Does Asymmetric DVD Exist? Improving Diagnosis with VOG
Susana Gamio, MD; Augusta Naranjo, MD
Ricardo Gutierrez Children Hospital
Buenos Aires, ARGENTINA
Introduction: Video-oculography (VOG) is a useful tool for diagnosing and planning surgical treatment of DVD, being the only method that allows to measure horizontal and vertical deviations in the 11 gaze positions, both fixating with each eye and in binocularity. Thus, asymmetric DVD cases that appear to be monocular can be unmasked. Purpose: to measure DVD in the 11 gaze positions with VOG and decide whether unilateral or bilateral surgery should be performed.
Methods: Prospective study of 23 patients with DVD measured with VOG between June 2016 and June 2017.
Results: The vertical deviation in primary position in binocularity in the 23 cases studied was 5.34^in average. When fixing with OS while occluding OD the right hypertropia registered was 7^ and when fixing with OD while occluding OS the left hypertropia was 9.34^. Nine cases had asymmetric DVD larger than 6^. In this group, when we occluded OD the DVD was 8^ and when OS was occluded it was 10.5^. The amount of asymmetry for DVD was 14^.
Discussion: Very asymmetric DVD cases are usually found associated with unilateral deep amblyopia. Our results demonstrate that amblyopia is not a necessary condition for determining asymmetry in DVD.|Just as oblique muscle dysfunction makes DVD incomitant in different gaze positions, the presence of a true vertical deviation makes it asymmetric.
Conclusion: VOG is a useful method for measuring vertical deviation in cases of DVD and it helps identifying asymmetric cases. Some cases that seem to be unilateral can be unmasked and therefore treated adequately.
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