Table 1

Clinical details of patients with spontaneous reversal of nystagmus in the dark

Case Sex Age at testing (years) Diagnosis Acuities (Snellen) Eye movements in the light Eye movements in the dark Handedness
1M4Congenital nystagmusRE 6/7.5 LE 6/6Horizontal left beating nystagmus with mixed linear and accelerating slow phase velocities. Nystagmus pronounced in all directions of gaze but dampens in right gaze. Occlusion of right eye does not alter nystagmus but left eye occlusion results in right beating nystagmus.Spontaneous right beating nystagmus with predominantly linear slow phases.Right
2F4Tuberous sclerosis and L convergent squintRE 6/12 LE 6/24Horizontal right beating nystagmus in all directions of gaze. The slow phases were of decelerating velocity. Occlusion of left eye does not alter nystagmus but right eye occlusion elicits left beating nystagmus.Spontaneous left beating nystagmus with decelerating and linear slow phase velocities. The nystagmus in the dark was of larger amplitude than that recorded in the light.Right
3F7L microphthalmia and retinal dysplasiaRE 6/9 LE NPLFine horizontal right beating nystagmus in all directions of gaze, more marked in right gaze, dampens slightly in left gaze. Slow phases were of decelerating velocity.Spontaneous left beating nystagmus with linear and decelerating slow phase velocities.Right
4M9L Peter's anomalyRE 6/6 LE PLFine horizontal right beating nystagmus that accentuated in lateral gaze without changing in direction of beat. The slow phases were of decelerating and linear velocities.Spontaneous marked left beating nystagmus of larger amplitude than that recorded in the light. Slow phases were of decelerating and linear velocities.Left
5M9R anophthalmosRE NPL LE 6/9Moderate amplitude horizontal left beating nystagmus in all directions of gaze, becoming more intense on left gaze and dampening in right gaze. The slow phase velocities were mixed linear and decelerating. This child could change the direction of his nystagmus by trying to look with his blind eye.Spontaneous right beating linear slow phase velocity nystagmus. He could wilfully reverse the direction of his nystagmus by trying to look with either eye.Right