Atropine treatment of amblyopia: is a swap in fixation necessary?
OBJECTIVE
To investigate the impact of fixation on vision outcomes in patients with amblyopia undergoing atropine treatment and the validity of the "cyclo-swap test" (CST) as a method of predicting atropine efficacy.


METHODS
Sixteen children with amblyopia were included. The initial examination included a vision assessment and CST, in which fixation was assessed at 1/3 m, 6 m, and at distances less than 1/3 m. Children were treated for 10 weeks and reviewed at 5-week intervals with cessation of atropine 4 days prior. Vision and fixation were assessed at the follow-up visits. Children demonstrating no fixation swap initially were additionally observed after 1 week of atropine treatment under maximum cycloplegia.


RESULTS
Eight children demonstrated a fixation swap (FS group) to the amblyopic eye during the CST at either 1/3 or 6 m, and 8 demonstrated no fixation swap (NFS group). By the end of the 10-week treatment period, both groups demonstrated a mean visual acuity improvement of between 2 and 3 lines (FS = 0.22 log units; NFS = 0.27 log units). Six of the 8 children in the NFS group demonstrated improvement in vision, all of whom also demonstrated a fixation swap at some stage.


CONCLUSIONS
Vision improvement in patients using atropine is likely to be attributable to a fixation swap that occurs during the treatment phase. The CST performed at 1/3 and 6 m has little value in predicting improvements in vision; however, when performed at distances of less than 1/3 m, it may provide valuable clinical information about atropine efficacy.
Leone
Josephine
J
Department of Clinical Vision Sciences, La Trobe University, Melbourne, Australia.
Georgievski
Zoran
Z
Koklanis
Konstandina
K
D000550:Amblyopia / Q000188:drug therapy* / Q000503:physiopathology; D001285:Atropine / Q000627:therapeutic use*; D002648:Child; D002675:Child, Preschool; D005260:Female; D005403:Fixation, Ocular / Q000502:physiology*; D006801:Humans; D008297:Male; D009184:Mydriatics / Q000627:therapeutic use*; D014787:Vision Tests; D014792:Visual Acuity / Q000502:physiology
D009184:Mydriatics; D001285:Atropine