Stage I intraoperative adjustment of eye muscle surgery under general anesthesia: consideration of graduated adjustment.

The eyes diverge under general anesthesia. The amount of divergence is predictable; there is a linear relationship between the preoperative and the anesthetized eye position. We have confirmed Apt and Isenberg's regression formula for this relationship (A = 0.8 P + 30). We have previously also reported that adjusting the amount of surgery to be done (stage I adjustment) in cases deviating from this correlation by one standard deviation or more (anomalous) significantly improved our surgical success rate to 85%. Since a fixed arbitrary adjustment of 1 mm more or less surgery had improved our surgical success rate significantly, but still left room for higher success rates, we reviewed our anomalous cases to determine whether a graduated adjustment might be expected to produce even higher success rates. A review of cases including additional ones since our last report failed to support this hypothesis. Satisfactory results in these most recent cases have, however, almost doubled the surgical success rate (in anomalous cases) for our stage I fixed arbitrary 1 mm intraoperative adjustment, from 47% to 90%.