an ophthalmological evaluation is mandatory to get a correct diagnosis in a case of acute acquired onset of concomitant esotropia ( aace ) with diplopia .
we describe a complex case of a child of 8 years affected by a short duration of diplopia and esodeviation ( from 2 to 4 h ) , so that signs are not directly recognized by the ophthalmologist , but just reported by the child , parents , or other health care providers .
the peculiarity of our case is the short duration of strabismus and diplopia and their spontaneous regression .
being transient , it can not be classified among aaces ; we therefore considered it as a different entity which we have called acute acquired onset of transient esotropia ( aate ) .
aate is probably due to ophthalmoplegic migraine ( om ) or accommodative spasm ( as ) .
this is the first report in the literature that differentiates aate from aace , trying to investigate possible causes , the diagnostic algorithm , and potential treatments .
an 8-year - old caucasian female was evaluated in the outpatient clinic of pediatric ophthalmology of melegnano hospital , after she had been hospitalized 1 week before in another hospital for aate .
the child was born at term with vaginal delivery , she had normal mental and motor growth , and she was in good health .
the presentation of symptoms first occurred at school : the patient suddenly complained of double vision , and the teachers noticed esodeviation of the left eye ( le ) .
three hours later , the patient was accompanied by her father to the nearest emergency department , but on the way , diplopia and strabismus regressed .
symptoms reappeared only when the child was solicited , first by her father in the waiting room and then during the pediatric visit , to fix on a near target . in these cases , diplopia and esotropia regressed in about 15 min . during the ophthalmological evaluation both diplopia and le esotropia were no longer present .
the patient had a best corrected visual acuity of 20/20 in both eyes using her own spectacles : right eye ( re ) 0.75 cylinder ( cyl)/160 and le 0.25 cyl/20. refraction after cycloplegia was not tested .
the ophthalmologist required further investigation . the neurological examination and the simpson test for myasthenia were negative .
brain ct , brain mri , and electroencephalogram were within the range of normality . finally , blood tests ( complete blood cell count , inflammatory markers , and thyroid function indices ) and neuropsychiatric evaluation were normal .
the diagnosis at discharge was of suspected om , because the patient had reported a slight headache with spontaneous resolution and without nausea and vomiting the day before the aate attack .
when we evaluated the patient , a week after hospital discharge , the ophthalmological and orthoptic examination was similar to that performed during hospitalization , the only difference being visual acuity of 20/25 in le with her glasses .
we performed refractive examination in cycloplegia half an hour after the administration of tropicamide 1% 3 times in each eye .
refractive cycloplegic values with an autorefractometer ( ar600 ; nidek , japan ) were re 1.00 cyl/160 and le + 0.75 cyl/85. cycloplegic visual acuity was 20/40 in re and 20/25 in le without lens correction , 20/20 in re and 20/32 in le with glasses in use , and 20/20 in le with + 0.75 cyl/85. the patient 's glasses had a low myopic astigmatism ( 0.25 cyl/20 ) in le , although in cycloplegia she presented a hyperopic astigmatism ( + 0.75 cyl/85 ) in the same eye .
therefore , in addition to the om , the as could be considered as a possible cause . for 18 months thereafter ,
the child was instructed to continuously wear glasses with the proper correction , and no episodes of strabismus occurred .
the case here described may meet group ii criteria , characterized by minimal hypermetropia and diplopia , but in the literature there are only a few case reports and case series about aace .
moreover , in these studies all patients of group ii were referred for strabismus surgery due to persistent esotropia [ 1 , 2 , 3 ] .
only kemmanu et al .   described a case of aace where the patient did not receive surgery .
in fact the cause was an as in le associated with mild hypermetropia in cycloplegia ( + 0.75 sphere ) .
the peculiarity of aate with respect to aace is the short duration of strabismus and diplopia ( about 3 h ) and their spontaneous regression .
aate could be caused by om , a rare neurological syndrome characterized by recurrent attacks of headache and ophthalmoplegia .
the oculomotor nerve is the most commonly involved cranial nerve , and diplopia , ptosis , and mydriasis are common ; also the other cranial nerves may be affected ( and , of note , in the case of om an inconcomitant deviation may be rarely present ) .
most patients recover completely within days to weeks , but a minority could show persistent neurological deficits .
in our case , the patient had a mild headache the day before the onset of symptoms , and the aate could have been caused by paralysis of the sixth cranial nerve ; but she had no abdominal pain , nausea , and vomiting .
moreover , a family history of migraine headaches was not reported ( table 2 ) . during the ophthalmological evaluation both diplopia and esotropia in le were no longer present , and it was not possible to assess whether the deviation was concomitant or inconcomitant .
however , the short duration of symptoms and spontaneous remission of aate could support the om diagnosis , especially if such attacks had recurred in the future .
it is an involuntary condition occurring in the presence of greater than normal accommodative response than accommodative stimulus . as is characterized by transient episodes of variable esotropia , pseudomyopia , and miosis .
it may begin suddenly , is more likely to be bilateral , disappears with cycloplegia , and may resolve spontaneously ( table 2 ) . in our case , aspects
which may be compatible with a diagnosis of as are as follows : ( a ) the patient had a hypermetropic astigmatism in le but the left lens presented a myopic astigmatism ; ( b ) symptoms reappeared when the father and the pediatrician showed fixation aims for a near target ; ( c ) longer reading / study sessions in the last 2 weeks ; ( d ) the short duration and spontaneous regression of symptoms ; and ( e ) the absence of aate after 18 months , using spectacles with proper correction in a continuous manner .
factors limiting the correct diagnosis were ( a ) features of aate were just reported by the patient , father , and pediatrician ; as symptoms regressed before the ophthalmological evaluation , the characteristic signs of as ( miosis and pseudomyopia ) could not be evaluated ; ( b ) the disorder was unilateral ; and ( c ) a slight hypermetropic defect was present in le .
it will be important to assess future recurrence of the condition , with proper lens correction , with long follow - ups .
the aate diagnosis is complex . it is necessary to exclude nonophthalmological causes through the execution of neurological examination , test for myasthenia , brain ct , blood tests ( complete blood count , inflammatory markers , and thyroid function indices ) , and neuropsychiatric evaluation . if all tests are negative , full ophthalmological ( including cycloplegic refraction ) and orthoptic evaluation are mandatory to avoid the unnecessary execution of expensive tests ( such as electroencephalogram and brain mri ) which may be a source of anxiety for children and their families .
the parents of the patient ( the patient was under 18 years of age ) signed a comprehensive consent form according to good clinical practice guidelines before proceeding with all examinations and treatments .
it satisfied all the requirements of the declaration of helsinki and the italian national law for the protection of personal data .
the local ethics committee decided that no formal ethics approval was required in this particular case .
 the aim of this report is to investigate the possible causes of acute acquired onset of transient esotropia ( aate ) in children and to help to differentiate ophthalmoplegic migraine ( om ) from accommodative spasm ( as ) . a case of an 8-year - old caucasian female affected by aate and diplopia 
 is described . the day before aate onset , the patient complained of slight headache without nausea and vomiting , with spontaneous resolution . 
 aate diagnosis is challenging . 
 the most likely ophthalmological causes of aate are as and om . in these cases 
 it is important to evaluate the presence of both a familial history of recurrent headaches and an aate associated with migraine , ptosis , nausea , and vomiting . 
 a full ophthalmological evaluation and a thorough refractive examination in cycloplegia are mandatory to exclude ophthalmological causes . 