Prognostic value of preoperative flash and pattern visual evoked potentials for diabetic retinopathy vitrectomy

In view of the continuing controversy about the prognostic value of preoperative visual evoked potentials in diabetic vitrectomy, we retrospectively studied 31 eyes undergoing vitrectomy for diabetic retinopathy after recording pattern and/or flash visual evoked potential recording. Preoperative pattern visual evoked potentials were of no prognostic value in these eyes but a decrease in the amplitude of preoperative flash visual evoked potentials was significantly correlated with unchanged or worsened postoperative visual acuity when compared with preoperative visual acuity (P = 0.0156, Fisher's exact test). Therefore, while acknowledging that diabetic vitrectomy functional prognosis is actually multifactorial, we still recommend recording preoperative flash visual evoked potentials for diabetic patients in whom significant opacities of the intraocular media preclude correct examination of the ocular fundus, because a decrease in peak III amplitude may indicate a guarded vitrectomy functional prognosis.