Investigating the effects of prism adaptation on surgery outcomes for esophoria

Prism Adaptation in Symptomatic Esophoria - Effect of Shorter Time Intervals and Surgical Outcomes Based on Prism Adaptation

Not applicable Interventional Rigshospitalet, Denmark · NCT06729710

This study is testing whether spending one hour or four hours using special glasses can help improve surgery results for people with esophoria.

Quick facts

PhaseNot applicable
Study typeInterventional
Enrollment100 (estimated)
Ages18 Years to 65 Years
SexAll
SponsorRigshospitalet, Denmark Academic / other
Locations1 site (Copenhagen)
Trial IDNCT06729710 on ClinicalTrials.gov

What this trial studies

This prospective randomized study aims to explore the impact of prism adaptation on surgical outcomes for patients with symptomatic esophoria. Participants will be divided into two groups to undergo either one hour or four hours of prism adaptation before strabismus surgery. The study will assess the number of reoperations, the occurrence of over- and under-correction, and the resolution of symptoms post-surgery. The goal is to determine the optimal duration of prism adaptation to improve surgical accuracy and patient outcomes.

Who should consider this trial

Good fit: Ideal candidates are patients aged 18 to 65 with symptomatic esophoria experiencing double vision, eye strain, or headaches.

Not a fit: Patients with conditions such as accommodative esotropia, previous strabismus surgery, or significant myopia may not benefit from this study.

Why it matters

Potential benefit: If successful, this study could lead to improved surgical outcomes and reduced need for reoperations in patients with esophoria.

How similar studies have performed: While the approach of using prism adaptation is established, this specific investigation into optimal duration and its surgical implications is novel.

Eligibility criteria

Show full inclusion / exclusion criteria
Inclusion Criteria:

Patients with symptomatic esophoria who meet one or more of the following criteria:

* Double vision
* Asthenopia (eye strain)
* Headaches related to esophoria
* Worsening of symptoms during fatigue, sleep deprivation, reading, illness, or alcohol consumption.

Exclusion Criteria:

* Age between 18 and 65 years at date of inclusion.
* Accommodative esotropia or esophoria
* Myopia exceeding 10 diopters in the most myopic meridian
* Treatment with botulinum toxin in an eye muscle within four months prior to inclusion
* Inability to undergo reliable orthoptic measurements or prism adaptation
* Previous strabismus surgery
* Pregnancy or breastfeeding within 12 months prior to inclusion
* Myogenic disorders (including Myasthenia Gravis)
* Restrictive strabismus (including previous eye muscle trauma or Graves' orbitopathy)
* Eye muscle paresis
* Maximum prism-adapted deviation angle \>40 prism diopters (PD) in any gaze direction for distance
* Maximum prism-adapted deviation angle with ≥20 PD difference between near and distance measurements

Where this trial is running

Copenhagen

Study contacts

How to participate

  1. Review the eligibility criteria above with your treating physician.
  2. Visit the official trial page on ClinicalTrials.gov for the most current contact information and recruitment status.
  3. Contact the listed study coordinator or principal investigator to request pre-screening. Pre-screening is free and never obligates you to enroll.
Conditions Esophoriaprism adaptationstrabismus surgery
Last reviewed 2026-06-13 by the Find a Trial editorial team. Information on this page is for educational purposes and is not medical advice. Always consult qualified healthcare professionals about clinical trial participation.