A Case of Cyclic Exotropia in a Pediatric Patient

PURPOSE: To report a case of cyclic exotropia in a pediatric patient. CASE SUMMARY: There was a pediatric exotropia patient with large variation of prism diopter on alternate cover test at each visits. Not large enough for going through the surgery, she was recommended for the regular check-ups. Sometimes, she was orthophoria and some other times, distinct exotropia. After a few times of follow up, she showed 25-prism diopter exotropia on alternate cover test. The surgery was scheduled and she was admitted after 2 weeks. At the preoperative evaluation, she was orthophoria. She was discharged without having the surgery. To evaluate daily eyeball deviation status, the parents were asked to write a daily note on patient's eye condition. For 3-months, daily strabismus note was thoroughly reviewed and alternate cover test was performed monthly. Patch test was performed twice, and results were 10 and 12 prism diopter exotropia, each. Analyzing the note, a cycle of being the orthophoria and exotropia was noted. With the cycle of 72-hours, she was diagnosed with cyclic exotropia and the surgery was re-scheduled. Ulnilateral lateral rectus recession was performed. Without undercorrection or recurrence, she has been stayed stable over two years of follow up period.

Cyclic Exotropia: One Case of Clinical Report

Cyclic strabismus is now well recognized, but remains a rare entity. This heterotropia represents an interesting ocular motility problem in which the ocular deviation is present on a rhythmic basis, usually a 48 hour cycle. On the strabismic day, constant heterotropia is large and associated with suppression and no diplopia. On the nonstrabismic day, no deviation or only a small heterophoria is present with good binocular function. Most of these strabismus were presented with esotropia, but in our case, the pattern of deviation is cyclic exotropia. This is a very rare and unique feature.