Clinical Trial: Observation Versus Occlusion Therapy for Intermittent Exotropia

Study Status: Completed
Recruit Status: Completed
Study Type: Interventional

Official Title: A Randomized Clinical Trial of Observation Versus Occlusion Therapy for Intermittent Exotropia

Brief Summary:

The present study is being conducted to assess the natural history of intermittent exotropia and to establish the effectiveness of occlusion in its treatment.

Study Objectives:

  • To determine the effectiveness of occlusion for the treatment of intermittent exotropia among patients aged 3 to < 11 years who have baseline near stereoacuity of 400 arcsec or better by Preschool Randot stereotest
  • To determine the natural history of intermittent exotropia among patients aged 3 to < 11 years who have baseline near stereoacuity of 400 arcsec or better by Preschool Randot stereotest

Detailed Summary:

Intermittent exotropia (IXT) is the most common form of childhood-onset exotropia with an incidence of 32.1 per 100,000 in children under 19 years of age. Intermittent exotropia is characterized by an exotropia that is not constant and is mainly present in the distance but may also be present at near. Many cases of IXT are treated using non-surgical interventions, such as part-time occlusion, fusional vergence exercises, and over-minus lenses. The rationale for such interventions is that they may improve the ability to control the IXT and preserve stereoacuity, thereby potentially addressing both visual function and social concerns, and may delay or eliminate the need for surgical correction of IXT. Nevertheless, the natural history of IXT is unknown and in many cases it is not known whether withholding treatment may in fact allow for spontaneous resolution or improvement in IXT, making non-surgical or surgical intervention unnecessary. Moreover, although non-surgical treatments for IXT are commonly prescribed, such treatments have not been subjected to rigorous study and their efficacy in improving visual function or social concerns remains unclear.

One aim of the present study is to better understand the natural history of IXT. Available reports on the natural history of IXT disagree on the progression of the disease. A 1966 study by von Noorden (cited in von Noorden and Campos) found that over an average of 3.5 years of follow-up, 75% of 51 patients showed signs of IXT progression, 9% showed no change, and 16% improved without therapy. A 1968 retrospective study by Hiles et al found that after a minimum of 6 years follow up with observation and nonsurgical treatment, 81% of 48 patients showed no change in angle of deviation. The results of more recent retrospective studies show some reporting that the majority of cases improve over time, others reporting that most case
Sponsor: Jaeb Center for Health Research

Current Primary Outcome:

  • Deterioration by 6 months as assessed by motor alignment and stereoacuity at near [ Time Frame: 6 months ]
  • Deterioration by 3 years as assessed by motor alignment and stereoacuity at near [ Time Frame: 3 years ]


Original Primary Outcome: Same as current

Current Secondary Outcome:

  • distance stereoacuity [ Time Frame: every 6 months for 3 years of follow-up ]
  • monofixation status [ Time Frame: every 6 months for 3 years of follow-up ]
  • development of amblyopia [ Time Frame: every 6 months for 3 years of follow-up ]
  • health related quality of life [ Time Frame: every 6 months for 3 years of follow-up ]


Original Secondary Outcome: Same as current

Information By: Jaeb Center for Health Research

Dates:
Date Received: December 11, 2009
Date Started: January 2010
Date Completion:
Last Updated: June 24, 2016
Last Verified: June 2016