Comparison of Early Postoperative Visual Acuity Between Intracapsular and Supracapsular Phacoemulsification: A Randomized Controlled Clinical Trial

NCT07407049 | Not Yet Recruiting

• 1 other identifier: 2025KYPJ174
• Study Type: interventional
• Target: 128
• Locations: 1 country
• Sites: 1

Brief Summary

Cataracts are the leading cause of blindness worldwide, and phacoemulsification combined with intraocular lens implantation has become the most mainstream surgical approach. With advancements in surgical techniques and equipment, this procedure has evolved from a simple vision-restoring surgery into the era of refractive surgery. Patients now have higher expectations for postoperative visual quality, particularly the recovery of early vision, which directly impacts their satisfaction. Intraoperative surgical details have a direct influence on postoperative visual acuity. Thanks to intraoperative optical coherence tomography (iOCT) technology, surgeons have gradually recognized that factors such as surgical incisions and intraoperative anterior chamber collapse can affect the survival of corneal endothelial cells after surgery, which is directly related to early postoperative vision and patient satisfaction. Swept-source intraoperative OCT (SS-iOCT) has further improved imaging range and clarity, helping us discover that the depth of intraoperative ultrasound energy use (such as cumulative dissipated energy) correlates with postoperative corneal endothelial cell loss. This suggests that compared to performing phacoemulsification at the capsular opening plane or in the anterior chamber, intracapsular phacoemulsification may reduce postoperative corneal endothelial cell loss, potentially leading to better early postoperative vision, which is crucial for patient satisfaction. However, evidence is still lacking. Therefore, this study aims to compare the effects of intracapsular versus extracapsular phacoemulsification on early postoperative vision, as well as long-term visual acuity, corneal endothelial cells, corneal changes, and the incidence of intraoperative and postoperative complications.

Conditions

Cataract

Outcome Measures

Primary Outcomes (1)

• The best-corrected distance visual acuity at 1 day postoperatively.

  It was evaluated using the ETDRS visual acuity chart by a masked optometrist, with the examination procedure following the standard ETDRS visual acuity testing protocol, and the unit of measurement was logMAR.

  1 day postoperatively

Secondary Outcomes (6)

• Coefficient of variation of corneal endothelial cell size

  Post-operative day 1, week 1, month 1, month 3, month 6

• The percentage loss of central corneal endothelial cell density compared to the preoperative baseline at post-operative day 1 and post-operative

  1 day and 1 month postoperatively

• Percentage of hexagonal cells

  Post-operative day 1, week 1, month 1, month 3, month 6

• Central corneal thickness

  Post-operative day 1, week 1, month 1, month 3, month 6

• Corneal endothelial cell density

  Post-operative day 1, week 1, month 1, month 3, month 6

Study Arms (2)

Supracapsular Phacoemulsification

ACTIVE COMPARATOR

Procedure: Supracapsular Phacoemulsification

Intracapsular Phacoemulsification

EXPERIMENTAL

Procedure: Intracapsular Phacoemulsification

Interventions

Supracapsular Phacoemulsification PROCEDURE

During phacoemulsification, real-time imaging of the anterior segment was performed using SS-iOCT (Tupai, China), but the surgeon was not able to view the images. The surgeon was instructed to proceed with phacoemulsification as per routine, using phaco energy (i.e., level 3). All other surgical steps were identical to conventional surgery.

Supracapsular Phacoemulsification

Intracapsular Phacoemulsification PROCEDURE

During phacoemulsification, real-time imaging of the anterior segment was performed using SS-iOCT (Tupai, China). The surgeon was required to confirm under SS-iOCT guidance that the phaco tip was located within the capsular bag (as judged by two observers not involved in the surgery) before applying phaco energy (i.e., level 3). All other surgical steps were identical to conventional surgery.

Intracapsular Phacoemulsification

Eligibility Criteria

• Age: 50 Years - 90 Years
• Sex: all
• Healthy Volunteers: No
• Age Groups: Adult (18-64), Older Adult (65+)

You may qualify if:

• Age ≥ 50 years and ≤ 90 years
• Able to cooperate with preoperative examinations
• At least one eye meets the study eye criteria
• Has the capacity and willingness to provide informed consent
• Age-related cataract
• Nuclear opacity (N) graded ≥4 according to the Lens Opacities Classification System III (LOCS III)
• Scheduled for phacoemulsification with intraocular lens implantation
• Pupil size ≥6 mm after dilation
• Corneal endothelial cell density ≥1500 cells/mm²

You may not qualify if:

• Considered unsuitable by the investigator for participation in this clinical trial for other reasons (e.g., unstable systemic condition, uncontrolled blood pressure/blood glucose, severe cardiovascular disease, renal disease, etc.)
• History of myocardial infarction or other cardiac disease requiring hospitalization, cerebral infarction, transient ischemic attack, or acute heart failure within 4 months prior to enrollment.
• Women with childbearing potential (i.e., currently pregnant, breastfeeding, or planning to become pregnant within the next 2 years). Women of childbearing potential should be asked about the possibility of pregnancy, and the investigator will determine when a pregnancy test is necessary.
• Currently participating in another clinical trial
• History of ocular trauma or surgery
• Presence of other ocular diseases (e.g., glaucoma, diabetic retinopathy)
• Other ocular factors that may complicate surgery (e.g., small pupil, shallow anterior chamber)

Sponsors & Collaborators

• Zhongshan Ophthalmic Center, Sun Yat-sen University: lead

Study Sites (1)

Zhongshan Ophthalmic Center, Sun Yat-sen University

Guangzhou, Guangdong, China

Location

MeSH Terms

Conditions

Cataract

Condition Hierarchy (Ancestors)

Lens Diseases; Eye Diseases

Central Study Contacts

Zitian Liu

CONTACT

020-66610729; liuzt25@mail.sysu.edu.cn

Study Design

• Study Type: interventional
• Phase: not applicable
• Allocation: RANDOMIZED
• Masking: DOUBLE
• Who Masked: PARTICIPANT, OUTCOMES ASSESSOR
• Purpose: TREATMENT
• Intervention Model: PARALLEL
• Sponsor Type: OTHER
• Responsible Party: SPONSOR

Study Record Dates

• First Submitted: February 5, 2026
• First Posted: February 12, 2026
• Study Start: February 24, 2026
• Primary Completion (Estimated): June 30, 2026
• Study Completion (Estimated): December 31, 2026
• Last Updated: February 12, 2026

Record last verified: 2026-02

Locations

CN (1)