Table 1: Demographic and ophthalmologic examination findings of the patients with IOOA.

Total (n: 173)Primary IOOA (n: 142)Secondary IOOA (n: 31) value

Age (years)9.15 ± 7.97.75 ± 5.9615 ± 12.050.001a
Gender
 Male887315
 Female8569160.84b
Primary position
 Orthotropia442222
 Esotropia93885
 Exotropia363240.001b
Spherical equivalent+1.25 (−5.5 to +9.75)+1.25 (−5.5 to +9.75)+0.25 (−1.5 to +5.25)0.001a
IOOA
 Unilateral835330
 Bilateral908910.001b
AHP5131200.001b
Pattern strabismus353410.019b
Convergence insufficiency191810.21b

IOOA: inferior oblique muscle overaction; AHP: abnormal head posture; aMann–Whitney U test; bx2 test.