Refractive Outcomes and Ocular Biometry of Two Swept-Source Optical Coherence Tomography-Based Biometers With Segmental or Equivalent Refractive Indices (ORION) (ORION)

May 12, 2026 updated by: Walailak University

Refractive Outcomes and Ocular Biometry of Two Swept-Source Optical Coherence Tomography-Based Biometers With Segmental or Equivalent Refractive Indices (ORION): A Non-Inferiority Randomized Clinical Trials

This prospective, single-centre, randomized, parallel-group comparative clinical study evaluated the refractive prediction accuracy of two swept-source optical coherence tomography (SS-OCT) biometers in a Thai cataract surgery cohort. The ARGOS biometer applies segmental refractive indices to individual ocular segments, whereas the IOLMaster 700 applies an equivalent refractive index to the whole eye. Each device is conventionally paired with a different keratometry-formula combination: ARGOS with the standard Barrett Universal II (Barrett UII K), and IOLMaster 700 with the Barrett Universal II using total keratometry (Barrett UII TK). The study compared these two device-formula pairings as they are used in routine clinical practice. Both biometers were performed on every eye on the same day, enabling a within-subject paired comparison of biometric agreement and refractive prediction error at one month after phacoemulsification cataract surgery with implantation of a TECNIS Monofocal one-piece IOL (model GCB00V)

Study Overview

Status

Status

Indicates the current recruitment status or the expanded access status.
Completed

Conditions

Conditions

The disease, disorder, syndrome, illness, or injury that is being studied. On ClinicalTrials.gov, conditions may also include other health-related issues, such as lifespan, quality of life, and health risks.

Intervention / Treatment

Intervention / Treatment

A process or action that is the focus of a clinical study. Interventions include drugs, medical devices, procedures, vaccines, and other products that are either investigational or already available. Interventions can also include noninvasive approaches, such as education or modifying diet and exercise.

Detailed Description

One hundred and forty-four eyes of 144 consecutive Thai cataract surgery patients aged 40-90 years presenting with visually significant age-related cataract were enrolled at the Ophthalmology Service, Walailak University Hospital between May 2024 and December 2024. Participants underwent preoperative biometric measurement on the same day with both the ARGOS (software version A2.4; Movu, Inc., a Santec company; distributed by Alcon Laboratories) and the IOLMaster 700 (software version 1.90.10; Carl Zeiss Meditec AG) by a single experienced operator. Participants were randomized 1:1 between two IOL-selection arms using a computer-generated allocation sequence (Research Randomizer, blocks of 12): Group 1 used the IOLMaster 700 with the Barrett Universal II TK formula for IOL power selection, and Group 2 used the ARGOS with the standard Barrett Universal II K formula. Allocation was concealed from the enrolling surgeon until completion of preoperative biometry. Participants were masked to the device-formula arm. All cataract surgeries were performed by four experienced surgeons (in approximately equal numbers) using a standardized phacoemulsification technique with in-the-bag implantation of the TECNIS Monofocal one-piece IOL (model GCB00V; Johnson & Johnson Vision). The primary outcome was mean absolute prediction error (MAE) at one month postoperatively, assessed by a masked refractionist using subjective manifest refraction. Secondary outcomes were median absolute prediction error and the proportion of eyes within ±0.25 D and ±0.50 D of target refraction. One eye per patient was enrolled. The study was registered prospectively as a non-inferiority trial; the implemented analysis is reported as a within-subject paired comparative analysis with descriptive accuracy thresholds rather than as a formal non-inferiority hypothesis test (CONSORT item 3b). The total enrolled sample was 144 patients; within-subject paired analyses included 138 eyes with complete data for both devices.

Study Type

Study Type

Describes the nature of a clinical study. Study types include interventional studies (also called clinical trials), observational studies (including patient registries), and expanded access.
Interventional

Enrollment (Actual)

Enrollment

The number of participants in a clinical study. The "anticipated" enrollment is the target number of participants that the researchers need for the study.
144

Phase

Phase

The stage of a clinical trial studying a drug or biological product, based on definitions developed by the U.S. Food and Drug Administration (FDA). The phase is based on the study's objective, the number of participants, and other characteristics. There are five phases: Early Phase 1 (formerly listed as Phase 0), Phase 1, Phase 2, Phase 3, and Phase 4. Not Applicable is used to describe trials without FDA-defined phases, including trials of devices or behavioral interventions.
  • Not Applicable

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Contact

Study Contact

The name and contact information for the person who can answer enrollment questions for a clinical study. Each location where the study is being conducted may also have a specific contact, who may be better able to answer those questions.

Study Locations

  • Thailand
    • Changwat Nakhon Si Thammarat
      • Nakhon Si Thammarat, Changwat Nakhon Si Thammarat, Thailand, 80160
        • Walailak University

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Eligibility Criteria

The key requirements that people who want to participate in a clinical study must meet or the characteristics they must have. Eligibility criteria consist of both inclusion criteria (which are required for a person to participate in the study) and exclusion criteria (which prevent a person from participating). Types of eligibility criteria include whether a study accepts healthy volunteers, has age or age group requirements, or is limited by sex.

Ages Eligible for Study

  • Adult
  • Older Adult

Accepts Healthy Volunteers

No

Description

Inclusion Criteria:

• Adults aged 40-90 years presenting with visually significant age-related cataract scheduled for elective phacoemulsification with implantation of a TECNIS Monofocal one-piece IOL (model GCB00V).

Exclusion Criteria:

  • Corneal astigmatism greater than 1.00 D on either device
  • Central corneal thickness outside 490-600 µm
  • Severe dry eye precluding reliable keratometry
  • Rigid or soft contact lens wear within 2 months prior to evaluation
  • Previous corneal refractive surgery or other corneal pathology
  • Prior intraocular surgery (other than uneventful cataract surgery in the fellow eye)
  • Clinically significant retinal pathology potentially affecting refractive outcome (e.g., epiretinal membrane, diabetic macular edema, advanced age-related macular degeneration)
  • Intraoperative complications including posterior capsule rupture, vitreous loss, or zonular dehiscence
  • Dense cataract that does not allow measurements with optical biometry
  • Inability to attend follow-up

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

  • Primary Purpose: Other
  • Allocation: Randomized
  • Interventional Model: Parallel Assignment
  • Masking: Double

Arms and Interventions

Participant Group / Arm

Participant Group / Arm

A group or subgroup of participants in a clinical trial that receives a specific intervention/treatment, or no intervention, according to the trial's protocol.
Intervention / Treatment

Intervention / Treatment

A process or action that is the focus of a clinical study. Interventions include drugs, medical devices, procedures, vaccines, and other products that are either investigational or already available. Interventions can also include noninvasive approaches, such as education or modifying diet and exercise.
Active Comparator: IOLMaster 700
Patients allocated to this arm underwent biometric measurement with the IOLMaster 700 swept-source OCT biometer (Carl Zeiss Meditec AG). IOL power for the implanted TECNIS Monofocal one-piece IOL (model GCB00V) was calculated using the Barrett Universal II formula with total keratometry input (Barrett UII TK
Device: IOLMaster 700 (Carl Zeiss Meditec AG)
Preoperative biometric measurement using the IOLMaster 700 (software version 1.90.10). IOL power was calculated using the Barrett Universal II TK formula and used for power selection in this arm.
Experimental: ARGOS
Patients allocated to this arm underwent biometric measurement with the ARGOS swept-source OCT biometer, which uses segmental refractive indices for axial length measurement. IOL power for the implanted TECNIS Monofocal one-piece IOL (model GCB00V) was calculated using the standard Barrett Universal II formula with anterior keratometry input (Barrett UII K
Device: ARGOS (Movu/Santec; distributed by Alcon)
Preoperative biometric measurement using the ARGOS (software version A2.4). IOL power was calculated using the Barrett Universal II K formula and used for power selection in this arm.

What is the study measuring?

Primary Outcome Measures

Primary Outcome Measures

In a clinical study's protocol, the planned outcome measure that is the most important for evaluating the effect of an intervention/treatment. Most clinical studies have one primary outcome measure, but some have more than one.
Outcome Measure
Measure Description
Time Frame
Mean absolute prediction error
Time Frame: 4 weeks
Mean absolute prediction error determining by the absolute disparity between the predicted spherical equivalent refraction derived from preoperative planning and the actual measured spherical equivalent refraction (manifest) from both devices (IOLMaster 700 and Argos)
4 weeks

Secondary Outcome Measures

Secondary Outcome Measures

In a clinical study's protocol, a planned outcome measure that is not as important as the primary outcome measure for evaluating the effect of an intervention but is still of interest. Most clinical studies have more than one secondary outcome measure.
Outcome Measure
Measure Description
Time Frame
Proportion of eyes with absolute prediction error ≤ 0.25 D
Time Frame: 4 weeks
Percentage of eyes in which the absolute prediction error (|measured SE - predicted SE|) was within ±0.25 D of the target refraction at one month postoperatively, for each device-formula pairing.
4 weeks
Median absolute prediction error
Time Frame: 4 weeks
Median of the absolute differences between predicted spherical equivalent refraction (derived from preoperative biometry and IOL formula) and the actual measured spherical equivalent (manifest refraction) at one month postoperatively, for both devices (IOLMaster 700 with Barrett UII TK and ARGOS with Barrett UII K)
4 weeks
Proportion of eyes within ±0.50 D of target refraction
Time Frame: 4 weeks
Percentage of eyes in which the absolute prediction error was within ±0.50 D of the target refraction at one month postoperatively, for each device-formula pairing.
4 weeks

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Sponsor

Sponsor

The organization or person who initiates the study and who has authority and control over the study.
Walailak University

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start (Actual)

Study Start

The actual date on which the first participant was enrolled in a clinical study. The "anticipated" study start date is the date that the researchers think will be the study start date.
May 1, 2024

Primary Completion (Actual)

Primary Completion

The date on which the last participant in a clinical study was examined or received an intervention to collect final data for the primary outcome measure. Whether the clinical study ended according to the protocol or was terminated does not affect this date. For clinical studies with more than one primary outcome measure with different completion dates, this term refers to the date on which data collection is completed for all the primary outcome measures. The "anticipated" primary completion date is the date that the researchers think will be the primary completion date for the study.
January 31, 2025

Study Completion (Actual)

Study Completion

The date on which the last participant in a clinical study was examined or received an intervention/treatment to collect final data for the primary outcome measures, secondary outcome measures, and adverse events (that is, the last participant's last visit). The "anticipated" study completion date is the date that the researchers think will be the study completion date.
January 31, 2025

Study Registration Dates

First Submitted

First Submitted

The date on which the study sponsor or investigator first submitted a study record to ClinicalTrials.gov. There is typically a delay of a few days between the first submitted date and the record's availability on ClinicalTrials.gov (the first posted date).
January 30, 2024

First Submitted That Met QC Criteria

First Submitted That Met QC Criteria

The date on which the study sponsor or investigator first submits a study record that is consistent with National Library of Medicine (NLM) quality control (QC) review criteria. The sponsor or investigator may need to revise and submit a study record one or more times before NLM's QC review criteria are met. It is the responsibility of the sponsor or investigator to ensure that the study record is consistent with the NLM QC review criteria.
April 16, 2024

First Posted (Actual)

First Posted

The date on which the study record was first available on ClinicalTrials.gov after National Library of Medicine (NLM) quality control (QC) review has concluded. There is typically a delay of a few days between the date the study sponsor or investigator submitted the study record and the first posted date.
April 22, 2024

Study Record Updates

Last Update Posted (Actual)

Last Update Posted

The most recent date on which changes to a study record were made available on ClinicalTrials.gov. There may be a delay between when the changes were submitted to ClinicalTrials.gov by the study's sponsor or investigator (the last update submitted date) and the last update posted date.
May 15, 2026

Last Update Submitted That Met QC Criteria

Last Update Submitted That Met QC Criteria

The most recent date on which the study sponsor or investigator submitted changes to a study record that are consistent with National Library of Medicine (NLM) quality control (QC) review criteria. It is the responsibility of the sponsor or investigator to ensure that the study record is consistent with the NLM QC review criteria.
May 12, 2026

Last Verified

Last Verified

The most recent date on which the study sponsor or investigator confirmed the information about a clinical study on ClinicalTrials.gov as accurate and current. If a study with a recruitment status of recruiting; not yet recruiting; or active, not recruiting has not been confirmed within the past 2 years, the study's recruitment status is shown as unknown.
May 1, 2026

More Information

Terms related to this study

Keywords

Additional Relevant MeSH Terms

Other Study ID Numbers

Other Study ID Numbers

Identifiers or ID numbers other than the NCT number that are assigned to a clinical study by the study's sponsor, funders, or others. These numbers may include unique identifiers from other trial registries and National Institutes of Health grant numbers.
  • WU66290 (Other Grant/Funding Number: Walailak individual grant)

Drug and device information, study documents

Studies a U.S. FDA-regulated drug product

No

Studies a U.S. FDA-regulated device product

No

product manufactured in and exported from the U.S.

No

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

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