Preoperative electroretinogram and postoperative visual outcome in patients with diabetic vitreous hemorrhage

Purpose: To determine whether the single-flash electroretinogram (ERG) can predict the postoperative outcome in diabetic cases where massive vitreous hemorrhage precludes fundus observation. Methods: Eighty-five diabetic patients (105 eyes) who underwent vitrectomy due to dense vitreous hemorrhage were studied retrospectively. Eyes with postoperative complications were excluded. Preoperative ERGs (mixed cone-rod ERG with maximum flash intensity) were classified as: Group A, the b-wave/a-wave ratio (b/a ratio) was ≥1.0 and the oscillatory potentials (OPs) were clearly recordable (22 eyes); Group B, the b/a ratio was ≥1.0 and the OPs were markedly reduced (33 eyes); and Group C, the b/a ratio was <1.0 (50 eyes). Results: The postoperative visual acuity in Group C (hand motion to 1.5) was significantly worse than in Group A (0.4-.2) (P<.01) or Group B (0.08-1.0) (P<.01). Thick preretinal membrane causing retinal traction around the optic disc was found intraoperatively in 1 eye (4.5%) in Group A, 9 eyes (27.3%) in Group B, and 28 eyes (56.0%) in Group C (P = .0132). Conclusion: Our findings suggested that the configuration of the single-flash ERG can provide important preoperative information for a functional prognosis following vitrectomy in diabetic patients with vitreous hemorrhage.