Acquired central fusional disruption with spontaneous recovery.

Acquired loss of central fusion occurs most frequently after severe head trauma. It has also been described as a result of disruption of binocular function by unilateral deprivation from a cataract and following mid-brain injury due to vascular lesions, tumours or abscess. Symptoms include diplopia in all positions of gaze associated with a squint of variable size. Occasionally some patients experience a spontaneous, partial recovery of fusion, which may be manipulated with strabismus surgery to minimise diplopia. Recovery of fusion may take months or even a few years to occur. We present two cases of patients who lost fusion but later regained it spontaneously with a high degree of stereopsis. Neither patient required strabismus surgery. In the first case, fusion was lost following a severe head injury which resulted in unconsciousness and a unilateral vitreous haemorrhage. The second case followed the removal of a long-standing, unilateral cataract.