Macular Hole Classifications

Macular Hole classificationMacular hole classification has been for decades based on the rather impressive biomicroscopic work by Donald Gass. It was mainly created for pathophysiological purposes with an essential emphasis on the posterior hyaloid attachment at the macula and optic disc areas. The surgical approach for full-thickness macular holeMacular hole (FTMH) was at its early inception. Twenty years later, with substantial improvements in imaging technologies, like spectral-domain (SD) optical coherence tomographyOptical coherence tomography (OCT), and surgical instrumentation and techniques, newer classifications were needed. The first meaningful one, based on SD-OCT, was proposed by the International Vitreomacular Traction Study (IVTS). They used the minimum hole width (currently named minimum linear diameter (MLD)) to classify eyes into small (< 250 μm), medium (≥ 250–400 μm), and large (> 400 μm). Pars plana vitrectomyPars plana vitrectomy (PPV) with wide (vascular arcade to arcade) internal limiting membrane (ILM)Internal Limiting Membrane (ILM) peeling and long-acting gas tamponade mainly became the gold standard. Holes ≤ 400 μm achieve nearly 100% closure rate with significant central vision improvement. But, for FTMH beyond 400 μm, closure rates after primary intervention drop down to an overall 80%. The Manchester Large Macular HoleLarge macular hole Study was the first classification proposed for idiopathic FTMHs based on surgical results with primary PPV, ILM peel, longer-acting gas, and prone positioning. Although retrospective, with a relatively small number of eyes with FTMH > 400 μm and using only horizontal scans to measure MLD, they found a cutoff of 630 μm beyond which anatomical closure rates dropped to < 80%. More recently, the CLOSE Study Group introduced a more inclusive surgical classification for FTMHs > 400 μm with a significantly higher number of cases, using radial scans to determine MLD and other OCT biomarkers to stratify not only primary but also persistent and recurrent holes undergoing PPV with ILM peeling or other recently introduced surgical techniques. This chapter summarizes the evolution of classifications, didactyly dividing them in pre- and post-operative FTMH characteristics, and highlighting valuable features for daily clinical and surgical practice use.