Comparison of torsional and longitudinal modes using phacoemulsification parameters
TL;DR: Torsional phacoemulsification was more effective than longitudinal phacoEmulsification in the amount of applied fluid and the quantity of US energy expended and with the torsional method, it was possible to maintain a constant ratio of amount of fluid flow to quantity ofUS energy used, regardless of nucleus density.
Abstract: Purpose To compare phacoemulsification parameters of torsional and longitudinal ultrasound modes. Setting Ophthalmology Department, Military Health Service Institute, Warsaw, Poland. Methods This prospective study evaluated eyes 1, 7, and 30 days after phacoemulsification with an Infiniti Vision System using the torsional or longitudinal ultrasound (US) mode. Cataract classification was according to the Lens Opacities Classification System II. Nucleus fragmentation was by the phaco-chop and quick-chop methods. Primary outcome measures were phaco time, mean phaco power, mean torsional amplitude, and aspiration time. Total energy, defined as cumulative dissipated energy (CDE) × aspiration time, and the effective coefficient, defined as aspiration time/phaco time, were also calculated. Results Four hundred eyes were evaluated. The CDE was statistically significantly lower in the torsional mode for nucleus grades I, II, and III (P .05). Aspiration time was statistically significantly shorter in the torsional mode than in the longitudinal mode for nucleus grades III and IV (P Conclusions Torsional phacoemulsification was more effective than longitudinal phacoemulsification in the amount of applied fluid and the quantity of US energy expended. With the torsional method, it was possible to maintain a constant ratio of amount of fluid flow to quantity of US energy used, regardless of nucleus density.
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TL;DR: The torsional mode was as safe as the longitudinal mode in phacoemulsification for age‐related cataract as well as conventional longitudinal mode, according to Conference on Harmonisation‐E9 Guidelines.
Abstract: Purpose To compare the intraoperative and postoperative outcomes of conventional longitudinal phacoemulsification and torsional phacoemulsification. Setting Department of Ophthalmology, University of Leipzig, Germany. Design Randomized single-center clinical trial. Methods Eyes with senile cataract were randomized to have phacoemulsification using the Infiniti Vision System and the torsional mode (OZil) or conventional longitudinal mode. Primary outcomes were corrected distance visual acuity (CDVA) and central endothelial cell density (ECD), calculated according to the Conference on Harmonisation-E9 Guidelines in which missing values were substituted by the median in each group (primary analysis) and the loss was then calculated using actual data (secondary analysis). Secondary outcomes were ultrasound (US) time, cumulative dissipated energy (CDE), and percentage total equivalent power in position 3. Postoperative follow-up was at 3 months. Results The mean preoperative CDVA was 0.41 logMAR in the torsional group and 0.38 logMAR in the longitudinal group, improving to 0.07 logMAR postoperatively in both groups. The mean ECD loss was 7.2% ± 4.6% in the torsional group (72 patients) and 7.1% ± 4.4% in the longitudinal group (76 patients), with no statistically significant differences in the primary analysis (P = .342) or secondary analysis (P = .906). The mean US time, CDE, and percentage total equivalent power in position 3 were statistically significantly lower in the torsional group (98 patients) than in the longitudinal group (94 patients) (P Conclusion The torsional mode was as safe as the longitudinal mode in phacoemulsification for age-related cataract. Financial Disclosure No author has a financial or proprietary interest in any material or method mentioned.
59 citations
TL;DR: Objective comparison of phacoemulsification efficiency and chatter found that optimized Ozil‐IP and Ellips‐FX were similar in both parameters and in general, both performed better than preceding technology.
Abstract: Purpose To compare efficiency and chatter of Infiniti Ozil with and without Intelligent Phacoemulsification (IP) and the Signature Ellips with and without FX. Setting John A. Moran Eye Center, University of Utah, Salt Lake City, Utah, USA. Design Experimental study. Methods Brunescent 2.0 mm human lens cubes were created by an instrument devised for this study. Cubes were tested (10 per test) for time of particle removal (efficiency) and for the number of times the lens particle bounced off the tip (chatter) at 300 mm Hg and 550 mm Hg, 50% and 100% power, and 50% and 100% amplitudes (amplitude for Ozil only). Results Of the ultrasound settings, efficiency varied from a mean of 3.3 seconds ± 1.4 (SD) to 50.4 ± 11.7 seconds and chatter from 0.0 to 52.0 ± 16.7 bounces per run. The Ozil-IP was generally more efficient than the Ozil and the Ellips FX more efficient than the Ellips. At optimized values, the Ozil-IP and Ellips-FX were similar. In general, efficiency and chatter were better at 550 mm Hg and at 50% power. The amplitude effect was complex. Efficiency closely correlated with chatter (Pearson r2 = .31, P Conclusions Objective comparison of phacoemulsification efficiency and chatter found that optimized Ozil-IP and Ellips-FX were similar in both parameters and in general, both performed better than preceding technology. The study parameters can significantly affect efficiency and chatter, which strongly correlate with each other. Financial Disclosure Dr. Olson has been a consultant to Abbott Medical Optics, Inc., Becton, Dickinson and Co., and Allergan, Inc., and has received grant support from Abbott Medical Optics, Inc., and Allergan, Inc. No author has a financial or proprietary interest in any material or method mentioned.
56 citations
TL;DR: The torsional machine outperformed the transversal and longitudinal machines, with a lower mean needle time, less chatter, and improved followability, which corresponded to less corneal edema 1 day postoperatively and better visual acuity.
Abstract: Purpose To compare the intraoperative performance and postoperative outcomes of 3 phacoemulsification machines that use different modes. Setting Kensington Eye Institute, Toronto, Ontario, Canada. Design Comparative case series. Methods This chart and video review comprised consecutive eligible patients who had phacoemulsification by the same surgeon using a Whitestar Signature Ellips-FX (transversal), Infiniti-Ozil-IP (torsional), or Stellaris (longitudinal) machine. Results The review included 98 patients. Baseline characteristics in the groups were similar; the mean nuclear sclerosis grade was 2.0 ± 0.8. There were no significant intraoperative complications. The torsional machine averaged less phacoemulsification needle time (83 ± 33 seconds) than the transversal (99 ± 40 seconds; P=.21) or longitudinal (110 ± 45 seconds; P=.02) machines; the difference was accentuated in cases with high-grade nuclear sclerosis. The torsional machine had less chatter and better followability than the transversal or longitudinal machines (P Conclusions All 3 phacoemulsification machines were effective with no significant intraoperative complications. The torsional machine outperformed the transversal and longitudinal machines, with a lower mean needle time, less chatter, and improved followability. This corresponded to less corneal edema 1 day postoperatively and better visual acuity. Financial Disclosure Dr. Braga-Mele was a consultant to Abbott Medical Optics, Alcon Laboratories, Bausch & Lomb, and Allergan at the time the study was performed. Neither author has a financial or proprietary interest in any material or method mentioned.
51 citations
Cites result from "Comparison of torsional and longitu..."
...The mechanism by which torsional ultrasound is more efficient than longitudinal ultrasound is thought to be decreased chatter and improved followability because the needle tip does not longitudinally push lens fragments away.(8,13) This is supported by our findings that the torsional machine had significantly less chatter and followability than the transversal and longitudinal machines (all comparisons P!....
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TL;DR: The Centurion phacoemulsification system required less energy to remove a cataractous lens with an adjusted average energy reduction of 38% across all surgeons in comparison to the Infiniti phaco Emulsification System.
Abstract: PURPOSE To compare cumulative dissipated energy between two phacoemulsification machines. SETTING An ambulatory surgical center, Honolulu, Hawaii, USA. DESIGN Retrospective chart review. METHODS A total of 2,077 consecutive cases of cataract extraction by phacoemulsification performed by five surgeons from November 2012 to November 2014 were included in the study; 1,021 consecutive cases were performed using the Infiniti Vision System, followed by 1,056 consecutive cases performed using the Centurion Vision System. RESULTS The Centurion phacoemulsification system required less energy to remove a cataractous lens with an adjusted average energy reduction of 38% (5.09 percent-seconds) (P<0.001) across all surgeons in comparison to the Infiniti phacoemulsification system. The reduction in cumulative dissipated energy was statistically significant for each surgeon, with a range of 29%-45% (2.25-12.54 percent-seconds) (P=0.005-<0.001). Cumulative dissipated energy for both the Infiniti and Centurion systems varied directly with patient age, increasing an average of 2.38 percent-seconds/10 years. CONCLUSION The Centurion phacoemulsification system required less energy to remove a cataractous lens in comparison to the Infiniti phacoemulsification system.
41 citations
Cites background from "Comparison of torsional and longitu..."
...fluidic dynamic energy, which can also have a pronounced negative effect on ocular structures.(13) The Centurion system uses an active fluid dynamic management system that applies pressure directly to the irrigation bag....
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TL;DR: Both of these machines were efficient, with similar endothelial cell loss related to the increased nuclear sclerosis grade and increased phacoemulsification power.
Abstract: AIM To compare and evaluate the phacoemulsification parameters and postoperative endothelial cell changes of two different phacoemulsification machines, each with different modes, but also to assess the relationship between postoperative endothelial cell loss and the phacoemulsification parameters, as well as the other factors in both groups. METHODS This prospective observational study was comprised of consecutive eligible cataract patients operated with phacoemulsification technique performed by the same surgeon using either a WHITESTAR Signature Ellips FX (transversal, group 1) or Infiniti OZil IP (torsional, group 2) machine. RESULTS The study included 86 patients. Baseline characteristics in the groups were similar. The median nuclear sclerosis grade was 3 (2-4) in the first group and 2 (2-4) in the second group (P=0.265). Both groups had similar phacoemulsification needle times (group 1: 60.63±36 s; group 2: 55.98±30 s; P=0.789). The percentage of endothelial cell loss 30d after surgery ranged from 3% to 15% with a median of 7% in group 1, and from 2% to 13% with a median of 6% in group 2; however, there was no statistically significant difference between the groups (P=0.407). Hexagonality (P=0.794) and the coefficient of variation (CV; P=0.142) did not differ significantly between the groups before and 30d after surgery. A significant positive correlation was found between the endothelial cell loss and nuclear sclerosis grade (group 1: P<0.001; group 2: P<0.001) and between the endothelial cell loss and average phacoemulsification power (group 1: P=0.007; group 2: P=0.008). CONCLUSION Both of these machines were efficient, with similar endothelial cell loss. This endothelial cell loss was related to the increased nuclear sclerosis grade and increased phacoemulsification power.
26 citations
References
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TL;DR: Very good interobserver reproducibility of the clinical gradings at the slit lamp, excellent intraobserver reproducecibility, very good to excellent interob server reproducible of photographic gradings, and good agreement between clinical and photographic grading are obtained.
Abstract: The Lens Opacities Classification System, version II (LOCS II), uses a set of colored slit-lamp and retroillumination transparencies to grade different degrees of nuclear, cortical, and subcapsular cataract. The system uses four nuclear standards for grading nuclear opalescence and color, five cortical standards, and four subcapsular standards. The LOCS II can be used to grade patients' cataracts at the slit lamp or to grade slit-lamp and retroillumination photographs; it is easy to learn and can be applied consistently by different observers. We obtained very good interobserver reproducibility of the clinical gradings at the slit lamp, excellent intraobserver reproducibility, very good to excellent interobserver reproducibility of photographic gradings, and good agreement between clinical and photographic gradings. The LOCS II is potentially useful for both cross-sectional and longitudinal studies of cataract.
559 citations
"Comparison of torsional and longitu..." refers methods in this paper
...Cataract classification was according to the Lens Opacities Classification System II....
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...The indication for surgical treatment was diagnosis of cataract (NO1NC1 to NO6NC6) according to the Lens Opacities Classification System II (LOCS II).(10) Exclusion criteria included chronic retinal or corneal disease, optic nerve disease, neuropathy, age-related macular degeneration, and uncontrolled glaucoma....
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...A high rate of flow through the anterior chamber seems to be necessary for maximum followability, which shortens the duration of the surgery in eyes with nucleus grade I or II....
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TL;DR: The location of corneoscleral incisions for phacoemulsification can be chosen according to the preoperative astigmatism without inducing additional adverse effects on the corneal endothelium.
Abstract: Purpose To evaluate the effect of the location of the corneoscleral tunnel incision as well as preoperative and intraoperative parameters on total and localized endothelial cell loss Setting Department of Ophthalmology, Humboldt-University of Berlin, Berlin, Germany Methods Fifty consecutive patients scheduled for routine cataract surgery were selected prospectively for this clinical trial Preoperatively, the axial length, anterior chamber depth, lens thickness, and astigmatism were measured Phacoemulsification time and relative energy as well as total surgical time were recorded With a specular microscope, endothelial cell counts were determined centrally, superiorly, and temporally preoperatively and 6 weeks and 6 and 12 months postoperatively Results After 12 months, the mean overall central endothelial cell loss in all eyes was 85% The mean endothelial cell loss was 119% in the lateral quadrant and 114% in the superior quadrant There were no significant differences between superior and temporal surgical approaches in intraoperative parameters of phacoemulsification time, relative intensity of phacoemulsification, and surgical time There were no significant differences in central endothelial cell loss or in the area localized in the quadrant of the positions of the corneal surgical site The only risk factors found significant for higher endothelial cell loss were shorter axial length and longer phacoemulsification time Conclusions The location of corneoscleral incisions for phacoemulsification can be chosen according to the preoperative astigmatism without inducing additional adverse effects on the corneal endothelium Shorter eyes have a significantly higher risk for greater endothelial cell loss
313 citations
"Comparison of torsional and longitu..." refers background in this paper
...Assessing postoperative changes in corneal curvature as well as endothelial cell dysfunction and decreases in endothelial cell density can indicate the quality of the surgery performed.(2,3) Cataract surgery generally aims to effectively introduce ultrasound (US) energy into the eye while eliminating or limiting its negative influence on tissue other than the lens....
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TL;DR: The torsional mode may provide more effective lens removal with a lower level of phacoemulsification time and energy.
Abstract: Purpose To compare the intraoperative and short-term postoperative outcomes of cataract surgery performed with torsional mode and conventional ultrasound mode using the Infiniti Vision System (Alcon Laboratories). Setting Cataract Service, Zhongshan Ophthalmic Center, Sun-Yat-Sen University, Guangzhou, China. Methods In this randomized comparative study, 525 eyes were assigned to phacoemulsification by torsional mode or conventional ultrasound (US) mode. The surgery was performed by an experienced surgeon, and the outcomes were evaluated by an examiner who was masked to treatment assignments. Primary outcome measures were US time (UST), cumulative dissipated energy (CDE), and surgical complications. Patients were seen 1, 7, and 30 days after surgery. Postoperative outcome measures were the final best corrected visual acuity (BCVA) and the change in corneal clarity, central corneal thickness (CCT), and endothelial cell count. Results The US group had 262 eyes and the torsional group, 263 eyes. All patients completed the follow-up visits. In the eyes with nucleus density grades of 1, 2, 3, and 4, the mean UST was 10.25 seconds ± 7.4 (SD), 25.14 ± 5.5 seconds, 36.45 ± 8.3 seconds, and 61.44 ± 17.8, respectively, in the US group and 8.32 ± 6.8 seconds, 18.45 ± 7.2 seconds, 29.48 ± 12.4 seconds, and 48.39 ± 20.3 seconds, respectively, in the torsional group ( P P P P >.01). At 1 day and 7 days, the mean CCT was 625 ± 80 μm and 568 ± 37 μm, respectively, in the US group and 601 ± 35 μm and 559 ± 40 μm, respectively, in the torsional group ( P P >.01). At 7 days and 30 days, the mean central corneal endothelial cell count was 2135 ± 858 cells/mm 2 and 2084 ± 527 cells/mm 2 , respectively, in the US group and 2004 ± 656 cells/mm 2 and 1953 ± 615 cells/mm 2 , respectively, in the torsional group ( P Conclusion The torsional mode may provide more effective lens removal with a lower level of phacoemulsification time and energy.
174 citations
"Comparison of torsional and longitu..." refers background or methods or result in this paper
...which is manipulation in the anterior chamber with an auxiliary instrument, is used primarily for chopping and breaking the lens nucleus, particularly in the phaco-chop technique, and this appears to have only a minor negative effect on endothelial cells.(7) Ultrasound and fluid dynamic energy, on the other hand, have a significantly more pronounced negative effect on ocular structures....
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...In the course of phacoemulsification, energy is delivered to the eye in 3 forms: mechanical, US, and fluid dynamics.(7) Mechanical energy, the source of...
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...Liu et al.7 also observed a continuous increase in CDE with increasing nuclear density....
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...Liu et al.(7) also observed a continuous increase in CDE with increasing nuclear density....
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...The amount of US energy supplied to the eye depends on surgeon experience and the nucleus density of the lens to be removed.(7,11,16,22) In our study, as nucleus density increased, the differences in CDE values between the torsional mode and longitudinal mode Table 5....
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TL;DR: Continual advances in phacoemulsification technology and adjunctive surgical devices allow cataract surgery to be performed more safely and efficiently.
Abstract: Purpose of review Familiarization with each of the manufacturers' latest machines and upgrades assists in understanding the advances made in phacoemulsification technology. Recent findings Improvements in the delivery of energy through power modulations, alternative and adjunctive energy sources, and advanced fluidics allow the safe use of bimanual microincision techniques for lens extraction. Summary Continual advances in phacoemulsification technology and adjunctive surgical devices allow cataract surgery to be performed more safely and efficiently.
95 citations
TL;DR: It is concluded that phacoemulsification most likely operates by a combination of mechanisms, including direct action of the vibrating tip against tissue and indirect cavitational effects.
Abstract: Despite its unparalleled success in the field of surgery, the precise mechanism of ultrasonic phacoemulsification cataract extraction remains controversial. We review the relevant peer-reviewed literature on the subject of power generation and tip-tissue interactions to clarify the current status of our knowledge. We conclude that phacoemulsification most likely operates by a combination of mechanisms, including direct action of the vibrating tip against tissue and indirect cavitational effects. Surgeons will benefit from understanding the physical principles underlying phacoemulsification because they will be better able to evaluate the performance of various parameters and different machine settings.
93 citations