STARGUS: Comparative STudy of the ARGos Biometer Compared to UltraSound Biometer in B-mode in Case of Measure Failure With a the Conventional Biometer

Sponsor
Assistance Publique - Hôpitaux de Paris (Other)
Overall Status
Not yet recruiting
CT.gov ID
NCT05534373
Collaborator
(none)
110
1
5
21.9

Study Details

Study Description

Brief Summary

Biometry has become one of the most important steps in modern cataract surgery (Sahin A et al. Curr Opin Ophthalmol 2012; 23: 47-53). The axial length of the eye may be measured by ultrasound (either contact or immersion) or by optical means (IOL Master, Lenstar or Argos).

Non-contact optical biometry has become the gold-standard because of its ease of use, accuracy, and reproducibility (Sahin A. et al. Curr Opin Ophthalmol 2012; 23: 47-53). However, the main disadvantage of the optical methods is their inability to obtain axial length measurements in approximately 10% of eyes, typically those with dense posterior subcapsular cataracts. (Mylonas G, et al. Acta Ophthalmol 2011; 89: e237-e241; Hill W et al. J Cataract Refract Surg 2008; 34: 920-924).

By Using SS-OCT device, it has been reported that the AL measurements cannot be made in 0.6 to 7.4% of cases . Therefore, measurement by US biometer is still necessary for advanced cataract. The ultrasound measure the LA between the corneal epithelium and the vitreomacular interface. Ultrasound in B mode (or Brilliance) with the help of the control vector allows a 2-dimensional control of the plan used for measurement; (Olsen T. et al., Acta Ophtalmol Scand,2007;85:472-485). This method is used in current practice in our centers when LA measurements is not possible with our optical SS-biometer.

Recently Alcon has integrated the ARGOS® biometer's diagnostic testing with Alcon's Cataract Refractive Suite technologies. ARGOS® is a non-invasive, non-contact biometer based on swept-source optical coherence tomography (SS-OCT). The device is intended to acquire ocular measurements as well as perform calculations to determine the appropriate intraocular lens (IOL) power and type for implantation during intraocular lens placement. ARGOS® measures the following 9 parameters: Axial Length, Corneal Thickness, Anterior Chamber Depth, Lens Thickness, K-values (Radii of flattest and steepest meridians), Astigmatism, White-to-White (corneal diameter) and Pupil Size. The Reference Image functionality is intended for use as a preoperative and postoperative image capture tool. ARGOS® includes an operation mode for when the retina is hardly or not visible at all denominated the "Enhanced Retinal Visualization mode" (ERV) that allows, in most cases, visualization of the retina. This signal in the retinal region is enhanced by shifting the coherence function (Argos Users manual).

In a prospective observational study conducted in 2 centers in USA involving 107 eyes, Shammas HJ et al. have evaluated the repeatability and reproducibility of ARGOS® measurements in comparison with IOLMaster®500 and LENSTAR LS 900. They have shown that the AL acquisition rate was higher with ARGOS® (96%) compared with both LENSTAR LS 900 (79%) and IOLMaster®500 (77%). The reason was that ARGOS® was more successful at measuring AL in eyes with dense cataract. (Shammas HJ et al. J Cataract Refract Surg 2016;42:50)

Condition or Disease Intervention/Treatment Phase

    Detailed Description

    Our recent experience with Argos has shown that LA measurements were even possible with our without ERV mode in case of very dense (ie: cataracts in diabetic patients) or posterior subcapsular cataracts.

    These observations lead us to propose a retrospective study to compare Argos to our gold standard "ultrasound biometer in mode B" for LA measurements in case of failure with the conventional optical biometer used in our current practice (Lenstar LS900, IOLMaster 500, 700) In current practice, the biometry measurements are conducted with our conventional optical biometer during the visit prior to cataract surgery.

    At the same time, measures will be conducted on Argos with or without the ERV mode If axial length measurements are impossible with our conventional optical biometer due to the level of cataract density, axial length measurements will be conducted with our ultrasound biometer in mode-B (Quantel Medical, Aviso S with the 10MHz probe) according to our current practice.

    We will retrospectively collect the consecutive data from eyes for which axial length measurements with our conventional biometer were not possible

    Study Design

    Study Type:
    Observational
    Anticipated Enrollment :
    110 participants
    Observational Model:
    Case-Only
    Time Perspective:
    Retrospective
    Official Title:
    Comparative STudy of the ARGos Biometer Compared to UltraSound Biometer in B-mode in Case of Measure Failure With a the Conventional Biometer
    Anticipated Study Start Date :
    Sep 1, 2022
    Anticipated Primary Completion Date :
    Dec 1, 2022
    Anticipated Study Completion Date :
    Feb 1, 2023

    Outcome Measures

    Primary Outcome Measures

    1. Axial length (AL) in millimeters obtained with Argos and ultrasound biometer in B-mode scans (considered to be the reference method for dense cataract) [2 months]

      To describe axial length (AL) measured by the Argos biometer in case of measure failure with a conventional optical biometer and to compare it with the AL measured with ultrasound biometry in B-mode (considered to be the gold standard) Key Endpoints Primary endpoint:

    Secondary Outcome Measures

    1. Pachymetry in micrometers obtained with Argos biometer, conventional biometer and ultrasound biometer [2 months]

      to describe Pachymetry in micrometers obtained with Argos biometer, conventional biometer and ultrasound biometer

    2. Anterior chamber depth in millimeters obtained with Argos biometer, conventional biometer and ultrasound biometer [2 months]

      to measure anterior chamber depth in millimeters obtained with Argos biometer, conventional biometer and ultrasound biometer

    3. Lens thickness obtained with Argos biometer and ultrasound biometer [2 months]

      to measure lens thickness obtained with Argos biometer and ultrasound biometer

    Eligibility Criteria

    Criteria

    Ages Eligible for Study:
    18 Years and Older
    Sexes Eligible for Study:
    All
    Accepts Healthy Volunteers:
    No
    Inclusion Criteria:
    • Patient over 18 years of age

    • All consecutive patient measured on Argos and any other conventional optical biometer and presenting a failure with one of the conventional optical biometer in AL measurement due to cataract density

    Exclusion Criteria:
    • Silicon tamponade in the posterior segment

    • Patients who are informed and objected to participating to the research

    • Patient subject to legal protection measures.

    Contacts and Locations

    Locations

    Site City State Country Postal Code
    1 Hôpital Avicenne Bobigny France 93009

    Sponsors and Collaborators

    • Assistance Publique - Hôpitaux de Paris

    Investigators

    None specified.

    Study Documents (Full-Text)

    None provided.

    More Information

    Publications

    None provided.
    Responsible Party:
    Assistance Publique - Hôpitaux de Paris
    ClinicalTrials.gov Identifier:
    NCT05534373
    Other Study ID Numbers:
    • APHP220627
    First Posted:
    Sep 9, 2022
    Last Update Posted:
    Sep 9, 2022
    Last Verified:
    Sep 1, 2022
    Individual Participant Data (IPD) Sharing Statement:
    No
    Plan to Share IPD:
    No
    Studies a U.S. FDA-regulated Drug Product:
    No
    Studies a U.S. FDA-regulated Device Product:
    No
    Keywords provided by Assistance Publique - Hôpitaux de Paris
    Additional relevant MeSH terms:

    Study Results

    No Results Posted as of Sep 9, 2022