Background: Weakening procedures on the inferior oblique muscle are numerous and include myectomy, graded recession- anteriorization, anterior transposition, anterior and nasal transposition, myotomy, marginal myotomy, nasal myotomy, disinsertion, and denervation and extirpation. Recently, New surgical Intervention for weakening of the inferior oblique muscle is inferior oblique retro-equatorial scleral fixation ( Myopexy).
Objective: The aim of the study was to compare between recession of inferior  oblique muscle(IO) and retroequatorial scleral fixation (myopexy) of inferior oblique muscle in  management of primary inferior oblique over action.(IOOA)
Patients and Methods: Thirty patients (60 eyes) presented by horizontal strabismus and primary inferior oblique over action, met the inclusion criteria, and were divided into two equal groups: Group A treated by recession of the inferior oblique muscle. And Group B treated by retro-equatorial scleral fixation (myopexy) of the inferior oblique muscle.
Results: Both IO graded recession and IO myopexy were equally effective in correcting the degree of IOOA (elevation in adduction) , correcting associated pattern,with no statistical significant difference and both were equally effective in correcting the degree of objective fundus extorsion with no statistical significant difference.
Conclusion: Our findings suggested that both surgical groups had positive outcomes, with good response and effect which was stable all over follow up visits uptill 6 months.