye than in the left eye. Conclusion: The combination of FLAK can be considered as a potential method for reducing corneal astigmatism ranging from 1.00D to <3.00D. The highest reduction was observed in the WTR group, along with a higher rate of intended correction without astigmatism meridian shift in the right eye for the WTR group. However, factors such as cyclotorsion resulting from the surgical technique, alignment of docking, incision length, and preoperative astigmatism need to be taken into account for further enhancement and predictability of astigmatism reduction with this method.

Cataract Grade and Pupil: Comparison Between Conventional Phacoemulsification and Low-Energy Femtosecond Laser Assisted Cataract Surgery.

Purpose: This study presents a comparison of pupil changes according to cataract grade between low-energy femtosecond laser-assisted cataract surgery (FLACS) and conventional phacoemulsification (CP) in the same patient. Patients and Methods: Data from surgical records from patients submitted to cataract surgery with CP in one eye and FLACS in the other were retrospectively reviewed. The inclusion criterion was both eyes of the same patient having the same cataract grade in accordance with Lens Opacity Classification System (LOCS) III. Total pupil variation (TPV) was measured after recorded images, with intraindividual comparison between techniques, according to cataract grade (≤3 and >3), age and cumulative dissipated energy (CDE). Results: The study included a total of 124 eyes of 62 patients (mean age 72.65 ± 7.64 years). Analysis showed a statistically significant difference in TPV between techniques in the grade ≤3 cataract group (0.08 ± 0.22 mm²; p=0.034), with less pupil narrowing with FLACS, but not in the grade >3 group (0.01 ± 0.23 mm²; p=0.849). Regarding CDE, a significant difference (p<0.001) was found between techniques in both softer and harder cataracts, with lower values for FLACS. Correlation between CDE and TPV was significant for CP (p=0.021) but not for FLACS (p=0.922). TPV was significantly lower in older patients (age >74 years) for both techniques (p<0.001). Conclusion: There was a statistically significant difference between techniques (although of mild clinical relevance), with less reduction of pupil area with FLACS in softer cataracts (grade ≤3), as compared to CP. Higher levels of CDE are associated with more pupil narrowing in CP.

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.

Study on leakage and explosion law of buried gas pipeline based on scenario construction.

Based on the Jilin Songyuan gas pipeline accident, FLACS software was used to numerically simulate its leakage and explosion process in order to study the change law of the equivalent gas cloud volume of gas leakage diffusion under various influencing factors. The simulation results were compared and analyzed with the accident investigation report in order to ensure the accuracy of the simulation results. On this premise, the three primary influencing factors-the obstacle distribution technique, the ambient wind speed magnitude, and the ambient temperature-are varied in order to study the equivalent gas cloud volume variation features of the leaking gas cloud. The findings indicate a positive association between the maximum equivalent gas cloud volume of the leaking gas cloud and the density of the obstacle distribution. There is a positive correlation between ambient wind speed and the equivalent gas cloud volume when the ambient wind speed is less than 5.0 m/s, and a negative correlation between ambient wind speed and the equivalent gas cloud volume when the ambient wind speed is greater than or equal to 5.0 m/s. A drop in Q8 is proportionately increased by around 5% for every 10 °C increase in ambient temperature when the temperature is below room temperature. There is a positive association between ambient temperature and the equivalent gas cloud volume Q8. When the temperature is higher than room temperature, the drop in Q8 is correspondingly increased by about 3% for every 10 °C increase in ambient temperature.

Comparison of Conventional and Femtosecond Laser-Assisted Cataract Surgery Regarding Macula Behavior and Thickness.

Background: The aim of the study was to compare macular thickness behavior and clinical outcomes after femtosecond laser-assisted cataract surgery (FLACS) versus phacoemulsification conventional surgery (PCS). Methods: Macular Optical Coherence Tomography OCT was analyzed in 42 patients preoperatively, 1 day, 12 days, 4 weeks and 6 weeks postoperatively according to the 9-field Early Treatment Diabetic Retinopathy Study (ETDRS) grid. Clinical findings were collected in both the FLACS group and the PCS group. Results: There was no significant difference in macular thickness between the FLACS and PCS groups (p > 0.05). However, from postoperative day 12 onwards, there was a significant increase in macular thickness observed in both groups (p < 0.001). In the FLACS group, a significant increase in visual acuity was observed on the first postoperative day, as compared to the PCS group (p = 0.006). Conclusions: The use of a low-energy high-frequency femtosecond laser has potentially no effect on postoperative macular thickness. In the FLACS group, visual rehabilitation was significantly faster as compared to the PCS group. No complications occurred intraoperatively in either group.

FLACS combined with IOLI is comparable to Phaco combined with IOLI in cataract patients after refractive surgery.

OBJECTIVE: To characterize the clinical features of cataract surgery performed after refractive surgery. METHODS: In this study, 23 patients with cataracts (38 eyes) who underwent cataract surgery following refractive surgery at the Shenzhen Aier Eye Hospital between the years 2017 and 2021 were retrospectively included for analysis. The patients had either femtosecond laser-assisted cataract surgery (FLACS) combined with intraocular lens implantation (IOLI), or conventional phacoemulsification (Phaco) combined with IOLI. The type and power of an intraocular lens (IOL) were selected based on the ocular condition, needs, and living habits of patients. Intraoperative complications, postoperative intraocular pressure (IOP), uncorrected visual acuity (UCVA), and postoperative refractive status were all recorded and analyzed. RESULTS: The patients had a postoperative UCVA that was significantly better than the baseline (prior to operation), a postoperative IOP and diopter (D) similar to the baseline and a high level of postoperative satisfaction. The postoperative visual acuity, D and complication rate of FLACS+IOLI group were not significantly different from those of Phaco+IOLI group, and the IOP of the former was statistically lower than that of the latter. CONCLUSIONS: FLACS with IOLI or conventional Phaco with IOLI is feasible for cataract patients who have undergone refractive surgery. In terms of IOL selection, multifocal, extended range of vision (ERV), or trifocal types can be selected to achieve the goal of lens removal after surgery, but the decision should be made based on the patient's specific eye condition, living needs, and economic circumstances. To achieve satisfactory curative effects, it is necessary to have a comprehensive understanding of the characteristics of the condition of such patients, to master the pre- and post-operative diagnosis and treatment methods, to accurately calculate the IOLP, to fully communicate with patients about their surgical expectations, and to develop feasible surgical plans.

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.

Efficacy of femtosecond laser for anterior capsulotomy in complex white cataracts.

OBJECTIVE: To determine the advantages and complication rate of capsulotomy performed with femtosecond laser in white complex cataract cases. STUDY DESIGN: Retrospective case series. PARTICIPANTS: Sixteen eyes of 16 patients. METHODS: This was a single-center retrospective review of white cataract surgery cases in which the femtosecond laser (LenSx, Alcon Laboratories, Fortworth, Texas, USA) was used between May 2019 and February 2021. Outcome measures included an assessment of the capsulotomy, identification of tags, surgical time, cumulative dispersed energy (CDE) and postoperative management. RESULTS: Sixteen eyes of 16 patients were included in this study; capsule tags occurred in six patients (37.5%). In 2 patients, the capsule presented small adhesions that were identified and removed. One patient presented a very significant contraction of the anterior capsule with an incomplete cut zone of 2 to 4hours. In a patient with nystagmus, the capsulotomy was performed without complications under peribulbar anesthesia. CONCLUSIONS: The femtosecond laser permitted capsulotomies of better shape, size and regularity in complex cases of white cataract and in combination with conditions such as nystagmus and prior corneal transplantation. The microadhesions and untreated areas were identified with trypan blue, which is essential to use in these cases to avoid associated complications.

Efficacy of a new fragmentation pattern in femtosecond laser-assisted cataract surgery with the Ziemer FEMTO LDV Z8.

PURPOSE: To determine the efficacy of different fragmentation patterns in femtosecond laser-assisted cataract surgery (FLACS) using Ziemer FEMTO LDV Z8. METHODS: We compared three different types of surgery: conventional cataract surgery (CCS), FLACS with conventional radial slices (named No-Spiderweb), and FLACS with a novel fragmentation pattern (radial slices combined with one or two rings) called "Spiderweb." Visual acuity (VA), nuclear opacity (NO) according to the Lens Opacities Classification System (LOCS lll), effective phacoemulsification time (EPT) and vacuum time were obtained for 845 eyes. RESULTS: Using FLACS (Spiderweb + No-Spiderweb), EPT was significantly reduced by 26% compared to CCS (FLACS: 2.46 ± 2.60 s; CCS: 3.34 ± 2.89 s; ΔM = - 0.88 s, p < .001). Furthermore, EPT as a function of progression of lens opacity was found to be not only lower in Spiderweb compared to CCS, but also in comparison with No-Spiderweb. At NO3, a significant reduction of 65% in EPT was observed by using Spiderweb compared to CCS (Spiderweb: 0.68 ± 1.23 s; CCS: 1.96 ± 1.53 s; ΔM = - 1.28 s, p <.001). Interestingly, EPT at NO3 was also significantly reduced by 57% in Spiderweb compared to No-Spiderweb (Spiderweb: 0.68 ± 1.23 s; No-Spiderweb: 1.57 ± 1 .59 s; ΔM = - 0.90 s, p <.001). The use of Spiderweb only marginally extends the vacuum time compared to No-Spiderweb by 11 s (Spiderweb: 209.13 ± 35.83 s; No-Spiderweb: 198.35 ± 36.84 s; p = .003) and the postoperative improved VA showed no significant difference among the different types of surgery (all ps ≥ .05). CONCLUSION: FLACS significantly reduces EPT compared to CCS. Furthermore, the novel Spiderweb pattern significantly reduces EPT in patients with a cataract of NO3 compared to CCS, but also to FLACS with the existing radial pattern (No-Spiderweb).

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.

Argentinian flag sign during refractive laser-assisted cataract surgery - A case report.

Purpose: The Argentinian flag sign, or radial capsular tear extensions, is a rare complication when performing capsulorhexis during cataract surgery. Identifying and managing this complication early is important to prevent the tear from propagating around the periphery leading to posterior capsular rupture or vitreous loss. Observations: The Argentinian flag sign was previously reported in a case of femtosecond laser-assisted cataract surgery (FLACS). However, our report presents the first case after FLACS using the Catalys™ Precision Laser System, a platform which has been associated with a larger percentage of complete capsulotomies when compared to other platforms. Radial extensions of the capsular tear were observed in a 27-year-old male patient with an intumescent cataract in left eye. The complication was managed by manually redirecting and completing the radial extension flaps, along with delicate phacoemulsification and manual cutting of capsular edge in areas with significant capsular-IOL overlap. Conclusions and importance: Our case report highlights that despite the Catalys™ Precision Laser System success rates, radial tears may occur, especially in highly pressurized intumescent cataract. Therefore, surgeons must be prepared to optimize the surgical techniques to prevent the occurrence of this complication, as well as identify and manage it when it presents.

Dexamethasone intravitreal implant along with femtosecond laser assisted cataract surgery in patients with diabetic macular edema and cataract.

PURPOSE: To assess the safety and efficacy of intraoperative dexamethasone intravitreal (DEX) implant in patients with diabetic macular edema (DME) undergoing femtosecond laser assisted cataract surgery (FLACS). METHODS: In this single-center retrospective study, the charts of patients who underwent combined FLACS and DEX implant in the previous three months were reviewed. Primary outcome measures were ocular complications; secondary outcome measures were the change of best-corrected visual acuity (BCVA) and central retinal thickness (CRT). RESULTS: 20 eyes of 20 patients were included. None developed intraoperative or postoperative complications. Mean BCVA was 20/120 (logMAR, 0.78 ± 0.31) at baseline and improved significantly to 20/63 (logMAR, 0.52 ± 0.24; p = 0.01), 20/58 (LogMAR, 0.48 ± 0.28; p < 0.001) and to 20/58 (LogMAR, 0.48 ± 0.31; p < 0.001) at month 1,2 and 3, respectively. A mean improvement of 0.30 LogMAR was recorded at month 1 and 3. Mean CRT decreased significantly from 416.6 ± 76.1 µm at baseline to 322.4 ± 46.4 µm (p < 0.001), to 300.7 ± 29.7 µm (p < 0.001), and to 319.8 ± 54.7 µm (p < 0.001) at month 1,2 and 3, respectively. Comparing to the 1-month follow-up, the largest mean reduction in CRT (112.4 ± 68.9 µm) was observed at month 2 (p = 0.001). Fourteen patients (70%) had an improvement of CRT over the first 2 months followed by a recurrence of edema at month 3. CONCLUSION: DEX implant following FLACS seems to be a safe and effective approach for patients with coexisting cataract and DME.

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

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