<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/NCT03264534</url>
  </required_header>
  <id_info>
    <org_study_id>17200119</org_study_id>
    <nct_id>NCT03264534</nct_id>
  </id_info>
  <brief_title>Manually Performed Limbal Relaxing Incisions vs Femtosecond Laser-guided Astigmatic Keratotomy</brief_title>
  <official_title>Manually Performed Limbal Relaxing Incisions vs Femtosecond Laser-guided Astigmatic Keratotomy for Correction of Corneal Astigmatism After Phacoemulsification</official_title>
  <sponsors>
    <lead_sponsor>
      <agency>Assiut University</agency>
      <agency_class>Other</agency_class>
    </lead_sponsor>
  </sponsors>
  <source>Assiut University</source>
  <oversight_info>
    <has_dmc>No</has_dmc>
    <is_fda_regulated_drug>No</is_fda_regulated_drug>
    <is_fda_regulated_device>No</is_fda_regulated_device>
  </oversight_info>
  <brief_summary>
    <textblock>
      Astigmatic keratotomy (AK) is used to treat numerous refractive disorders, including&#xD;
      congenital astigmatism, residual corneal astigmatism at the time of or following cataract&#xD;
      surgery, post-traumatic astigmatism, and astigmatism after corneal transplantation.&#xD;
&#xD;
      Within the past few years, much consideration has been given to an evolutionary variant of&#xD;
      the procedure, the limbal relaxing incision (LRI). By moving the incision farther to the&#xD;
      periphery, cataract surgeons can safely and predictably remediate mild to moderate amounts of&#xD;
      regular astigmatism at the time of cataract surgery by performing this incisional technique.&#xD;
&#xD;
      Recent technological developments have shifted ophthalmologist's attention from manually&#xD;
      created LRIs and astigmatic keratotomy procedures to femtosecond laser-guided procedures.&#xD;
      Femtosecond lasers offer superior incisional accuracy and reproducibility coupled with&#xD;
      minimal effects on collateral tissues, achieving levels of safety and reproducibility&#xD;
      exceeding those of mechanical techniques. A major clinical application of the femtosecond&#xD;
      laser is for creating arcuate incisions that have a precise and accurate length, depth,&#xD;
      angular position, and optical zone.&#xD;
    </textblock>
  </brief_summary>
  <detailed_description>
    <textblock>
      Pre-operative evaluation:&#xD;
&#xD;
        1. Close examination of the peripheral cornea by slit lamb, particularly in the areas where&#xD;
           the incisions will be placed.&#xD;
&#xD;
        2. Fundus examination to exclude other causes of diminution of vision.&#xD;
&#xD;
        3. IOP measure.&#xD;
&#xD;
        4. Precise manifest refraction, uncorrected visual acuity and best corrected visual acuity&#xD;
           by snellen's chart.&#xD;
&#xD;
        5. Standard keratometry to confirm diopters of corneal astigmatism.&#xD;
&#xD;
        6. Corneal Tomography (Pentacam).&#xD;
&#xD;
      Surgical procedures:&#xD;
&#xD;
      LRIs are performed using topical anesthesia. Patients are instructed to fixate on the&#xD;
      microscope light. Before surgery, the steep meridian was identified with a marker dyed with&#xD;
      methylene blue with the patient sitting up right. A diamond knife is set at a depth of 0.600&#xD;
      mm to 0.650 mm based on the peripheral pachymetric readings over the area of intended&#xD;
      incision. The goal was a maximum reduction in astigmatism without overcorrection in with-the&#xD;
      rule cases and with little overcorrection in against the rule cases. In the case of an&#xD;
      overcorrection, the LRI can be sutured without creating any irregular astigmatism.&#xD;
&#xD;
      Performing femtosecond laser-guided astigmatic keratotomy requires the parameters of length,&#xD;
      position, depth and distance from the visual axis where the incisions will be created. The&#xD;
      depth of our incisions is 85% of the corneal pachymetry in the area of the incision. We have&#xD;
      set our distance from the visual axis at 8 mm. This information is all downloaded onto the&#xD;
      femtosecond laser. Then, we begin the surgical procedure by docking the laser onto the&#xD;
      cornea. An overlay of the incisions is then visible on the surgical screen. After treatment,&#xD;
      we bring the patient to the operating microscope and open the incisions with a Sinskey hook.&#xD;
      By using low energy, the incisions do not have significant effect until they are opened.&#xD;
    </textblock>
  </detailed_description>
  <overall_status>Unknown status</overall_status>
  <last_known_status>Not yet recruiting</last_known_status>
  <start_date type="Anticipated">March 2018</start_date>
  <completion_date type="Anticipated">October 2019</completion_date>
  <primary_completion_date type="Anticipated">April 2019</primary_completion_date>
  <phase>N/A</phase>
  <study_type>Interventional</study_type>
  <has_expanded_access>No</has_expanded_access>
  <study_design_info>
    <allocation>Randomized</allocation>
    <intervention_model>Parallel Assignment</intervention_model>
    <primary_purpose>Treatment</primary_purpose>
    <masking>None (Open Label)</masking>
  </study_design_info>
  <primary_outcome>
    <measure>Keratometric reading</measure>
    <time_frame>1 week</time_frame>
    <description>measured by Corneal Tomography (Pentacam)</description>
  </primary_outcome>
  <number_of_arms>2</number_of_arms>
  <enrollment type="Anticipated">80</enrollment>
  <condition>Corneal Astigmatism</condition>
  <arm_group>
    <arm_group_label>limbal relaxing incisions</arm_group_label>
    <arm_group_type>Active Comparator</arm_group_type>
    <description>Manually performed limbal relaxing incisions</description>
  </arm_group>
  <arm_group>
    <arm_group_label>astigmatic keratotomy</arm_group_label>
    <arm_group_type>Active Comparator</arm_group_type>
    <description>femtosecond laser-guided astigmatic keratotomy</description>
  </arm_group>
  <intervention>
    <intervention_type>Procedure</intervention_type>
    <intervention_name>limbal relaxing incisions</intervention_name>
    <description>Manually performed surgical procedure</description>
    <arm_group_label>limbal relaxing incisions</arm_group_label>
  </intervention>
  <intervention>
    <intervention_type>Procedure</intervention_type>
    <intervention_name>astigmatic keratotomy</intervention_name>
    <description>femtosecond laser guided surgical procedure</description>
    <arm_group_label>astigmatic keratotomy</arm_group_label>
  </intervention>
  <eligibility>
    <criteria>
      <textblock>
        Inclusion Criteria:&#xD;
&#xD;
          1. patients who have undergo phacoemulsification.&#xD;
&#xD;
          2. Clear cornea.&#xD;
&#xD;
          3. Astigmatism from 1 diopter up to 4 diopters&#xD;
&#xD;
        Exclusion Criteria:&#xD;
&#xD;
          1. corneal opacity.&#xD;
&#xD;
          2. History of corneal surgery.&#xD;
&#xD;
          3. Thin cornea.&#xD;
&#xD;
          4. Other cause of diminution of vision rather than corneal astigmatism (eg: optic disc&#xD;
             atrophy &amp; maculopathy).&#xD;
&#xD;
          5. Astigmatism less than 1 diopter and more than 4 diopters.&#xD;
      </textblock>
    </criteria>
    <gender>All</gender>
    <minimum_age>21 Years</minimum_age>
    <maximum_age>65 Years</maximum_age>
    <healthy_volunteers>No</healthy_volunteers>
  </eligibility>
  <verification_date>August 2017</verification_date>
  <study_first_submitted>August 24, 2017</study_first_submitted>
  <study_first_submitted_qc>August 25, 2017</study_first_submitted_qc>
  <study_first_posted type="Actual">August 29, 2017</study_first_posted>
  <last_update_submitted>January 9, 2018</last_update_submitted>
  <last_update_submitted_qc>January 9, 2018</last_update_submitted_qc>
  <last_update_posted type="Actual">January 11, 2018</last_update_posted>
  <responsible_party>
    <responsible_party_type>Principal Investigator</responsible_party_type>
    <investigator_affiliation>Assiut University</investigator_affiliation>
    <investigator_full_name>Ashraf Rashwan</investigator_full_name>
    <investigator_title>Principal Investigator</investigator_title>
  </responsible_party>
  <condition_browse>
    <!-- CAUTION:  The following MeSH terms are assigned with an imperfect algorithm            -->
    <mesh_term>Astigmatism</mesh_term>
  </condition_browse>
  <patient_data>
    <sharing_ipd>Undecided</sharing_ipd>
    <ipd_description>There is a possibility of using these data in another related study so i am not sure about the time of sharing the individual participant data</ipd_description>
  </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/NCT03264534
org study id: 17200119
nct id: NCT03264534
lead sponsor: 
has dmc: No
is fda regulated drug: No
is fda regulated device: No
Astigmatic keratotomy (AK) is used to treat numerous refractive disorders, including
      congenital astigmatism, residual corneal astigmatism at the time of or following cataract
      surgery, post-traumatic astigmatism, and astigmatism after corneal transplantation.

      Within the past few years, much consideration has been given to an evolutionary variant of
      the procedure, the limbal relaxing incision (LRI). By moving the incision farther to the
      periphery, cataract surgeons can safely and predictably remediate mild to moderate amounts of
      regular astigmatism at the time of cataract surgery by performing this incisional technique.

      Recent technological developments have shifted ophthalmologist's attention from manually
      created LRIs and astigmatic keratotomy procedures to femtosecond laser-guided procedures.
      Femtosecond lasers offer superior incisional accuracy and reproducibility coupled with
      minimal effects on collateral tissues, achieving levels of safety and reproducibility
      exceeding those of mechanical techniques. A major clinical application of the femtosecond
      laser is for creating arcuate incisions that have a precise and accurate length, depth,
      angular position, and optical zone.
Pre-operative evaluation:

        1. Close examination of the peripheral cornea by slit lamb, particularly in the areas where
           the incisions will be placed.

        2. Fundus examination to exclude other causes of diminution of vision.

        3. IOP measure.

        4. Precise manifest refraction, uncorrected visual acuity and best corrected visual acuity
           by snellen's chart.

        5. Standard keratometry to confirm diopters of corneal astigmatism.

        6. Corneal Tomography (Pentacam).

      Surgical procedures:

      LRIs are performed using topical anesthesia. Patients are instructed to fixate on the
      microscope light. Before surgery, the steep meridian was identified with a marker dyed with
      methylene blue with the patient sitting up right. A diamond knife is set at a depth of 0.600
      mm to 0.650 mm based on the peripheral pachymetric readings over the area of intended
      incision. The goal was a maximum reduction in astigmatism without overcorrection in with-the
      rule cases and with little overcorrection in against the rule cases. In the case of an
      overcorrection, the LRI can be sutured without creating any irregular astigmatism.

      Performing femtosecond laser-guided astigmatic keratotomy requires the parameters of length,
      position, depth and distance from the visual axis where the incisions will be created. The
      depth of our incisions is 85% of the corneal pachymetry in the area of the incision. We have
      set our distance from the visual axis at 8 mm. This information is all downloaded onto the
      femtosecond laser. Then, we begin the surgical procedure by docking the laser onto the
      cornea. An overlay of the incisions is then visible on the surgical screen. After treatment,
      we bring the patient to the operating microscope and open the incisions with a Sinskey hook.
      By using low energy, the incisions do not have significant effect until they are opened.
allocation: Randomized
intervention model: Parallel Assignment
primary purpose: Treatment
masking: None (Open Label)
measure: Keratometric reading
time frame: 1 week
description: measured by Corneal Tomography (Pentacam)
arm group label: limbal relaxing incisions
arm group type: Active Comparator
description: Manually performed limbal relaxing incisions
arm group label: astigmatic keratotomy
arm group type: Active Comparator
description: femtosecond laser-guided astigmatic keratotomy
intervention type: Procedure
intervention name: limbal relaxing incisions
description: Manually performed surgical procedure
arm group label: limbal relaxing incisions
intervention type: Procedure
intervention name: astigmatic keratotomy
description: femtosecond laser guided surgical procedure
arm group label: astigmatic keratotomy
criteria: 
gender: All
minimum age: 21 Years
maximum age: 65 Years
healthy volunteers: No
responsible party type: Principal Investigator
investigator affiliation: Assiut University
investigator full name: Ashraf Rashwan
investigator title: Principal Investigator
mesh term: Astigmatism
sharing ipd: Undecided
ipd description: There is a possibility of using these data in another related study so i am not sure about the time of sharing the individual participant data