Comparison of epiretinal membranes of differing pathogenesis using optical coherence tomography

Purpose: To compare optical coherence tomography (OCT) images of idiopathic epiretinal membranes (ERMs) with those of secondary ERMs. Methods: OCT was performed on 70 eyes of 63 consecutive patients with biomicroscopic evidence of ERMs and 23 eyes of 23 healthy volunteers without ERMs. OCT findings were correlated with the clinical pathogenesis of the ERM. Results: Evaluation by OCT established that 48 of 70 ERMs were globally adherent to the retina and that 22 of 70 ERMs were focally adherent to the retina. When correlated to clinical pathogenesis, 20% of idiopathic membranes and 52% of secondary membranes were focally attached to the retina. There was a significant difference in the pattern of membrane attachment to the retina in the two pathogenic groups (P = 0.007). Eight of nine eyes with macular pseudoholes were associated with globally adherent membranes. Conclusion: Secondary ERMs are more likely to be characterized by focal retinal adhesion than are primary ERMs. Primary ERMs tend to be globally adherent. This finding may contribute to understanding the underlying mechanisms of ERM formation in different clinical settings.