Abstract
Purpose: :
To evaluate the results of bilateral inferior oblique triple marginal myotomy (TMM) in patients with dissociated vertical deviation (DVD) with inferior oblique muscle overaction (IOOA).
Methods: :
We evaluated a case series of patients with horizontal deviation associated to manifest or latent DVD and significant IOOA (≥2+). We recorded preoperative (preop) and postoperative (postop) size of DVD, grade of preop and postop IOOA, and complications. DVD was graded 1+ to 4+, grade 1+ represented 5Δ, 2+ 10Δ, 3+ 15Δ, and 4+ 20Δ. IOOA was estimated on a grading scale 1+ to 4+, grade 1+ represented 1mm of higher elevation of the adducting eye in gaze up, grade 4+ represented 4 mm of higher elevation. Recession or resection of the horizontal rectus muscles were planned depending on the base deviation, and TMM of the inferior oblique muscle was simoultaneously performed to treat DVD and IOOA. Patients with concomitant superior oblique muscle overaction or those with previous surgical treatment for DVD were excluded. Briefly, surgical technique was as follows: By an inferior temporal incision, the inferior oblique muscle was approached through conjunctiva and Tenon's capsule. The inferior muscle is isolated from its attachments to Tenon's capsule. Three fine clamps are placed across the muscle body and then three alternating marginal cuts involving 2/3 of muscle thickness were performed using electrocautery to elongate it. The conjunctiva was sutured up.
Results: :
Ten patients who underwent this procedure were included. Age range from 3 to 14 years old. Four cases with esodeviation and 6 with exodeviation. Preop DVD ranged 1 to 3+ and IOOA 2 to 3+. All patients had a decrease of DVD magnitude after surgery. Postop DVD was 0 to 1+. No patient showed postop IOOA. Two patients showed postop mild elevation deficiency in adduction. One patient with manifest DVD (3+) improved after surgery to 1+ latent DVD.
Conclusions: :
In this case series, inferior oblique muscle weakening, using TMM was effective in controlling mild to moderate DVD associated to IOOA.. Control of DVD can be achieved with this surgical technique which is easier and less invasive than other procedures. This technique may be considered as a primary treatment in patients with horizontal strabismus and concomitant DVD and IOOA
Keywords: eye movements: recording techniques • strabismus: treatment • strabismus