Clinical Observations in Sensory Heterotropia

Chang, Ki Cheol; Ahn, Min

Abstract

PURPOSE
We reviewed the clinical features and the treatment results of sensory heterotropia with the purpose of finding etiologic causes, factors influencing the the direction of deviation, and characterisitics of sensory deviations subsequent to cataract. METHODS: The charts of 134 patients diagnosed as sensory heterotropia in Chonbuk national university hospital between 1994 and 2001 were reviwed retrospectively. Visual acuity, the deviation in primary gaze, refractive error, the onset of vision loss and its etiology were analyzed. RESULTS: The major causative factor was cataract (29.1%) and anisometropic amblyopia (23.1%). When onset of visual impairment occurred between birth and the age of 5 years, 20 (33%) developed esotropia, and 41 (67%) developed exotrpia. In older children and adults, 9 (12%) developed esotropia, and 64 (88%) developed exotropia. A significant difference was noted between the age of onset and the type of horizontal strabismus (x2= 8.18, P<0.005). The difference between the refractive error in the sound eye and the type of deviation was statistically significant (x2=7.52, P<0.01). We found no correlation between the duration of visual impairment and the amount of deviation (P>0.05). While all of bilateral congenital cataract patients (4) had esotropia, unilateral congenital cataract patients showed exotropia to be predominated (4 of 5 eyes). The majority (17 of 21) of the sensory deviations subsequent to senile, traumatic cataract, uncorrected traumatic aphakia were converted from tropia to phoria, and showed the reduced angle of deviation after cataract operation or secondary IOL implantation. CONCLUSIONS: The age of onset of visual loss and the refractive error in the sound eye are thought to be the major factors influencing the direction of the deviation.