An interventional study of Prism adaptation test and other in Esophoria, sponsored by Rigshospitalet, Denmark. Recruiting at 1 site in Denmark. Open to participants aged 18 Years to 65 Years. Per ClinicalTrials.gov, last updated 2025-07-22.
Sponsored by Rigshospitalet, Denmark · Not applicable, Interventional, and Treatment
This study is a prospective randomized study aiming to investigate the effect of prism adaptation before surgery for symptomatic esophoria on the number of reoperations, the occurrence of over- and under-correction after the first surgery, and symptom resolution. Additionally, we aim to define the optimal duration of prism adaptation.
SUBSTUDY 1 The Optimal Duration of Prism Adaptation in Symptomatic Esophoria Study Design: Prospective, randomized controlled study Patient Group: 100 participants with symptomatic esophoria, randomized into two groups of 50 participants each to undergo either one hour or four hours of prism adaptation.
The purpose of this study is to determine the optimal duration of prism adaptation.
The hypothesis is that the measured deviation angle is expected to increase after one hour of prism adaptation compared to before prism adaptation. Furthermore, it is expected that the measured deviation angle will not differ significantly between the two randomization groups. The primary endpoint is the measured deviation angle at the conclusion of prism adaptation.
The results are highly relevant for accurate surgical dosing (and thus postoperative symptoms and reoperation rates), efficient use of hospital resources, and reduced patient waiting times in the outpatient clinic.
SUBSTUDY 2 Strabismus Surgery for Symptomatic Esophoria Based on Prism Adaptation Study Design: Prospective, randomized controlled study Patient Group: 100 participants with symptomatic esophoria, using the same patients and randomization groups as in Substudy 1.
The purpose of this study is to investigate the effectiveness of strabismus surgery for symptomatic esophoria based on prism adaptation. Patients randomized in Substudy 2 to either one or four hours of prism adaptation will undergo surgery based on the full prism-adapted angle.
The hypothesis for this substudy is that surgical dosing based on one hour of prism adaptation will be equivalent to dosing based on four hours of prism adaptation. The primary endpoint will be the reoperation rate. Secondary endpoints will include comparisons of preoperative surgical planning metrics (target deviation and number of eye muscles operated), symptom resolution after the first surgery, and prism measurements (including rates of over- and undercorrections).
33 studies on the registry are indexed under Esotropia; 10 are open to participants now.
This study's planned enrollment of 100 is above the median of 63 across 21 interventional studies indexed under Esotropia.
Browse Esotropia studies →Rigshospitalet, Denmark is the lead sponsor of 1,017 studies on the registry; 183 are open to participants now.
Counted across the registry records on this site, refreshed daily.
Patients with symptomatic esophoria who meet one or more of the following criteria:
Exclusion Criteria:
Patients who receive one hour of prism adaptation.
Procedure: Prism adaptation test · Procedure: other
Patients who receive four hour of prism adaptation.
Procedure: Prism adaptation test · Procedure: other
Prism Adapation test for 1 hour in one group, and 4 hours in second group
Surgery based on prism adaptation test of 1 hour in one group and 4 hours in second group
Also known as: Surgery based on prism adaptation test
Reoperation rate
Number of patients in need of reoperation after initial surgery for symptomatic esophoria
Time frame: Up to 5 years
Measured deviation angle at the conclusion of prism adaptation.
Measured deviation angle in prism diopters at the conclusion of prism adaptation.
Time frame: Up to 5 years
Motor success
Motor success: 10 prism diopters of esophoria to 5 prism diopters of exophoria measured with prism alternating cover test. Motor failure: Manifest strabismus measured with prism alternating cover test
Time frame: 1 year from date of surgery
Sensory success
Sensory success: Postoperative unchanged or improvement in stereopsis measured in seconds of arc with the same method (LANG I/II or TNO) in compared to baseline.
Time frame: 1 year from date of surgery
Symptomatic success
Symptomatic success: Single vision (defined as the absence of double vision in daily life) and/or absence of asthenopia (defined as eye strain that is significant in daily life)
Time frame: 1 year from date of surgery
Plan to share: No
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Rigshospitalet, Denmark