J Korean Ophthalmol Soc.  2002 Feb;43(2):337-342.

The Change of Deviation Angle according to Gaze Position in Exotropes with Inferior Oblique Overaction

• Lee YC
• Kim M
• Lee SY

Abstract

PURPOSE: To determine the correlation between the grade of inferior oblique overaction and the change of deviation angle according to gaze position.
METHODS
We classified 90 patients into 4 groups according to the grade of inferior oblique overaction. Deviation angle was respectively measured in upward, primary and downward position at far and the difference between them was analyzed. And we assessed the frequency of V and Y pattern and the concordance of deviating eye between at primary position and at upgaze.
RESULTS
Mean bilateral sum of the IOOA was +3.58 and average of deviation angle was 33.64 PD in upward position, 27.82 PD in primary position and 24.72 PD in downward position. Difference of deviation angle between upward and primary position was 5.82 PD (P<0.05) in that 3.10 PD between primary and downward position (p>0.05). The frequency of V pattern exotropia was 17.6% in group A, 17.1% in group B, 50% in group C and 85.7% in group D while the frequency of Y pattern among V pattern was 100%, 66.7%, 75% and 25% respectively. The chief deviating eye or IOOA predominant eye at primary position diverged during upgaze only in 67% of patients.
CONCLUSIONS
The larger the inferior oblique overaction, the more V pattern exotropia was observed and deviation angle was increased at higher IOOA groups. Overall exotropia patients with IOOA shows rather Y shape than V shape. And chief deviating eye was not always deviating eye at upgaze.

Keyword

Exotropia; Inferior oblique overaction; V pattern exotropia

MeSH Terms

Exotropia
Humans