Clinical study using a new phacoemulsification system with surgical intraocular pressure control

Phacoemulsification using an active fluidics system at physiologic vs high intraocular pressure: impact on anterior and posterior segment physiology

PURPOSE

Evaluate the impact of high vs low intraoperative intraocular pressure (IOP) during phacoemulsification on anterior and posterior physiology.

SETTING

Private practice in Des Moines, Iowa.

DESIGN

Prospective, randomized, paired-eye clinical trial of patients anticipating bilateral cataract surgery.

METHODS

27 participants randomized at the time of their first cataract surgery to either low IOP or high IOP group. The subsequent cataract surgery was performed under the alternate condition. During phacoemulsification and cortex removal, IOP was maintained either at low (≤28 mm Hg) or at high (≥55 to 60 mm Hg) levels. The primary outcome was fluid usage, with secondary outcomes of central corneal thickness, foveal avascular zone area, foveal and macular thickness, endothelial cell density (ECD), and postoperative inflammation.

RESULTS

Surgery with low IOP settings used less fluid (40.0 mL vs 55.6 mL, P < .0001). Corneal thickness changes were smaller in low IOP eyes at 1 day and 1 week (3.0% vs 8.1%, P = .01; 3.1% vs 4.4%, P = .01) but were similar by 1 and 3 months. ECD dropped less in low IOP eyes at 1 and 3 months (-1.7% vs -12.3%, P = .001, 2.1% vs -8.9%, P = .0003.) IOP remained a significant predictor of ECD change when relationship was controlled for fluid use and phacoemulsification energy. Retinal parameters did not vary among all eyes or when compared by IOP setting. Visual acuity was similar at all timepoints.

CONCLUSIONS

Low IOP settings resulted in less inflammation and less corneal trauma, as evidenced by a smaller drop in ECD and less postoperative corneal edema, when compared with high IOP settings. Retinal parameters did not change significantly. The different outcomes did not result in a difference in visual acuity.

Phaco-Chop versus Divide-and-Conquer in Patients Who Underwent Cataract Surgery: A Systematic Review and Meta-Analysis

Background

Cataract surgery is one of the most frequently performed eye surgeries worldwide, and among several techniques, phacoemulsification has become the standard of care due to its safety and efficiency. We evaluated the advantages and disadvantages of two phacoemulsification techniques: phaco-chop and divide-and-conquer.

Methods

PubMed, Cochrane, Embase, and Web of Science databases were queried for randomized controlled trial (RCT), prospective and retrospective studies that compared the phaco-chop technique over the divide-and-conquer technique and reported the outcomes of (1) Endothelial cell count change (ECC); (2) Ultrasound time (UST); (3) Cumulated dissipated energy (CDE); (4) Surgery time; and (5) Phacoemulsification time (PT). Heterogeneity was examined with I2 statistics. A random-effects model was used for outcomes with high heterogeneity.

Results

Nine final studies, (6 prospective RCTs and 3 observational), comprising 837 patients undergoing phacoemulsification. 435 (51.9%) underwent the phaco-chop technique, and 405 (48.1%) underwent divide-and-conquer. Overall, the phaco-chop technique was associated with several advantages: a significant difference in ECC change postoperatively (Mean Difference [MD] -221.67 Cell/mm2; 95% Confidence Interval [CI] -401.68 to -41.66; p < 0.02; I2=73%); a shorter UST (MD -51.16 sec; 95% CI -99.4 to -2.79; p = 0.04; I2=98%); reduced CDE (MD -8.68 units; 95% CI -12.76 to -4.60; p < 0.01; I2=84%); a lower PT (MD -55.09 sec; 95% CI -99.29 to -12.90; p = 0.01; I2=100). There were no significant differences in surgery time (MD -3.86 min; 95% CI -9.55 to 1.83; p = 0.18; I2=99%).

Conclusion

The phaco-chop technique proved to cause fewer hazards to the corneal endothelium, with less delivered intraocular ultrasound energy when compared to the divide-and-conquer technique.

Intraoperative Performance and Early Postoperative Outcomes Following Phacoemulsification With Three Fluidic Systems: A Randomized Trial

PURPOSE

To compare intraoperative performance and early postoperative outcomes following phacoemulsification with two systems using active fluidics and one using gravity-based fluidics.

METHODS

In this prospective randomized trial, 200 eyes were randomized to the traditional and Active Sentry groups (n = 80 eyes each) where the Centurion Vision System was used with traditional or Active Sentry (Alcon Laboratories, Inc) hand-pieces, respectively, or the Infinit group (n = 40 eyes) where the Infiniti Vision System (Alcon Laboratories, Inc) was used. Within the traditional and Active Sentry groups, there were two subgroups with low (30 mm Hg) or high (55 mm Hg) intraocular pressure (IOP) used. Outcome measures compared were: cumulative dissipated energy (CDE), percentage change in central corneal thickness (CCT) at 1 day, 1 week, and 1 month, anterior chamber cells at 1 day and 1 week, rate of rise and fall of IOP following occlusion break, corneal endothelial cell density (ECD), and macular thickness 6 months postoperatively.

RESULTS

CDE was significantly lower in group II compared to the traditional group (2.96 ± 1.4 vs 4.14 ± 2.2, P = .001). With 30 mm Hg IOP, the Active Sentry group had significantly less percentage change in CCT at 1 week postoperatively compared to the traditional handpiece group (0.01% vs 0.02%, P = .008). Incidence of anterior chamber cells less than grade 2 on day 1 was significantly higher in the Active Sentry group (82.9% vs 52%, P = .03). Percentage change in ECD was significantly lower in the Active Sentry group (-0.957 vs -0.98%, P = .005). Significantly faster rise of IOP to baseline following occlusion break was seen in the Active Sentry group.

CONCLUSIONS

The use of Active Sentry handpiece was associated with lower CDE, less postoperative increase in CCT, fewer anterior chamber cells, and faster rise of IOP following occlusion break. [J Refract Surg. 2024;40(5):e304-e312.].

Surgical Efficiency Comparison Between Two Phacoemulsification Systems

Purpose

To assess the surgical efficiency in cataract surgery comparing two phacoemulsification systems.

Methods

Prospective, consecutive-comparative study in a two-site private practice. Three hundred and one eyes undergoing standard or femtosecond laser-assisted (FLACS) cataract surgery with either the R-Evo Smart (BVI, Waltham, USA) and/or the Centurion Vision System (Alcon, Fort Worth, USA). Preoperative eye characteristics (degree of cataract using the lens opacities classification system LOCS III grading) and intraoperative outcomes (total ultrasound time and total estimated fluid aspirated/drainage bag weighting) were registered in all cases.

Results

One hundred and fifty-five eyes undergone cataract surgery with the R-Evo Smart and 146 eyes with the Centurion Vision System phacoemulsification systems. Mean cataract grade was 3.07 ± 0.78 and 2.96 ± 0.85 for the R-Evo Smart and Centurion Vision System groups, respectively (p = 0.12). Mean total ultrasound time was 18.99 ± 12.85 and 40.24 ± 21.91 seconds for the R-Evo Smart and Centurion Vision System groups, respectively (p < 0.01). Mean total estimated fluid aspirated/drainage bag weighting was 53.00 ± 14.56 g and 54.33 ± 14.88 cc for the R-Evo Smart and Centurion Vision System groups, respectively (p = 0.21). Considering non-FLACS surgery (98 eyes with the R-Evo Smart and 63 eyes with the Centurion Vision System), mean cataract grade was 2.95 ± 0.74 and 2.97 ± 0.91 for the R-Evo Smart and Centurion Vision System groups, respectively (p = 0.44). Mean total ultrasound time was 19.96 ± 11.20 and 42.84 ± 28.35 seconds for the R-Evo Smart and Centurion Vision System groups, respectively (p < 0.01). Mean total estimated fluid aspirated/drainage bag weighting was 55.95 ± 14.76 g and 55.97 ± 13.62 cc for the R-Evo Smart and Centurion Vision System groups, respectively (p = 0.49). No adverse events were found in the two groups of eyes.

Conclusion

The objective measurement of surgical efficiency through total ultrasound time during lens removal and fluid consumption during both lens removal and irrigation/aspiration proved R-Evo Smart to be an efficient phacoemulsification platform, in comparison with the current standard of care Centurion Vision System.

Effect and Safety of Pressure Sensor-equipped Handpiece in Phacoemulsification System

PURPOSE

To evaluate the effect of the Active Sentry handpiece of the Centurion Vision System compared to the Centurion Ozil handpiece for phacoemulsification in cataract surgery.

METHODS

A retrospective study was conducted on 281 patients (449 eyes) who underwent cataract surgery between August 2020 and June 2021. Preoperative measurements, intraoperative parameters, complication rate, and postoperative outcomes were compared between the Active Sentry handpiece and the Centurion Ozil handpiece groups. Additionally, the parameters were compared in different cataract severity groups and multiple predictive factors for the number of active surge mitigation (ASM) actuations were assessed with the Active Sentry handpiece.

RESULTS

There were 198 eyes in the Active Sentry group and 251 eyes in the Centurion Ozil group. There were no statistically significant differences between the two groups, as the cumulative dissipated energy in the Active Sentry and Centurion Ozil groups were 8.32 ± 7.74 and 7.87 ± 9.25 μJ, respectively (p = 0.576). Total surgery time, ultrasound usage time, aspiration time, amount of fluid aspirated, postoperative corrected distant visual acuity, and postoperative decrease in corneal endothelial cell density were comparable between the two groups. The significant contributors to the number of ASM actuations were age, preoperative corrected distant visual acuity, axial length, and total ultrasound time.

CONCLUSIONS

There was no clear advantage of the Active Sentry handpiece compared to the Centurion Ozil handpiece. ASM actuation increases with age, poor visual acuity before surgery, short axial length, and prolonged ultrasound usage time. It is expected that in more severe and high-risk cataract surgery, the Active Sentry handpiece functions more effectively, possibly affecting the safety and prognosis.

Application of the Active-Fluidics System in Phacoemulsification: A Review

The fluidics system is an indispensable and primary component of phacoemulsification. Both the gravity-fluidics system and active-fluidics system are commonly used in practice. The irrigation pressure of the gravity-fluidics system is determined by the bottle height, which is relatively constant, while the active-fluidics system is paired with a cassette that contains pressure sensors to monitor intraocular pressure changes. The active-fluidics system allows surgeons to preset a target intraocular pressure value, and it replenishes the fluids proactively; thus, the intraocular pressure is consistently maintained near the target value. Under such circumstances, stable intraocular pressure and anterior chamber volume values could be acquired. Research on surgical safety, efficiency and results have reported several strengths of the active-fluidics system. It is also advantageous in some complicated cataract surgeries. However, the system is not widely used at present, mainly due to its low penetration rate and high equipment cost. Some of its updates such as the new Active Sentry handpiece showed potential superiority in laboratory studies recently, but there is still further research to be conducted. This article gives an overview of the mechanism and performance of the active-fluidics system, and it is expected to provide clues for future research.

Active-fluidics versus gravity-fluidics in lens extraction: A systematic review and meta-analysis of randomized controlled trials

OBJECTIVE

To investigate differences in outcomes between active-fluidics and gravity-fluidics phacoemulsification systems.

METHODS

We searched PubMed, Embase, and Cochrane Library databases for randomized controlled trials (RCTs) published no later than December 1, 2021. The Cochrane Collaboration risk of bias tool was used for quality assessment. We presented the outcomes as standardized mean differences (SMDs) with 95% confidence intervals (CI). Sensitivity analysis was performed by removing studies that included ≥2 types of phacoemulsification tips.

RESULTS

We analyzed six RCTs that totally enrolled 884 patients. Patients undergoing lens extraction with active-fluidics systems exhibited lower cumulative dissipated energy (CDE), total aspiration time (TAT), and estimated fluid usage (EFU) compared with patients who did not (SMD [95% CI]: CDE, - 0.818 [ - 1.054 to - 0.582]; TAT, - 0.664 [ - 0.850 to - 0.479]; EFU, - 0.655 [ - 0.932 to - 0.378]). A sensitivity analysis revealed similar results for CDE, TAT, and EFU. For endothelial cell density (ECD) 1 week after surgery, ECD 1 month after surgery, and central corneal thickness (CCT) 1 week after surgery, outcomes of both systems were comparable (ECD at 1 week, 0.074 [ - 0.177 to 0.325]; ECD at 1 month, 0.069 [ - 0.167 to 0.305]; CCT 1 week after surgery, 0.077 [ - 0.173 to 0.328]). No severe adverse events in patients treated with either system were reported in the studies.

CONCLUSION

Active-fluidics systems are superior to gravity-fluidics systems with respect to CDE, TAT, and EFU; no differences in postoperative ECD and CCT were observed. Future studies are required to determine the reasons for heterogeneity and to detect rare adverse events.

A prospective randomized clinical trial of active-fluidics versus gravity-fluidics system in phacoemulsification for age-related cataract (AGSPC)

BACKGROUND

To figure out the efficacy, effects, safety and patient's subjective perceptions of phacoemulsification with the active-fluidics system (AFS).

PATIENTS AND METHODS

This was a prospective, randomized, double-masked, controlled clinical study. Age-related cataract patients were recruited and randomly assigned to the AFS group and gravity-fluidics system (GFS) group in a ratio of 1:1 to have phacoemulsification. Participants were followed up at one day, one week, one month and three months postoperatively (Chinese Clinical Trial Registry, ChiCTR2100044409).

RESULTS

The overall included participants were 107 finally. The total aspiration time of the AFS group was significantly less than that of the GFS group (p = .020), while no significant difference existed in cumulative dissipated energy and estimated fluid usage between the two groups. The best corrected visual acuity was significantly better in the AFS group at one day and one week postoperatively (p = .002, p = .038 respectively). The recovery of central corneal thickening and macular superficial vasculature increase was earlier in the AFS group. The central retinal thickness was significantly higher in the GFS group at one month and three months postoperatively (p = .029, p = .016 respectively). The incidence of corneal adverse events was higher in GFS group (p = .035). No serious adverse events occurred in either group. Pain scores and the scores of Cat-PROM5 questionnaire of the AFS group were significantly lower than that of the GFS group (p = .011, p = .002 respectively).

CONCLUSION

AFS improves the efficiency, effects, safety and patients' subjective perceptions of phacoemulsification compared with GFS. It is worthwhile to promote its application in cataract surgery.KEY MESSAGESThe active-fluidics system automatically detects and maintains stable intraocular pressure at the set value.The active-fluidics system improves the efficiency, effects, safety and patients' subjective perceptions in phacoemulsification.

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.

Zero Phaco: A new technique for dealing with soft cataracts

Phacoemulsification in soft cataracts can be challenging due to the lack of rigid cleavage planes and the inability to crack. We describe a new phacoemulsification technique for dealing with soft cataracts using high vacuum and zero energy. Following capsulorhexis and hydrodissection, we introduced the phacoemulsification probe, keeping the torsional and longitudinal power at zero. A central groove was created in sculpting mode. We held the nucleus with adequate vacuum in chop mode and divided the nucleus. Then, we rotated and chopped the nucleus similarly into small pieces without using any power. For emulsification, we increased the vacuum to 600 mmHg and then shredded and stuffed the pieces into the phaco probe by the chopper. A newer generation phaco machine with active fluidic system and monitored pressurized infusion helps the surgeon control the intraocular pressure (IOP) and hold the nucleus with vacuum alone, allowing chopping and emulsifying of the pieces without any energy.

Active-fluidics versus gravity-fluidics system in phacoemulsification for age-related cataract (AGSPC): study protocol for a prospective, randomised, double-blind, controlled clinical trial

INTRODUCTION

The active-fluidics system is a new irrigation system of phacoemulsification that automatically detects and maintains stable intraocular pressure at the set value. This trial is designed to compare the efficacy, visual outcomes, safety and patients' subjective perceptions of cataract surgery with the active-fluidics system and gravity-fluidics system.

METHODS AND ANALYSIS

This trial will recruit 110 patients with age-related cataract at the Chinese People's Liberation Army (PLA) General Hospital (Beijing, China) and they will be randomly assigned to the active-fluidics group and gravity-fluidics group in a ratio of 1:1 to have phacoemulsification. Patients will be followed up at 1 day, 1 week, 1 month and 3 months postoperatively. The primary outcomes are the cumulative dissipated energy and best corrected visual acuity. Secondary outcomes include: estimated fluid usage, U/S time, total aspiration time, intraocular pressure, corneal endothelium parameters, retinal thickness, macular superficial vessel density, pain scores, scores of the Cataract surgery Patient-Reported Outcome Measures Questionnaire and the complication rates. The data will be independently analysed by the statistical team, who will be masked for the allocation information as participants are.

ETHICS AND DISSEMINATION

This study was approved by the Ethics Committee of Chinese PLA General Hospital (approval no. S2021-068-01). Informed consent will be obtained from each participant. All the results will be published in peer-reviewed journals and used for scholarly communication or technical guidance. Protocol version 1.0.

TRIAL REGISTRATION NUMBER

Chinese Clinical Trial Registry (ChiCTR2100044409).

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.

Point your SmartPhone at the code above. If you have a QR code reader the video abstract will appear. Or use:

https://youtu.be/xzalrupRtlw

Active sentry versus ozil hand piece - A prospective randomized comparative study

PURPOSE

To compare the safety and efficacy of active sentry hand piece with ozil hand piece for centurion phacoemulsification system.

SETTING

Tertiary eye centre, South India.

DESIGN

Prospective observational study.

METHODS

A total of 204 eyes of 204 patients with uncomplicated cataract who underwent phacoemulsification cataract surgery with centurion vision system were randomized into two groups: Ozil hand piece (n=101) and active sentry hand piece (n =103). Intra-operative factors like patient's pain perception, surgeon's comfort level, amount of phacoemulsification energy and aspiration fluid used, frequency of activation of active surge mitigation (ASM) were analyzed and post-operatively corrected distance visual acuity (CDVA) and corneal edema on day one were compared.

RESULTS

Patient's pain perception was comparable between the groups with no significant differences in proportion of patients who had pain free surgery (66% vs 61.3%) or those experienced moderate pain (24.3% vs 28.7%). Surgeons were more comfortable using ozil hand piece during entry into anterior chamber and emulsification of hard nuclei (48.5% vs 28.6%). The mean CDE for soft cataracts was 5.6 and 4.8 and for hard cataracts it was 9.3 and 9.4 for ozil and active sentry group respectively. ASM was activated for 53 (51.5%) eyes, of which 42 (79.2%) eyes had soft cataract and 11 (20.7%) had hard cataract. Post-operative CDVA and incidence of corneal edema was comparable between the groups.

CONCLUSION

For centurion vision system, active sentry hand piece is safe and efficacious as the ozil hand piece with added benefit of operating at lower IOP levels.

Optical coherence tomography angiography evaluation of the effects of phacoemulsification cataract surgery on macular hemodynamics in Chinese normal eyes

PURPOSE

To quantitatively evaluate the possible effects of phacoemulsification cataract surgery on macular hemodynamics using optical coherence tomography angiography (OCTA).

METHODS

This was a prospective observational study. Superficial and deep macular vascular densities, as well as parameters of foveal avascular zone (FAZ), were measured preoperatively (baseline) and at 1 day, 1 week, and 4 weeks postoperatively in normal eyes (≥ 22 mm and ≤ 24 mm) of patients scheduled for phacoemulsification cataract surgery with intraocular lens implantation. The correlations between the rate of change of pre- and postoperative vascular densities and surgical parameters were analyzed.

RESULTS

A total of 107 eyes of 107 patients were included in this study. Compared to the baseline measurements, no statistically significant variation was found in macular vascular densities at 1 day after the surgery (P > 0.05). Both superficial and deep macular vascular densities were significantly increased postoperatively at weeks 1 and week 4 (P < 0.05; P < 0.05); however, no statistically significant differences were detected in any of the FAZ parameters between the baseline measurements and the entire follow-up period (P > 0.05 for all). Also, no statistically significant correlations were established between main surgical parameters and macular vascular densities changes.

CONCLUSIONS

In normal eyes, macular blood perfusion gradually increased after phacoemulsification cataract surgery and was stabilized in one week. The foveal avascular zone was stabilized before and after the surgery. The main parameters and intraoperative perfusion of phacoemulsification surgery may not be the key factors affecting macular hemodynamics.

Early changes in retinal microcirculation after uncomplicated cataract surgery using an active-fluidics system

PURPOSE

To evaluate the early changes in retinal microcirculation after uncomplicated cataract surgery using an active-fluidics system.

MATERIALS AND METHODS

Patients underwent uncomplicated cataract surgery for both eyes were enrolled. The two eyes of the patients were randomly assigned to two groups, the active-fluidics group and the gravity-fluidics group. One eye using an active-fluidics system, and the other using a gravity-fluidics system. Optical coherence tomography angiography (OCTA) was performed at 1 day, 7 days, 30 days, and 90 days after surgery.

RESULTS

Fifty eyes (25 patients) were included in the final analysis. A significantly lower cumulative dissipated energy (CDE), estimated fluid usage (EFU), and total aspiration time (TAT) were observed in the active-fluidics group (all P<0.05). The superficial vessel density at parafoveal region increased at 7 days and 30 days after cataract surgery in the eyes of both the active-fluidics and gravity-fluidics groups, with the fluctuation in eyes of the gravity-fluidics group more significant. The vessel density of deep capillary plexus remained stable during the follow-up period. Significant changes of retinal thickness in macular region (fovea, parafovea) were observed in eyes of the gravity-fluidics group through the comparison of corresponding values at different time points (p = 0.008, 0.005). No significant change in retinal thickness was observed in eyes of the active-fluidics.

CONCLUSIONS

Retinal microcirculation and thickness were disturbed after cataract surgery using the gravity-fluidics infusion system. The active-fluidics system not only improved the surgical efficacy but also protected the retinal vasculature during cataract surgery.

CLINICAL TRIALS REGISTRATION

The study has been registered at www.clinicaltrials.gov with its clinical trial accession number of NCT0130500.

Elevated intraocular pressure causes cellular and molecular retinal injuries, advocating a more moderate intraocular pressure setting during phacoemulsification surgery

PURPOSE

To evaluate the cellular and molecular retinal injuries induced by various intraocular pressure (IOP) settings in a mouse model of acute ocular hypertension (AOH), and to advise using a more moderate target IOP during phacoemulsification (phaco) surgery.

METHODS

A mouse model of AOH that mimics a transient IOP elevation during phacoemulsification cataract surgery was established. Six groups with various settings of target IOP were included. Retinal tissues were assessed with terminal deoxynucleotidyl transferase-mediated 2'-deoxyuridine 5'-triphosphate nick end-labeling (TUNEL) staining for neuron loss, immunofluorescence with Iba1 for microglia activation, and quantitative real-time polymerase chain reaction analysis with tight junction proteins (claudin-3 and claudin-5) or classic inflammation markers (IL-1β and eNOS) for impairment of the blood-retinal barrier (BRB) and inflammatory injury.

RESULTS

Compared with those in the 45-mmHg IOP group, significantly increased number of neurons loss and increased microglia activation were observed in 90-mmHg IOP group. In addition, the expression of claudin-3 and claudin-5 was significantly decreased, while the expression of IL1-β and eNOS was up-regulated, indicating impairment of the BRB and inflammatory injury in the retina. Furthermore, these findings of neuron loss, microglia activation, and inflammation in the 90-mmHg groups were exacerbated when an IOP-induced retinal injury was established 5 days earlier, while those in the 45-mmHg groups remained almost unchanged.

CONCLUSIONS

In conclusion, these results showed that a relatively commonly used high IOP setting (90 mmHg) could induce significantly more serious retinal injury. An IOP setting around 45 mmHg is relatively safe and might be recommended in phaco surgery, especially in patients with advanced glaucoma, previous acute angle closure crisis, or other diseases with fragile retina and optic nerve.

Effect of high-vacuum setting on phacoemulsification efficiency

PURPOSE

To evaluate the effect of a high-vacuum setting versus a low-vacuum setting on the efficiency of phacoemulsification.

SETTING

Sunderland Eye Infirmary, Sunderland, United Kingdom.

DESIGN

Prospective clinical trial.

METHODS

Consecutive patients having cataract surgery in 2014 were recruited. Cataract surgery was performed by 2 experienced surgeons using a phacoemulsification machine with monitored forced infusion. The cataractous lens was split into 2 heminuclei using the stop-and-chop technique; in 1 heminucleus, phacoemulsification and aspiration used a high-vacuum setting (600 mm Hg; treatment group) and in the other heminucleus, a low-vacuum setting (350 mm Hg; control group). The high and low settings were alternated by case per the operating list to reduce surgeon bias. The main outcome measures were cumulative dissipated energy (CDE) and active heminucleus removal time.

RESULTS

One hundred sixty patients (160 eyes) were enrolled in the study, and 158 were included in the analysis. The CDE per heminucleus was significantly lower with the high-vacuum setting than with the low-vacuum setting (mean 2.81 percent-seconds; 95% confidence interval (CI), 2.44-3.21 versus 3.81 percent-seconds; 95% CI, 3.38-4.20; P < .001). The active heminucleus removal time was significantly shorter in the high-vacuum group than the low-vacuum group (mean 27.77 seconds; 95% CI, 25.26-30.19 versus 33.59 seconds; 95% CI, 31.07-35.92; P < .001). The observed differences were independent of the surgeon, patient age and sex, incision size, and nucleus density. No intraoperative complications were observed in either group.

CONCLUSION

A high-vacuum setting improved phacoemulsification efficiency using an active fluidics system and torsional phacoemulsification.

Active-fluidics-based torsional phacoemulsification in diabetic eyes: A prospective interventional study

Purpose

To compare the outcomes of active-fluidics based torsional phacoemulsification in diabetics and nondiabetics using a balanced tip.

Methods

Two hundred and forty-eight patients undergoing senile cataract surgery using torsional phacoemulsification on an active-fluidics-based platform from December 2016 to August 2017 were included in this prospective, nonrandomized, interventional cohort study; of the 248 patients, 54 were controlled diabetics and 194 were nondiabetics. Intraoperative parameters such as cumulative dissipated energy (CDE), total ultrasound time, torsion usage time, torsion amplitude, aspiration time, and fluid usage were documented and compared. Endothelial cell loss (ECL) and central corneal thickness (CCT) were evaluated at 1 month postoperatively.

Results

Diabetics and nondiabetics did not differ in CDE, total ultrasound time, torsion amplitude, aspiration time, fluid usage, endothelial cell count, and CCT. ECL on Day 1 (10.2 ± 8.0%) and Day 30 (11.05 ± 8.3%) were significantly higher in diabetics (P = 0.025 and P = 0.045, respectively). There was an increase in CCT on Day 1 (P = 0.018), which settled by Day 30. Grade 4 cataracts in diabetics had significantly higher CCT at Day 1 (P = 0.032) and Day 30 (P = 0.007). In the diabetic subgroup, Grades 3 and 4 cataracts required lower CDE (P < 0.001) and Grade 4 cataracts showed higher ECL than others till 1 month of follow-up (P < 0.05).

Conclusion

Intraoperative and postoperative parameters after torsional phacoemulsification are comparable in diabetics and nondiabetics. Endothelial changes and pachymetry may be related to the grade of cataract in diabetics.

Intraoperative intraocular pressure fluctuation during standard phacoemulsification in real human patients

INTRODUCTION

To evaluate the results of the fluctuations of intraocular pressure (IOP) and calculated mean ocular perfusion pressure (MOPP) during the usual steps of standard phacoemulsification.

METHODS

Nine human eyes were evaluated. The IOP was measured indirectly by electronic applanation tonometer. The MOPP was calculated using the systolic blood pressure (SBP), the diastolic blood pressure (DBP) and the IOP: MOPP = 2/3x[DBP + 1/3x(SBP - DBP)] - IOP. The operations were performed with the INFINITI^® Vision System: main incision 2.2 mm, coaxial handpiece, 2 paracenteses 1.1 mm, bimanual irrigation/aspiration, bottle height 100 cm. As ocular viscoelastic device (OVD) Hypromel 2.5% (UNIMED) was used.

RESULTS

The initial and final IOPs were 17-30 Torr (median 18) and 6-16 Torr (median 8), respectively. The IOP values oscillated between 4 and 63 Torr during the procedure. The highest values of the IOP were achieved at the beginning of phacoemulsification (from 42 to 63 Torr). The maximum pressure higher than 50 mmHg and 60 mmHg was found in 89% and 30% of cases, respectively. The mean ocular perfusion pressure (MOPP) at the beginning of the procedure was 46.4-67.0 (median 53.3) and 0.4-42.0 (median 19.3) during the maximum intraocular pressure.

CONCLUSIONS

Measured IOP as well as MOPP varied in all normal steps of real phacoemulsification. High values of intraoperative IOL induced by irrigation may compromise the intraocular perfusion. These fluctuations may induce impairment of the optic nerve perfusion, as well as retina, or choroid.

Comparative studies between longitudinal and torsional modes in phacoemulsification, using active fluidics technology along with the intrepid balanced tip

Purpose:

To compare and report the intra- and postoperative outcomes of phacoemulsification between longitudinal (LPKE) and torsional (TPKE) mode, using active fluidics along with the intrepid balanced tip.

Methods:

This single center prospective randomized comparative study comprised a total 108 consecutive eyes of 108 patients having senile cataract subdivided into nuclear opalescence (NO) grades II–IV according to the lens opacities classification system III (LOCS III). Cataracts of each grade were randomly assigned to two groups LPKE (n = 54) and TPKE (n = 54) mode, who were operated on by the same surgeon using same machine (Centurion^® Alcon Laboratories, Inc., USA) having features of both active fluidics and intrepid balanced tip. Pre-, intra-, and postoperative evaluations were done independently by a different author, who was masked to the surgical procedures. Patients were evaluated on the postoperative days (PODs) 1, 7, 15, and 28. Intraoperative outcome measures were cumulative dissipated energy (CDE) and ultrasound time (UST). Postoperative outcome measures were endothelial cell loss (ECL), central corneal thickness (CCT), and best-corrected visual acuity (BCVA).

Results:

Age, gender, and NO-grade distribution among two modes were comparable (P > 0.05). Difference of CDE and UST between modes were found to be significant (P < 0.001) in favor of TPKE with all NO-grades. TPKE mode performs better than LPKE mode with regard to ECL, CCT-change, and BCVA-change, although the differences were found to be insignificant (P > 0.05).

Conclusion:

When using active fluidics along with the intrepid balanced tip, TPKE mode appeared to be a more efficient mode of PKE with reduced mean UST and CDE across all NO-grades, as compared to LPKE mode. However, ECL, CCT-change, and BCVA-change were seemed to be comparable between the two modes.

Complications of cataract surgery in eyes filled with silicone oil

INTRODUCTION

The aim of the study was to evaluate complications of cataract surgery in eyes filled with silicone oil.

METHODS

This retrospective, noncomparative, consecutive case series analyzed medical files of patients with eyes filled with silicone oil undergoing cataract surgery. Phacoemulsification with posterior chamber intraocular lens implantation was conducted with or without concurrent silicone oil removal.

RESULTS

In this study, 121 eyes of 120 patients were included. In 32 eyes (26.4%) with evident silicone oil microemulsification or silicone oil-associated open-angle glaucoma, silicone oil was removed prior to phacoemulsification through a pars plana incision and no cases of posterior capsular rupture occurred during the subsequent cataract surgery. In the remaining 89 eyes, phacoemulsification was performed with silicone oil in the vitreous cavity. In these eyes, the rate of posterior capsular rupture was 9/89 (10.1%) and the rate of silicone oil migration into the anterior chamber through an apparently intact posterior capsule was 5/89 (5.6%). In 94 eyes (77.7%), an intraocular lens was inserted into the capsular bag, in 3 eyes (2.5%) into the sulcus, and in 1 eye (0.8%) a transscleral suturing was performed.

CONCLUSIONS

In this series, complications related to the silicone oil were not uncommon during cataract surgery. In the majority of patients without evident silicone oil microemulsification or silicone oil-associated open-angle glaucoma, cataract surgery and posterior chamber intraocular lens implantation were performed while leaving the silicone oil in place.

Prospective study of Centurion® versus Infiniti® phacoemulsification systems: surgical and visual outcomes

AIM

To evaluate surgical outcomes (SOs) and visual outcomes (VOs) in cataract surgery comparing the Centurion^® phacoemulsification system (CPS) with the Infiniti^® phacoemulsification system (IPS).

METHODS

Prospective, consecutive study in a single-site private practice. Totally 412 patients undergoing cataract surgery with either the CPS using the 30-degree balanced^® tip (n=207) or the IPS using the 30-degree Kelman^® tip (n=205). Intraoperative and postoperative outcomes were documented prospectively up to one month follow-up. Nuclear sclerosis (NS) grade, cumulated dissipated energy (CDE), preoperative corrected distance visual acuity (CDVA), and CDVA at one month were recorded.

RESULTS

CDE was 13.50% less in the whole CPS compared with the whole IPS subcohort. In eyes with NS grade III or greater, CDE was 28.87% less with CPS (n=70) compared with IPS (n=44) (P=0.010). Surgical complications were not statistically different between the two subcohorts (P=0.083), but in the one case of vitreous loss using the CPS, CDVA of 6/4 was achieved at one month. The mean CDVAs (VOs) at one month for NS grade III and above cataracts were -0.17 logMAR (6/4.5) in the CPS and -0.15 logMAR (6/4.5) in the IPS subcohort respectively (P=0.033).

CONCLUSION

CDE is 28.87% less, and VOs are significantly improved, in denser cataracts in the CPS compared with the IPS. The authors recommend the CPS for cases with denser nuclei.

Outcomes study between femtosecond laser-assisted cataract surgery and conventional phacoemulsification surgery using an active fluidics system

Purpose

The purpose of this study was to compare intraoperative parameters between femtosecond laser-assisted cataract surgery (FLACS) and conventional phacoemulsification using Centurion^® Vision System with Active Fluidics.

Setting

This study was performed at Brasília Ophthalmologic Hospital, Brasília, Federal District, Brazil.

Patients and methods

This was a prospective randomized comparative study. Patients with the diagnosis of cataract and surgical extraction programmed were divided into two groups: conventional phacoemulsification and FLACS. Intraoperative data were collected and submitted for statistical analysis.

Results

A total of 400 eyes were enrolled, 200 in each group. There were no surgical complications. Groups were statistically equivalent in age and nucleus density. Cumulative dissipated energy and torsional time were significantly reduced in the FLACS group. Conventional surgery had less fluid usage, total case time and aspiration (ASP) time.

Conclusion

FLACS with Active Fluidics System can reduce the ultrasound energy use during cataract surgery, in spite of increasing case time, fluid usage and ASP time.

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.

COMPARISON OF RECENTLY USED PHACOEMULSIFICATION SYSTEMS USING A HEALTH TECHNOLOGY ASSESSMENT METHOD

Objectives: To compare the recently used phacoemulsification systems using a health technology assessment (HTA) model.

Methods: A self-administered questionnaire, which included questions to gauge on the opinions of the recently used phacoemulsification systems, was distributed to the chief cataract surgeons in the departments of ophthalmology of eighteen tertiary hospitals in Shanghai, China. A series of senile cataract patients undergoing phacoemulsification surgery were enrolled in the study. The surgical results and the average costs related to their surgeries were all recorded and compared for the recently used phacoemulsification systems.

Results: The four phacoemulsification systems currently used in Shanghai are the Infiniti Vision, Centurion Vision, WhiteStar Signature, and Stellaris Vision Enhancement systems. All of the doctors confirmed that the systems they used would help cataract patients recover vision. A total of 150 cataract patients who underwent phacoemulsification surgery were enrolled in the present study. A significant difference was found among the four groups in cumulative dissipated energy, with the lowest value found in the Centurion group. No serious complications were observed and a positive trend in visual acuity was found in all four groups after cataract surgery. The highest total cost of surgery was associated with procedures conducted using the Centurion Vision system, and significant differences between systems were mainly because of the cost of the consumables used in the different surgeries.

Conclusions: This HTA comparison of four recently used phacoemulsification systems found that each of system offers a satisfactory vision recovery outcome, but differs in surgical efficacy and costs.