Clinical Trial Details
— Status: Active, not recruiting
Administrative data
NCT number |
NCT03610997 |
Other study ID # |
H-6604 |
Secondary ID |
|
Status |
Active, not recruiting |
Phase |
N/A
|
First received |
|
Last updated |
|
Start date |
January 1, 2001 |
Est. completion date |
October 1, 2028 |
Study information
Verified date |
June 2023 |
Source |
Baylor College of Medicine |
Contact |
n/a |
Is FDA regulated |
No |
Health authority |
|
Study type |
Interventional
|
Clinical Trial Summary
Photorefractive keratectomy (PRK) with excimer laser has been used successfully to treat
myopia, hyperopia, and astigmatism in adults for over 35 years. Children with high refractive
errors that go untreated will develop severe amblyopia. PRK can normalize high refractive
errors and potentially improve the visual acuity 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.
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.