A Clinical Study on A and V Patterns.

Kim, Sang Jin; Bae, Eun Hee; Oh, Joon Sup

Original Article

Journal of the Korean Ophthalmological Society 1987;28(6):1329-1338.
Published online June 1, 1987.

A Clinical Study on A and V Patterns.

Sang Jin Kim, Eun Hee Bae, Joon Sup Oh

Department of Ophthalmology, College of Medicine, Keimyung University, Daegu, Korea.

A-V 형사시의 임상적 고찰

김상진(Sang Jin Kim),배언희(Eun Hee Bae),오준섭(Joon Sup Oh)

Abstract

A and V patterns are manifest by a horizontal change of alignment of the eyes that occurs on midline upgaze and downgaze as the eyes are moved from the primary position. A and V patterns may be associated with orthophoria, esodeviation, or exodeviation in the primary position. Compensatory head postures are frequently found in patients having A and V patterns. A great deal has been written about the etiology, however, no single etiologic factor can explain all A and V patterns. A and V patterns are revealed by prism and alternate cover midline measurements, comparing 30 degrees upgaze, primary position, and 30 degrees downgaze. A difference of 15 delta between up and down measurements in V patterns and 10 delta in A patterns is necessary for a valid diagnosis. Some surgical methods were described to correct the A and V patterns, only two methods receive widespread acceptance: vertical transposition of the insertions of the horizontal rectus muscles and weakening of the oblique muscles. The authors studied clinically 8 cases of V patterns and 1 case of A pattern in 118 strabismic patients. The results were as follows; 1) The prevalence of A and V patterns was about 8%(9/118). 2) In V patterns, weakening procedures on the inferior oblique muscles with surgery on the horizontal rectus muscles corrected 7 delta to 12 delta between primary position and upgaze. And combining vertical transposition of horizontal rectus muscles corrected an additional 17 delta to 28 delta of V patterns between up and downgaze. 3) In A pattern, resecting inferior rectus muscle with surgery on the horizontal rectus muscles corrected 6 delta of A pattern.