Table 4:

Definition of Suboptimal Surgical Outcome by Three Years

Suboptimal Surgical Outcome by Three Years (Primary Outcome)
A participant’s IXT was considered to be a suboptimal surgical outcome if at any visit occurring 6 months or later, ANY of the following criteria are present by masked examiner testing:
1. Exotropia at distance OR near at any time during the exam (i.e., can be constant or intermittent; determined by a cover/uncover test) with a magnitude of ≥10Δ by SPCT, confirmed by a retest
2. Constant esotropia at distance OR near (determined by at least 3 cover/uncover tests—one must be before any dissociation) with a magnitude of ≥6Δ by SPCT, confirmed by a retest
3. Decrease in Randot Preschool near stereoacuity ≥2 octaves (≥0.6 log arcsec) from enrollment, or to nil, confirmed by a retest

Randot Preschool Stereotest (Stereo Optical, Chicago, Illinois)
Baseline Stereoacuity, in arcsec	Stereoacuity level needed at follow-up visit to meet suboptimal surgical outcome criteria, in arcsec
40”	200” or worse
60”	400” or worse
100”	400” or worse
200”	800” or worse
400”	Nil

Participants who underwent reoperation (or treatment with botulinum toxin) without first meeting any of the above suboptimal surgical outcome criteria were also counted as suboptimal surgical outcomes in the primary analysis.

IXT = intermittent exotropia; SPCT = simultaneous prism and cover test; Δ = prism diopter; arcsec = seconds of arc