Table 1

 Summary of study patients

Case noSexType*Age (years)RefractionVisual acuity (logMAR)NystagmusStrabismus
XT  =  exotropia; ET  =  esotropia.
*Type: A  =  no other midline abnormality on imaging except small chiasm; B  =  septo-optic dysplasia (optic nerve hypoplasia, hypopituitarism, deficient septum pellucidum); C  =  skull base encephalocele + agenesis of the corpus callosum + hypopituitarism.
†Angle of strabismus in prism dioptres.
1MA9RE −1.50 + 0.50 × 901.0HorizontalXT small angle†
LE 0.00 + 1.00 × 900.6R head turnV pattern
2FA4RE 0.00 + 0.50 × 900.6HorizontalXT small angle
LE 0.00 + 1.50 × 900.5HorizontalV pattern
3FA12RE +1.50 sph0.1Minimal rotary nystagmusET small angle
LE +1.50 sph0.6Amplitude L>>R
4FB4RE +1.00 sphVery poorRotary + horizontalRight XT angle 30
LE +2.00 sph0.6
5FB12RE +3.0 sphGreater than 1.0Highly variableRight ET angle 45
LE +1.0 +4.0 × 900.6Horizontal and vertical(not seesaw)
6FC10RE −5.00 −1.00 × 800.7Seesaw variant: circumrotary+ dysconjugate verticalNo detectable strabismus
LE −3.50 −2.50 × 1200.5
7MC14RE −0.50 +1.00 × 900.8HorizontalNo detectable strabismus
LE +1.00 +1.00 × 900.5Left beating, rotary component in 1°
8MCDeceasedRE −4.50 + 2.00 × 120Greater than 1.0Type unclearVertical gaze palsy
LE −1.50 + 1.00 × 1801.0
9MOther6RE +0.50 +1.00 × 1200.6HorizontalNo detectable strabismus
LE +0.50 +0.50 × 900.6Head shake