To determine anatomical success and best-corrected visual acuity after secondary surgery with heavy silicone oil tamponade in patients with persistent full-thickness macular holes.

In this retrospective study, 63 eyes with persistent full-thickness macular holes after primary pars plana vitrectomy and internal limiting membrane peeling underwent secondary surgery with heavy silicone oil tamponade. Macular spectral domain optical coherence tomography and best-corrected visual acuity measurements were performed during the follow-up.

Fifty of 63 eyes (79.4%) achieved anatomical success. In eyes achieving anatomical success, best-corrected visual acuity before primary vitreoretinal surgery was significantly better (0.77 [∼20/125 Snellen] ± 0.24 [1.3–0.3] logarithm of the minimum angle of resolution) compared with eyes not achieving anatomical success (0.88 [∼20/160 Snellen] ± 0.17 [1.1–0.6] logarithm of the minimum angle of resolution, P = 0.044). Minimum linear diameter of full-thickness macular holes was significantly smaller in eyes achieving anatomical success, both before primary (403.4 ± 128.7 [199.0–707.0] µm vs. 568.1 ± 209.1 [307.0–953.0] µm, P = 0.009) and secondary surgery (464.1 ± 215.0 [178.0–1,521.0] µm vs. 663.3 ± 228.5 [451.0–1,301.0] µm, P = 0.010). Patients remaining phakic during all three surgeries did not benefit from best-corrected visual acuity improvement, although anatomical success was achieved.

Heavy silicone oil tamponade in secondary surgery for persistent full-thickness macular holes is a safe and efficient surgical method. Best-corrected visual acuity and minimum linear diameter before surgery may be indicators for anatomical success.