Torsional ultrasound modality for hard nucleus phacoemulsification cataract extraction

Air bubble guide for adequacy of ophthalmic viscosurgical device during phacoemulsification

Phacoemulsification in hard cataracts is a challenge. The use of dispersive ophthalmic viscosurgical devices (OVDs) to protect the endothelium is a routine step in such scenarios. However, as OVD is transparent, it is difficult to spot within the anterior chamber. Therefore, surgeons may not be aware when the OVD coating of the endothelium disappears during surgery. Consequently, there may be too frequent OVD injections, resulting in a waste of resources. On the contrary, the surgeon may fail to inject OVD at an appropriate time, leading to greater endothelial damage. We propose a novel technique of using an air bubble as a guide that helps in identifying the time when OVD disappears from the anterior chamber, thereby suggesting the surgeon to reinject before proceeding further.

Ultrasound-assisted ocular drug delivery: A review of current evidence

Efficient ocular drug delivery is a challenging clinical problem with various therapeutic options but no clearly preferred methodology. Given the ubiquity of ultrasound as a diagnostic technique, the safety profile of ultrasound in an ocular context, and the prospect of custom-made ultrasound-sensitive contrast agents, ultrasound presents an attractive ocular drug delivery modality. In this review, we evaluate our present understanding of ultrasound as it relates to ocular drug delivery and significant knowledge gaps in the field. In doing so, we hope to call attention to a potentially novel drug delivery pathway that could be manipulated to treat or cure ocular diseases.

Comparison of the phaco chop and drill-and-crack techniques for phacoemulsification of hard cataracts: A fellow eye study

PURPOSE

To quantify the intraoperative parameters and postoperative outcomes after using the phaco chop technique in one eye and drill-and-crack technique in the other eye in patients with bilateral dense brunescent cataract.

METHODS

The Lens Opacities Classification System III grading system was used to select 132 eyes of 66 patients with bilateral nuclear opalescence (NO) grade NO4 or grade NO5. One eye in each patient with bilateral dense brunescent cataract was subjected to phacoemulsification using the phaco chop technique, while the other eye was subjected to phacoemulsification with the drill-and-crack technique for nucleus disassembly. The intraoperative parameters were quantified. Surgical outcome was assessed preoperatively and 1 day, 4 weeks and 12 weeks postoperatively, and the outcomes of the two techniques were compared.

RESULTS

There was no significant difference between the techniques in operative parameters [cumulative dissipated energy (p = 0.74), surgical time (p = 0.68) or surgical difficulty during nucleus disassembly (p = 0.80)]. There was no significant difference in the postoperative change in central corneal thickness between the techniques at day 1, 4 weeks and 12 weeks or in corneal endothelial cell density loss at 4 and 12 weeks (p > 0.05). There was no significant difference between the techniques in the mean corrected distance visual acuity (logarithm of the minimum angle resolution) at 4 weeks postoperatively (p = 0.25).

CONCLUSION

The phaco chop and drill-and-crack techniques are equally effective for disassembly of hard NO4 and NO5 cataracts.

Laminin α4 overexpression in the anterior lens capsule may contribute to the senescence of human lens epithelial cells in age-related cataract

Senescence is a leading cause of age-related cataract (ARC). The current study indicated that the senescence-associated protein, p53, total laminin (LM), LMα4, and transforming growth factor-beta1 (TGF-β1) in the cataractous anterior lens capsules (ALCs) increase with the grades of ARC. In cataractous ALCs, patient age, total LM, LMα4, TGF-β1, were all positively correlated with p53. In lens epithelial cell (HLE B-3) senescence models, matrix metalloproteinase-9 (MMP-9) alleviated senescence by decreasing the expression of total LM and LMα4; TGF-β1 induced senescence by increasing the expression of total LM and LMα4. Furthermore, MMP-9 silencing increased p-p38 and LMα4 expression; anti-LMα4 globular domain antibody alleviated senescence by decreasing the expression of p-p38 and LMα4; pharmacological inhibition of p38 MAPK signaling alleviated senescence by decreasing the expression of LMα4. Finally, in cataractous ALCs, positive correlations were found between LMα4 and total LM, as well as between LMα4 and TGF-β1. Taken together, our results implied that the elevated LMα4, which was possibly caused by the decreased MMP-9, increased TGF-β1 and activated p38 MAPK signaling during senescence, leading to the development of ARC. LMα4 and its regulatory factors show potential as targets for drug development for prevention and treatment of ARC.

Comparison of surgical parameters using different lens fragmentation patterns in eyes undergoing laser-assisted cataract surgery

PURPOSE

To compare surgical parameters among eyes undergoing laser-assisted cataract surgery (LACS) using different lens fragmentation patterns (LFP).

METHODS

Prospective, randomized, unmasked clinical trial. One-hundred eyes underwent LACS and were randomly assigned to 1 of 3 LFP treatment groups: (1) laser capsulotomy only; no lens fragmentation (NLF) (n = 34); (2) three-plane chop (TPC) (n = 33); and, (3) pie-cut pattern (PCP) fragmentation (n = 33). Prechop phacoemulsification (PHACO) was performed on all eyes using the same femtosecond (FS) laser and active-fluidics PHACO machine.

MAIN OUTCOME MEASURES

FS laser dock time (s), PHACO time (s), PHACO power (%), cumulative dissipated energy (CDE) (%-s), irrigating fluid volume, and operative time.

RESULTS

The 3 treatment groups were comparable in terms of patient age (P = 0.164) and nuclear density (P = 0.669). FS dock time was higher in the PCP group (184.18 ± 25.86) compared to the TPC (145.09 ± 14.15) group (P < 0.001). PHACO time was significantly shorter in the PCP (23.19 ± 17.20 s) compared to TPC (35.27 ± 17.70) and NLF (46.15 ± 23.72) groups (P < 0.001). PHACO power was lower in the PCP (11.81 ± 3.71) compared to the NLF (14.41 ± 1.88) and TPC (14.04 ± 2.46) groups (P < 0.001). CDE was lower in the PCP (2.85 ± 2.32) compared to NLF (6.55 ± 3.32) and TPC (6.55 ± 5.45) groups (P < 0.001). Fluid volumes and operative times were similar.

CONCLUSION

LFP can influence PHACO surgical parameters. Extensive fragmentation patterns such as PCP appear to lower PHACO time, power, and CDE and may potentially reduce the risk of PHACO related complications.

[Comparison of ultrasound and hydrodynamic parameters in phacoemulsification]

Modern phacoemulsifiers have the widest selection of ultrasound parameters. Existing approaches to comparing the settings of the phaco machines have shortcomings and thus cannot be considered objective.

PURPOSE

To find a technique that would allow objective in vivo evaluation of various ultrasound and hydrodynamic parameters after performing phacoemulsification. To compare the two types of phaco settings using the proposed technique.

MATERIAL AND METHODS

The principle of the 'Femtocomparison' method is to have each patient undergo femtolaser pretreatment before phacoemulsification, in which the lens is divided by laser into equal parts and a corneal incision and capsulotomy are performed with the same settings. Then, during the manual part, basic ultrasound and hydrodynamic data is recorded after the removal of each quadrant of the lens. The study included 58 patients with cataracts of varying densities who underwent femtosecond laser-assisted cataract surgery. In each case, one half of the nucleus was removed using torsional ultrasound with IP technology, while the other half - using a combination of torsional and longitudinal ultrasound.

RESULTS

The 'Femtocomparison' technique allowed objective in vivo comparison of two types of ultrasound settings. When assessing these parameters, no significant differences were found in any of the patients regardless of the density of the lens nucleus (p>0.05). In soft nuclei group (NC 1-3) CDE were significantly lower when using torsional ultrasound and IP (p<0.05). In the group with dense nuclei (NC 6+), CDE and aspiration time were significantly lower when using combination ultrasound (p<0.05).

CONCLUSION

The 'Femtocomparison' technique has shown that torsional ultrasound with IP technology is preferable for aspiration of soft cataracts, while combined use of torsional and longitudinal ultrasound is better when removing dense lenses.

Comparison of clinical outcomes between cystotome-assisted prechop phacoemulsification surgery and conventional phacoemulsification surgery for hard nucleus cataracts: A CONSORT-compliant article

BACKGROUND

This study aimed to investigate the safety and efficacy of the cystotome-assisted prechop phacoemulsification surgery (CAPPS) and conventional phacoemulsification surgery (CPS) in patients with IV degree nucleus cataract.

METHODS

The prospective, randomized, consecutive, comparative cohort study consecutively recruited Chinese age-related cataract patients, CAPPS and CPS were performed by a seasoned surgeon. Postoperative follow-up was at 1 day, 1 week, 1 month, 3 months, 6 months, and 1 year, and the outcome measures comprised ultrasound power, effective phacoemulsification time (EPT), corrected distance visual acuity (CDVA), endothelial cell density (ECD), corneal endothelium loss rate (ECL), central corneal thickness (CCT), and intraoperative and postoperative complications.

RESULTS

Patients in both groups gained a better CDVA postoperatively. The ultrasound power and EPT in the CAPPS group were lower than the CPS group (P < .001). ECD value decreased at each follow-up visit and did not return to the preoperative level; CPS resulted in greater endothelial cell loss than CAPPS did, which was significant. CCT increased immediately after the surgery, and decreased thereafter. The mean CCT values returned to preoperative levels at 3 months after surgery in the CAPPS group while it took 6 months in the CPS group. The differences in cornea edema and anterior chamber flare between the 2 groups were not significant at 1 day postoperatively (P = .070 and .094, respectively), while at the 1-week time point, the differences were statistically significant (P = .002 and .001, respectively).

CONCLUSION

CAPPS appears to be an excellent method for treating hard nucleus cataract.

A Rabbit Model Study to Determine the Efficacy of a Prototype Corneal Endothelium Protector during Cataract Surgery

Purpose. We evaluated the efficacy and safety of a mechanical device, the P-chute, in corneal endothelium preservation during phacoemulsification in a rabbit model. Methods. Twenty-four rabbits were randomly assigned into 2 groups. One eye of each rabbit underwent phacoemulsification that simulated the removal of a dense nucleus, with or without the P-chute. Serial slit-lamp examinations, anterior segment optical coherence tomography (ASOCT) scans, and specular microscopy were performed. Three rabbits from each group were sacrificed on postoperative days (PODs) 1, 5, 7, and 14. Histological analysis of the corneas was performed. Results. There was a trend towards lesser endothelial cell loss for the P-chute group at POD1 (4.9% versus 12.5%, p = 0.53), POD5 (10.4% versus 12.2%, p = 0.77), and POD7 (10.5% versus 17.2%, p = 0.52). There was no significant difference in the corneal thickness (p = >0.05) between the 2 groups. The insertion of the device was challenging. The use of the P-chute only added an extra 15% to the surgical time. Conclusions. There was a trend towards better endothelium preservation with the P-chute even though the results were not statistically significant. We believe that the device could be useful in certain surgical situations. Further work is needed to improve the device insertion.

Intravitreal Phacoemulsification Using Torsional Handpiece for Retained Lens Fragments

Purpose:

To evaluate the results of intravitreal phacoemulsification with torsional hand piece in eyes with posteriorly dislocated lens fragments.

Methods:

In this prospective, interventional case series, 15 eyes with retained lens fragments following phacoemulsification were included. All patients underwent standard three-port pars plana vitrectomy and intravitreal phacoemulsification using sleeveless, torsional hand piece (OZiL™, Alcon's Infiniti Vision System). Patients were followed up for a minimum of six months to evaluate the visual outcomes and complications.

Results:

The preoperative best-corrected visual acuity (BCVA) ranged from light perception to 0.3. No complications such as thermal burns of the scleral wound, retinal damage due to flying lens fragments, or difficult lens aspiration occurred during intravitreal phacoemulsification. Mean post-operative BCVA at the final follow-up was 0.5. Two eyes developed cystoid macular edema, which was managed medically. No retinal detachment was noted.

Conclusion:

Intravitreal phacoemulsification using torsional hand piece is a safe and effective alternative to conventional longitudinal phacofragmentation.

An evaluation of intraoperative and postoperative outcomes of torsional mode versus longitudinal ultrasound mode phacoemulsification: a Meta-analysis

AIM

To evaluate and compare the intraoperative parameters and postoperative outcomes of torsional mode and longitudinal mode of phacoemulsification.

METHODS

Pertinent studies were identified by a computerized MEDLINE search from January 2002 to September 2013. The Meta-analysis is composed of two parts. In the first part the intraoperative parameters were considered: ultrasound time (UST) and cumulative dissipated energy (CDE). The intraoperative values were also distinctly considered for two categories (moderate and hard cataract group) depending on the nuclear opacity grade. In the second part of the study the postoperative outcomes as the best corrected visual acuity (BCVA) and the endothelial cell loss (ECL) were taken in consideration.

RESULTS

The UST and CDE values proved statistically significant in support of torsional mode for both moderate and hard cataract group. The analysis of BCVA did not present statistically significant difference between the two surgical modalities. The ECL count was statistically significant in support of torsional mode (P<0.001).

CONCLUSION

The Meta-analysis shows the superiority of the torsional mode for intraoperative parameters (UST, CDE) and postoperative ECL outcomes.

Refractive outcomes of combined phacovitrectomy and delayed cataract surgery in retinal detachment

OBJECTIVE

To compare the accuracy of refractive outcomes between combined pars plana vitrectomy (PPV) and cataract surgery and delayed cataract surgery after PPV in cases with rhegmatogenous retinal detachment (RD).

DESIGN

Retrospective case series.

PARTICIPANTS

Thirty-eight eyes underwent combined phacovitrectomy (combined group) and 25 eyes underwent delayed cataract surgery after PPV (delayed group).

METHODS

RD height was measured using optical coherence tomography. Refractive outcomes were evaluated using mean absolute error (MAE; the difference between final refractive error and target refractive error).

RESULTS

Combined group showed significant myopic shift (mean error; -0.40 ± 1.07 vs 0.07 ± 0.56 D, p = 0.028) and large MAE (0.81 ± 0.81 vs 0.48 ± 0.29 D, p = 0.028) compared with delayed group. Multiple logistic regression analysis revealed that only RD height was significantly associated with MAE greater than 2 D after combined surgery (in 100-µm unit, odds ratio 3.23, 95% CI 1.04-10.02, p = 0.042). RD height was also significantly correlated with the difference in axial length (AL) between 2 eyes of the patients (p = 0.006, r = 0.406) and the difference in AL measured at pre- versus post-RD repair in the delayed group (p < 0.001, r = 0.774).

CONCLUSIONS

Combined phacovitrectomy in patients with rhegmatogenous RD induced significant myopic shift because of underestimation of AL, especially in patients with high RD height. Thus, in cases with high temporal RD or large AL differences between eyes, either delayed cataract surgery or combined cataract surgery using the contralateral AL is recommended.

Torsional power study using CENTURION phacoemulsification technology

BACKGROUND

To evaluate the effect of varying levels of power on phacoemulsification efficiency using the CENTURION Vision System.

METHODS

Formalin-soaked porcine lenses were divided into 2-mm cubes; 0.9-mm, balanced tips were used. Torsional power levels were tested from 10% to 100% at 10% intervals. Vacuum was set to 550 mmHg, aspiration to 50 ml/min, and intraocular pressure at 50 mmHg. Efficiency (time to lens removal) and chatter (number of lens fragment repulsions from the tip) were determined.

RESULTS

Increasing torsional power up to 60% increased efficiency. This effect was linear from 30 to 60% power (R²  = .90; P < 0.05). There were no significant differences in efficiency past 60%. Chatter was highest at 10% power and decreased linearly (R²  = .87; P = 0.007) as power was increased up to 60% power, and chatter did not improve above this power level.

CONCLUSIONS

Power improved efficiency only up to a 60% power level, and then was negligible. Chatter correlated well with power up to the 60% level, so that as power was increased, chatter decreased. Because there are no additional benefits in efficiency past 60% power, and because chatter is minimal at 60% power, we recommend torsional ultrasound at 60% as the optimal power setting for using the CENTURION System for phacoemulsification.l.

Corneal endothelial morphology and function after torsional and longitudinal ultrasound mode phacoemulsification

PURPOSE

To study the endothelial cell morphology and corneal thickness changes after phacoemulsification by using the OZil torsional and longitudinal ultrasound techniques (Infiniti Vision System, Alcon Laboratories).

SETTING

Department of Ophthalmology, Clinical Center, University of Debrecen, Debrecen, Hungary.

METHODS

52 patients with cataract were randomly assigned to longitudinal ultrasound and torsional mode group. All surgeries were performed through a 2.2 mm clear corneal incision, the method employed being divide and conquer. The endothelial morphometry such as cell density (ECD), mean cell area, coefficient of variation of cell area, and central corneal thickness were examined with specular microscopy (EM-1000, Tomey) preoperatively and 4, 8 weeks postoperatively.

RESULTS

ECD values decreased significantly in both surgical groups (P < .001, repeated- mesures ANOVA), the postoperative endothelial cell loss was higher in the longitudinal ultrasound mode group (3.5% and 6.5%, at 4 and 8 weeks after surgery) than in the torsional group (3.3% and 5.5%, at 4 and 8 weeks after surgery), the difference not being significant between the two groups (P = .164 and P = .479, at 4 and 8 weeks after surgery, Mann-Whitney test). There was no statistically significant difference in any of the assessed parameters between the two surgical groups (P > .05). No significant correlation was found between the endothelial cell loss and the nucleus density.

CONCLUSIONS

Both phacoemulsification techniques were safe and effective. The torsional handpiece performs oscillatory movements and delivers less energy into the eye than the longitudinal ultrasound technique, therefore providing more favorable energy and thermal safety profile.

Low intensity-pulsed ultrasound induced apoptosis of human hepatocellular carcinoma cells in vitro

The present study was conducted to determine whether low intensity-pulsed ultrasound (LIPUS) could induce apoptosis of human hepatocellular carcinoma cells, SMMC-7721, and to define the mechanism of ultrasound-induced apoptosis, in vitro. MTT assay was used to measure cell proliferation. Apoptosis was investigated by multiple methods such as flow cytometry, DNA fragmentation, Ca(2+) mobilizations, pro- and anti-apoptotic protein expression, and light as well as ultramicroscopic morphology. The results provide evidence that LIPUS induced a dose-dependent effect on cell viability and apoptosis of SMMC-7721 cells. Specifically, exposure of cells to >0.5 W/cm(2) intensity significantly increased cell apoptosis, caused shifts in cell cycle phase, and induced structural changes. Ultrasound significantly increased intracellular Ca(2+) concentrations and modulated expression of caspase-3, Bcl-2 and Bax. The findings suggest that this novel technology can be used to induce SMMC-7721 apoptosis via the Ca(2+)/mitochondrial pathway and could potentially be of clinical use for the treatment of hepatocellular carcinoma (SMMC-7721 cell line) and other cancers.

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.

Efficacy and safety of femtosecond laser-assisted cataract surgery versus conventional phacoemulsification for cataract: a meta-analysis of randomized controlled trials

The aim of this study was to evaluate the efficacy and safety of femtosecond laser-assisted cataract surgery (FLACS) versus conventional phacoemulsification cataract surgery (CPCS) in the treatment of cataract. Randomized controlled trials (RCTs) were searched in PubMed, Embase and the Cochrane Central Register of Controlled Trials. Nine qualified studies with a total of 989 eyes were included. Compared with CPCS, FLACS significantly reduced mean phaco energy and effective phacoemulsification time (EPT) required in the surgery. Central corneal thickness (CCT) was significantly lower in FLACS at 1 day of follow-up, but CCT and corneal endothelial cells count was comparable at 1 week of follow-up or longer. FLACS achieved a better visual outcome at postoperative 1 week and 6 months, but the difference was not significant at postoperative 1-3 months. Regard to surgical complications, the incidences of intraoperative anterior capsule tear, postoperative macular edema and elevated intraocular pressure were similar. In conclusion, femtosecond laser pretreatment can reduce phaco energy and EPT, which may reduce the heat damage to ocular tissues by ultrasound. This novel technique might be beneficial for patients with dense cataract and/or low preoperative endothelial cell values. Well-designed RCTs with longer follow-up are still necessary to provide more reliable evidence.

Effect of torsional mode phacoemulsification on cornea in eyes with/without pseudoexfoliation

AIM

To evaluate the effect of torsional mode phacoemulsification on central corneal thickness, corneal endothelial cell density, and morphology in eyes with/without pseudoexfoliation (PEX) syndrome.

METHODS

Fourty-two consecutive patients with and 42 patients without PEX as a control group scheduled for cataract surgery was studied. Phacoemulsification, using OZiL IP system, was performed with quick chop technique. Using noncontact specular microscopy, the central endothelial cell density (ECD), coefficient of variation, percentage of hexagonal cells, and the central corneal thickness (CCT) were evaluated preoperatively and postoperatively at 1, 7 and 30d.

RESULTS

The ECD in PEX syndrome was statistically significantly lower than that in the control group preoperatively and postoperatively (P≤0.001). Percentage change in ECD was statistically significantly higher in PEX than that in control group after surgery follow up (P≤0.04). There was no statistically significant difference between both groups comparing percentage of hexagonal cells and coefficient of variation in the cell size before and after the surgery. At 1 and 7d after surgery, percentage change in CCT was statistically significantly higher in PEX group than that in the control group (P≤0.041).

CONCLUSION

Although torsional mode phacoemulsification and intraocular lens (IOL) implantation provided a safe and favorable surgical outcome in patients with/without PEX, torsional phacoemulsification led to significantly higher ECD loss in the PEX group than that in the control group during the whole follow up period. In addition, more corneal swelling in the PEX group than that in the control group during the early postoperative period has indicated that the corneal endothelium, in presence of PEX endotheliopathy, seems to be more susceptible to the effects of phacoemulsification surgery in eyes with PEX. The increased risk of anterior chamber manipulations in patients with PEX should be taken into account for an increased risk of bullous keratopathy.

The Impact of Reused Phaco Tip on Outcomes of Phacoemulsification Surgery

PURPOSE

To evaluate the impact of reused phaco tip on intraoperative performance and postoperative outcomes after 2.2 mm micro-coaxial torsional and transversal phacoemulsification.

MATERIAL AND METHODS

This prospective randomized study enrolled 136 eyes of 136 cataract patients; 68 eyes in torsional group (34 eyes with single use tip, 34 eyes with reused tip) and 68 eyes in transversal group (34 eyes with single use tip, 34 eyes with reused tip). Intraoperative measurements were total ultrasound (U/S) time, torsional U/S time, cumulative dissipated energy (CDE), estimated fluid use (EFU) in the torsional group and total phacoemulsification time (TPT), and effective phacoemulsification time (EPT) in transversal phacoemulsification. The central endothelial cell density (ECD) and the central corneal thickness (CCT) were evaluated preoperatively and postoperatively at 1 and 30 days using noncontact specular microscopy.

RESULTS

Intraoperative measurements in torsional phacoemulsification showed significant increase in total U/S time (p = 0.01), torsional U/S time (p = 0.01), and CDE (p = 0.01) with the reused tip. The EFU was similar in both tip groups (p = 0.36). The total U/S time, torsional U/S time, and CDE in torsional group were significantly increased with the reused tip for grade III (p = 0.03 for all parameters) and grade IV cataracts (p = 0.005 for torsional U/S time and CDE; p = 0.006 for total U/S time). Intraoperative measurements in transversal phacoemulsification showed no differences in TPT and EPT between tip groups (p > 0.05). The change in ECD and CCT in torsional and transversal phacoemulsification groups were similar in both tip groups (p > 0.05).

CONCLUSIONS

This study showed that sharpness of phaco tip edge increases the efficiency of torsional phacoemulsification for hard cataracts. This result does not mean that reused phaco tip may be used in soft and medium cataracts. As the timing of tip's change is a user-dependent procedure, a new single phaco tip should be used in each case if possible.

Determining optimal torsional ultrasound power for cataract surgery with automatic longitudinal pulses at maximum vacuum ex vivo

PURPOSE

To determine the optimal longitudinal power settings for Infiniti OZil Intelligent Phaco (IP) at varying torsional amplitude settings; and to test the hypothesis that increasing longitudinal power is more important at lower torsional amplitudes to achieve efficient phacoemulsification.

DESIGN

Laboratory investigation.

METHODS

setting: John A. Moran Eye Center, University of Utah, Salt Lake City, Utah. procedure: Individual porcine nuclei were fixed in formalin, then cut into 2.0 mm cubes. Lens cube phacoemulsification was done using OZil IP at 60%, 80%, and 100% torsional amplitude with 0%, 10%, 20%, 30%, 50%, 75%, or 100% longitudinal power. All experiments were done using a 20 gauge 0.9 mm bent reverse bevel phaco tip at constant vacuum (550 mm Hg), aspiration rate (40 mL/min), and bottle height (50 cm). main outcome measure: Complete lens particle phacoemulsification (efficiency).

RESULTS

Linear regression analysis showed a significant increase in efficiency with increasing longitudinal power at 60% torsional amplitude (R(2) = 0.7269, P = .01) and 80% torsional amplitude (R(2) = 0.6995, P = .02) but not at 100% amplitude (R(2) = 0.3053, P = .2). Baseline comparison of 60% or 80% vs 100% torsional amplitude without longitudinal power showed increased efficiency at 100% (P = .0004). Increasing longitudinal power to 20% abolished the efficiency difference between 80% vs 100% amplitudes. In contrast, 75% longitudinal power abolished the efficiency difference between 60% vs 100% torsional amplitudes.

CONCLUSIONS

Results suggest that longitudinal power becomes more critical at increasing phacoemulsification efficiencies at torsional amplitudes less than 100%. Increasing longitudinal power does not further increase efficiency at maximal torsional amplitudes.

Intraocular lens-shell technique: adjustment of the surgical procedure leads to greater safety when treating dense nuclear cataracts

Objective

To compare the efficacy and safety of the intraocular lens (IOL)-shell procedure versus conventional phacoemulsification for the surgical treatment of dense cataracts.

Methods

Eighty eyes with dense nuclear cataracts were enrolled in a prospective, randomized controlled study. Patients were assigned to two groups. In Group I, the IOL was traditionally implanted after all nuclear fragments were completely removed, and in Group II, the IOL was innovatively implanted in the bag before the last residual nuclear fragment was removed. This novel adjusted surgical procedure, named the “IOL-shell technique”, features use of the IOL as a protective barrier rather than simply as a refractive alternative, and it is conceptually different from the traditional step-by-step procedure. Clinical examinations, including uncorrected visual acuity, central corneal thickness (CCT), temporal clear corneal incision thickness and corneal endothelial cell density, were carried out.

Results

The inter-group difference in temporal corneal thickness was found to be of no statistical significance at any of the visits. Compared to eyes in Group I, those in Group II were shown to have significantly less corneal endothelial cell loss on both the 7th and 30th day following surgery. At 7 days after surgery, the mean corneal endothelial cell loss in Group II was 10.29%, compared to 14.37% in Group I (P<0.05). The mean endothelial cell loss measured on postoperative day 30 was 16.88% in Group II compared to 23.32% in Group I (P<0.05). On the 1st day after surgery, the mean CCT of eyes in Group II was significantly smaller compared to Group I (Group I vs. Group II: 19.42% vs. 13.50%, P<0.05).

Conclusions

Compared to conventional phacoemulsification, the IOL-shell technique was shown to be a relatively safer procedure without compromised efficiency for dense cataracts, and it caused less corneal endothelial cell loss and milder postoperative corneal edema (Clinical Trials Identifier: NCT02138123).

Trial Registration

ClinicalTrials.gov NCT02138123

Ozil® versus conventional ultrasound phacoemulsification: a randomized comparative study

The purpose of this study is to compare and assess the performance and the postoperative outcomes of torsional mode and ultrasound (US) mode performed in the phacoemulsification of cataract with different nuclear densities. This is a randomized comparative clinical study. Two groups of 75 eyes (the first operated by Ozil(®) and the second by US) were comparable in age, gender, cataract density, corneal incision size, and intraocular lens type. We assessed peroperative parameters: US time (UST) and cumulative dissipated energy (CDE). Postoperative outcome measures were corneal edema and final best-corrected visual acuity. The UST was significantly lower in the ozil(®) group for all nucleus grades (73.43 s ± 8.3 with US vs. 46.02 s ± 23 with Ozil(®)) (p = 0.0003). The CDE was lower in the Ozil(®) group for grade III and IV cataract (p = 0.005). However, no significant difference was noted for grade II cataract (p = 0.07). Immediate postoperative corneal edema was significantly harder in the US group (p = 0.00002). The mean one month postoperative visual acuity was 0.2 ± 0.03 logMAR and 0.15 ± 0.07 logMAR, respectively, in the US group and the Ozil(®) group (p = 0.06). Ozil(®) mode seems to dissipate less energy in the eye than US mode. The visual outcome at one month is comparable in the two groups.

Thermal imaging comparison of Signature, Infiniti, and Stellaris phacoemulsification systems

Background

To compare the heat production of 3 different phacoemulsification machines under strict laboratory test conditions. More specifically, the thermal behavior was analyzed between the torsional modality of the Infiniti system and longitudinal modalities of the Abbot WhiteStar Signature Phacoemulsification system and Bausch and Lomb Stellaris system.

Methods

Experiments were performed under in-vitro conditions in this study.

Three phacoemulsification handpieces (Infiniti, Signature, and Stellaris) were inserted into balanced salt solution-filled silicone test chambers and were imaged side-by-side by using a thermal camera. Incision compression was simulated by suspending 30.66-gram weights from the silicone chambers. The irrigation flow rate was set at 0, 1, 2, 3, 4, and 5 cc/min and the phacoemulsification power on the instrument consoles was set at 40, 60, 80, and 100%. The highest temperatures generated from each handpiece around the point of compression were measured at 0, 10, 30, and 60 seconds.

Results

Under the same displayed phacoemulsification power settings, the peak temperatures measured when using the Infiniti were lower than when using the other two machines, and the Signature was cooler than the Stellaris. At 10 seconds, torsional phacoemulsification with Infiniti at 100% power showed data comparable to that of the Signature at 80% and the Stellaris at 60%. At 30 seconds, the temperature from the Infiniti at 100% power was lower than the Signature at 60% and the Stellaris at 40%.

Conclusions

Torsional phacoemulsification with the Infiniti generates less heat than longitudinal phacoemulsification with the Signature and the Stellaris. Lower operating temperatures indicate lower heat generation within the same fluid volume, which may provide additional thermal protection during cataract surgery.

Removal of posterior segment retained lens material using the OZil phacoemulsification handpiece versus Fragmatome during pars plana vitrectomy

PURPOSE

To assess the utility of the torsional phacoemulsification handpiece compared to the Fragmatome during pars plana vitrectomy for removal of posterior segment retained lens material.

DESIGN

: Retrospective comparative case series.

METHODS

Thirty-four eyes of 34 patients at 2 centers who underwent pars plana vitrectomy for retained lens material with either torsional phacoemulsification or the Fragmatome were retrospectively reviewed. Lens material was graded by nuclear density and percentage of total nuclear size. The primary outcome measure was mean change in visual acuity. Secondary outcomes included intraoperative or postoperative complications, occurrence of mechanical malfunctions and metric data including the total ultrasound, phacoemulsification, and torsional times.

RESULTS

In the torsional ultrasound group (17 eyes), mean nuclear density was 3.6 and mean size was 63%. Mean initial logarithm of minimum angle of resolution visual acuity was 1.58 (20/760) and improved to 0.66 (20/80) at postoperative Month 3, a gain of 0.92 (P = 0.003). One eye developed a self-limited, peripheral, serous, choroidal detachment intraoperatively, whereas two eyes developed postoperative cystoid macular edema. Mean total ultrasound, phacoemulsification, and torsional times were 76.7, 13.4, and 63.3 seconds, respectively. Mean total operative time to remove retained lens material (excluding vitreous gel removal) was 111 seconds. All the patients demonstrated excellent followability based on independent observations by the surgeons. In the Fragmatome group (17 eyes), initial logarithm of minimum angle of resolution visual acuity was 1.51 (20/640) and improved to 0.6 (20/80) at postoperative Month 3, a gain of 0.91 (P < 0.001). One eye developed a retinal detachment at postoperative Week 2, whereas 3 eyes developed postoperative cystoid macular edema.

CONCLUSION

The use of torsional phacoemulsification during pars plana vitrectomy for retained lens material is a novel approach with potential advantages over the standard 20-gauge Fragmatome, including improved followability and purchase of lens material attributable to the addition of torsional movement.

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.

Clinical evaluation of three incision size-dependent phacoemulsification systems

PURPOSE

To compare the outcomes of cataract surgery performed with 3 incision size-dependent phacoemulsification groups (1.8, 2.2, and 3.0 mm).

DESIGN

Prospective randomized comparative study.

METHODS

One hundred twenty eyes of 120 patients with age-related cataract (grades 2 to 4) were categorized according to the Lens Opacities Classification System III. Eligible subjects were randomly assigned to 3 surgical groups using coaxial phacoemulsification through 3 clear corneal incision sizes (1.8, 2.2, and 3.0 mm). Different intraoperative and postoperative outcome measures were obtained, with corneal incision size and surgically induced astigmatism as the main clinical outcomes.

RESULTS

There were no statistically significant differences in most of the intraoperative and postoperative outcome measures among the 3 groups. However, the mean cord length of the clear corneal incision was increased in each group after surgery. The mean maximal clear corneal incision thickness in the 1.8-mm group was significantly greater than for the other groups at 1 month. The mean surgically induced astigmatism in the 1.8- and 2.2-mm groups was significantly less than that in the 3.0-mm group after 1 month, without significant difference between the 1.8- and 2.2-mm groups.

CONCLUSIONS

With appropriate equipment, smaller incisions may result in less astigmatism, but the particular system used will influence incision stress and wound integrity, and may thus limit the reduction in incision size and astigmatism that is achievable.

Relationship between endothelial cell loss and microcoaxial phacoemulsification parameters in noncomplicated cataract surgery

Purpose

To assess the relationship between postoperative endothelial cell loss and microcoaxial phaco parameters using Ozil IP (Alcon Laboratories, Inc, Fort Worth, TX) in noncomplicated cataract surgery.

Methods

In this prospective observational study, 120 consecutive cases of cataract patients with different grades of nuclear hardness underwent microcoaxial phacoemulsification through a 2.2-mm clear corneal incision. An Alcon Infinity Vision System with Ozil IP (Alcon Laboratories) was used with an Ozil torsional handpiece and a Kelman-style 45° phacoemulsification tip. Patients underwent preoperative and postoperative central endothelial cell counts.

Results

The study included 120 cases of age-related cataract whose mean age (standard deviation [SD]) was 59.68 years (9.47). There was a highly statistically significant endothelial cell loss (P < 0.001). The endothelial cell loss ranged 11–1149 cells/mm² with a median (interquartile range) of 386 cells/mm² (184.5–686 cells/mm²). The percentage of postoperative ECLoss% ranged from 0.48% to 47.8% with a median (interquartile range) of 15.4% (7.2% to 26.8%). A significant positive correlation was found between the ECLoss% and different phaco parameters. The Spearman’s rank-order correlation coefficient values, rho, (ρ) were as follows: CDE (ρ = 0.425), aspiration time (ρ = 0.176), and volume (ρ = 0.278). Also, ECLoss% was significantly correlated with the grade of nuclear opalescence (Kendall’s tau τ = 0.42).

Conclusion

Microcoaxial phacoemulsification was efficient in removing noncomplicated cataracts; however a statistically significant endothelial cell loss was noted, especially with increased nuclear hardness. This endothelial cell loss was mostly related to the increased cumulative dissipated energy (CDE), aspiration time, and volume of balanced salt solution used.

Comparison of bimanual and micro-coaxial phacoemulsification with torsional ultrasound

PURPOSE

To evaluate the efficacy and postoperative outcomes of bimanual and micro-coaxial phacoemulsification with torsional ultrasound.

METHODS

In this prospective randomized series, eyes with age-related cataract were randomly divided into bimanual phacoemulsification and micro-coaxial phacoemulsification groups. Data included preoperative and postoperative corrected distance visual acuity (CDVA), central/temporal corneal thickness, endothelial cell density and intraoperative ultrasound time, cumulative dissipated energy and balanced salt solution volume.

RESULTS

The study evaluated 89 patients (89 eyes). When compared between micro-coaxial and bimanual phaco groups, ultrasound time (57 ± 24 second versus 85 ± 40 second, p < 0.01), cumulative dissipated energy (10 ± 7 versus 14 ± 7, p = 0.01) and balanced salt solution volume (55 ± 19 ml l versus 75 ± 20 ml, p < 0.01) were significantly lower in micro-coaxial phaco group. At 1 day, there were no statistically significant differences in CDVA (p = 0.68) or central corneal thickness (p = 0.48) between two groups; temporal corneal thickness was statistically significantly thicker in bimanual phaco group (1247 ± 123 μm) than that in micro-coaxial phaco group (1108 ± 131 μm, p = 0.01). There were no statistically significant differences in CDVA, central/temporal corneal thickness, or endothelial cell density between two groups 30 days postoperatively (all p values >0.05).

CONCLUSION

With rapid visual rehabilitation and comparable endothelial cell loss, both bimanual and micro-coaxial phacoemulsification procedures with torsional ultrasound are efficient for moderate nuclear cataract extraction.

Torsional ultrasound mode versus combined torsional and conventional ultrasound mode phacoemulsification for eyes with hard cataract

Purpose

To compare torsional versus combined torsional and conventional ultrasound modes in hard cataract surgery regarding ultrasound energy and time and effect on corneal endothelium.

Settings

Kasr El Aini hospital, Cairo University, and International Eye Hospital, Cairo, Egypt.

Methodology

Ninety-eight eyes of 63 patients were enrolled in this prospective comparative randomized masked clinical study. All eyes had nuclear cataracts of grades III and IV using the Lens Opacities Classification System III (LOCS III). Two groups were included, each having an equal number of eyes (49). The treatment for group A was combined torsional and conventional US mode phacoemulsification, and for group B torsional US mode phacoemulsification only. Pre- and post-operative assessments included best corrected visual acuity (BCVA), intraocular pressure (IOP), slit-lamp evaluation, and fundoscopic evaluation. Endothelial cell density (ECD) and central corneal thickness (CCT) were measured preoperatively, 1 day, 7 days, and 1 month postoperatively. All eyes were operated on using the Alcon Infiniti System (Alcon, Fort Worth, TX) with the quick chop technique. All eyes were implanted with AcrySof SA60AT (Alcon) intraocular lens (IOL). The main phaco outcome parameters included the mean ultrasound time (UST), the mean cumulative dissipated energy (CDE), and the percent of average torsional amplitude in position 3 (%TUSiP3).

Results

Improvement in BCVA was statistically significant in both groups (P < 0.001). Comparing UST and CDE for both groups revealed results favoring the pure torsional group (P = 0.002 and P < 0.001 for UST; P = 0.058 and P = 0.009 for CDE). As for %TUSiP3, readings were higher for the pure torsional group (P = 0.03 and P = 0.01). All changes of CCT, and ECD over time were found statistically significant using one-way ANOVA testing (P < 0.001).

Conclusion

Both modes are safe in hard cataract surgery, however the pure torsional mode showed less US energy used.

The comparison between torsional and conventional mode phacoemulsification in moderate and hard cataracts

Purpose

To compare the intraoperative performances and postoperative outcomes of cataract surgery performed with longitudinal phacoemulsification and torsional phacoemulsification in moderate and hard cataracts.

Methods

Of 85 patients who had senile cataracts, 102 eyes were operated on using the Infiniti Vision System. Preoperative examinations (slit lamp examination, mean central corneal thickness, and central endothelial cell counts) were performed for each patient. Cataracts were subdivided into moderate and hard, according to the Lens Opacities Classification System III grading of nucleus opalescence (NO). Eyes in each cataract group were randomly assigned to conventional and torsional phaco-mode. Intraoperative parameters, including ultrasound time (UST), cumulative dissipated energy (CDE), and the balanced salt solution plus (BSSP) volume utilized were evaluated. Best corrected visual acuity (BCVA) was checked on postoperative day 30; mean central corneal thickness and central endothelial cell counts were investigated on postoperative days 7 and 30.

Results

Preoperative BCVA and mean grading of NO showed no difference in both groups. Preoperative endothelial cell count and central corneal thickness also showed no significant difference in both groups. In the moderate cataract group, the CDE, UST, and BSSP volume were significantly lower in the torsional mode than the longitudinal mode, but they did not show any difference in the hard cataract group. Torsional group showed less endothelial cell loss and central corneal thickening at postoperative day seven in moderate cataracts but showed no significant differences, as compared with the longitudinal group, by postoperative day 30.

Conclusions

Torsional phacoemulsification showed superior efficiency for moderate cataracts, as compared with longitudinal phacoemulsification, in the early postoperative stage.