ISSN: 2155-9570
Mostafa A Arafa, El Sayed M Eltoukhy, Mahmoud A Kamal, Mohamed M Said
Objective: This study aims at determining the efficacy of anterior and nasal transposition of Inferior Oblique to
manage dissociated vertical deviation and vertically incomitant horizontal strabismus (V pattern).
Method: This study was both prospective and uncontrolled; it included 60 patients who suffered from inferior
oblique overaction. The participants were divided into two groups: Group A had 30 patients with vertically
incomitant horizontal strabismus while group B had 30 patients with dissociated vertical deviation.
Preoperative examination included: Assessment of vision, ductions and versions in the six cardinal directions of
gaze and severity of IOOA graded from 0 to +4. The percentage of dissociated vertical deviation was measured using
the prism under cover test in primary position.
Follow-up visits occurred in the following intervals: After one week, one month, four months, and six months
respectively. In each follow-up visit, the measurements of ductions, versions, and alignment in primary position were
recorded.
Results: Group A showed no pattern in 93.3% of cases postoperatively while 6.7% of cases developed insignificant V
pattern (0.8 ± 2.9 ΔD), with statistically significant difference between the pre-and post-operative values (pvalue<
0.001). Meanwhile, group B showed a complete resolution of DVD in 100% of cases with preoperative
(DVD<15 ΔD) and in 20% of cases with preoperative DVD ≥ 15 ΔD; the remaining cases had residual DVD (3.6 ±
4.1 ΔD).
Conclusion: Anterior-nasal transposition of the Inferior Oblique muscle is an effective procedure for cases with
severe or recurrent inferior oblique overaction when other standard procedures of Inferior Oblique muscle fail. For
DVD ≥ 15 ΔD, we recommend a combined anterior-nasal transposition of inferior oblique with superior rectus
recession.