Skip to main content
Download PDF

Safety and prognosis of phacoemulsification using active sentry and active fluidics with different IOP settings - a randomized, controlled study

BMC Ophthalmology volume 24, Article number: 350 (2024) Cite this article

Abstract

Purpose

To explore the impact of different intraoperative intraocular pressure (IOP) settings on the safety and prognosis in phacoemulsification.

Methods

Age related cataract patients who met the inclusion criteria and underwent phacoemulsification by using active sentry handpiece and active fluidics system. According to different intraoperative IOP settings during surgery, they were randomly divided into two groups: the 20mmHg group and the 60mmHg group. The best corrected visual acuity (BCVA), cumulative dissipated energy (CDE), total U/S time, active surge mitigation (ASM), estimated fluid usage (EFU) as well as the changes in corneal thickness (CT), corneal epithelial layer thickness (CELT) and endothelial cell density (ECD) were collected. The post-operative follow-up was only 1 day.

Results

A total of 110 cases (110 eyes) were included in the study. There were 55 eyes in each group. There was no statistically significant difference in postoperative BCVA (p = 0.839). The CDE, total U/S time and EFU during surgery were (5.22 ± 3.31), (30.60 ± 15.06), (45.07 ± 12.68) and (4.70 ± 2.83), (27.39 ± 13.75), (42.38 ± 11.93) in the 20mmHg group and 60mmHg group (p = 0.381, 0.246, 0.254). The ASM during surgery in the 20mmHg group and 60mmHg group were (0.95 ± 2.77) and (7.24 ± 6.34), respectively. The 20mmHg group showed a significant decrease in ASM (p < 0.001). There was no statistically significant difference in the changes in CT, CELT and ECD before and after surgery between the two groups (p = 0.913, 0.825, 0.624). Both groups did not experience any intraoperative complications, such as posterior capsule rupture.

Conclusion

A lower IOP setting of 20 mmHg can significantly reduce the occurrence of intraoperative surges during phacoemulsification. And there was no increase in rate of complications.

Trial Registration

The trial registration number is ChiCTR2100050240. The registered date is August 24th, 2021.

Peer Review reports

Introduction

The fluidics system is an indispensable and primary component of phacoemulsification. Currently, both the gravity fluidics system (GFS) and active fluidics system (AFS) are commonly used in practice [1]. The irrigation pressure of the GFS is determined by the bottle height, which is usually set at 80 to 100 mm [2, 3]. The irrigation pressure is approximately 59 to 74 mmHg. The AFS allows surgeons to preset a target intraoperative IOP, which is usually set to be 50 to 60 mmHg [4, 5].

In order to avoid the harm caused by high intraoperative IOP, we gradually reduced the preset target intraoperative IOP in practice. In our study, we found phacoemulsification can also be performed safely even when the preset target intraoperative IOP was 20mmHg by using active sentry handpiece accompany with AFS. Active sentry handpiece is a new kind handpiece with an integrated sensor for dynamic measurement of IOP very close to the patient’s eye, which enabled precise and timely IOP measurement [6].

In this study, we compared safety and prognosis of phacoemulsification by using active sentry handpiece and AFS with high and low intraoperative IOP settings.

Methods

Study design and patients

This study was approved by the Ethics Committee of the Yantai Aier Eye Hospital (approval ID: YTAE2021001). The protocol was registered at Chictr.org.cn (ChiCTR2100050240). This was a single center prospective randomized controlled clinical study. Both patients and examiners masked. However, the surgeon was not masked to the settings of intraoperative IOP.

The inclusion criteria for these patients were: 50–80 years of age, 22.0–25.0 mm axial lengths, more than 2000 endothelial cells/mm2, anterior chamber depth beyond 2.5 mm, dilated pupil diameter beyond 6 mm, cataract nucleus grade 3 (according to Emery-Little classification [7]), without any other oculopathy. Only one eye of each patient was included in this study.

All the included patients were randomly assigned to 20mmHg group and 60mmHg group in a 1:1 ratio according to the different settings of the intraoperative IOP during the surgery by using a random number table method.

Surgical procedure and follow-up

All surgeries were performed by the same surgeon (Wang S), who is experienced in phacoemulsification, using the Alcon Centurion Vision system under active sentry handpiece with AFS (Alcon Laboratories, Inc.). The phaco-chop technique was employed to emulsify the nucleus (torsional power: 0-100%, vacuum, 500mmHg, and aspiration flow: 40 cc/min). IA was then used to clear the cortex (vacuum, 500mmHg, and aspiration flow: 38 cc/min). In both phaco and IA procedures, the settings of IOP were 20mmHg and 60mmHg in the 20mmHg group and 60mmHg group respectively. The post-operative follow-up was only 1 day.

Outcome measures and data analysis

Before and 1 day after surgery, the following clinical data of each case were collected: best corrected visual acuity (BCVA), corneal thickness (CT), corneal epithelial layer thickness (CELT) and endothelial cell density (ECD). CT and CELT were measured by Cirrus HD-OCT 5000 (Carl Zeiss Meditec, Inc.). ECD was measured by SP-1P Specular microscope (Topcon, Inc).

During the surgery, cumulative dissipated energy (CDE), total U/S time, estimated fluid usage (EFU) and active surge mitigation (ASM) the occurrence of posterior capsular rupture (PCR) were collected.

The independent-samples t-test was used to compare continuous variables between two groups. The assumption of equal variance was used. The Chi-square tests was used to evaluate differences in categorical variables. Data were analyzed using Statistical Package for Social Sciences software (version 27, International Business Machines Corp.). The level of significance was set to a P-value of 0.05.

Results

Clinical

Fifty-five patients were evaluated in each group. The characteristics of the patients in both groups are shown in Table 1. There were no statistically significant differences in any characteristics between two groups.

Table 1 Demographics and baseline characteristics
Full size table

Primary outcomes

The CDE, total U/S time and EFU during surgery in the 20mmHg group and 60mmHg group were (5.22 ± 3.31), (30.60 ± 15.06), (45.07 ± 12.68) and (4.70 ± 2.83), (27.39 ± 13.75), (42.38 ± 11.93), respectively. There was no significant difference in CDE, total U/S time and EFU between two groups (p = 0.381, 0.246, 0.254) (Table 2). The ASM during surgery in the 20mmHg group and 60mmHg group were (0.95 ± 2.77) and (7.24 ± 6.34), respectively. Compared with the 60mmHg group, the occurrence of ASM was decreased significantly in the 20mmHg group (p < 0.001) (Table 2). There was no occurrence of PCR in both groups.

Table 2 Intraoperative and postoperative parameters
Full size table

Secondary outcomes

Postoperative BCVA was 0.16 ± 0.15 and 0.17 ± 0.14 in the 20mmHg group and 60mmHg group, respectively. There was no difference between two groups (p = 0.839). Changes in CT and CELT were 29.58 ± 25.48 μm, 3.51 ± 3.08 μm in the 20mmHg group and 30.16 ± 30.29 μm, 3.36 ± 3.77 μm in the 60mmHg group. There was no difference between two groups (p = 0.913, 0.825) (Table 2). Changes in ECD were 114.31 ± 242.85/mm2 in the 20mmHg and 136.24 ± 224.34/mm2 in the 60mmHg group. There was no difference between two groups (p = 0.624) (Table 2).

Discussion

Active sentry handpiece can automatically detect patient’s eye level, estimate incision leakage and ASM, which is expected to improve anterior chamber stability [6]. In addition, active sentry handpiece can detect the occlusion break instantaneously by the integrated sensor. While, the traditional handpiece is without sensor, and the sensor is on the cartridge, which led to a longer time delay upon stabilization of the anterior chamber [6]. The integrated sensor in the active sentry handpiece can signal the quick valve technology to release fluid into the aspiration tubing so that an occlusion break surge event is prevented [8]. Therefore, active sentry handpiece offers additional advantages for maintaining the anterior chamber depth even during occlusion breaks [9, 10].

The AFS allows surgeons to preset a target intraoperative IOP, which is usually set to be 50 to 60 mmHg [4, 5]. Due to the advantages of the active sentry handpiece and AFS, lower target intraoperative IOP setting become possible. Previous study also found that lower target intraoperative IOP setting (30-50mmHg) is one benefit of active sentry handpiece [8, 11]. As a high IOP during the surgery may induce ocular perfusion reduction and optic nerve damage, even increasing patients’ anxiety and worsening the surgical outcome [12]. In our study, the target intraoperative IOP was set to be 20 mmHg, which is within the range of physiological IOP. And we explored the impact of low target intraoperative IOP setting on the stability of the anterior chamber, prognosis of cornea and postoperative visual acuity.

ASM is a new feature introduced with the active sentry handpiece, which can reduce the vacuum demand from the anterior chamber by partially venting the aspiration line [8]. It dampens the surge volume demand once the onset of an occlusion break is detected by the sensor in the handpiece [6, 13]. Therefore, ASM can represent the stability of the anterior chamber. In our study, compared with the 60mmHg group, the ASM was significantly reduced in the 20mmHg group. This result indicated that the stability of the anterior chamber was better, when the target intraoperative IOP was set to 20mmHg. It was inconsistent with the previous opinion that higher target intraoperative IOP can improve anterior chamber stability [13]. The different conclusion may be due to the pressure gradient, which the irrigation should compensate during an occlusion break, is lower at a low target intraoperative IOP setting [14].

Previous studies had found that the ultrasonic energy in phacoemulsification could be reduced by using the active sentry handpiece compared with other kinds of handpiece [12, 15, 16]. We researched the effect of different target intraoperative IOP settings on CDE and total U/S time when using an active sentry handpiece. There was no statistically significant difference in the CDE and total U/S time between both groups. We also found there was no difference in the change of ECD between both groups. Previous studies had revealed that the loss of endothelial cells is related to the use of ultrasonic energy in phacoemulsification [17, 18]. Therefore, there was no difference in ECD between both groups, possibly because there was no difference in the use of CDE and total U/S time. Visual recovery, EFU, changes in CT and CELT in the immediate postoperative period were satisfied and comparable between both groups. These results may be related to that only simple cataract patients with nucleus grade 3 were enrolled in our study. If patients with hard nucleus or complicated cataract were enrolled, the results may be different. Chen’s study found that a low target intraoperative IOP setting (30mmHg) could decrease the change of central corneal thickness for low pre-operative ECD patients [11]. While in our study, the pre-operative ECD of included patients was normal.

There were also some limitations of the study. The follow-up time was only one day. The influence of difference target intraoperative IOP settings for retina and optic nerve were not researched. As well, the influence of difference target intraoperative IOP settings for complicated cataract cases should be focused on in the future.

Data availability

The datasets generated and analyzed during the current study are available from the corresponding author on reasonable request.

Abbreviations

IOP:

Intraocular pressure

BCVA:

Best corrected visual acuity

CDE:

Cumulative dissipated energy

ASM:

Active surge mitigation

EFU:

Estimated fluid usage

CT:

Corneal thickness

CELT:

Corneal epithelial layer thickness

ECD:

Endothelial cell density

GFS:

Gravity fluidics system

AFS:

Active fluidics system

PCR:

Posterior capsular rupture

References

  1. Luo Y, Xu G, Li H, Ma T, Ye Z, Li Z. Application of the active-Fluidics System in Phacoemulsification: a review. J Clin Med. 2023;12(2):611. Published 2023 Jan 12.

    Article  PubMed  PubMed Central  Google Scholar 

  2. Nicoli CM, Dimalanta R, Miller KM. Experimental anterior chamber maintenance in active versus passive phacoemulsification fluidics systems. J Cataract Refract Surg. 2016;42(1):157–62.

    Article  PubMed  Google Scholar 

  3. Ward MS, Georgescu D, Olson RJ. Effect of bottle height and aspiration rate on postocclusion surge in Infiniti and Millennium peristaltic phacoemulsification machines. J Cataract Refract Surg. 2008;34(8):1400–2.

    Article  PubMed  Google Scholar 

  4. Chang JS, Ng JC, Chan VK, Law AK. Cataract surgery with a New Fluidics Control Phacoemulsification System in Nanophthalmic eyes. Case Rep Ophthalmol. 2016;7(3):218–26. Published 2016 Oct 21.

    Article  PubMed  PubMed Central  Google Scholar 

  5. Jensen JD, Boulter T, Lambert NG, Zaugg B, Stagg BC, Pettey JH, Olson RJ. Intraocular pressure study using monitored forced-infusion system phacoemulsification technology. J Cataract Refract Surg. 2016;42(5):768–71.

    Article  PubMed  Google Scholar 

  6. Jirásková N, Stepanov A. Our experience with active sentry, and centurion ozil handpieces. Naše zkušenosti s použitím fakoemulzifikační koncovky active sentry a centurion ozil. Cesk Slov Oftalmol. 2021;77(1):18–21.

    PubMed  Google Scholar 

  7. Emery JM, Little JH. Patient selection. In: Emery JM, Little JH, editors. Phacoemulsification and aspiration of cataracts; Surgical techniques, complications, and results. St. Louis, MO: CV Mosby; 1979. pp. 45–8.

    Google Scholar 

  8. Cyril D, Brahmani P, Prasad S, Rashme VL, Kamble RS, Balakrishnan NR, Nagu L, Shekhar K. Comparison of two phacoemulsification system handpieces: prospective randomized comparative study. J Cataract Refract Surg. 2022;48(3):328–33.

    Article  PubMed  Google Scholar 

  9. Suzuki H, Igarashi T, Takahashi H. Effect of a new phacoemulsification and aspiration handpiece on anterior chamber stability. J Cataract Refract Surg. 2023;49(1):91–6.

    Article  PubMed  Google Scholar 

  10. Vasavada V, Vasavada AR, Vasavada VA, Vasavada SA, Bhojwani D. Real-time dynamic changes in intraocular pressure after occlusion break: comparing 2 phacoemulsification systems. J Cataract Refract Surg. 2021;47(9):1205–9.

    Article  PubMed  Google Scholar 

  11. Liu Y, Hong J, Chen X. Comparisons of the clinical outcomes of Centurion® active fluidics system with a low IOP setting and gravity fluidics system with a normal IOP setting for cataract patients with low corneal endothelial cell density. Front Med (Lausanne). 2023;10:1294808.

    Article  PubMed  Google Scholar 

  12. Mansukhani SA, Chen JJ, Fairbanks AM, Foster RC, Erie JC, Baratz KH, Hodge DO, Bhatti MT. A Population-based study of Anterior Ischemic Optic Neuropathy following cataract surgery. Am J Ophthalmol. 2021;222:157–65.

    Article  PubMed  Google Scholar 

  13. Thorne A, Dyk DW, Fanney D, Miller KM. Phacoemulsifier occlusion break surge volume reduction. J Cataract Refract Surg. 2018;44(12):1491–6.

    Article  PubMed  Google Scholar 

  14. Beres H, de Ortueta D, Buehner B, Scharioth GB. Does low infusion pressure microincision cataract surgery (LIPMICS) reduce frequency of post-occlusion breaks? Rom J Ophthalmol. 2022 Apr-Jun;66(2):135–9.

  15. Brézin AP, Monnet D, Lignereux F, Rozot P, Jilet L, Abdoul H. Impact of a handpiece with a built-in fluidics pressure sensor on phacoemulsification: a multicentre prospective comparative study. BMJ Open Ophthalmol. 2023;8(1):e001431.

    Article  PubMed  PubMed Central  Google Scholar 

  16. Sabur H, Unsal U. The efficacy and safety profile of cataract procedures performed with a sensor-embedded handpiece and a new hybrid phaco tip. Eur J Ophthalmol. 2022;32(6):3438–43.

    Article  PubMed  Google Scholar 

  17. Dewan T, Malik PK, Kumari R. Comparison of effective phacoemulsification time and corneal endothelial cell loss using 2 ultrasound frequencies. J Cataract Refract Surg. 2019;45(9):1285–93.

    Article  PubMed  Google Scholar 

  18. Dewan T, Malik PK, Tomar P. Comparison of effective phacoemulsification time and corneal endothelial cell loss using three different ultrasound frequencies: a randomized controlled trial. Indian J Ophthalmol. 2022;70(4):1180–5.

    Article  PubMed  PubMed Central  Google Scholar 

Download references

Acknowledgements

Not applicable.

Our study adheres to CONSORT guidelines and include a completed CONSORT checklist as an additional file.

Funding

This study was funded by research grant from Alcon (IIT75272985).

Author information

Authors and Affiliations

  1. Yantai Aier Eye Hospital, Yantai, China

    Shouyan Wang, Jianjian Tao & Weilin Diao

  2. Department of Ophthalmology, Affiliated Qingdao Third People’s Hospital, Qingdao University, Qingdao, China

    Xiao Yu

  3. Department of Ophthalmology, The Affiliated Hospital of Qingdao University, 16th, Jiangsu Road, Qingdao, 266003, China

    Haiqing Bai

  4. Qingdao Aier Eye Hospital, 519th, Zhujiang Road, Qingdao, 266400, China

    Lin Yao

Authors
  1. Shouyan Wang
    View author publications

    You can also search for this author in PubMed Google Scholar

  2. Jianjian Tao
    View author publications

    You can also search for this author in PubMed Google Scholar

  3. Xiao Yu
    View author publications

    You can also search for this author in PubMed Google Scholar

  4. Weilin Diao
    View author publications

    You can also search for this author in PubMed Google Scholar

  5. Haiqing Bai
    View author publications

    You can also search for this author in PubMed Google Scholar

  6. Lin Yao
    View author publications

    You can also search for this author in PubMed Google Scholar

Contributions

SW, JT and LY were responsible for data collection and performing the statistical analysis. SW, JY, XY, WD, HB and LY were involved in study conception, data interpretation and the drafting and final approval of the manuscript. All authors reviewed the manuscript.

Corresponding authors

Correspondence to Haiqing Bai or Lin Yao.

Ethics declarations

Ethics approval and consent to participate

This study involves human participants and was approved by the Ethics Committee of the Yantai Aier Eye Hospital (approval ID: YTAE2021001). Informed consent to participate was obtained from all of the participants in the study.

Consent for publication

Not applicable.

Competing interests

The authors declare no competing interests.

Additional information

Publisher’s Note

Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations.

Rights and permissions

Open Access This article is licensed under a Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International License, which permits any non-commercial use, sharing, distribution and reproduction in any medium or format, as long as you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons licence, and indicate if you modified the licensed material. You do not have permission under this licence to share adapted material derived from this article or parts of it. The images or other third party material in this article are included in the article’s Creative Commons licence, unless indicated otherwise in a credit line to the material. If material is not included in the article’s Creative Commons licence and your intended use is not permitted by statutory regulation or exceeds the permitted use, you will need to obtain permission directly from the copyright holder. To view a copy of this licence, visit http://creativecommons.org/licenses/by-nc-nd/4.0/.

Reprints and permissions

About this article

Check for updates. Verify currency and authenticity via CrossMark

Cite this article

Wang, S., Tao, J., Yu, X. et al. Safety and prognosis of phacoemulsification using active sentry and active fluidics with different IOP settings - a randomized, controlled study. BMC Ophthalmol 24, 350 (2024). https://doi.org/10.1186/s12886-024-03626-z

Download citation

  • Received:

  • Accepted:

  • Published:

  • DOI: https://doi.org/10.1186/s12886-024-03626-z

Keywords

BMC Ophthalmology

ISSN: 1471-2415

Contact us