Comparing Outcomes of Femtosecond Laser-Assisted Cataract Surgery and Conventional Phacoemulsification in a Randomized Controlled Trial

Summary

This protocol describes a randomized trial workflow for comparing femtosecond laser-assisted cataract surgery with conventional phacoemulsification in age-related cataract. It standardizes screening, allocation, operative steps, follow-up, and outcome analysis to support reproducible evaluation of early visual recovery, intraoperative energy use, and corneal safety.

Abstract

This protocol compares femtosecond laser-assisted cataract surgery (FLACS) with conventional phacoemulsification cataract surgery (CPCS) for age-related cataract using a standardized randomized trial workflow. A total of 113 patients were allocated 1:1 to FLACS (n = 56) or CPCS (n = 57), stratified by nuclear hardness, and assessed at Day 1, Week 1, Month 1, and Month 3. The protocol specifies eligibility screening, concealed allocation, harmonized perioperative care, predefined intraoperative settings, and masked outcome assessment. Primary and secondary outcomes included corrected and uncorrected distance visual acuity, refractive prediction, corneal endothelial cell density, central corneal thickness, intraoperative energy metrics, and adverse events. FLACS reduced cumulative dissipated energy and effective phaco time and showed better Day 1 visual acuity, smaller early central corneal thickening, and milder anterior chamber inflammation (all P < 0.05). At Month 1 and Month 3, between-group differences in visual acuity, refractive prediction error, absolute prediction error, endothelial cell loss, and complications were not significant (all P > 0.05). The protocol supports reproducible evaluation of early recovery advantages while showing comparable short-term safety for both procedures.

Introduction

Cataract remains the leading cause of reversible blindness globally, with its incidence rising sharply in parallel with the aging population trend. Recent epidemiological data indicate that age-related cataracts account for significant visual impairment in hundreds of millions of individuals worldwide^1,2. Conventional phacoemulsification cataract surgery (CPCS) is generally regarded as a mature technical system that has proven effective in the clinical treatment of cataracts³. However, with advances in refractive ophthalmology, postoperative patient expectations have shifted from basic ....

Protocol

The study protocol was approved by the Institutional Ethics Committee of Taiyuan Central Hospital (Approval No. YK2025102) and was conducted in accordance with the principles of the Declaration of Helsinki. Prior to inclusion, comprehensive counseling was provided to all participants regarding the differences between femtosecond laser-assisted cataract surgery (FLACS) and conventional phacoemulsification cataract surgery (CPCS). The patients were explicitly informed about the procedural specifics, potential risks, and the additional out-of-pocket costs associated with the FLACS procedure. Written informed consent was obtained from all participants, ensuring they fully....

Results

A total of 113 participants were included, with 56 allocated to the FLACS group and 57 allocated to the CPCS group. Baseline demographic, ocular, biometric, cataract-grade, refractive, and corneal safety variables were balanced between groups, supporting comparability for subsequent outcome assessment (Table 1).

Intraoperative measurements showed lower ultrasound-energy exposure in the FLACS group. CDE and effective phaco time were lower with FLACS than with CPCS (

Discussion

This protocol emphasizes reproducible implementation of FLACS and CPCS rather than outcome comparison alone. The principal procedural safeguards are standardized patient selection, concealed stratified randomization, identical perioperative care, controlled phacoemulsification settings, systematic recording of CDE and rescue maneuvers, and masked outcome assessment. These steps reduce avoidable variation and allow differences in energy use, early visual recovery, and anterior segment response to be interpreted within a c.......

Materials

List of materials used in this article

Name	Company	Catalog Number	Comments
Case report form and device logs	Study site	N/A	Records software/version identifiers, device settings, rescue maneuvers, and protocol deviations; Reproducibility audit trail for surgical and statistical protocol
CellChek XL	Konan Medical	https://konanmedical.com/cellchek-sl-xl/	Specular microscope used for measurement of corneal endothelial cell density and morphology
CENTURION Vision System	Alcon Laboratories	https://www.myalcon.com/professional/cataract-surgery/surgical-equipment/centurion/	Phacoemulsification system for ultrasound emulsification and removal of cataract lens nucleus; ; maximum longitudinal ultrasound power 60%; vacuum limit 400 mmHg; aspiration flow 35 mL/min
IOLMaster 700	Carl Zeiss Meditec	https://www.zeiss.com/meditec/en/products/optical-biometers/iolmaster-700-us/specifications-us.html	Optical biometry device used for Measurement of axial length, corneal curvature, and intraocular lens power calculation
LenSx Laser System	Alcon Laboratories	https://www.myalcon.com/professional/cataract-surgery/surgical-equipment/lensx-laser-system/	Femtosecond laser system for cataract surgery for performing laser-assisted corneal incision, capsulotomy, and lens fragmentation; ; capsulotomy 5.0 mm at 4.0 microjoules; lens fragmentation 8.0 microjoules with 10 micrometer spot separation
SL-D701	Topcon Corporation	https://topconhealthcare.jp/products/sl701/	Slit-lamp biomicroscope used for preoperative and postoperative anterior segment examination
SPSS Statistics	IBM Corporation	v26.0; https://www.ibm.com/products/spss-statistics	Generalized Linear Mixed Models module; multiple imputation sensitivity analysis; Statistical analysis of clinical outcomes and group comparisons