Related Experiment Video
Updated: Feb 5, 2026

Full-Endoscopic Interlaminar Approach for Decompression of Lateral Recess Stenosis
Published on: February 24, 2023
A Randomized Trial Comparing Bilateral Lateral Rectus Recession versus Unilateral Recess and Resect for Basic-Type
, , Sean P Donahue1
1Department of Ophthalmology and Visual Sciences, Vanderbilt University Medical Center, Nashville, Tennessee.
Purpose:
To compare long-term outcomes after bilateral lateral rectus recession (BLRc) or unilateral lateral rectus recession combined with medial rectus resection in the same eye (R&R) for primary treatment of childhood intermittent exotropia (IXT).
Design:
Multicenter, randomized clinical trial.
Participants:
One hundred ninety-seven children 3 to younger than 11 years of age with basic-type IXT, a largest deviation by prism and alternate cover test at any distance of 15 to 40 prism diopters (PD), and near stereoacuity of at least 400 seconds of arc.
Methods:
Random assignment to BLRc or R&R and masked examinations conducted every 6 months after surgery for 3 years.
Main Outcome Measures:
Proportion of participants meeting suboptimal surgical outcome by 3 years, defined as: (1) exotropia of 10 PD or more at distance or near using simultaneous prism and cover test (SPCT); or (2) constant esotropia of 6 PD or more at distance or near using SPCT; (3) loss of 2 octaves or more of stereoacuity from baseline, at any masked examination; or (4) reoperation without meeting any of these criteria.
Results:
Cumulative probability of suboptimal surgical outcome by 3 years was 46% (43/101) in the BLRc group versus 37% (33/96) in the R&R group (treatment group difference of BLRc minus R&R, 9%; 95% confidence interval [CI], -6% to 23%). Reoperation by 3 years occurred in 9 participants (10%) in the BLRc group (8 of 9 met suboptimal surgical outcome criteria) and in 4 participants (5%) in the R&R group (3 of 4 met suboptimal surgical outcome criteria; treatment group difference of BLRc minus R&R, 5%; 95% CI, -2% to 13%). Among participants completing the 3-year visit, 29% (25 of 86) in the BLRc group and 17% (13 of 77) in the R&R group underwent reoperation or met suboptimal surgical outcome criteria at 3 years (treatment group difference of BLRc minus R&R, 12%; 95% CI, -1% to 25%).
Conclusions:
We did not find a statistically significant difference in suboptimal surgical outcome by 3 years between children with IXT treated with BLRc compared with those treated with R&R. Based on these findings, we are unable to recommend one surgical approach over the other for childhood IXT.
Related Concept Videos
Energy Basics
Clinical Trials: Overview
Trial and Error and Algorithm
Clinical Trials
There are four phases in a clinical trial. A phase one...
Random Error
Random Variables
Uppercase letters such as X or Y denote a random variable. Lowercase letters like x or y denote the value of a random variable. If X is a random variable, then X is written in words, and x is given as a number.
For example, let X = the...

