Cumulative Dissipated Energy (CDE) in Three Phaco-Fragmentation Techniques for Dense Cataract Removal.

Purpose: To determine the energy expenditure in phacoemulsification surgery expressed as cumulative dissipated energy (CDE) among the divide and conquer, ultrachopper-assisted divide and conquer, and phaco-chop techniques for dense cataract removal. Patients and Methods: The clinical data were obtained from the medical charts of dense cataracts patients undergoing routine phacoemulsification employing any of three phaco-fragmentation techniques, including divide and conquer using the Kelman 0.9 mm tip, the ultrachopper tip, and the phaco-chop technique using the Kelman 0.9 mm tip. Cumulated dissipated energy (CDE), longitudinal ultrasound time (UST), and endothelial cell loss were compared among groups at the one-month postoperative. Results: Surgeries from 90 eyes were analyzed, among whom the conventional divide-and-conquer technique group included 30 patients, 32 in the ultrachopper group, and 28 in the phaco-chop technique group. The average CDE in the conventional divide and conquer group was 44.52 ± 23.00, the ultrachopper technique was 43.27 ± 23.18, and 20.11 ± 11.06 in the phaco-chop group. Phaco-fragmentation chop demonstrated significantly lower CDE than the other techniques (p= <0.0001). The phaco-chop technique showed statistically significantly lower CDE when compared to the other two groups (p=<0.0001) with 93.96 ± 39.71 seconds. There were no statistically significant differences in postoperative endothelial cell density between groups (p=0.4916). Conclusion: The use of the phaco-chop technique in hard cataract phacoemulsification represents a lower energy expenditure than divide and conquer and ultrachopper techniques; nevertheless, no differences regarding endothelial density loss were evidenced.

Clinical outcomes of femtosecond laser-assisted cataract surgery versus conventional phacoemulsification: A retrospective study in a tertiary eye care center in South India.

Purpose: To compare the clinical outcomes of femtosecond laser-assisted cataract surgery (FLACS) versus conventional phacoemulsification (CP) in terms of refractive outcomes, cumulative dissipated energy, and intraoperative complications. Methods: In this retrospective study performed in a tertiary care ophthalmic hospital, we reviewed 2124 eyes that underwent FLACS or CP. Uncorrected distance visual acuity (UDVA), corrected distance visual acuity (CDVA), cumulative dissipated energy (CDE), and intraoperative complications were analyzed in the study. Results: Out of 2124 eyes, 873 underwent FLACS and 1251 underwent CP. The postoperative mean UCVA after one month was 0.05 ± 0.11 logMAR and 0.14 ± 0.23 logMAR for FLACS and CP, respectively (P < 0.00001). Mean CDVA one month post operation was 0.02 ± 0.07 logMAR and 0.06 ± 0.19 logMAR for FLACS and CP, respectively (P < 0.0001). The CDE for the FLACS group was 6.17 ± 3.86 (P < 0.00001) and it was 9.74 ± 6.02 for the CP group. The intraoperative complication for the FLACS group was 1.60% and the CP group was 2.39% (P < 0.00001). Conclusion: The visual outcomes were better in FLACS compared to CP. The CDE was lower for the FLACS group and FLACS had significantly less intraoperative complications.

Femtosecond Laser-Assisted Cataract Surgery: Analysis of Surgical Phases and Comparison with Standard Phacoemulsification in Uncomplicated Cataracts.

The aim of this work is to compare the time of surgical phases and the cumulative dissipated energy (CDE) of the phacoemulsification phase in femtosecond laser-assisted cataract surgery (FLACS) and in standard surgical procedures of phacoemulsification (PCS). This prospective, non-randomized study analyzed the data of 100 cataract surgeries, 66 using FLACS and 34 with standard PCS. The time of surgical phases was recorded by a digital chronometer; an additional parameter recorded was the CDE of the phacoemulsification phase. The mean time of femtosecond laser phase was 121.7 ± 27.3 s with minimal fluctuations in duration; the mean opening time of the corneal tunnel and the service incisions was 60.5 ± 20.4 s in the PCS, and 48.8 ± 17.4 s in FLACS (p = 0.04); the mean time of capsulorhexis was 39.6 ± 12.9 s in the PCS and 7.0 ± 5.2 s in FLACS (p < 0.0001); the mean time of phacoemulsification was 180.1 ± 45.6 s in the PCS and 163.0 ± 38.2 s in FLACS (p = 0.12); the mean aspiration time of the residual cortical was 66.3 ± 27.5 s in the PCS and 91.5 ± 35.7 s in FLACS (p = 0.02). Overall, the total surgical time of the cataract surgery was 742.3 ± 185.8 s in PCS and 985.1 ± 118.6 s in FLACS (p = 0.03). The mean CDE was 11.35 in the PCS and 8.3 in FLACS (p = 0.01). In conclusion, the greatest advantage obtained from the use of the femtosecond laser was the reduction of the duration of the phacoemulsification time and of the CDE parameter.

Cumulative dissipated energy in eyes with and without corneal opacity.

Objective: To compare ultrasonic energy delivered into the eye [cumulative dissipated energy, (CDE)] and frequencies of required auxiliary surgical methods during phacoemulsification surgery in eyes with and without corneal opacity. Methods: The study was designed as a retrospective comparative observational study. The study group [Corneal Opacity Group, (COG)] was comprised of 31 eyes of 31 cataract patients with corneal opacity. Only nebular and macular corneal opacities (according to slit-lamp based classification of Agrawal) were included in the study. The control group (CG) was comprised of 40 eyes of 40 cataract patients without corneal opacity. The CDE values were obtained using the Centurion system (Alcon, Fort Worth, TX) and the patients were followed-up postoperatively for a period of one month. Results: The mean age of the subjects was 71.46 ± 8.86 years (52-89) in COG and 66.12 ± 5.96 years (55-80) in CG (p >0.05). In COG, the most common etiologic factors were trauma, keratitis, and degenerative diseases. The mean CDE value was 15.16 ± 8.71 (2.20-42.65) in COG and 10.04 ± 6.28 (3.77-31.80) in CG and it was found as significantly higher in COG (p=0.003). Some auxiliary surgical methods including posterior synechiolysis and anterior capsule staining were more commonly performed in COG (p=0.044 and p=0.040, respectively). No intraoperative or postoperative complication was observed. Conclusion: More ultrasonic energy is delivered into the eye and more auxiliary surgical methods are needed in cataract patients with corneal opacity who underwent phacoemulsification. Abbreviations: CDE = Cumulative dissipated energy, COG = Corneal Opacity Group, CG = Control group, IOL = Intraocular lens, LOCS = Lens Opacities Classification System, BCVA = best-corrected visual acuity, SRK/T = Sanders, Retzlaff, and Kraff theoretical, OVD = ophthalmic viscosurgical device, SPSS = Statistical Package for the Social Sciences.

Topical NSAIDs and Oral Acetazolamide for Macular Edema after Uncomplicated Phacoemulsification: Outcome and Predictors of Non-Response.

PURPOSE: To investigate the effectiveness of nonsteroidal anti-inflammatory eye drops (NSAIDs) combined with oral acetazolamide for postoperative macular edema (PME) after uncomplicated phacoemulsification (PE) and identify predictors of non-response. METHODS: We analyzed data of uncomplicated PE and identified eyes with PME. First-line therapy included topical NSAIDs combined with oral acetazolamide. In the case of non-response, triamcinolone was administered subtenonally. Outcome measures included best-corrected visual acuity (BCVA) and central macular thickness (CMT). RESULTS: 94 eyes out of 9750 uncomplicated PE developed PME, of which 60 eyes were included. Follow-ups occurred 6.4 ± 1.8, 12.5 ± 3.7 and 18.6 ± 6.0 weeks after diagnosis. BCVA and CMT improved significantly in all follow-ups. In total, 40 eyes showed a response to first-line therapy at the first follow-up (G1). The remaining 20 eyes showed no response and required subtenon triamcinolone (G2), of which 11 eyes showed complete regression at the second follow-up and 4 eyes at third follow-up. A further 5 eyes showed no response and required intravitreal injection. Multivariate linear regression model showed that Diabetes mellitus (DM) and increased cumulative dissipated energy (CDE) are predictors of non-response. CONCLUSION: Topical NSAIDs with acetazolamide resulted in complete regression of PME in 67% of all cases. DM and increased CDE might be considered as predictors of non-response to this treatment.

Comparisons of the energy efficiency and intraocular safety of two torsional phacoemulsification tips.

BACKGROUND: During cataract phacoemulsification surgery, an Intrepid® balanced (IB) tip can achieve a larger amplitude, which may lead to higher energy efficiency than a Kelman (K) tip when paired with a torsional phaco platform. In this retrospective cohort study, we compared their energy efficiency and damage to the cornea under a new energy setting. METHODS: The medical records of 104 eyes of 79 patients were reviewed, with 47 eyes belonging to the IB group and 57 eyes belonging to the K group. All surgeries were performed on an Alcon Centurion® platform with gravity infiltration. Surgical parameters, visual outcome, central corneal thickness (CCT) changes, and endothelial cell density (ECD) loss rate were recorded and calculated. RESULTS: No significant differences in postoperative best corrected visual acuity (BCVA), intraocular pressure (IOP), total ultrasound time, estimated fluid aspirated, CCT changes, or ECD loss rate were observed between the two groups. We divided the included eyes into soft nucleus and hard nucleus subgroups and found lower cumulative dissipated energy (CDE, 8.15 ± 8.02 vs 14.82 ± 14.16, P = 0.023), cumulative torsional energy (CTE, 8.06 ± 7.87 vs 14.13 ± 13.02, P = 0.027), and cumulative longitudinal energy (CLE, 0.09 ± 0.17 vs 0.69 ± 1.37, P = 0.017) in the IB group than in the K group, implying less energy used and higher energy efficiency of the IB tip. CONCLUSION: Lower CLE in the IB group indicates fewer phaco tip obstructions and a significantly higher capability to conquer hard nuclei with IB tips with statistical significance. With an ultra-perfusion cannula, the balanced tip does not cause more corneal damage.

Comparing surgical efficiencies between phacoemulsification systems: a single surgeon retrospective study of 2000 eyes.

AIM: To compare under similar conditions intraoperative surgical efficiencies metrics between an active fluidics and a gravity based phacoemulsification systems. METHODS: Adult patients who were diagnosed with a cataract that compromised visual acuity inferior to 20/40 were included in the study. Patients were excluded from the study if they had a history of severe retinal disorders, clinically significant corneal endothelial dystrophy or history of corneal disease. All phacoemulsification surgeries were performed by a single surgeon. Both phacoemulsification systems used the 0.9 mm 45-degree aspiration bypass system Intrepid Balanced tip and the 0.9 mm Intrepid Ultra infusion sleeve. All cataracts were classified using the Lens Opacities Classification System III, cumulative dissipated energy (CDE) and aspiration fluids were measured in each surgery. RESULTS: Totally 2000 eyes were included in the study. Phacoemulsification was performed in 1000 (50%) eyes with an active fluid dynamics system and in 1000 (50%) eyes with a gravity-based fluidic system. Mean CDE until fracture of the lens was 1.1 and 1.9 percent-seconds and total mean CDE used was 5.6 and 7.2 percent-seconds using an active fluidics dynamics system and gravity-based fluidic system, respectively (P<0.001). Mean aspiration fluids used were 70 mL using an active fluidics dynamics system and 85 mL using a gravity-based fluidic system (P<0.001). CONCLUSION: This study evidences that surgeries performed under similar conditions (same surgeon, phaco tip and sleeve) with the active fluidics dynamics system required significantly lower CDE and aspiration fluids.

Retrospective evaluation of phacoemulsification and aspiration in 182 eyes: Visual outcomes and CDE-predictive value.

OBJECTIVE: To determine the effect of cumulative dissipated energy (CDE) on complications and visual outcome following cataract surgery in dogs. ANIMALS STUDIED: Records of 182 canine eyes that had undergone cataract surgery. PROCEDURES: Retrospective medical record review was conducted on dogs that underwent unilateral or bilateral elective cataract surgery by a single surgeon. Preoperative variables such as age, cataract duration, and pre-existing conditions were recorded. Intraoperative variables such as intraocular lens (IOL) status, phacoemulsification time, average power, irrigation fluid volume, and CDE were recorded. Postoperative complications and visual status at last follow-up were compared to these variables. RESULTS: Eighty-six percent of dogs were visual in one or both eyes at last follow-up (LFU) examination. Median follow-up time was 186 days postoperatively. Eyes that developed glaucoma had a significantly greater mean CDE (77.73 ± 80.11) than eyes that did not develop glaucoma (49.21 ± 38.93). Eyes that remained visual at the LFU examination had a significantly lower mean CDE (48.31 ± 37.14) than eyes that were blind at LFU (82.05 ± 82.73). Significantly lower mean CDEs were found in diabetic eyes, younger eyes, early-operated eyes (<1 month duration), and eyes with preoperative lens-induced uveitis. CONCLUSIONS: Higher CDE may be associated with an increased risk of postoperative glaucoma and loss of vision in dogs. Cumulative dissipated energy may be a useful prognostic indicator for success of canine cataract surgery.

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

PURPOSE: To determine factors impacting cumulative dissipated energy (CDE) and postoperative best-corrected visual acuity (BCVA) in phacoemulsification. DESIGN: Review of 1102 cases at University of California, San Francisco (UCSF) and at Zhongshan Ophthalmic Center (ZOC), China. SUBJECTS: Patients who underwent cataract surgery at UCSF 03/2014-03/2019 and at ZOC 10/2018-05/2019. METHODS: Patient demographics, medical history, routine ocular examination, and surgical information, including disassembly method, complications, and surgeon training level were recorded. Univariable and multivariable regression models were used to determine factors associated with CDE and good postoperative BCVA (20/40 or better) at 1 month. OUTCOME MEASURES: CDE, postoperative BCVA. RESULTS: In multivariable analysis, patient age at time of surgery, diabetes, degree of nuclear sclerosis (NS), white-to-white corneal diameter, disassembly method, preoperative BCVA, surgeon training level, and surgical center were significantly associated with CDE. Log10CDE increased by 0.20-0.31 for patient age ≥ 70 years, by 0.07 if the patient had diabetes, by 0.12-0.41 for NS grade ≥ 2, by 0.48 per 10 mm increase in white-to-white corneal diameter, by 0.34-0.47 for disassembly method other than non-stop chop, by 0.16 per unit increase in preoperative logMAR BCVA, and by > 0.09 when phacoemulsification was performed by residents early in their training. Log10CDE was 0.33 higher at UCSF than ZOC. In multivariable analysis, worse baseline visual acuity and age above 90 years at time of surgery decreased the odds of good BCVA (OR = 0.26 per unit increase in preoperative logMAR BCVA; OR = 0.12 for age > 90); comorbid retinal issues decreased the odds of good postoperative BCVA (OR = 0.13-0.39); greater anterior chamber depth (ACD) or shorter axial length (AL), increased the odds of good postoperative outcome (OR = 2.64 per 1 mm increase ACD, OR = 0.84 per 1 mm increase AL). CONCLUSIONS: Cataract grade determined by slit lamp exam and, for the first time, older patient age, were noted to be important predictors of high CDE. CDE was not a risk factor for postoperative BCVA measured at postoperative 1 month. When surgery was performed by trainees under supervision, lower training level was associated with higher CDE, but not with worse postoperative BCVA.

Investigation on Fatigue Performance of Asphalt Mixture Reinforced by Basalt Fiber.

Basalt fiber has been widely used in asphalt mixture due to its excellent mechanical properties and good combination with asphalt. In order to systematically evaluate the enhancement effect of basalt fiber on the fatigue performance of the mixtures, gradations of Stone Mastic Asphalt and Superpave with different nominal maximum aggregate sizes, namely SMA-13, SUP-20 and SUP-25, were prepared, and a four-point bending beam fatigue test was adopted under the strain control mode. The fatigue damage mode was assessed based on the phenomenology theory, energy dissipation theory and change rate of dissipated energy. The results showed that basalt fiber could well increase the fatigue life of the mixtures. Basalt fiber could also increase the cumulative dissipated energy of the mixtures, and it was linearly correlated with the fatigue life in double logarithmic coordinates. In the meantime, adding basalt fiber could increase the change rate of dissipated energy of the mixtures. Furthermore, it is not appropriate to take the stiffness modulus declined to 50% of the original as the fatigue failure criterion of the mixture; this paper suggested that it is reasonable when the stiffness modulus was 15-25% that of the initial. These findings provide a theoretical basis for exploring the fatigue failure of asphalt pavements.

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

PURPOSE: To compare the effects of femtosecond laser assisted cataract surgery (FLACS) and manual phacoemulsification on cumulative dissipated energy (CDE), torsional amplitude, and endothelial cell density (ECD). PATIENTS AND METHODS: This prospective, randomized study was conducted at Oka Eye Clinic (Fukuoka, Japan). Surgeries were performed using FLACS (with LenSx) or conventional technique in adults ≥20 years with grade 2-4 cataracts. Visits included preoperative, surgery day, and 5 postoperative visits (days 1, 4-10, 20-40, 60-120, and 150-210). Primary endpoint was CDE. Secondary endpoints included ECD percent change at day 150-210 versus preoperative visit and average torsional amplitude on surgery day. Exploratory endpoints included central corneal thickness and corrected distance visual acuity (CDVA). Superiority of FLACS to conventional technique was evaluated using t-tests based on a mixed model for repeated measures. RESULTS: Full analysis set included 53 eyes per group. Mean cataract grade was 2.92±0.58 in FLACS and 2.94±0.57 in conventional group. FLACS versus conventional method had significantly lower mean CDE (0.213±0.334 versus 1.718±0.898%-seconds, respectively; P<0.0001), demonstrating superiority of FLACS. Low endothelial cell loss (ECL) was achieved with both FLACS and conventional methods (1.5±5.6% and 2.7±5.2%; P=0.260). Torsional amplitude was significantly lower for FLACS versus conventional method (19.6±16.0% versus 31.1±6.6%; P<0.0001). Central corneal thickness was comparable for both methods at all visits except day 1; CDVA was comparable for both methods at all postoperative visits. CONCLUSION: FLACS achieved significantly lower CDE compared with the conventional surgical method (P<0.0001). Low ECL was achieved with both FLACS (1.5%) and conventional (2.7%) methods.

OUR EXPERIENCE WITH ACTIVE SENTRY AND CENTURION OZIL HANDPIECES.

AIM: To compare parameters of phacoemulsification using handpiece Active Sentry and Centurion Ozil. METHODS: We have evaluated results of 200 eyes of 129 patients that were operated for cataract at the Department of Ophthalmology. All surgeries were performed by one surgeon (NJ). In 100 eyes handpiece Active Sentry was used and in 100 eyes handpiece Centurion Ozil was used. The intraocular pressure during surgery (IOP), cumulative dissipated energy (CDE), ultrasound time (U/S time) and estimated consumption of balanced salt solution (BSS) were evaluated. RESULTS: Using handpiece Ozil Centurion the IOP was 65 mmHg, use handpiece Active Sentry enabled decrease safely peroperative IOP to 46 mm Hg withouth increase of fluctuation or declension of stability of the anterior chamber. The mean CDE a U/S time were significantly statistically decreased using Active Sentry versus Centurion Ozil handpieces. Difference in estimated consumption of balanced salt solution was not statistically significant. CONCLUSION: Our results proved that using handpiece Active Sentry enabled statistically significantly decrease IOP during phacoemulsification and eliminated post-occlusion surge. This brings several advantages: more painless surgery for patients and more user-friendly procedure for surgeon especially in challenging cases (intraoperative floppy iris syndrome or severe myopia).

Impact of lens density and lens thickness on cumulative dissipated energy in femtosecond laser-assisted cataract surgery.

To evaluate the required cumulative dissipated energy (CDE) to fragment the crystalline lens in femtosecond laser-assisted cataract surgery (FLACS) in relation to lens density and lens thickness. Consecutive eyes that underwent FLACS between September 2014 and March 2017 by a single surgeon using in all cases the same femtosecond laser and phacoemulsification platform were included in our retrospective study. Prior to surgery, corrected distance visual acuity (CDVA), optical biometry corneal, and crystalline lens tomographies were performed to assess anterior chamber depth (ACD), axial length (AL), and crystalline lens parameters (i.e., lens density, thickness, and nucleus staging (NS)). After surgery, CDE was calculated and analyzed in relation to lens density (LD) and lens thickness (LT). Zero ultrasound expenditure cases were recorded and their occurrence analyzed. The chart review identified 236 eyes of 200 patients, 98 males and 102 females aged 65± 15 years which were included in the study. Mean LD was 11.26 ± 2.05 pixel intensity units (range 7.30-18.80), and the mean LT was 3417 ± 405.17 µm (range 2545-4701). LD and LT correlated moderately (r = 0.50, p < 0.001) and weakly (r = 0.23, p < 0.001), with post-laser CDE. Higher LD and LT were also associated with lower rates of zero phaco (eyes in which no phacoemulsification energy was necessary). Furthermore, NS (r = 0.528, p < 0.001) and CDVA (r = - 0.3524, p < 0.001) also correlated with CDE. Higher LD, LT, NS values, and low CDVA are associated with higher ultrasound expenditure (CDE-cumulative dissipated energy) and with lower rates of zero ultrasound expenditure during FLACS.

Comparison of two popular nuclear disassembly techniques for cataract surgeons in training: divide and conquer versus stop and chop.

PURPOSE: To compare two common phacoemulsification techniques in the learning curve phase, and their effect on ultrasound energy dissipation. METHODS: One hundred and ten consecutive patients scheduled for cataract surgery with the same surgeon in training were prospectively enrolled. Study was divided in two parts. In the first one, 60 patients were stratified for cataract grade [nuclear opalescence (NO) grade 2-4] and divided in two groups receiving surgery with the divide-and-conquer technique (Group-1) and with the stop-and-chop technique (Group-2). In the second part, 50 patients were stratified according to cataract grade (NO2-6), and the surgeon had to choose one of the two techniques according to personal preference. The primary outcome was the cumulative dissipated energy (CDE). RESULTS: Significant differences of CDE were observed between the NO3 and NO4 cataracts in Group-1. In Group-2, this difference was not significant, suggesting that with more advanced cataracts, the stop-and-chop technique allows less ultrasound use. In the second part of the study, the stop and chop was most frequently used for more advanced cataracts. When considering harder cataracts (NO5-NO6), patients receiving surgery with the divide-and-conquer technique had higher CDE values compared to stop and chop. CONCLUSIONS: Both divide-and-conquer and stop-and-chop techniques are efficient in the learning curve. Stop and chop dissipates less energy in harder nuclei. Once surgeons reach sufficient experience with both techniques, they should switch to a stop-and-chop technique, allowing lower levels of ultrasound energy.

Comparison of clinical outcomes between femtosecond laser-assisted versus conventional phacoemulsification.

BACKGROUND: To compare femtosecond laser-assisted versus conventional phacoemulsification in terms of visual and refractive outcomes, cumulative dissipated energy, anterior chamber inflammation and endothelial cell loss. METHODS: In this retrospective cohort study, records of eyes that underwent femtosecond laser-assisted cataract surgery (FLACS) or conventional phacoemulsification (CP) were reviewed. The Victus femtosecond laser (Bausch and Lomb, Germany) was used to carry out corneal incisions, anterior capsulotomy, and lens fragmentation in FLACS procedures. Manifest refraction spherical equivalence (MRSE), uncorrected distance visual acuity (UDVA), corrected distance visual acuity (CDVA), cumulative dissipated energy (CDE), postoperative cells and flare and endothelial cell count data were collected. Subgroup analysis of the visual acuity tests was performed based on the type of intraocular lens implanted (monofocal, monofocal toric, multifocal, multifocal toric, accommodating). RESULTS: A total of 735 eyes were included in the study (296 eyes for the FLACS group and 439 eyes for the CP group). At one year follow-up, 120 eyes comprised the FLACS group and 265 eyes for the CP group. MRSE in the FLACS group was - 0.16 ± 0.58 D and - 0.20 ± 0.52 D in the CP group (P = 0.50). UDVA in the FLACS group was 20/25 (mean logMAR 0.12 ± 0.13) and 20/25 (mean logMAR 0.11 ± 0.13) in the CP group (P = 0.48). CDVA was 20/20 (mean logMAR 0.03 ± 0.07) in the FLACS group and 20/20 (mean logMAR 0.02 ± 0.06) in the CP group (P = 0.15). No statistically significant trend was seen for FLACS versus CP by intraocular type for visual acuity. CDE for the different cataract grades ranged from 6.97 ± 5.74 to 29.02 ± 16.07 in the FLACS group and 7.59 ± 6.42 to 35.69 ± 18.30 in the CP group. The FLACS group was significantly lower for post-operative central corneal edema (P = 0.05), cells and flare (P = 0.01), and endothelial cell loss (P = 0.04). CONCLUSIONS: Femtosecond laser-assisted cataract surgery and conventional phacoemulsification had similar refractive and visual outcomes. Phacoemulsification energy, anterior chamber inflammation and corneal endothelial cell loss were less in the femtosecond laser group.

Comparison of cumulative dissipated energy delivered by active-fluidic pressure control phacoemulsification system versus gravity-fluidics.

PURPOSE: To compare the cumulative dissipated energy (CDE), aspiration time and estimated aspiration fluid utilized during phacoemulsification cataract surgery using two phacoemulsification systems . METHODS: A total of 164 consecutive eyes of 164 patients undergoing cataract surgery, 82 in the active-fluidics group and 82 in the gravity-fluidics group were enrolled in this study. Cataracts graded NII to NIII using LOCS II were included. Each subject was randomly assigned to one of the two platforms with a specific configuration: the active-fluidics Centurion ® phacoemulsification system or the gravity-fluidics Infiniti ® Vision System. CDE, aspiration time (AT) and the mean estimated aspiration fluid (EAF) were registered and compared. RESULTS: A mean age of 68.3 ± 9.8 years was found (range 57-92 years), and no significant difference was evident between both groups. A positive correlation between the CDE values obtained by both platforms was verified (r = 0.271, R 2 = 0.073, P = 0.013). Similarly, a significant correlation was evidenced for the EAF (r = 0.334, R 2 = 0.112, P = 0.046) and AT values (r = 0.156, R 2 = 0.024, P = 0.161). A statistically significantly lower CDE count, aspiration time and estimated fluid were obtained using the active-fluidics configuration when compared to the gravity-fluidics configuration by 19.29, 12.10 and 9.29%, respectively (P = 0.001, P < 0.0001 and P = 0.001). CONCLUSIONS: The active-fluidics Centurion ® phacoemulsification system achieved higher surgical efficiency than the gravity-fluidics Infiniti ® IP system for NII and NIII cataracts.

Effect of IOP based infusion system with and without balanced phaco tip on cumulative dissipated energy and estimated fluid usage in comparison to gravity fed infusion in torsional phacoemulsification.

BACKGROUND: To evaluate the effect of three different combinations of tip designs and infusion systems in torsional phacoemulsification (INFINITI and CENTURION) in patients with cataract. According to the manufacturer, two unique improvements in the Centurion are: active fluid dynamic management system and use of an intrepid balanced tip. The study specifically aimed to evaluate the beneficial effects, if any, of change in tip design and infusion system individually and in combination on both per-operative parameters as well as endothelial health over 6 months. METHODS: One hundred and twenty six consenting patients of grade 4.0-6.9 senile cataract were randomized into three groups for phacoemulsification: Group A (n = 42): Gravity fed infusion system and 450 Kelman miniflared ABS phaco tip; Group B (n = 42): intraocular pressure (IOP) based infusion system and 450 Kelman miniflared ABS phaco tip; Group C (n = 42): IOP based infusion system and 450 Intrepid balanced phaco tip. The cumulative dissipated energy (CDE), estimated fluid usage (EFU) and total aspiration time (TAT) were compared peroperatively. The endothelial parameters were followed up postoperatively for six months. RESULTS: The three arms were matched for age (p = 0.525), gender (p = 0.96) and grade of cataract (p = 0.177). Group C was associated with significant reductions in CDE (p = 0.001), EFU (p < 0.0005) as well as TAT (p = 0.001) in comparison to the other groups. All three groups had comparable baseline endothelial cell density (p = 0.876) and central corneal thickness (p = 0.561). On post-operative evaluation, although all groups were comparable till 3 months, by 6 months, the percentage losses in endothelial cell density were significantly lower in group C as compared to the other groups. CONCLUSIONS: Use of an IOP based phacoemulsification system in association with use of the Intrepid balanced tip reduces the CDE, EFU and TAT in comparison to a gravity fed system with a mini flared tip or IOP based system with a mini flared tip while also providing better endothelial preservation thus favouring the use of an IOP fed system with a balanced tip. TRIAL REGISTRATION: Trial registration No.: CTRI/2016/06/007022.

Combined 30-degree bevel up and down technique against 0-degree phaco tip for phacoemulsification surgery of hard cataracts.

PURPOSE: To evaluate the effective phaco time (EPT), cumulative dissipated energy (CDE) and nucleus emulsification time (NET) as phaco parameters with 0- and 30-degree phaco tip. PATIENTS AND METHODS: This prospective, interventional and observational case series included 294 patients scheduled for cataract removal by phacoemulsification technique. Patients with nuclear cataracts of grade 4 and 5 nuclear opalescence of Lens Opacities Classification System III were included in the study. Patients were consecutively allocated to phaco chop technique with 0-degree (0-degree group, n=147) and combined bevel up and down position using 30-degree phaco tip (combined bevel up/down group, n=147). The 0-degree group had phacoemulsification with 0-degree phaco tip, while the 30-degree group had chopping of the nucleus with bevel down phaco tip and emulsification of nuclear fragments was accomplished with bevel up tip. EPT, CDE, NET and intraoperative complications were noted and compared between the groups using analysis of variance. RESULTS: Average EPT, CDE and NET were lower in the 30-degree group than in the 0-degree group. However, no statistically significant difference was found in EPT (P=0.0733), CDE (P=0.0663) and NET (P=0.0633) between the two groups. No serious intraoperative complications were noted. The anterior chamber was maintained throughout the procedure in both groups. No patients had wound burn and miosis during the procedure. None of the patients developed bullous keratopathy, uveitis and cystoid macular edema during the follow-up period. CONCLUSION: Combined bevel up and down 30-degree tip can yield effective hard nucleus phacoemulsification. Bevel down tip of 30-degree helps in effective chopping and bevel up tip assists in emulsification of the nuclear fragments. Although combined bevel up and down 30-degree tip can yield effective hard nucleus phacoemulsification, no statistically significant difference was found in EPT, CDE and NET between the two groups.

Comparison between Active and Gravity-based Phacoemulsification Fluidics Systems in Immediate Sequential Bilateral Cataract Surgery

PURPOSE: To compare the clinical outcomes during phacoemulsification when using active fluidics (Centurion®) and gravity-based fluidics (Infiniti®) in immediate sequential bilateral cataract surgery. METHODS: From January 2015 to September 2015, 68 eyes of 34 patients with bilateral cataract were assigned to receive immediate sequential bilateral cataract surgery by Centurion® in one eye and Infiniti® in the other eye. We measured and compared intraoperative factors, including cumulative dissipated energy (CDE), ultrasound time, mean amount of balanced salt solution (BSS) used, and pain using a scale. Best corrected visual acuity (BCVA), central corneal thickness (CCT), and endothelial cell density (ECD) were also evaluated preoperatively and 1 month postoperatively. RESULTS: Intraoperative measurements showed significantly less CDE (5.05 ± 2.18 vs. 7.05 ± 3.82), ultrasound time (24.65 ± 9.68 vs. 34.95 ± 17.95 seconds), and mean amount of BSS used (37.06 ± 10.25 vs. 44.88 ± 16.38 mL) in the Centurion® group than in the Infiniti® group (p = 0.011, p = 0.005, p = 0.021, respectively). The intraoperative pain scale was 0.26 ± 0.51 in the Centurion® group and 0.50 ± 0.71 in the Infiniti® group, and was not significantly different (p = 0.121). BCVA, increase of CCT and decrease of ECD were not significantly different between the two groups at 1 month postoperatively. CONCLUSIONS: The efficacy of phacoemulsification in the Centurion® group was superior to that in the Infiniti® group. The level of intraoperative pain and clinical outcomes 1 month after surgery were not significantly different between the two groups.

A comparison of pop and chop to divide and conquer in resident cataract surgery.

In this randomized prospective study, the cumulative dissipated energy and case time of pop and chop and of traditional four-quadrant divide and conquer in the first 60 cases (in total 120 eyes) of cataract surgery performed by two residents at the Veterans Administration Hospital in Hampton, Virginia, were compared. Overall and individually, the residents had significantly shorter case times and used significantly less cumulative dissipated energy for performing pop and chop than that for divide and conquer technique. There was no difference in complication rates or visual outcomes between these two techniques. The results of this study suggest that pop and chop is a more time- and energy-efficient method of nucleofractis than divide and conquer for novice resident surgeons.