Original papers: Large bimedial rectus recession (6.5 mm or more) in the management of large-angle esotropia

A total of 101 patients (total group) with primary large angle esotropia who had primary bimedial rectus recession (BMR) of 6.5 mm or more were reviewed in a retrospective study. The average pre-operative size of the deviation was 63.5 prism diopters (PD) for near and 58.2 PD for distance. Of these, 26 patients (group I) attended for one post-operative visit only. The remaining 75 patients (group II) were followed for an average period of 17.7 months. Among group II patients there was an average shift in the post-operative deviation towards divergence consisting of-6.4 PD for near and-5.5 PD for distance. The alignment (deviation of 10 PD or below) rate in the first postoperative visit was 31.7%; undercorrection was 60.4% and overcorrection was 7.9%. At the end of the period of follow-up the above rates were 40%, 42.7%, and 17.3% respectively without further surgery. This increase in the overcorrection rate was solely derived from the initially aligned patients. Amblyopia and/or poor fixation were found to be of significance in the production of overcorrection. There was no direct relationship between the age of surgery, duration of follow-up or the degree of the BMR and the rate of correction. Among group II patients, post-operative ocular movements analysis revealed limitation of adduction of-0.5 to-0.75 (out of scale 0 to-4.00) in 22.7% (17/75) and-1.00 to-1.50 in 6.7% (5/75). None had more than-1.5 limitation of adduction. Large BMR is an acceptable surgical modality for the management of large angle esotropia. It has approximately 50% alignment rate. Slight undercorrection is recommended especially in the presence of significant amblyopia and/or poor fixation. No significant limitation of adduction was encountered.