Evaluation of anterior transposition of inferior oblique muscle for correction of V- pattern associated with DVD and inferior oblique overaction

Background: V pattern strabismus is common with horizontal deviations as well as DVD. It is a common condition, and difficult to manage. While the only effective treatment is surgery, routine surgery often fails, and special surgical procedures need to be used. 20 Dissociated vertical deviation (DVD) is an ocular motor disorder characterized by slow upward drifting of one eye when the patient fixates with the other eye. This can be unilateral or bilateral. The deviation may be manifest or latent.Methods: Four patients from 9 to 15 years old with V pattern strabismus associated with DVD and primary IOOA were evaluated by prism cover test to assess the grade of IOOA and amplitude of V-pattern. Maximal recession and anteriorization of IO muscle was done to address the condition. Two cases were of grade 2 V pattern and two cases were of grade 3. They underwent maximum recession and anterior transposition (AT). Simultaneous correction of the horizontal deviation was performed. Follow up after I week, 1 month,3 months, and 6 months.Results: The mean age of the study patients was 12 ± 3.464. Two cases had esotropia and two cases with exotropia. Two cases (50%) were of grade 2 V-pattern and the other two cases were of grade 3. Inferior oblique maximal recession with anteriorization reduced a presurgical vertical imbalance. Of four cases, 2 cases (50%) were fully corrected with no residual IOOA, and one case (25%) was under-corrected, and one case (25%) was complicated with limited elevation in all directions. V-pattern was corrected in 2 cases (50%) and the other two cases (50%) were either under-corrected or complicated with limited elevation.Conclusions: AT is an effective procedure for version normalization and for correction of the vertical deviation in the primary position of gaze in cases of V- pattern associated with DVD and IOOA.