Variability of tereoacuity in Intermittent Exotropia Original Reearch Article

Purpoe Ditance tereoacuity i ued to monitor deterioration of intermittent exotropia (IXT), but variability of tereoacuity ha not been tudied rigorouly. The purpoe of thi tudy wa to ae the variability of tereoacuity over one day in children with IXT. Deign Propective cohort tudy. Method Twelve children with IXT were recruited. tereoacuity wa aeed uing the Friby Davi Ditance tet and the Ditance Randot tet at ditance, and the Friby and Prechool Randot tet at near. Tet were repeated three or four time over the day, with at leat two hour between aement. The main outcome meaure wa variable tereoacuity defined a a change by two or more log level between any two time point over the day. Reult Variable tereoacuity at ditance wa found in five (42%) of 12 patient. Four (33%) of 12 patient demontrated variable reult uing the Ditance Randot tet, three of whom alo howed variable reult uing the Friby Davi Ditance tet. One patient had variable reult uing the Friby Davi Ditance tet only. Nine (75%) of 12 patient completed near tereoacuity teting; two (22%) of nine howed variable near tereoacuity. Two (22%) of nine howed variable reult uing the Prechool Randot tet, one (11%) of whom alo had variable reult uing the Friby tet. In ome cae, tereoacuity changed from meaurable tereoacuity on one aement to nil on another. Concluion Nearly half of children with IXT how marked change in tereoacuity over the coure of a ingle day. When baed on iolated meaure, an apparent change in ditance tereoacuity between viit hould be interpreted with caution.