MACULAR HOLE SURGERY AND RETINAL TECTONICSThe Impact of Internal Limiting Membrane Peeling Size on Tangential Retinal Displacement

Purpose: To evaluate the tangential retinal displacement occurring following macular hole (MH) surgery and to assess the impact of the internal limiting membrane (ILM) peeling size on the extent of the retinal movement. Methods: This retrospective study included patients with full-thickness MH undergoing 25-gauge pars plana vitrectomy with ILM peeling. Patients received either a small ILM peeling with a size of two-disk diameters or a large peeling extended up to the vascular arcades. Near-infrared retinal imaging was performed with the Spectral is (Heidelberg Engineering, Carlsbad, Germany) before and 6 months after the surgery. The tangential retinal displacement was evaluated comparing the optical flow of near-infrared images with a custom digital image analysis algorithm. Results: Forty-four eyes of 44 patients undergoing vitrectomy with small (n = 24) or large (n = 20) ILM peeling were included. An average overall displacement of 31.3 +/- 22.8 mu m toward the optic disk was observed after the surgery. Large ILM peeling was associated with a significantly higher overall displacement (P = 0.009), displacement in the central 4-mm circle (P < 0.001), and displacement in outer 8-mm ring (P = 0.001). Macular holes closure was achieved in 100% and 83.3% of patients in the large and small peeling group, respectively (P = 0.055). Conclusion: Pars plana vitrectomy with ILM peeling for MH results in a tangential retinal displacement toward the optic disk. A larger extent of the ILM peeling leads to a greater tangential movement, possibly improving the MH closure rate.