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Trial record 23 of 831 for:    Texas Children's Hospital | ( Map: United States )

Photorefractive Keratectomy for Severe Anisometropia and Isoametropia Associated With Amblyopia

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ClinicalTrials.gov Identifier: NCT03610997
Recruitment Status : Recruiting
First Posted : August 2, 2018
Last Update Posted : August 2, 2018
Sponsor:
Information provided by (Responsible Party):
Evelyn, Baylor College of Medicine

Brief Summary:
Photorefractive keratectomy (PRK) with excimer laser has been used successfully to treat myopia, hyperopia, and astigmatism in adults for over 30 years. Children with high refractive errors that go untreated will develop severe amblyopia. PRK can normalize high refractive errors and potentially improve the amblyopia in affected children. The purpose of this study is to investigate whether children with high anisometropia or isoametropia with amblyopia that are nonresponsive to standard therapy and receive PRK develop better longterm visual acuity.

Condition or disease Intervention/treatment Phase
Anisometropia Hyperopia High Myopia Amblyopia Isometropic Amblyopia Bilateral High Astigmatism Procedure: Photorefractive keratectomy Not Applicable

Detailed Description:

Anisometropia is a condition in which one eye has a significantly different refractive error from the other and commonly leads to the development of refractive amblyopia in the affected eye. High isoametropia is the condition in which both eyes have high refractive error and commonly leads to bilateral refractive amblyopia if untreated. Amblyopia is the condition in which vision does not develop fully in the brain due to disuse or misuse of one or both eyes. Typically, in high anisometropia, a contact lens in the eye with the stronger refractive error and/or glasses must be used to correct the refractive error. Commonly, infants and children with this condition refuse to wear the contact lens or glasses because the other eye sees normally. There are other problems in treating high anisometropia with glasses. One is aniseikonia, the condition of image size disparity between the two eyes. This causes difficulty for the brain of the affected person to fuse the images from the two eyes because the image from one eye is much larger than that from the other eye. This results in asthenopia (eye fatigue) and sometimes even diplopia. If the anisometropia is severe, significant amblyopia will result in the eye with the stronger refractive error and, if not treated at an early age, permanent and potentially severe vision loss will result.

In high isoametropia, contact lenses or glasses must likewise be used in order for normal vision to develop. Most children with isoametropia will wear glasses well because they cannot see well without them. By contrast, children with developmental delays, chromosomal abnormalities, autism, or attention deficit hyperactivity disorder and high isoametropia very commonly will not wear the needed refractive correction due to strong tactile aversion to anything touching the face or head. If the refractive error is high, significant bilateral (isoametropic) amblyopia will result and, if not treated at an early age, permanent and potentially severe vision loss will result.

PRK can normalize high refractive errors and potentially improve the amblyopia in affected children. The purpose of this study is to investigate whether children with high anisometropia or isoametropia with amblyopia that are nonresponsive to standard therapy and receive PRK develop better longterm visual acuity. Secondary outcomes are stability of refractive correction, and corneal health.


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Study Type : Interventional  (Clinical Trial)
Estimated Enrollment : 300 participants
Intervention Model: Single Group Assignment
Intervention Model Description: Photorefractive Keratectomy
Masking: None (Open Label)
Primary Purpose: Treatment
Official Title: Photorefractive Keratectomy for Anisometropic and Isoametropic Amblyopia in Children Refractory to Conventional Treatment
Actual Study Start Date : January 1, 2001
Estimated Primary Completion Date : August 1, 2028
Estimated Study Completion Date : October 1, 2028

Resource links provided by the National Library of Medicine

MedlinePlus related topics: Amblyopia

Arm Intervention/treatment
Photorefractive keratectomy
The children will undergo PRK in the affected eye(s) using previously derived formulas for PRK.
Procedure: Photorefractive keratectomy



Primary Outcome Measures :
  1. Visual acuity [ Time Frame: 10 years ]
    Snellen equivalent


Secondary Outcome Measures :
  1. Refractive error [ Time Frame: 10 years ]
    cycloplegic refraction

  2. Corneal clarity [ Time Frame: 10 years ]
    slit lamp exam



Information from the National Library of Medicine

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Ages Eligible for Study:   2 Years to 17 Years   (Child)
Sexes Eligible for Study:   All
Accepts Healthy Volunteers:   No
Criteria

Inclusion Criteria:.

  • Children aged 2 to 17 with significant anisometropia or isoametropia and amblyopia that have failed traditional treatment for at least 6 months.
  • Anisometropic group:
  • The anisometropia must be at least 3.00 diopters.
  • The amblyopic eye best corrected visual acuity must be at least 2 lines worse than the fellow eye in verbal children
  • Isoametropic group
  • Myopia must be at least -4.00 diopters in both eyes
  • Hyperopia must be at least 4.00 diopters in both eyes
  • Astigmatism must be at least 2.50 diopters in both eyes.

Exclusion Criteria:

  • History of significant corneal abnormality that, in the investigator's opinion, may limit visual rehabilitation.
  • History of known collagen disorder
  • History of known corneal ectasia
  • History of previous herpes simplex keratitis
  • Corneal thickness of less than 450u

Information from the National Library of Medicine

To learn more about this study, you or your doctor may contact the study research staff using the contact information provided by the sponsor.

Please refer to this study by its ClinicalTrials.gov identifier (NCT number): NCT03610997


Contacts
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Contact: Evelyn Paysse, MD eapaysse@texaschildrens.org
Contact: Gihan Romany 832-832-3222 Gihan.Romany@bcm.edu

Locations
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United States, Texas
Texas Children's Hospital Recruiting
Houston, Texas, United States, 77030
Contact: Gihan Romany    832-822-3222    Gihan.Romany@bcm.edu   
Principal Investigator: Evelyn Paysse, MD         
Sponsors and Collaborators
Baylor College of Medicine
Investigators
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Principal Investigator: Evelyn Paysse, MD Texas Children's Hospital

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Responsible Party: Evelyn, Professor of Ophthalmology and Pediatrics, Baylor College of Medicine
ClinicalTrials.gov Identifier: NCT03610997     History of Changes
Other Study ID Numbers: H-6604
First Posted: August 2, 2018    Key Record Dates
Last Update Posted: August 2, 2018
Last Verified: July 2018
Individual Participant Data (IPD) Sharing Statement:
Plan to Share IPD: No

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Product Manufactured in and Exported from the U.S.: No

Additional relevant MeSH terms:
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Astigmatism
Amblyopia
Hyperopia
Anisometropia
Refractive Errors
Eye Diseases
Brain Diseases
Central Nervous System Diseases
Nervous System Diseases
Vision Disorders
Sensation Disorders
Neurologic Manifestations
Signs and Symptoms