Brain abnormalities in infantile esotropia as predictor for consecutive exotropia

Cerebral palsy, neurological abnormalities, prematurity or periventricular lesions may affect motor and sensory fusion mechanisms that favorably control eye alignment. White matter damage of immaturity (WMDI) is a form of white matter brain injury characterized by the necrosis of white matter near the lateral ventricles. In these cases, it is difficult to establish fusion after strabismus surgery and consecutive deviations may be seen more frequently especially in association with WMDI. The aim of this study is to evaluate and compare the cerebral magnetic resonance imaging (MRI) findings in operated infantile esotropia cases with and without consecutive exotropia and to relate them to the occurance of consecutive exotropia.Seventeen patients that had consecutive exotropia after bilateral medial rectus recession surgery for infantile esotropia were included in this study (group 1) and patients that were operated with the same diagnosis with a successful surgical outcome (≤10 PD of deviation) were recruited as group 2. Age, sex, consanguinity, associated systemic and neurological diseases, prematurity, visual acuity, angle of deviations at first visit, at last and follow-up visit and after surgery, cycloplegic retinoscopy, fundus and cerebral MRI findings were recorded. Demographic and clinical findings of patients in two groups and MRI findings were evaluated and compared.The mean age at the time of first examination was 8.21 ± 6.62 and 7.45 ± 4.94 months in infantile esotropia patients with (group 1) and without consecutive exotropia (group 2), respectively. The mean cycloplegic refractive errors (+1.92 ± 1.57 D vs. +2.30 ± 1.10 D), the mean preoperative angle of deviation (46.33 ± 18.8 PD vs. 34.8 ± 12.5 PD), sex, percentage of consanguinity, percentage of prematurity, presence of latent nystagmus, dissociated vertical deviation and amblyopia and fundus findings were similar in both groups. Patients with consecutive exotropia had a mean deviation angle of 37.5 ± 9.48 PD postoperatively. Cerebral MRI findings were consistent with WMDI (three patients), myelinization delay (one patient), septooptic dysplasia (one patient) and periventricular cysts (one patient) in group 1. Cerebellar hemispheres and vermis hypoplasia (one patient), myelinization delay (one patient), cerebellar atrophy (one patient) were the MRI findings of patients in group 2.White matter damage of immaturity was only present in the consecutive exotropia group. This finding may suggest that WMDI can be a risk factor for consecutive deviation in infantile esotropia patients.