Quantification (grading) of inferior oblique muscle recession for V-pattern strabismus.

PURPOSE

To determine the effectiveness of grading such surgery according to the magnitude of the V pattern and inferior oblique muscle overaction (IOOA).

METHODS

We retrospectively reviewed all 53 cases we operated since 1984 for V pattern with IOOA, who had undergone graded inferior oblique recession, recessed according to the anatomical recession table of Apt and Call, ranging from 8mm for V pattern of 12 PD with +1 IOOA to 12mm for 30+ PD with +3 IOOA.

RESULTS

A "satisfactory outcome" (defined as = V pattern of 8 PD or less) was observed in 75% of the cases with a preoperative V pattern less than 20 PD, in 70% of those with a preop' V pattern between 20 PD and 29 PD, and in 57% of those with a preop' V pattern greater than 29 PD. There were no overcorrections. All unsatisfactory outcomes were undercorrections.

CONCLUSIONS

The principle of grading this surgery is supported and affirmed by these results. However, the results also suggest a need to increase the amount of surgery for all categories and add anterior transposition for larger V patterns.