Objective: To study the surgical effects of bilateral graded inferior oblique muscle (IO) recession on the reduction of the V pattern deviation and severity of inferior oblique muscle overaction (IOOA) in children who had bilateral superior oblique muscle palsies (SOP) with secondary inferior oblique muscle overaction.
Material and method: Seven patients who presented with bilateral SOP with secondary IOOA were included. All patients had V pattern deviation and bilateral graded IO recession was done. The data of age, sex, deviation in primary position, V pattern and severity of IOOA was recorded both pre- and post -operatively. The comparison of pre-operative and post-operative amount of V pattern and IOOA was analyzed with nonparametric statistical analysis.
Results: Four females and three males had the average age of 5.7 +/- 1.8 years old. The mean pre-operative severity of IOOA was + 3 and the mean pre-operative deviation of the V pattern was 36 +/- 11.4 prism diopters (PD). The mean post-operative severity of IOOA was + 0.4 and of V pattern deviation was 10.7 +/- 4.4 PD. Comparing the pre-operative and post-operative severity of lOOA and V pattern deviation by non-parametric statistical analysis and the result was statistically significant.
Conclusion: Bilateral graded IO recession is an effective surgical procedure to reduce the V pattern and the severity of IOOA in the children who are suffering from bilateral SOP with secondary IOOA.