RESUMEN
PURPOSE: To compare the outcome of bupivacaine (BUP) injection vs mini-tenotomy of extra-ocular muscles in treating small angle horizontal strabismus in children. METHODS: A prospective comparative study that included a total of 40 patients. Twenty patients received 3 ml of 0.75% Bupivacaine (BUP) injection in both medial recti in case of exotropia and in both lateral recti in case of esotropia. MRI orbit was performed before and 30-60 days' post injection of bupivacaine to estimate changes in muscle size. Mini-tenotomy was done in the other 20 patients, performed on both lateral recti in case of exotropia and on both medial recti in case of esotropia. RESULTS: Mean change of alignment at the end of 6 months in exotropic patients in bupivacaine group was 5.50 ± 4.10 PD and in esotropia patients 4.00 ± 3.38 PD with an average increase in muscle thickness of 0.12 mm ± 0.08 and 0.13 mm ± 0.09 in exotropia and esotropia, respectively. There was an average increase in volume 23 mm3 ± 17.3 and 17.00 mm3 ± 9.50 in exotropia and esotropia, respectively, as measured with MRI. The mean change of alignment in mini-tenotomy was 5.33 ± 4.12 PD, 5.75 ± 4.95 PD in exotropia and esotropia, respectively. CONCLUSION: Bupivacaine and mini-tenotomy are safe and effective alternative treatment, that improved eye alignment in 65% of patients with small angle horizontal deviation.