The tendency to operate early developed in the 1970s. The main argument employed was that binocular vision can be restored if the child is operated on early enough. However, the extent to which binocular vision can be restored has not been measured in a controlled study. In that study, three out of the series of 84 children had full stereopsis. These three did not need surgery, probably because they had intermittent strabismus.
Cosmetic considerations are also very important.
It seems possible that, in this regard, there is a critical threshold in the swing towards early surgery. In a society where a very high percentage of squinting children is operated upon at an early age, the remaining squinting children will become cosmetically less acceptable, and this may decide the balance in favour of early surgery in an entire country. It will be very important for further developments in the field of strabismus to know what surgical therapy, at what age, is best for the child. It is likely that different aspects of therapeutic response, concerning the number of operations, the degree of binocular vision reached, the final angle of strabismus and the degree of success in the treatment of the accompanying amblyopia will be affected differently by operating early or late. The aim of the trial is to establish guidelines for ophthalmologists on surgical therapy in infantile strabismus.