Clinical Trial Details
— Status: Completed
Administrative data
| NCT number |
NCT00000163 |
| Other study ID # |
NEI-65 |
| Secondary ID |
|
| Status |
Completed |
| Phase |
N/A
|
| First received |
September 23, 1999 |
| Last updated |
September 16, 2009 |
| Start date |
December 1997 |
| Est. completion date |
July 2000 |
Study information
| Verified date |
September 2009 |
| Source |
National Eye Institute (NEI) |
| Contact |
n/a |
| Is FDA regulated |
No |
| Health authority |
United States: Federal Government |
| Study type |
Observational
|
Clinical Trial Summary
To observe the early course of congenital esotropia, a form of childhood strabismus. This
will determine the probability of spontaneous resolution. Researchers then will try to
correlate this finding with various aspects of the esotropia such as the (1) size of the
esotropia, (2) variability, and (3) presence of hyperopia. This information will be used to
determine the feasibility of conducting a clinical trial to assess the benefit of early
surgery for congenital esotropia and, if feasible, to refine eligibility criteria for the
trial.
Description:
Congenital esotropia is the most common form of childhood strabismus. Despite its common
occurrence, limited information is available about its early clinical course. Such data are
needed to determine the earliest age at which surgery can be safely performed without
concern that the esotropia is likely to resolve spontaneously. Although the term congenital
esotropia implies that the esotropia is present at birth, in many cases the esotropia
actually develops sometime during the first few months of life. It is well recognized that
congenital esotropia persisting through 6 months of age rarely if ever resolves
spontaneously and therefore requires surgical correction. However, it is not clear how often
congenital esotropia occurs and then resolves (at an earlier age such that surgery is not
necessary) before surgery is required.
Current clinical practice is to defer surgery for congenital esotropia until 6 to 12 months
of age. Assuming that characteristics of congenital esotropia at 2 to 4 months of age can be
identified to predict which cases will require surgery, then a trial will be warranted to
determine whether performing earlier surgery enhances the development of binocular vision.
The potential benefit to very early surgery is supported by neurophysiologic research, which
has shown that (1) congenital esotropes may be born with the innate ability to develop
binocular vision, (2) there is a critical period for development of normal binocular
function within the first few months of life that is dependent on alignment of the visual
axes of the two eyes, and (3) ocular misalignment alone, regardless of its mechanism,
without a coexisting primary cortical fusion deficit, can account for abnormal development
of binocular vision. Clinical reports have demonstrated that surgical correction of the
esotropia between 6 and 12 months of age provides for enhanced development of stereoacuity
compared with later surgery. However, there are limited data on the outcomes in infants who
had surgical correction before age 6 months.
The protocol for the study is identical to usual clinical practice. Following informed
consent, two followup visits are conducted: one 2 to 4 weeks after the first examination and
the other when the child is between 28 and 32 weeks of age. The examinations will be
identical to the pediatric ophthalmologist's usual routine, and no additional procedures are
being performed specifically for the study. Management of refractive error and amblyopia is
left to the ophthalmologist's discretion. A sample size of 150 has been projected for the
study.
