refractive accommodative esotropia ( rae ) is an esotropia that is restored to orthotropia at all fixation distances and all gaze positions by optical correction of the underlying hypermetropic refractive error .
retinal image blur induces accommodation to focus the image ; then , this accommodative effort elicits accommodative convergence when fixating at distance or near .
when fusional divergence is insufficient to compensate for the excessive convergence innervation , esotropia develops .
vergence movements including divergence require the cooperation of the cerebral cortex , in particular , a state of visual attention called the psychooptical reflex .
the child behavior checklist ( cbcl ) is widely used in the field of psychology and consists of 113 questions used to rate the behavioral and emotional problems of children .
there are two dimensions : internalizing symptoms ( withdrawn , somatic complaints , and depression / anxiety ) and externalizing symptoms ( social problems , thought problems , attention problems , delinquent behavior , and aggressive behavior ) .
therefore , i evaluated the relationships between rae and psychological symptoms as measured by the cbcl .
i prospectively recruited patients aged 36 years with more than 3.0 diopters of hyperopia who presented at kim 's eye hospital from january 2011 to march 2013 .
this research study was reviewed and approved by the institutional review board ( irb ) of kim 's eye hospital , and all procedures conformed to the guidelines of the declaration of helsinki .
all patients underwent a full ophthalmologic examination including slit - lamp biomicroscopy , fundoscopy , alternate prism cover testing , and cycloplegic refraction using 1% cyclopentolate .
refractive accommodative esotropia was defined as an esotropia that was corrected to > 10 prism diopters ( pd ) of orthotropia at both far and near distance with use of the full cycloplegic hyperopic correction .
the control group had hyperopia of > 3 diopters ( d ) and orthotropia at near and far distance .
subjects were excluded if they had worn glasses previously or had a history of ophthalmic surgery .
further , children with anisometropia > 1.0  d and astigmatism > 1.5  d were excluded .
the angle of esodeviation was measured by alternate cover test , and the mean deviation of two consecutive measurements was used .
the k - cbcl was completed by parents at the first visit before glasses were prescribed .
the child behavior checklist ( cbcl ) is a parent - report questionnaire in which the child is rated on various behavioral and emotional behaviors .
the reliability and validity of the korean version of the cbcl ( k - cbcl ) are well established in korean children and adolescents .
the checklist assesses internalizing ( i.e. , anxious , depressive , and overcontrolled ) and externalizing ( i.e. , aggressive , hyperactive , noncompliant , and undercontrolled ) behaviors .
several subareas are measured , including internalizing factors ( social withdrawal , somatic complaints , anxiety , and depression ) and externalizing factors ( social problems , thought problems , attention problems , delinquent behavior , and aggressive behavior ) .
the k - cbcl score was computed based on korean normative samples , with the total problem behavior score computed by summing the scores obtained for each item .
raw scores for each clinical factor were transformed into t - scores based on published norms .
i investigated the relationship between the k - cbcl score and the amount of esodeviation in rae children .
independent student 's t - test was performed to investigate the differences in k - cbcl indexes between groups .
the correlation between k - cbcl score and the angle of esodeviation was measured using the pearson correlation method .
a total of 20 rae children and 34 hyperopic children were included in the study .
the mean ages of rae children and controls were 5.0  1.7 and 5.4  0.8 , respectively ( p = 0.233 ) .
mean refractive errors were slightly higher in the control group ( rae children , 4.6 d ; control group , 5.3 d ) ; however , there was no significant difference between groups ( table 1 ) . 

two out of three internalizing indexes were significantly different between groups ( somatic complaints : rae children 50.1  4.6 and controls  46.6  5.8 , p = 0.026 ; depression / anxiety : rae children 48.8  7.9 and controls 43.9  6.8 , p = 0.024 ) .
although there was no significant difference , rae children scored slightly higher on the externalizing behavior index .
regarding the relationship between the angle of esodeviation and the k - cbcl score , although the frequency of withdrawn behavior did not differ between groups , the far angle of esodeviation showed a moderate correlation with withdrawn behaviors ( table 2 ) . among the rae children who scored higher on indices related to social and attention problem , the near angle of esodeviation was larger than the far angle of esodeviation ( r = 0.725 and r = 0.650 ; p = 0.018 and p = 0.042 , resp . ) .
the present study revealed that psychosocial problems might be related to the pathogenesis of refractive accommodative esotropia .
hypermetropic children with several characteristics including a positive family history , low binocular sensory function , low hypermetropia ( < + 3.0  d ) , and significant anisometropia had a high risk of developing refractive accommodative esotropia .
unfortunately , i did not investigate sensory function and family history in the present study .
mean refractive error was slightly reduced in the rae group ( rae children 4.6  d and control group 5.3  d ) , though this trend was not significant .
the present study showed that rae children scored higher than controls on the indexes for somatic complaints and depression / anxiety .
somatic complaints include fatigue , aches , nausea , vomiting , headaches , dizziness , and skin , stomach , or eye problems .
children with significant medical disorders tend to score high on the internalizing subscale and particularly on the somatic complaints subscale of the cbcl .
somatic complaints are a predominant characteristic of anxiety disorders and are believed to play an important role in anxious states [ 7 , 8 ] .
furthermore , children with anxiety disorders exhibit more somatic complaints compared to normal control children .
control subjects tended to score higher on other externalizing indexes , though these trends were not significant .
internalizing factors such as withdrawn behavior , somatic symptoms , and depression / anxiety refer to a broad class of behaviors in which children direct feelings and emotions inward ; these are commonly in contrast to externalizing factors .
as shown in figure 1 , although the associations with externalizing factors had no statistical significance , the rae group scored higher on internalizing indexes and lower on externalizing indexes than the control group .
the angle of deviation in rae is usually variable . to minimize deviation variability , i used the mean of two consecutive deviation measurements for all analyses .
the angle of esodeviation correlated with withdrawn behaviors on the cbcl , but the near angle was not associated with the score on any subsection of the cbcl .
withdrawn behavior is defined as the behavioral tendency to isolate oneself from one 's peers ; nine items on the cbcl indicate withdrawn behavior such as a preference for being alone , sadness , unwillingness to talk , shy demeanor , and withdrawn or underactive behavior .
withdrawn behavior was negatively correlated with the angle of deviation . in other words , rae children with lower scores on indexes of withdrawn behavior , who are outgoing and active , are more likely to have larger angles of esodeviation . as mentioned earlier ,
however , there was no significant correlation between either of these measures and the angle of esodeviation .
therefore , somatic complaints and depression / anxiety might be related to the pathogenesis of rae .
as i mentioned earlier , i did not evaluate related factors such as binocular sensory function or family history .
however , these biases can be excluded because the study was designed as a prospective study . in conclusion ,
hypermetropic children with high scores on the somatic complaint and depression / anxiety subscales of the cbcl could be at high risk for developing rae .
 
 purpose . to investigate the psychophysiologic aspects of refractive accommodative esotropia ( rae ) . 
 methods . 
 i prospectively recruited patients aged 36 years with more than 3.0 diopters of hyperopia who presented at kim 's eye hospital from january 2011 to march 2013 . 
 i compared korean child behavior checklist ( k - cbcl ) which consists of internalizing factors ( social withdrawal , somatic complaints , anxiety , and depression ) and externalizing factors ( social problems , thought problems , attention problems , delinquent behavior , and aggressive behavior ) between rae group and control group . 
 results . 
 two out of three internalizing indexes were significantly different between groups ( somatic complaints : rae children 50.1  4.6 and controls 46.6  5.8 , p = 0.026 ; depression / anxiety : rae children 48.8  7.9 and controls 43.9  6.8 , p = 0.024 ) . 
 although there was no significant difference , rae children scored slightly higher on the externalizing behavior index . in the rae group , 
 the far angle of esodeviation showed a moderate correlation with withdrawn behaviors . 
 conclusion . 
 hypermetropic children with high scores on the somatic complaint and depression / anxiety subscales of the cbcl could be at high risk for developing rae . 
 psychosocial problems might be related to the pathogenesis of refractive accommodative esotropia . 
1. Introduction
2. Methods
3. Results 
4. Discussion