The reasons for consecutive exotropia of 49 patients

Objective To investigate the related factors resulting in consecutive exotropia.Methods Forty-nine cases with consecutive exotropia after esotropia in our hospital from June 2006 to September 2011 were analyzed retrospectively.Results In our study,the age at onset of esotropia was 2-72 months old,mean 18.43 months,48 patients (97.96％) appeared esotropia below 4 years of age and 29 patients (59.18％) appeared esotropia below 1 year of age; 28 patients (96.55％) had suppression in one eye before esotropia (5m and 33cm),42 patients (100％) had no binocular function; 28 patients (57.14％) hadvertical deviation from 3Δ to 25Δ before exotropia surgery,mean deviation was 8.54Δ(5m) and 8.43Δ(33cm); l0 patients,accommodative convergence/accommodation ratio (AC/A ratio) was less than 4 (28.57％) prior to esotropia and 18 patients' AC/A ratio was less than 4 (75％) prior to exotropia; 10 patients had anisometropia between 2.00D and 5.00D and 8 patients had limitation of adduction prior to exotropia; consecutive exotropia happened 4.08 years after surgery of esotropia and the incidence was 93.88％ within 9 years.Conclusions The important factors related to the development of consecutive exotropia include the early onset of esotropia,bad binocular function or without binocular function; accompaning with vertical deviation,low AC/A,anisometropia,limitation of adduction.Since consecutive exotropia may develop many years after esotropia surgery,a long-term follow-up period in patients without consecutive exotropia is advised. Key words: Consetive exotropia; Esotropia; Binocular function; Anisometropia