<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/NCT04424069</url>
  </required_header>
  <id_info>
    <org_study_id>33553/12/19</org_study_id>
    <nct_id>NCT04424069</nct_id>
  </id_info>
  <brief_title>OCTA Analysis of Macular and Papillary Perfusion After Refractive Surgery in Myopes</brief_title>
  <official_title>Optical Coherence Tomography Angiography Analysis of Macular and Papillary Perfusion After Variable Refractive Surgery Methods in Myopic Patients</official_title>
  <sponsors>
    <lead_sponsor>
      <agency>Tanta University</agency>
      <agency_class>Other</agency_class>
    </lead_sponsor>
  </sponsors>
  <source>Tanta University</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>
      Refractive surgery for correction of myopia is very common nowadays. However, various&#xD;
      refractive techniques may be associated with increase in the IOP, especially during flap&#xD;
      creation. It is assumed that marked intraoperative IOP increase lead to macular and optic&#xD;
      disc head circulation compromise. The purpose of this study is to assess the change of&#xD;
      macular and papillary perfusion, using optical coherence tomography angiography (OCTA)&#xD;
      imaging of the macula and optic disc of myopic patients before and after various refractive&#xD;
      surgery methods.&#xD;
    </textblock>
  </brief_summary>
  <detailed_description>
    <textblock>
      Myopia is the most prevalent ocular disorder in children worldwide, and one of the major&#xD;
      causes of visual deterioration in all age groups. Highest prevalence rates are in East Asian&#xD;
      countries (affecting up to 83% of Singaporean teenagers), however, it is very common in all&#xD;
      other countries. While mild to moderate myopia usually stabilizes within the third decade,&#xD;
      pathological myopia is associated with progressive globe elongation, and development of&#xD;
      various macular complications including; foveoschisis, choroidal neovascularization (CNV),&#xD;
      myopic macular hole, and myopic vitreomacular traction (VMT).&#xD;
&#xD;
      Refractive surgery has become popular for correcting ametropia including myopia. Most&#xD;
      commonly used refractive procedures include corneal refractive surgeries especially laser&#xD;
      in-situ keratomileusis (LASIK), and Photorefractive keratectomy (PRK), Phakic Intraocular&#xD;
      Lenses (Phakic IOLs) and refractive lens exchange.&#xD;
&#xD;
      In LASIK, the creation of a corneal lamellar flap requires placement of a suction ring on the&#xD;
      anterior segment of the eye, which transiently elevates the intraocular pressure (IOP) to&#xD;
      levels exceeding 65 mmHg. Experimental studies in animal eyes have found that the IOP can&#xD;
      increase to between 80 mmHg and 360 mmHg during this vacuum phase and lamellar cut with the&#xD;
      microkeratome. Recent advances utilizing the femtosecond laser may serve as an alternative to&#xD;
      the mechanical microkeratome, with a low-pressure suction ring. In studies using porcine&#xD;
      eyes, the IOP during the suctioning or laser application phase reached a maximum of 135 mmHg&#xD;
      using the femtosecond laser, lower than pressures reached with a traditional microkeratome,&#xD;
      but for a longer duration of time. Similarly in refractive lens procedures, intraoperative&#xD;
      IOP was found to exceed 60 mmHg.&#xD;
&#xD;
      Intraocular pressure elevation during refractive procedures may cause a reduction in the&#xD;
      perfusion of the retina and optic nerve head, posterior displacement of the lamina cribrosa,&#xD;
      and a decline in ocular perfusion pressure of the posterior ciliary arteries. Although this&#xD;
      IOP elevation is temporary, the potential for ischemic or pressure-induced damage to the&#xD;
      optic nerve head and the retinal nerve fiber layer exists.&#xD;
&#xD;
      Optical coherence tomography angiography (OCTA) is a recent noninvasive imaging technique&#xD;
      that allows for volumetric visualization of eye vasculature. OCTA has shown promise in better&#xD;
      elucidating the pathophysiology of several retinal vascular diseases. Swept-source OCTA uses&#xD;
      long wavelength ̰ 1,050nm, which can penetrate through deeper layers of the eye and can&#xD;
      traverse opacities of media such as cataracts, hemorrhages and vitreous opacities [6].&#xD;
      Optical coherence tomographic angiograms can further be manually or automatically segmented&#xD;
      with preprogrammed software to highlight individual layers of the retina, optic nerve head&#xD;
      choriocapillaris, and choroid. The user can either analyze en face images extending from the&#xD;
      inner limiting membrane to choroid or use automated views to locate a vascular or structural&#xD;
      lesion within the retina.&#xD;
&#xD;
      The purpose of this study is to assess the change of macular and papillary perfusion, using&#xD;
      optical coherence tomography angiography (OCTA) imaging of the macula and optic disc of&#xD;
      myopic patients subject to various refractive surgery methods. We will compare between these&#xD;
      methods to evaluate which one is associated with least adverse effect on ocular perfusion. To&#xD;
      date no such evaluation has been done using OCTA, because of relatively recent onset of this&#xD;
      technology. Traditional imaging methods such as color fundus photography and fluorescein&#xD;
      angiography have limited resolution for retinal vasculature that mad such evaluation in the&#xD;
      past using these methods not feasible, however, OCTA is very promising for the proper&#xD;
      analysis of changes in the ocular perfusion. Results of this study will have significant&#xD;
      clinical and practical implications and may change the approach for surgical correction of&#xD;
      such patients.&#xD;
    </textblock>
  </detailed_description>
  <overall_status>Unknown status</overall_status>
  <last_known_status>Recruiting</last_known_status>
  <start_date type="Actual">March 1, 2020</start_date>
  <completion_date type="Anticipated">December 2020</completion_date>
  <primary_completion_date type="Anticipated">October 2020</primary_completion_date>
  <phase>N/A</phase>
  <study_type>Interventional</study_type>
  <has_expanded_access>No</has_expanded_access>
  <study_design_info>
    <allocation>Non-Randomized</allocation>
    <intervention_model>Parallel Assignment</intervention_model>
    <primary_purpose>Screening</primary_purpose>
    <masking>Single (Investigator)</masking>
  </study_design_info>
  <primary_outcome>
    <measure>Vessel density from enface OCT angiogram</measure>
    <time_frame>6 months</time_frame>
    <description>VD analysis computes the percentage of area occupied by OCTA detected vasculature in a measured area</description>
  </primary_outcome>
  <number_of_arms>5</number_of_arms>
  <enrollment type="Anticipated">100</enrollment>
  <condition>Myopia</condition>
  <condition>Perfusion; Complications</condition>
  <arm_group>
    <arm_group_label>LASIK group</arm_group_label>
    <arm_group_type>Active Comparator</arm_group_type>
    <description>Patients will do excimer laser LASIK operation for correction of myopia with flap creation by mechanical keratome</description>
  </arm_group>
  <arm_group>
    <arm_group_label>SMILE group</arm_group_label>
    <arm_group_type>Active Comparator</arm_group_type>
    <description>Patients will do Femtosecond laser assisted corneal refractive surgery for correction of myopia</description>
  </arm_group>
  <arm_group>
    <arm_group_label>Photorefractive keratectomy group</arm_group_label>
    <arm_group_type>Active Comparator</arm_group_type>
    <description>Patients that will undergo photorefractive keratectomy for correction of myopia</description>
  </arm_group>
  <arm_group>
    <arm_group_label>Refractive lens exchange</arm_group_label>
    <arm_group_type>Active Comparator</arm_group_type>
    <description>Include eyes that will undergo refractive lens exchange</description>
  </arm_group>
  <arm_group>
    <arm_group_label>Control group</arm_group_label>
    <arm_group_type>No Intervention</arm_group_type>
    <description>Myopic control eyes with no surgical intervention</description>
  </arm_group>
  <intervention>
    <intervention_type>Procedure</intervention_type>
    <intervention_name>Refractive surgery</intervention_name>
    <description>Myopic patients seeking refractive surgery will be assigned to the study groups to assess the change in myopic and papillary perfusion in these different prodecures</description>
    <arm_group_label>LASIK group</arm_group_label>
    <arm_group_label>Photorefractive keratectomy group</arm_group_label>
    <arm_group_label>Refractive lens exchange</arm_group_label>
    <arm_group_label>SMILE group</arm_group_label>
  </intervention>
  <eligibility>
    <criteria>
      <textblock>
        Inclusion Criteria:&#xD;
&#xD;
          1. Age: between 20 - 35 years&#xD;
&#xD;
          2. Patients: who are seeking and fit for refractive surgery&#xD;
&#xD;
          3. Spherical equivalent refractive error: between (-2 to -9 D)&#xD;
&#xD;
        Exclusion Criteria:&#xD;
&#xD;
          1. Maculopathies (hereditary or acquired)&#xD;
&#xD;
          2. optic nerve head pathologies (tilted disc, drusen, optic disc edema, atrophy, etc.)&#xD;
&#xD;
          3. optic neuropathies (demyelinating, infectious, ischemic, etc.)&#xD;
&#xD;
          4. adjusted IOP for central corneal thickness more than 21 mmHg&#xD;
&#xD;
          5. surgery-induced corneal edema&#xD;
&#xD;
          6. dense cataracts that can disrupt images&#xD;
&#xD;
          7. systemic diseases (vasculitis, diabetes mellitus, hypertension, etc.)&#xD;
&#xD;
          8. any previous ocular surgery,&#xD;
&#xD;
          9. patients with bad quality images or complicated surgeries will be excluded&#xD;
      </textblock>
    </criteria>
    <gender>All</gender>
    <minimum_age>18 Years</minimum_age>
    <maximum_age>35 Years</maximum_age>
    <healthy_volunteers>No</healthy_volunteers>
  </eligibility>
  <overall_official>
    <last_name>Rauf A gaber, MD</last_name>
    <role>Study Chair</role>
    <affiliation>Tanta University</affiliation>
  </overall_official>
  <overall_contact>
    <last_name>Osama A Sorour, MD</last_name>
    <phone>00201110813589</phone>
    <email>dr.osamasorour@gmail.com</email>
  </overall_contact>
  <overall_contact_backup>
    <last_name>ELSAYED A NASSAR, MD</last_name>
    <phone>00201222889473</phone>
    <email>SAYED.NASSAR@YAHOO.COM</email>
  </overall_contact_backup>
  <location>
    <facility>
      <name>Ophthalmology Department, Faculty of medicine, Tanta Univeristy</name>
      <address>
        <city>Tanta</city>
        <zip>31515</zip>
        <country>Egypt</country>
      </address>
    </facility>
    <status>Recruiting</status>
    <contact>
      <last_name>Magdy Moussa, MD</last_name>
      <email>magdymoussa60@gmail.com</email>
    </contact>
  </location>
  <location_countries>
    <country>Egypt</country>
  </location_countries>
  <reference>
    <citation>Flitcroft DI, He M, Jonas JB, Jong M, Naidoo K, Ohno-Matsui K, Rahi J, Resnikoff S, Vitale S, Yannuzzi L. IMI - Defining and Classifying Myopia: A Proposed Set of Standards for Clinical and Epidemiologic Studies. Invest Ophthalmol Vis Sci. 2019 Feb 28;60(3):M20-M30. doi: 10.1167/iovs.18-25957.</citation>
    <PMID>30817826</PMID>
  </reference>
  <reference>
    <citation>Renones de Abajo J, Estevez Jorge B, Gonzalez Martin JM, Carreras Diaz H, Loro Ferrer JF, Anton Lopez A. Effect of femtosecond laser-assisted lens surgery on the optic nerve head and the macula. Int J Ophthalmol. 2019 Jun 18;12(6):961-966. doi: 10.18240/ijo.2019.06.13. eCollection 2019.</citation>
    <PMID>31236353</PMID>
  </reference>
  <reference>
    <citation>Vetter JM, Schirra A, Garcia-Bardon D, Lorenz K, Weingartner WE, Sekundo W. Comparison of intraocular pressure during corneal flap preparation between a femtosecond laser and a mechanical microkeratome in porcine eyes. Cornea. 2011 Oct;30(10):1150-4. doi: 10.1097/ICO.0b013e318212110a.</citation>
    <PMID>21912236</PMID>
  </reference>
  <reference>
    <citation>Khng C, Packer M, Fine IH, Hoffman RS, Moreira FB. Intraocular pressure during phacoemulsification. J Cataract Refract Surg. 2006 Feb;32(2):301-8. doi: 10.1016/j.jcrs.2005.08.062.</citation>
    <PMID>16565009</PMID>
  </reference>
  <reference>
    <citation>Whitson JT, McCulley JP, Cavanagh HD, Song J, Bowman RW, Hertzog L. Effect of laser in situ keratomileusis on optic nerve head topography and retinal nerve fiber layer thickness. J Cataract Refract Surg. 2003 Dec;29(12):2302-5. doi: 10.1016/s0886-3350(03)00466-8.</citation>
    <PMID>14709290</PMID>
  </reference>
  <reference>
    <citation>Or C, Sabrosa AS, Sorour O, Arya M, Waheed N. Use of OCTA, FA, and Ultra-Widefield Imaging in Quantifying Retinal Ischemia: A Review. Asia Pac J Ophthalmol (Phila). 2018 Jan-Feb;7(1):46-51. doi: 10.22608/APO.201812. Epub 2018 Feb 13.</citation>
    <PMID>29436208</PMID>
  </reference>
  <verification_date>July 2020</verification_date>
  <study_first_submitted>June 6, 2020</study_first_submitted>
  <study_first_submitted_qc>June 6, 2020</study_first_submitted_qc>
  <study_first_posted type="Actual">June 9, 2020</study_first_posted>
  <last_update_submitted>July 24, 2020</last_update_submitted>
  <last_update_submitted_qc>July 24, 2020</last_update_submitted_qc>
  <last_update_posted type="Actual">July 28, 2020</last_update_posted>
  <responsible_party>
    <responsible_party_type>Principal Investigator</responsible_party_type>
    <investigator_affiliation>Tanta University</investigator_affiliation>
    <investigator_full_name>Osama Abdelfattah Sorour</investigator_full_name>
    <investigator_title>Retina consultant &amp; the principal investigator</investigator_title>
  </responsible_party>
  <condition_browse>
    <!-- CAUTION:  The following MeSH terms are assigned with an imperfect algorithm            -->
    <mesh_term>Myopia</mesh_term>
  </condition_browse>
  <patient_data>
    <sharing_ipd>No</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/NCT04424069
org study id: 33553/12/19
nct id: NCT04424069
lead sponsor: 
is fda regulated drug: No
is fda regulated device: No
Refractive surgery for correction of myopia is very common nowadays. However, various
      refractive techniques may be associated with increase in the IOP, especially during flap
      creation. It is assumed that marked intraoperative IOP increase lead to macular and optic
      disc head circulation compromise. The purpose of this study is to assess the change of
      macular and papillary perfusion, using optical coherence tomography angiography (OCTA)
      imaging of the macula and optic disc of myopic patients before and after various refractive
      surgery methods.
Myopia is the most prevalent ocular disorder in children worldwide, and one of the major
      causes of visual deterioration in all age groups. Highest prevalence rates are in East Asian
      countries (affecting up to 83% of Singaporean teenagers), however, it is very common in all
      other countries. While mild to moderate myopia usually stabilizes within the third decade,
      pathological myopia is associated with progressive globe elongation, and development of
      various macular complications including; foveoschisis, choroidal neovascularization (CNV),
      myopic macular hole, and myopic vitreomacular traction (VMT).

      Refractive surgery has become popular for correcting ametropia including myopia. Most
      commonly used refractive procedures include corneal refractive surgeries especially laser
      in-situ keratomileusis (LASIK), and Photorefractive keratectomy (PRK), Phakic Intraocular
      Lenses (Phakic IOLs) and refractive lens exchange.

      In LASIK, the creation of a corneal lamellar flap requires placement of a suction ring on the
      anterior segment of the eye, which transiently elevates the intraocular pressure (IOP) to
      levels exceeding 65 mmHg. Experimental studies in animal eyes have found that the IOP can
      increase to between 80 mmHg and 360 mmHg during this vacuum phase and lamellar cut with the
      microkeratome. Recent advances utilizing the femtosecond laser may serve as an alternative to
      the mechanical microkeratome, with a low-pressure suction ring. In studies using porcine
      eyes, the IOP during the suctioning or laser application phase reached a maximum of 135 mmHg
      using the femtosecond laser, lower than pressures reached with a traditional microkeratome,
      but for a longer duration of time. Similarly in refractive lens procedures, intraoperative
      IOP was found to exceed 60 mmHg.

      Intraocular pressure elevation during refractive procedures may cause a reduction in the
      perfusion of the retina and optic nerve head, posterior displacement of the lamina cribrosa,
      and a decline in ocular perfusion pressure of the posterior ciliary arteries. Although this
      IOP elevation is temporary, the potential for ischemic or pressure-induced damage to the
      optic nerve head and the retinal nerve fiber layer exists.

      Optical coherence tomography angiography (OCTA) is a recent noninvasive imaging technique
      that allows for volumetric visualization of eye vasculature. OCTA has shown promise in better
      elucidating the pathophysiology of several retinal vascular diseases. Swept-source OCTA uses
      long wavelength ̰ 1,050nm, which can penetrate through deeper layers of the eye and can
      traverse opacities of media such as cataracts, hemorrhages and vitreous opacities [6].
      Optical coherence tomographic angiograms can further be manually or automatically segmented
      with preprogrammed software to highlight individual layers of the retina, optic nerve head
      choriocapillaris, and choroid. The user can either analyze en face images extending from the
      inner limiting membrane to choroid or use automated views to locate a vascular or structural
      lesion within the retina.

      The purpose of this study is to assess the change of macular and papillary perfusion, using
      optical coherence tomography angiography (OCTA) imaging of the macula and optic disc of
      myopic patients subject to various refractive surgery methods. We will compare between these
      methods to evaluate which one is associated with least adverse effect on ocular perfusion. To
      date no such evaluation has been done using OCTA, because of relatively recent onset of this
      technology. Traditional imaging methods such as color fundus photography and fluorescein
      angiography have limited resolution for retinal vasculature that mad such evaluation in the
      past using these methods not feasible, however, OCTA is very promising for the proper
      analysis of changes in the ocular perfusion. Results of this study will have significant
      clinical and practical implications and may change the approach for surgical correction of
      such patients.
allocation: Non-Randomized
intervention model: Parallel Assignment
primary purpose: Screening
masking: Single (Investigator)
measure: Vessel density from enface OCT angiogram
time frame: 6 months
description: VD analysis computes the percentage of area occupied by OCTA detected vasculature in a measured area
arm group label: LASIK group
arm group type: Active Comparator
description: Patients will do excimer laser LASIK operation for correction of myopia with flap creation by mechanical keratome
arm group label: SMILE group
arm group type: Active Comparator
description: Patients will do Femtosecond laser assisted corneal refractive surgery for correction of myopia
arm group label: Photorefractive keratectomy group
arm group type: Active Comparator
description: Patients that will undergo photorefractive keratectomy for correction of myopia
arm group label: Refractive lens exchange
arm group type: Active Comparator
description: Include eyes that will undergo refractive lens exchange
arm group label: Control group
arm group type: No Intervention
description: Myopic control eyes with no surgical intervention
intervention type: Procedure
intervention name: Refractive surgery
description: Myopic patients seeking refractive surgery will be assigned to the study groups to assess the change in myopic and papillary perfusion in these different prodecures
arm group label: LASIK group
arm group label: Photorefractive keratectomy group
arm group label: Refractive lens exchange
arm group label: SMILE group
criteria: 
gender: All
minimum age: 18 Years
maximum age: 35 Years
healthy volunteers: No
last name: Rauf A gaber, MD
role: Study Chair
affiliation: Tanta University
last name: Osama A Sorour, MD
phone: 00201110813589
email: dr.osamasorour@gmail.com
last name: ELSAYED A NASSAR, MD
phone: 00201222889473
email: SAYED.NASSAR@YAHOO.COM
facility: 
status: Recruiting
contact: 
country: Egypt
citation: Flitcroft DI, He M, Jonas JB, Jong M, Naidoo K, Ohno-Matsui K, Rahi J, Resnikoff S, Vitale S, Yannuzzi L. IMI - Defining and Classifying Myopia: A Proposed Set of Standards for Clinical and Epidemiologic Studies. Invest Ophthalmol Vis Sci. 2019 Feb 28;60(3):M20-M30. doi: 10.1167/iovs.18-25957.
PMID: 30817826
citation: Renones de Abajo J, Estevez Jorge B, Gonzalez Martin JM, Carreras Diaz H, Loro Ferrer JF, Anton Lopez A. Effect of femtosecond laser-assisted lens surgery on the optic nerve head and the macula. Int J Ophthalmol. 2019 Jun 18;12(6):961-966. doi: 10.18240/ijo.2019.06.13. eCollection 2019.
PMID: 31236353
citation: Vetter JM, Schirra A, Garcia-Bardon D, Lorenz K, Weingartner WE, Sekundo W. Comparison of intraocular pressure during corneal flap preparation between a femtosecond laser and a mechanical microkeratome in porcine eyes. Cornea. 2011 Oct;30(10):1150-4. doi: 10.1097/ICO.0b013e318212110a.
PMID: 21912236
citation: Khng C, Packer M, Fine IH, Hoffman RS, Moreira FB. Intraocular pressure during phacoemulsification. J Cataract Refract Surg. 2006 Feb;32(2):301-8. doi: 10.1016/j.jcrs.2005.08.062.
PMID: 16565009
citation: Whitson JT, McCulley JP, Cavanagh HD, Song J, Bowman RW, Hertzog L. Effect of laser in situ keratomileusis on optic nerve head topography and retinal nerve fiber layer thickness. J Cataract Refract Surg. 2003 Dec;29(12):2302-5. doi: 10.1016/s0886-3350(03)00466-8.
PMID: 14709290
citation: Or C, Sabrosa AS, Sorour O, Arya M, Waheed N. Use of OCTA, FA, and Ultra-Widefield Imaging in Quantifying Retinal Ischemia: A Review. Asia Pac J Ophthalmol (Phila). 2018 Jan-Feb;7(1):46-51. doi: 10.22608/APO.201812. Epub 2018 Feb 13.
PMID: 29436208
responsible party type: Principal Investigator
investigator affiliation: Tanta University
investigator full name: Osama Abdelfattah Sorour
investigator title: Retina consultant & the principal investigator
mesh term: Myopia
sharing ipd: No