Y-Split Recession of the Medial Rectus Muscle as a Secondary and/or Unilateral Procedure in the Treatment of Esotropia with Distance/Near Disparity

INTRODUCTION: In esotropia with larger angles > near than at distance, splitting of the medial rectus muscle has been suggested as a treatment option. Previous reports of bilateral medial rectus Y-splitting as a first intervention showed a reduction of the distance/near disparity with fewer side effects compared to posterior fixation surgery. We address whether a medial rectus Y-splitting as a secondary and/or a unilateral procedure also reduce distance/near disparity. MATERIALS AND METHODS: We retrospectively reviewed the charts of four patients undergoing Y-split recession as a second and/or unilateral surgery. Main outcomes were distance/near disparity and squint angles. RESULTS AND DISCUSSION: Three of the four patients had undergone unilateral Y-splitting of the medial rectus as a secondary surgery, three as a unilateral procedure. Mean distance/near disparity was reduced from 17 PD preoperatively to zero at the final follow-up (FU). Preoperative angles ranged from 45 PD to 66 PD at near and from 25 PD to 55 PD at distance. At the final FU, these angles ranged from 0 PD to 20 PD at near and at distance. Mean FU was 42 months (range: 12–60 months). CONCLUSION: Y-split recession as a secondary and/or unilateral surgery for distance/near esotropia can reduce distance/near disparity with good long-term results. Residual esotropia can be corrected by adding resection of the lateral rectus muscle.