Inverted Internal Limiting Membrane flap peeling technique for large macular holes: 1-year results

Purpose : To evaluate the clinical efficacy of Inverted Internal Limiting Membrane (ILM) flap technique for the treatment of large versus small macular holes. Methods : 89 eyes of 85 patients, who underwent 25-gauge pars plana vitrectomy (25G PPV) with inverted flap (IF) or standard peeling (SP) technique for a full-thickness macular hole, were included. Simultaneous cataract surgery (PE) was performed in 60 eyes. All eyes were divided into 2 groups according to hole size as found with OCT: Large Holes (LH) (>500 µm), 41 eyes, and Small/Medium Holes (SMH) (<500 µm), 48 eyes. A complete ophthalmological evaluation and OCT scans were performed at every follow-up visit. Hole closure day was recorded by OCT. Primary study outcome was the evaluation of differences in the hole’s closing rate and time between the two groups and techniques; secondary outcome was the evaluation of differences in best corrected visual acuity (BCVA) change. Results : 38 eyes completed the 1-year follow-up. There weren’t significant differences between groups at baseline except for the median hole size (μm) (603.5 and 327 for LH and SMH, respectively). Primary macular hole closure was achieved in 92.7% of eyes in LH group (33 eyes with IF, 5 with SP) and 85.4% of eyes in SMH group (33 eyes with IF, 8 with SP). In 10 patients an open flat hole (type 2 closure) was detected at the end of follow-up. OCT showed macular hole closure after a median time for LH of 20.5 days with IF and 27 days with SP; for SMH of 26.5 days with IF and 32.5 days with SP. Median BCVA improved significantly from baseline to week 4, 8, 12, 16, 24, 38 and 52 with both techniques in SMH group; whereas in LH group improved significantly only with IF technique starting from week 8. ANOVA analysis with a Mixed Effect Model showed that BCVA was influenced significantly by PE (p=0.02), SF6 tamponade (p=0.02) and hole size > 500 μm (p=0.01). Contour plot graphs (Fig 1) showed that: PE always gives better BCVA; IF technique gives better BCVA in SMH if they close within 80 days, while in LH if they close after 100 days; with SP, instead, better BCVA will be reached with longer closure times, regardless of hole size. Conclusions : 25G PPV with IF ILM peeling seems to be safe and effective for either large or small macular holes; small holes with prompt closure are associated with high post-op BCVA, while large holes will benefit of a longer closure time.