Purpose:
Computed tomography (CT) imaging is commonly performed on pediatric strabismus patients especially to identify displacement of the rectus muscle(s) that may cause unusual vertical or pattern strabismus; normative data on extraocular muscle positions are not available.
Methods:
Retrospective analysis of CT images; aligned in a standardized fashion for each patient. Data was collected within 3 age groups: 0-1, 1-2 and 2-4 years. The horizontal and vertical distances between the extraocular muscles as well as the points of intersection between the two resulting lines were measured. The angles of the horizontal and vertical lines to true orthogonal lines were measured as well. Mean, standard deviation and range were computed for each variable in each age group
Results:
The horizontal and vertical distances between the extraocular muscles and the points of intersection between the two resulting lines increased significantly with age. The angles of the horizontal and vertical lines to true orthogonal lines remained roughly constant among children age 0-4. Summary statistics along with estimated reference ranges are listed below (Table 1). Estimated reference ranges should be considered preliminary and interpreted with caution given the small sample size
Conclusions:
Computed tomography imaging is useful in assessment of extraocular muscle position. Normative data derived from CT images might be a valuable tool in pediatric strabismus evaluation and help in devising an orbital growth chart. A larger number of patients will be analyzed to reach statistical significance of the generated values
Keywords: strabismus • imaging/image analysis: clinical • development