Adult-onset cyclic esotropia:  a case report.
OBJECTIVE
This case report presents the diagnosis and management of an adult patient with cyclic esotropia, a rare and poorly understood form of strabismus, that is characterized by alternating periods of manifest strabismus and orthotropia. Few cases of adult-onset cyclic strabismus have been reported. The etiology, pathogenesis, and treatment for this condition are reviewed.


METHODS
A 37-year-old man with high unilateral myopia and anisometropic amblyopia in his left eye developed cyclic esotropia 2 months after a scleral buckle procedure for a retinal detachment. A 48-hour cycle that consisted of a 24-hour period of orthotropia followed by a 24-hour period of constant left esotropia was present. Magnetic resonance imaging, electromyography, electroencephalography, and ocular and orbital echography were unremarkable, as was a neurological assessment that included fatigue and edrophonium testing. The patient was successfully managed with muscle surgery.


CONCLUSIONS
The etiology and pathogenesis of adult-onset cyclic esotropia remain unknown. Cyclic esotropia should be considered in the differential diagnosis when an individual presents with a history of intermittent strabismus that is present some days and not others.
Clinica Oculistica, Seconda Università degli Studi di Napoli, Napoli, Italy.
Antonio
A
Di Meo
Ciro
C
Costagliola
Michele
M
Della Corte
Antonio
A
Romano
Consuelo
C
Foria
Alfonso
A
Di Costanzo
D000328:Adult; D003937:Diagnosis, Differential; D004569:Electroencephalography / Q000379:methods*; D004576:Electromyography / Q000379:methods*; D004948:Esotropia / Q000175:diagnosis / Q000209:etiology / Q000601:surgery*; D005133:Eye Movements; D005500:Follow-Up Studies; D006801:Humans; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D009801:Oculomotor Muscles / Q000473:pathology / Q000503:physiopathology / Q000601:surgery*; D012163:Retinal Detachment / Q000601:surgery; D012591:Scleral Buckling / Q000009:adverse effects