Combined occlusion-triggered longitudinal and torsional phacoemulsification during coaxial microincision cataract surgery: Effect on 30-degree mini-flared tip behavior

The Effect of Cumulative Dissipated Energy on Changes in Intraocular Pressure After Uncomplicated Cataract Surgery by Phacoemulsification

PURPOSE

To investigate the association between ultrasound energy, expressed as cumulative dissipated energy (CDE), and changes in intraocular pressure (IOP) after uncomplicated cataract surgery by phacoemulsification.

METHODS

In this prospective study, nonglaucomatous subjects underwent cataract surgery by phacoemulsification. IOP was compared by clustered linear regression at 4 separate time-points: preoperative, 1 day, 1 month, and 3 months after cataract surgery. Changes in the IOP were evaluated as a function of CDE using univariate and multivariate clustered linear regression models, which adjusted for sex, ethnicity, age, axial length, spherical equivalent, mean preoperative Shaffer gonioscopy grade of all 4 quadrants, cataract grade, preoperative IOP, central corneal thickness, and use of both eyes in the same subject.

RESULTS

One hundred sixty-one eyes (89 Asian, 49 white, 12 African, and 11 Hispanic) from 116 nonglaucomatous subjects were analyzed. The 161 eyes included 81 right and 80 left eyes. The 89 Asian eyes included 46 Chinese, 35 Filipino, and 8 Vietnamese. Preoperative IOP was 14.9±3.2 mm Hg. Postoperative IOP significantly increased to 16.0±4.9 mm Hg at 1 day (P=0.037) and decreased to 12.4±3.1 and 12.3±3.0 mm Hg at 1 and 3 months, respectively (both P<0.0001). IOP changes at 1 day, 1 month, and 3 months did not demonstrate significant associations with CDE measurements in either univariate or multivariate clustered linear regression analyses (all P>0.05).

CONCLUSIONS

The amount of ultrasound energy delivered to the eye during phacoemulsification, expressed as CDE, was not associated with postoperative changes in IOP.

Comparison of 45-degree Kelman and 45-degree balanced phaco tip designs in torsional microcoaxial phacoemulsification

AIM

To compare the intraoperative performance and postoperative outcome after microcoaxial torsional phacoemulsification using either a Kelman or balanced phaco tip.

METHODS

Cataracts were treated using 2.2 mm microcoaxial torsional phacoemulsification using either a 45-degree mini-flared Kelman(®) or a 45-degree Intrepid(®) Balanced phaco tip. Intraoperative measurements included total ultrasound (US) time, cumulative dissipated energy (CDE), torsional US time, and balanced salt solution (BSS) use. The central endothelial cell density (ECD) and central corneal thickness (CCT) were evaluated preoperatively and postoperatively 1, 7, and 30d after surgery using noncontact specular microscopy.

RESULTS

The 116 enrolled eyes (116 patients) were divided equally between the Kelman and balanced tip groups. Intraoperative measurements showed significantly less total US time, torsional US time, CDE, and BSS use in the balanced group than in Kelman group (P<0.05). The total US time, torsional US time, CDE, and BSS use were 17.45±14.53s, 16.63±13.97s, 6.38±5.26, and 48.21±17.21 mL in the Kelman group and 11.39 ± 9.60s, 10.90 ± 9.25s, 4.04 ± 3.42, and 41.36 ± 12.70 mL in the balanced group, respectively.

CONCLUSION

Torsional phacoemulsification performed with a balanced tip provided more effective lens removal with less total US time, torsional time, CDE, and BSS use, as well as similar changes in ECD with a Kelman tip in all cataract grades. This special designed phaco tip for torsional phacoemulsification provides an alternative phaco tip for many surgeons' preference with straight phaco tip.

Comparison of two different ultrasound methods of phacoemulsification

PURPOSE

To compare the safety and efficacy of microcoaxial phacoemulsification surgeries performed with the OZil Intelligent Phaco torsional mode (Alcon Laboratories, Inc., Fort Worth, USA) and combined torsional/longitudinal ultrasound mode using 45 degree aperture angled tips.

DESIGN

Prospective randomized clinical trial.

METHODS

setting: Maltepe University, Istanbul. patient population: Eighty eyes of 80 cataract patients were randomly assigned to 2.2 mm microcoaxial phacoemulsification using the OZil Intelligent Phaco torsional mode (Group 1) or combined torsional/longitudinal ultrasound mode (Group 2). observation procedure: Intraoperative fluid and energy usage and postoperative examinations were evaluated. main outcome measures: Ultrasound time, cumulative dissipated energy, longitudinal and torsional ultrasound amplitudes, mean operation time, mean volume of fluid used, and surgical complications.

RESULTS

Both groups included 40 eyes. Mean ultrasound time, cumulative dissipated energy, and longitudinal and torsional ultrasound amplitudes in Group 1 were 58.21±33.81 seconds, 7.74±6.23, 0.45±0.30, and 26.30±12.60%, respectively, and these parameters in Group 2 were 64.75±30.23 seconds, 12.61±6.21, 26.32±5.85, and 40.98±8.33%, respectively. Cumulative dissipated energy and longitudinal and torsional amplitudes were found to be significantly lower in Group 1 (P=.001, P<.001, P<.001). Mean volumes of fluid used in Groups 1 and 2 were 73.30±19.87 cc and 107.07±21.82 cc, respectively (P<.001).

CONCLUSION

With the aid of a 45 degree aperture angled tip, the OZil Intelligent Phaco torsional mode provided more effective lens removal than the combined torsional/longitudinal ultrasound mode, with a lower cumulative dissipated energy and volume of fluid used.

Feasibility of the New Torsional Phacoemulsification Software Phacoemulsification (Ozil IP) in Hard Cataracts

PURPOSE

To assess the feasibility of using the new torsional intelligent phacoemulsification software (Ozil IP) phacoemulsification in hard cataracts of N3+.

DESIGN

A cohort study.

METHODS

Eighty patients were recruited and randomized into 2 groups, the study group and the control group. Each group consisted of 40 eyes. Routine cataract surgeries were performed using standard torsional software (Ozil) and Ozil IP in hard cataracts of N3+. Main outcome measures included cumulative dissipated energy (CDE), amount of balanced salt solution (BSS) used, and changes in central corneal thickness (CCT).

RESULTS

The mean CDE was significantly less in the study group compared with the control group (P = 0.05). The mean time in foot pedal position 3 (FP3) for varying grades of cataract density ranged from 16.3 to 30.2 seconds in the study group and from 19.1 to 39.7 seconds in the control group, which was statistically significant (P = 0.03). The amount of BSS used was 34.19 mL in the study group and 44.05 mL in the control group. On the first postoperative day, CCT was significantly different between the study and the control group (P = 0.005).

CONCLUSIONS

The 3 parameters (CDE, FP3 and BSS amount) were found to be effective with no significant complications. The new Ozil IP required less CDE and less FP3 time with less postoperative corneal edema, and thus patients had a more rapid visual recovery.

Comparative analysis of corneal morphological changes after transversal and torsional phacoemulsification through 2.2 mm corneal incision

Purpose

This paper compares and evaluates the corneal morphological changes occurring after cataract surgery through a 2.2 mm corneal incision. We use two platforms for comparison and evaluation, transversal and torsional phacoemulsification.

Patients and methods

This study includes 139 consecutive cataractous eyes (nuclear color 2–4, according to the Lens Opacities Classification System III [LOCSIII]) of 82 patients undergoing cataract surgery through a 2.2 mm corneal incision. Two different phacoemulsification platforms were used and assigned randomly: we used the WhiteStar Signature^® system with the Ellips™ FX transversal continuous ultrasound (US) mode for group I (mean age: 65.33 ± 6.97 years), and we used the Infiniti^® system with the OZil^® Intelligent Phaco (IP) torsional US mode for group II (mean age: 64.02 ± 7.55 years). The corneal endothelium and pachymetry were evaluated preoperatively and at 1 month postoperatively. Incision size changes were also evaluated.

Results

All surgeries were uneventful. Before intraocular lens implantation, the mean incision size was 2.24 ± 0.06 mm in both groups (P = 0.75). In terms of corneal endothelial cell density, neither preoperative (I vs II: 2304.1 ± 122.5 cell/mm² vs 2315.6 ± 83.1 cell/mm², P = 0.80) nor postoperative (I vs II: 2264.1 ± 124.3 cell/mm² vs 2270.3 ± 89.9 cell/mm², P = 0.98) differences between the groups were statistically significant. The mean endothelial cell density loss was 1.7% ± 1.6% and 2.0% ± 1.4% in groups I and II, respectively. Furthermore, no significant differences between groups I and II were found preoperatively (P = 0.40) and postoperatively (P = 0.68) in central pachymetry. With surgery, the mean increase in central pachymetry was 28.1 ± 23.6 μm and 24.0 ± 24.0 μm in groups I and II, respectively (P = 0.1).

Conclusion

Ellips™ FX transversal and OZil^® IP torsional phacoemulsification modes are safe for performing cataract surgery, inducing minimal corneal thickness and endothelial changes.

Impact of intelligent phacoemulsification software on torsional phacoemulsification surgery

Background

The purpose of this study was to compare phacoemulsification energy parameters during torsional phacoemulsification with or without the use of intelligent phacoemulsification (IP) software.

Methods

One hundred and twenty-eight eyes with nuclear grades ranging from 1 to 5 were enrolled in this randomized prospective study. Operated eyes were divided into two groups, ie, those operated on using IP software (Group 1, n = 67) and those operated on without IP software (Group 2, n = 61). The two groups were compared in terms of ultrasound energy level, ultrasound energy time, aspiration time, and amount of fluid used during surgery.

Results

Operated eyes were further grouped according to soft (grade 1 and 2, n = 37), medium (grade 3, n = 46), and hard (grade 4 and 5, n = 31) nuclear densities. Both the study and the control groups were similar in distribution of nuclear density (P > 0.05). Cumulative dissipated energy was measured as 14.06 ± 9.92 in Group 1 and 14.22 ± 10.99 in Group 2 (P = 0.92). Total ultrasound time was 49 seconds in Group 1 and 52 seconds in Group 2 (P = 0.58). Although the torsional amplitude used was similar (P = 0.86) when IP was either on (71%) or off (68.4%), aspiration time was found to be 4 minutes 17 seconds in Group 1 (P = 0.86) and 5 minutes and 17 seconds in Group 2 (P = 0.007). Total fluid used was measured as 91 cc (P = 0.86) in Group 1 and 109 cc (P = 0.02) in Group 2.

Conclusion

The new IP software did not cause a difference in ultrasound energy levels. However, the new software was found to be advantageous in regards to fluid use and aspiration time.

Ozil IP torsional mode versus combined torsional/longitudinal microcoaxial phacoemulsification

Purpose.

To compare the safety and efficacy of microcoaxial phacoemulsification surgeries performed with the Ozil Intelligent Phaco (IP) torsional mode and combined torsional/longitudinal ultrasound (US) mode using the Infiniti Vision System (Alcon Laboratories).

Methods.

In this prospective randomized comparative study, 60 eyes were assigned to 2.2-mm microcoaxial phacoemulsification using the Ozil IP torsional mode (group 1) or combined torsional/longitudinal US mode (group 2). The primary outcome measures were US time (UST), cumulative dissipated energy (CDE), longitudinal and torsional ultrasound amplitudes, mean operation time, mean volume of balanced salt solution (BSS) used, and surgical complications.

Results

Both groups included 30 eyes. Mean UST, CDE, and longitudinal and torsional ultrasound amplitudes in group 1 were 1 minute 15±34.33 seconds, 8.74±5.64, 0.43±0.74, and 25.56±8.56, respectively, and these parameters in group 2 were 1 minute 40±51.44 seconds, 9.28±5.99, 3.64±1.55, and 3.71±1.34, respectively. UST and longitudinal amplitudes were found to be significantly low in group 1 (p<0.001, p<0.001), whereas torsional amplitude was found to be significantly high in this group (p=0.001). Mean volumes of BSS used in groups 1 and 2 were 63.30±18.00 cc and 84.50±28.65 cc, respectively (p=0.001).

Conclusions.

The Ozil IP torsional mode may provide more effective lens removal than the combined torsional/longitudinal US mode with a lower UST and volume of BSS used.