<clinical_study>
  <!-- This xml conforms to an XML Schema at:
    https://clinicaltrials.gov/ct2/html/images/info/public.xsd -->
  <required_header>
    <download_date>ClinicalTrials.gov processed this data on September 20, 2023</download_date>
    <link_text>Link to the current ClinicalTrials.gov record.</link_text>
    <url>https://clinicaltrials.gov/ct2/show/NCT03749486</url>
  </required_header>
  <id_info>
    <org_study_id>ArcScan</org_study_id>
    <nct_id>NCT03749486</nct_id>
  </id_info>
  <brief_title>High Resolution Immersion Ultrasound for iIOL Power Calculation</brief_title>
  <official_title>To Assess if Using a High Resolution Immersion Ultrasound Measurement Improves Intraocular Lens Power Calculation</official_title>
  <sponsors>
    <lead_sponsor>
      <agency>Prim. Prof. Dr. Oliver Findl, MBA</agency>
      <agency_class>Other</agency_class>
    </lead_sponsor>
  </sponsors>
  <source>Vienna Institute for Research in Ocular Surgery</source>
  <oversight_info>
    <is_fda_regulated_drug>No</is_fda_regulated_drug>
    <is_fda_regulated_device>No</is_fda_regulated_device>
  </oversight_info>
  <brief_summary>
    <textblock>
      Assess is the additional use of high resolution immersion ultrasound measurements improve the&#xD;
      refractive outcome after cataract surgery.&#xD;
    </textblock>
  </brief_summary>
  <detailed_description>
    <textblock>
      Since the beginning of biometry, immersion ultrasound was shown to be accurate and&#xD;
      reproducible. It is important to distinguish between immersion ultrasound techniques and&#xD;
      contact ultrasound. The later was shown to be less accurate and examiner dependent.&#xD;
&#xD;
      Although immersion ultrasound has been improved significantly and novel high resolution&#xD;
      ultrasound devices are available, the drawback of this technique is that measurement s take&#xD;
      longer compared to optical biometry. The advantage of immersion ultrasound is that structures&#xD;
      behind the iris are visible, whereas in optical biometry only structures within the pupil are&#xD;
      visible.&#xD;
&#xD;
      Immersion ultrasound as well optical biometry can be used to calculate the needed power of an&#xD;
      intraocular lens (IOL) to achieve the aimed post-operative refraction. Although IOL power&#xD;
      calculation improved within the last decades, refractive surprises occur, especially in cases&#xD;
      with very short eyes.&#xD;
&#xD;
      The estimation of the post-operative IOL position and therefore the estimated anterior&#xD;
      chamber depth (ACD) is presently the main source of error (35% to 42%) in IOL power&#xD;
      calculation and therefore for the refractive outcome of the patients after cataract surgery.&#xD;
      Early IOL power calculation formulae, such as the Binkhorst I formula, used a fixed ACD value&#xD;
      to predict the position of the IOL, but the refractive results were not appropriate because&#xD;
      the post-operative position of the IOL varied significantly between patients. Later&#xD;
      observations showed a correlation between the axial eye length and the post-operative ACD&#xD;
      (more myopic eyes showed a larger ACD post-operatively). These correlations were taken into&#xD;
      account in later developed formulas (such as the Binkhorst II formula). Olsen et al. measured&#xD;
      the post-operative ACD and substituted the predicted post-operative ACD with the true,&#xD;
      post-operative ACD in each case. The result after correcting the IOL position was a highly&#xD;
      accurate IOL power calculation, where no fudge factors were needed. Presently the&#xD;
      pre-operatively measured ACD is taken into account for several IOL power calculation&#xD;
      formulas, such as the Haigis formula, the Holladay II formula and the Olsen formula. However,&#xD;
      this new generation of formulas use the pre-operative ACD, without considering the thickness&#xD;
      of the crystalline lens. The ACD is measured as the distance between the anterior surface of&#xD;
      the cornea (anatomically speaking this should be the posterior surface of the cornea, but in&#xD;
      an optical context, as in IOL power calculations, the anterior surface is used) and the&#xD;
      anterior surface of the crystalline lens . Therefore the thickness of the crystalline lens&#xD;
      has a significant impact on the predicted post-operative position of the IOL. This parameter&#xD;
      was first taken into account by Olsen and later modified by Norrby.&#xD;
&#xD;
      It should be mentioned that IOL power calculations developed from theoretical calculations&#xD;
      based on Gaussian optics to regression formulas, such as the SRK formula that uses&#xD;
      retrospective data of a large number of patients. All these findings suggest that proper&#xD;
      measurements not only of the dimensions of the crystalline lens but also of the lens capsule&#xD;
      after removing the crystalline lens are necessary to improve IOL power calculation.&#xD;
&#xD;
      A prototype of a combination of an anterior segment OCT (VISANTE; Carl Zeiss Meditec AG) and&#xD;
      an operating microscope (OPMI 200; Carl Zeiss Meditec AG) was introduced that allowed&#xD;
      measurements of the crystalline lens as well as the lens capsule itself after removing the&#xD;
      crystalline lens of cataract patients intraoperatively. This device uses OCT technology to&#xD;
      create high resolution B-scans (=images) of the anterior segment of the eye. The OCT was&#xD;
      shown to be highly reproducible for ACD measurements pre-operatively and small changes of the&#xD;
      IOL/crystalline lens can be detected.&#xD;
&#xD;
      This prototype set-up was used in a previous study published in the journal &quot;Investigative&#xD;
      Ophthalmology &amp; Visual Science&quot;. It was shown that intra-operative measurements of the&#xD;
      anterior lens capsule were a better predictor for the post-operative lens position than other&#xD;
      factors and could improve the refractive outcome theoretically. Furthermore it was shown that&#xD;
      intra-operatively measured anterior chamber depth is useful to predict refractive outcome&#xD;
      using fourth-generation formulae. A further study aimed to observe, whether the postoperative&#xD;
      refractive outcome could be improved theoretically by using both pre- and intra-operative&#xD;
      measurements for retrospective IOL power calculation with new eye models.&#xD;
&#xD;
      In a recent study a high resolution swept-source OCT was used to perform the measurements and&#xD;
      results were very promising (DIATHLAS; Carl Zeiss Meditec AG, Germany).&#xD;
&#xD;
      However, disadvantage of swept-source OCT technology is that the measured area is only within&#xD;
      the pupil, but structures behind the iris cannot be visualised.&#xD;
&#xD;
      Most recent findings suggest that measuring the equator of the lens capsule and the cilliary&#xD;
      body could improve IOL power calculation.&#xD;
&#xD;
      One CE marked device that allows measurements behind the iris is the ArcScan Insight 100&#xD;
      scanner. This immersion ultrasound device is a precision high frequency device for imaging&#xD;
      and biometry of the eye. A 20-60 MHz transducer scans the eye although its curvature&#xD;
      approximates the anterior ocular surface. During this process the device produces images with&#xD;
      1 micron resolution of the cornea or the anterior segment. In addition, measurements can also&#xD;
      be made of the anatomic structures comprising the anterior of the eye such as anterior&#xD;
      chamber depth, angle-to-angle width, and sulcus-to-sulcus width, and pathologic structures,&#xD;
      such as solid masses and cysts.&#xD;
    </textblock>
  </detailed_description>
  <overall_status>Unknown status</overall_status>
  <last_known_status>Recruiting</last_known_status>
  <start_date type="Actual">January 1, 2018</start_date>
  <completion_date type="Anticipated">January 1, 2020</completion_date>
  <primary_completion_date type="Anticipated">January 1, 2020</primary_completion_date>
  <phase>N/A</phase>
  <study_type>Interventional</study_type>
  <has_expanded_access>No</has_expanded_access>
  <study_design_info>
    <allocation>N/A</allocation>
    <intervention_model>Single Group Assignment</intervention_model>
    <primary_purpose>Diagnostic</primary_purpose>
    <masking>None (Open Label)</masking>
  </study_design_info>
  <primary_outcome>
    <measure>Difference in mean absolute error in refractive outcome</measure>
    <time_frame>12 months</time_frame>
    <description>The difference in refractive error will be measured using auto- and subjective refraction</description>
  </primary_outcome>
  <secondary_outcome>
    <measure>Anterior chamber depth and lens thickness measurement</measure>
    <time_frame>12 months</time_frame>
    <description>Anterior chamber depth and lens thickness will be measured using the IOL Master 700</description>
  </secondary_outcome>
  <secondary_outcome>
    <measure>IOL tilt and decentration</measure>
    <time_frame>12 months</time_frame>
    <description>IOL tilt and decentration will be assessed using the Purkinjemeter</description>
  </secondary_outcome>
  <number_of_arms>1</number_of_arms>
  <enrollment type="Anticipated">40</enrollment>
  <condition>Cataract</condition>
  <arm_group>
    <arm_group_label>ArcScan</arm_group_label>
    <arm_group_type>Experimental</arm_group_type>
    <description>High resolution immersion ultrasound measurement before Cataract surgery</description>
  </arm_group>
  <intervention>
    <intervention_type>Procedure</intervention_type>
    <intervention_name>Cataract surgery</intervention_name>
    <description>Cataract surgery will be done following ArcScan measurement</description>
    <arm_group_label>ArcScan</arm_group_label>
  </intervention>
  <eligibility>
    <criteria>
      <textblock>
        Inclusion Criteria:&#xD;
&#xD;
          -  Cataract&#xD;
&#xD;
          -  Age 21 and older&#xD;
&#xD;
          -  Able to understand the patient information&#xD;
&#xD;
          -  Willing to follow the instructions and attend all follow-up visits&#xD;
&#xD;
          -  Willing to sign informed consent prior to surgery&#xD;
&#xD;
        Exclusion Criteria:&#xD;
&#xD;
          -  Relevant other ophthalmic diseases that are likely to reduce the refractive outcome,&#xD;
             such as pseudoexfoliation syndrome, traumatic cataract, severe corneal scars&#xD;
&#xD;
          -  Previous ocular surgeries on the study eye&#xD;
&#xD;
          -  Patients who are not able to cooperate, with eccentric fixation or insufficient&#xD;
             ability to fixate (tremor, nystagmus)&#xD;
&#xD;
          -  Pregnant or lactating women (pregnancy testing will be performed preoperatively on&#xD;
             women of reproductive age)&#xD;
      </textblock>
    </criteria>
    <gender>All</gender>
    <minimum_age>21 Years</minimum_age>
    <maximum_age>105 Years</maximum_age>
    <healthy_volunteers>No</healthy_volunteers>
  </eligibility>
  <overall_contact>
    <last_name>Sahand Amir-Asgari, MD</last_name>
    <phone>01 910 21-57557</phone>
    <email>office@viros.at</email>
  </overall_contact>
  <overall_contact_backup>
    <last_name>Julius Hienert, MD</last_name>
    <phone>01 910 21-57564</phone>
    <email>office@viros.at</email>
  </overall_contact_backup>
  <location>
    <facility>
      <name>Vienna Institute for Research in Ocular Surgery (VIROS)</name>
      <address>
        <city>Vienna</city>
        <zip>1140</zip>
        <country>Austria</country>
      </address>
    </facility>
    <status>Recruiting</status>
    <contact>
      <last_name>Sahand Amir-Asgari, MD</last_name>
      <phone>01 910 21-57557</phone>
      <email>office@viros.at</email>
    </contact>
    <contact_backup>
      <last_name>Julius Hienert, MD</last_name>
      <phone>01 910 21-57564</phone>
      <email>office@viros.at</email>
    </contact_backup>
  </location>
  <location_countries>
    <country>Austria</country>
  </location_countries>
  <verification_date>November 2018</verification_date>
  <study_first_submitted>November 19, 2018</study_first_submitted>
  <study_first_submitted_qc>November 19, 2018</study_first_submitted_qc>
  <study_first_posted type="Actual">November 21, 2018</study_first_posted>
  <last_update_submitted>November 19, 2018</last_update_submitted>
  <last_update_submitted_qc>November 19, 2018</last_update_submitted_qc>
  <last_update_posted type="Actual">November 21, 2018</last_update_posted>
  <responsible_party>
    <responsible_party_type>Sponsor-Investigator</responsible_party_type>
    <investigator_affiliation>Vienna Institute for Research in Ocular Surgery</investigator_affiliation>
    <investigator_full_name>Prim. Prof. Dr. Oliver Findl, MBA</investigator_full_name>
    <investigator_title>Principal Investigator</investigator_title>
  </responsible_party>
  <keyword>Cataract surgery</keyword>
  <keyword>High resolution immersion ultrasound</keyword>
  <condition_browse>
    <!-- CAUTION:  The following MeSH terms are assigned with an imperfect algorithm            -->
    <mesh_term>Cataract</mesh_term>
  </condition_browse>
  <patient_data>
    <sharing_ipd>Undecided</sharing_ipd>
  </patient_data>
  <!-- Results have not yet been posted for this study                                          -->
</clinical_study>


download date: ClinicalTrials.gov processed this data on September 20, 2023
link text: Link to the current ClinicalTrials.gov record.
url: https://clinicaltrials.gov/ct2/show/NCT03749486
org study id: ArcScan
nct id: NCT03749486
lead sponsor: 
is fda regulated drug: No
is fda regulated device: No
Assess is the additional use of high resolution immersion ultrasound measurements improve the
      refractive outcome after cataract surgery.
Since the beginning of biometry, immersion ultrasound was shown to be accurate and
      reproducible. It is important to distinguish between immersion ultrasound techniques and
      contact ultrasound. The later was shown to be less accurate and examiner dependent.

      Although immersion ultrasound has been improved significantly and novel high resolution
      ultrasound devices are available, the drawback of this technique is that measurement s take
      longer compared to optical biometry. The advantage of immersion ultrasound is that structures
      behind the iris are visible, whereas in optical biometry only structures within the pupil are
      visible.

      Immersion ultrasound as well optical biometry can be used to calculate the needed power of an
      intraocular lens (IOL) to achieve the aimed post-operative refraction. Although IOL power
      calculation improved within the last decades, refractive surprises occur, especially in cases
      with very short eyes.

      The estimation of the post-operative IOL position and therefore the estimated anterior
      chamber depth (ACD) is presently the main source of error (35% to 42%) in IOL power
      calculation and therefore for the refractive outcome of the patients after cataract surgery.
      Early IOL power calculation formulae, such as the Binkhorst I formula, used a fixed ACD value
      to predict the position of the IOL, but the refractive results were not appropriate because
      the post-operative position of the IOL varied significantly between patients. Later
      observations showed a correlation between the axial eye length and the post-operative ACD
      (more myopic eyes showed a larger ACD post-operatively). These correlations were taken into
      account in later developed formulas (such as the Binkhorst II formula). Olsen et al. measured
      the post-operative ACD and substituted the predicted post-operative ACD with the true,
      post-operative ACD in each case. The result after correcting the IOL position was a highly
      accurate IOL power calculation, where no fudge factors were needed. Presently the
      pre-operatively measured ACD is taken into account for several IOL power calculation
      formulas, such as the Haigis formula, the Holladay II formula and the Olsen formula. However,
      this new generation of formulas use the pre-operative ACD, without considering the thickness
      of the crystalline lens. The ACD is measured as the distance between the anterior surface of
      the cornea (anatomically speaking this should be the posterior surface of the cornea, but in
      an optical context, as in IOL power calculations, the anterior surface is used) and the
      anterior surface of the crystalline lens . Therefore the thickness of the crystalline lens
      has a significant impact on the predicted post-operative position of the IOL. This parameter
      was first taken into account by Olsen and later modified by Norrby.

      It should be mentioned that IOL power calculations developed from theoretical calculations
      based on Gaussian optics to regression formulas, such as the SRK formula that uses
      retrospective data of a large number of patients. All these findings suggest that proper
      measurements not only of the dimensions of the crystalline lens but also of the lens capsule
      after removing the crystalline lens are necessary to improve IOL power calculation.

      A prototype of a combination of an anterior segment OCT (VISANTE; Carl Zeiss Meditec AG) and
      an operating microscope (OPMI 200; Carl Zeiss Meditec AG) was introduced that allowed
      measurements of the crystalline lens as well as the lens capsule itself after removing the
      crystalline lens of cataract patients intraoperatively. This device uses OCT technology to
      create high resolution B-scans (=images) of the anterior segment of the eye. The OCT was
      shown to be highly reproducible for ACD measurements pre-operatively and small changes of the
      IOL/crystalline lens can be detected.

      This prototype set-up was used in a previous study published in the journal "Investigative
      Ophthalmology & Visual Science". It was shown that intra-operative measurements of the
      anterior lens capsule were a better predictor for the post-operative lens position than other
      factors and could improve the refractive outcome theoretically. Furthermore it was shown that
      intra-operatively measured anterior chamber depth is useful to predict refractive outcome
      using fourth-generation formulae. A further study aimed to observe, whether the postoperative
      refractive outcome could be improved theoretically by using both pre- and intra-operative
      measurements for retrospective IOL power calculation with new eye models.

      In a recent study a high resolution swept-source OCT was used to perform the measurements and
      results were very promising (DIATHLAS; Carl Zeiss Meditec AG, Germany).

      However, disadvantage of swept-source OCT technology is that the measured area is only within
      the pupil, but structures behind the iris cannot be visualised.

      Most recent findings suggest that measuring the equator of the lens capsule and the cilliary
      body could improve IOL power calculation.

      One CE marked device that allows measurements behind the iris is the ArcScan Insight 100
      scanner. This immersion ultrasound device is a precision high frequency device for imaging
      and biometry of the eye. A 20-60 MHz transducer scans the eye although its curvature
      approximates the anterior ocular surface. During this process the device produces images with
      1 micron resolution of the cornea or the anterior segment. In addition, measurements can also
      be made of the anatomic structures comprising the anterior of the eye such as anterior
      chamber depth, angle-to-angle width, and sulcus-to-sulcus width, and pathologic structures,
      such as solid masses and cysts.
allocation: N/A
intervention model: Single Group Assignment
primary purpose: Diagnostic
masking: None (Open Label)
measure: Difference in mean absolute error in refractive outcome
time frame: 12 months
description: The difference in refractive error will be measured using auto- and subjective refraction
measure: Anterior chamber depth and lens thickness measurement
time frame: 12 months
description: Anterior chamber depth and lens thickness will be measured using the IOL Master 700
measure: IOL tilt and decentration
time frame: 12 months
description: IOL tilt and decentration will be assessed using the Purkinjemeter
arm group label: ArcScan
arm group type: Experimental
description: High resolution immersion ultrasound measurement before Cataract surgery
intervention type: Procedure
intervention name: Cataract surgery
description: Cataract surgery will be done following ArcScan measurement
arm group label: ArcScan
criteria: 
gender: All
minimum age: 21 Years
maximum age: 105 Years
healthy volunteers: No
last name: Sahand Amir-Asgari, MD
phone: 01 910 21-57557
email: office@viros.at
last name: Julius Hienert, MD
phone: 01 910 21-57564
email: office@viros.at
facility: 
status: Recruiting
contact: 
contact backup: 
country: Austria
responsible party type: Sponsor-Investigator
investigator affiliation: Vienna Institute for Research in Ocular Surgery
investigator full name: Prim. Prof. Dr. Oliver Findl, MBA
investigator title: Principal Investigator
mesh term: Cataract
sharing ipd: Undecided