Perinatal asphyxia (also known as neonatal asphyxia or birth asphyxia) is the medical condition resulting from deprivation of oxygen to a newborn infant that lasts long enough during the birth process to cause physical harm, usually to the brain. It is also the inability to establish and sustain adequate or spontaneous respiration upon delivery of the newborn. It remains a serious condition which causes significant mortality and morbidity. It is an emergency condition and requires adequate and quick resuscitation measures. Perinatal asphyxia is also an oxygen deficit from the 28th week of gestation to the first seven days following delivery. It is also an insult to the fetus or newborn due to lack of oxygen or lack of perfusion to various organs and may be associated with a lack of ventilation. In accordance with WHO, perinatal asphyxia is characterised by: profound metabolic acidosis, with a PH < 7.20 on umbilical cord arterial blood sample, persistence of an APGAR score of 3 at the 5th minute,                                                           clinical neurologic sequelae in the immediate neonatal period, or evidence of multiorgan system dysfunction in the immediate neonatal period.
Surgery
Controversy has arisen regarding the selection and planning of surgical procedures, the timing of surgery and about what constitutes a favourable outcome. 1. Selection and planning
Some ophthalmologists, notably Ing  and Helveston, favour a prescribed approach often involving multiple surgical episodes whereas others prefer to aim for full alignment of the eyes in one procedure and let the number of muscles operated upon during this procedure be determined by the size of the squint. 2. Timing and outcome
This debate relates to the technical anatomical difficulties of operating on the very young versus the possibility of an increased potential for binocularity associated with early surgery. Infants are often operated upon at the age of six to nine months of age and in some cases even earlier at three or four months of age. Some emphasize the importance of intervening early such as to keep the duration of the patients abnormal visual experience to a minimum. Advocates of early surgery believe that those who have their surgery before the age of one are more likely to be able to use both eyes together post-operatively. A Dutch study (ELISSS) compared early with late surgery in a prospective, controlled, non-randomized, multicenter trial and reported that:

Children operated early had better gross stereopsis at age six as compared to children operated late. They had been operated more frequently, however, and a substantial number of children in both [originally-recruited] groups had not been operated at all. Other studies also report better results with early surgery, notably Birch and Stager and Murray et al.