Prognostic value of preoperative statokinetic dissociation (SKD) for delayed improvement of visual field in patients with suprasellar tumors

Clinical records of 61 cases with suprasellar tumors that also had visual field defects were reviewed to determine whether statokinetic dissociation (SKD) could be used to predict recovery of the visual field after transsphenoidal surgery. Static and kinetic visual field testing was performed with Humphrey perimetry (HP) and Goldmann perimetry (GP) preoperatively, and followed by HP both immediately and several months after the surgery. SKD was defined as being positive if the area ratio, which was determined by the static field visible with a luminance of 25dB in HP divided by the kinetic field within the I3e isopter in GP, was less than 75%. Out of the 61 preoperative cases, 20 were deemed to have undergone sufficient visual field tests and therefore SKD was evaluated in 28 eyes from these 20 cases. There were 8 eyes of 6 cases with perioperative residual visual field defect that were included in the portion of the study that examined delayed visual field improvement. At 4 to 10 months after the surgery, the 4 eyes that had been determined to be positive exhibited a significant recovery in the visual field as compared to the 4 eyes that had been classified as negative, despite the fact that there had been no significant difference in early improvement. In summary, SKD may be useful in the prediction of delayed visual field recovery following surgery in patients with suprasellar tumors. This predictive ability may be related to the severity of the anterior visual pathway compression.