Purpose: To investigate correlations of the optical coherence tomography-based epiretinal membrane (ERM) classification with metamorphopsia and tangential retinal displacement after ERM surgery.
Methods: ERM stage (stage 1-4) was defined as originally described. Metamorphopsia scores at baseline, 1 month, 3 months, and 6 months after ERM surgery were measured with M-CHARTS (Inami, Co, Tokyo). Tangential retinal displacement was measured as described previously. Eyes with retinal cysts, lamellar hole with epiretinal proliferation, or retinoschisis were excluded.
Results: One hundred thirty-five eyes of 135 consecutive patients who underwent ERM surgery at a single academic hospital were enrolled. There were 20 eyes of stage 1, 57 eyes of stage 2, 54 eyes of stage 3, and 4 eyes of stage 4. Epiretinal membrane stage correlated with tangential retinal displacement at 1 month, 3 months, and 6 months postoperatively (Spearman rank correlation coefficient, P < 0.001), which also correlated with both horizontal and vertical preoperative M-CHARTS scores (P < 0.001) and horizontal scores at 1 month (P = 0.001) and 3 months (P = 0.016). Visual acuities did not show any correlations with the stage.
Conclusion: Optical coherence tomography-based ERM classification correlates strongly with tangential retinal displacement after ERM surgery. This classification is particularly useful to predict pre- and postoperative metamorphopsia, but not for visual acuity.