- ICH GCP
- US Clinical Trials Registry
- Clinical Trial NCT03610997
Photorefractive Keratectomy for Severe Anisometropia and Isoametropia Associated With Amblyopia
Photorefractive Keratectomy for Anisometropic and Isoametropic Amblyopia in Children Refractory to Conventional Treatment
Study Overview
Status
Conditions
Intervention / Treatment
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 their 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 reduce or eliminate 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.
Study Type
Enrollment (Estimated)
Phase
- Not Applicable
Contacts and Locations
Study Locations
-
-
Texas
-
Houston, Texas, United States, 77030
- Texas Children's Hospital
-
-
Participation Criteria
Eligibility Criteria
Ages Eligible for Study
Accepts Healthy Volunteers
Description
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
Study Plan
How is the study designed?
Design Details
- Primary Purpose: Treatment
- Allocation: N/A
- Interventional Model: Single Group Assignment
- Masking: None (Open Label)
Arms and Interventions
Participant Group / Arm |
Intervention / Treatment |
---|---|
Other: Photorefractive keratectomy
The children will undergo PRK in the affected eye(s) using previously derived formulas for PRK.
|
What is the study measuring?
Primary Outcome Measures
Outcome Measure |
Measure Description |
Time Frame |
---|---|---|
Visual acuity
Time Frame: 10 years
|
Snellen equivalent
|
10 years
|
Secondary Outcome Measures
Outcome Measure |
Measure Description |
Time Frame |
---|---|---|
Refractive error
Time Frame: 10 years
|
cycloplegic refraction
|
10 years
|
Corneal clarity
Time Frame: 10 years
|
slit lamp exam
|
10 years
|
Collaborators and Investigators
Sponsor
Investigators
- Principal Investigator: Evelyn Paysse, MD, Baylor College of Medicine
Study record dates
Study Major Dates
Study Start (Actual)
Primary Completion (Estimated)
Study Completion (Estimated)
Study Registration Dates
First Submitted
First Submitted That Met QC Criteria
First Posted (Actual)
Study Record Updates
Last Update Posted (Actual)
Last Update Submitted That Met QC Criteria
Last Verified
More Information
Terms related to this study
Additional Relevant MeSH Terms
Other Study ID Numbers
- H-6604
Plan for Individual participant data (IPD)
Plan to Share Individual Participant Data (IPD)?
Drug and device information, study documents
product manufactured in and exported from the U.S.
This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.
Clinical Trials on Hyperopia
-
Bausch & Lomb IncorporatedRecruitingMyopia and Hyperopia and PresbyopiaUnited States
-
Lee, Steven, M.D.CompletedMyopia, | Hyperopia, | Astigmatism, | Presbyopia, | Eye Strain,
-
Donald O Mutti, OD, PhDCompleted
-
Jaeb Center for Health ResearchNational Eye Institute (NEI); Pediatric Eye Disease Investigator GroupCompleted
-
University Hospital, ToulouseCentre de Référence National du KératocôneTerminated
-
Medipol UniversityCompleted
-
Alcon ResearchEnrolling by invitation
-
Coopervision, Inc.CompletedMyopia | HyperopiaSpain
-
Canyon City EyecareNevakar, Inc.Enrolling by invitationMyopia | HyperopiaUnited States
Clinical Trials on Photorefractive keratectomy
-
Tabriz UniversityCompletedAstigmatismIran, Islamic Republic of
-
Assiut UniversityRecruitingCompare Corneal High Order Aberrations Before and After Stream Light Trans-PRK and Mechanical Photorefractive KeratectomyEgypt
-
Walter Reed Army Medical CenterUnited States Naval Medical Center, San DiegoCompleted
-
Assiut UniversityCompletedMyopia ≤ -6 Diopters or Myopic Astigmatism ≤ -4 DioptersEgypt
-
Assiut UniversityCompleted
-
University of UtahTerminatedTopo-guided LASIK and Photorefractive Keratectomy vs Wavefront LASIK and Photorefractive KeratectomySurgery | MyopiaUnited States
-
Bausch & Lomb IncorporatedCompletedAmetropiaPhilippines
-
Shahid Beheshti UniversityTehran University of Medical Sciences; Negah Eye CenterActive, not recruitingKeratoconus | Corneal Cross-LinkingIran, Islamic Republic of
-
Minia UniversityCompletedMyopia | Refractive SurgerySaudi Arabia, Egypt
-
University of Sao PauloCompleted