The Fourth Monitoring Report of the Early vs. Late Infantile Strabismus Surgery Study: The Early vs. Late Infantile Strabismus Surgery Study Group.

The Early vs. Late Infantile Strabismus Surgery Study Group is a group of strabismologists and orthoptists from 58 clinics in 11 European countries. They investigate whether early or late surgery is preferable in infantile strabismus, in a non-randomized, prospective, multi-center trial.(1) Infants between 6 and 18 months of age receive a standardized entry examination and are then operated either before their second anniversary in clinics A, or between their 32nd and 60th month of age in clinics B. The children are evaluated at age six. After completion of the study, the two groups can then be compared regarding degree of binocular vision, angle of strabismus and visual acuity of the worse eye relative to the better. The current status of the study is reported here. Up to December 13, 1996, 58 clinics have entered a total of 532 patients. Currently, 232 children have been entered in the early surgery group and 300 in the late surgery group. Completeness of data and forms are excellent. Thirty-eight patients have definitively dropped out. There is no evidence for inhomogeneities between the two therapy groups concerning the distribution of the four most important prognostic factors: spherical equivalents, horizontal angle of squint, degree of amblyopia and limitation of abduction.