[Squint angle, eyeball length and surgical results in horizontal strabismus]

The studies comprised 70 patients with convergent and divergent strabismus. Deviation of the eye was measured before and after surgery with commonly applied methods. The anterior-posterior axial length of the eyeball was determined with A-scan and B-scan USG. Typical surgical methods, recession and reaction of the horizontal muscles were performed in one- (79.8%) or two-stage (20.2%) operations. The patients were divided in 5 groups depending on the range of the operation. Coefficient of correlation (r) between the deviation and length of the eyeball after surgery was determined for each group. Its values were highest in esotropia; 0.87 when the recession/resection ratio was 3.5/7 mm and 0.82 when it was 3.5/6. In exotropia, the coefficient was low but this group was not numerous enough for statistics. The results of surgery correlated more strongly with the length of the eyeball than with the degree of deviation. The authors concluded that the axial length of the eyeball should be taken in calculation of the operation range.