Factors influencing binocular vision in children with successful surgical alignment for esotropia

Objective To investigate the binocular vision achieved in children after successful surgical alignment for esotropia and to identify clinical factors that may be associated with the outcome.Methods Consecutive cases surgically aligned within ±8 PD of orthotropia were consecutively reviewed during a follow-up period from Nov 2008 to Sept 2011 in the Eye Center of Provincial Hospital affiliated with Shandong University.The Worth 4 dots flashlight test was used to evaluate the central and peripheral fusion of the children after successful surgical alignment for esotropia,and a titmus stereogram was used to evaluate stereoacuity.A Chi-square test was used to compare the status of postoperative peripheral binocular fusion for differeut types of esotropia.A logisitic regression analysis with odds ratios comparison was used to investigate the influence of the type of esotropia:the duration of the treatment for amblyopia,age at the time of the operation,the anisometropic equivalent of the two eyes and alignment at the last follow-up on the re-establishment of postoperative peripheral fusion.Results Of the 111 children with successful surgical alignment for esotropia,sixty-eight (61.3％) achieved peripheral fusion,six (5.4％) achieved central fusion,and fifty-six (50.5％)achieved different degrees of stereoacuity.The age at the time of the operation (b=-0.842,P＜0.001),the treatment duration of the amblyopia (b=-0.135,P＜0.05),and the alignment at the last follow-up (b=-1.305,P＜0.05) showed negative correlations with the postoperative peripheral fusion.There was no significant correlation between anisometropic equivalent of the two eyes and postoperative peripheral fusion (b=-19.670,P＞0.05).This was statistically significant (x2=15.977,P＜0.01) since differences in postoperative peripheral fusion were achieved for different types of esotropia.Patients with congenital esotropia were least likely to achieve peripheral fusion (OR=1.0),followed by non-accommodative esotropia (OR=3.008),partially accommodative esotropia (OR=4.475),and high AC/A ratio esotropia (OR=82.217).Conclusion The earlier the age at the time of surgery,the more likely that surgical alignment is successful.The shorter the duration of the treatment for amblyopia and the smaller the angle of orthotropia after surgery led to a greater probability for achieving peripheral fusion.The ease of achieving peripheral fusion after successful surgical alignment for esotropia depends on high AC/A ratio of esotropia,partially accommodative esotropia,non-accommodative esotropia,and congenital esotropia. Key words: Esotropia; Children; Fusion; Stereoacuity