Very little information is available about persistent macular holes, and most of the information was provided in the early 1990s. The lack of interest in this group of patients may be related to the increasing primary success rates or because publications about macular hole surgery in the last years have mainly concentrated on technical advances, delamination of the internal limiting membrane (ILM), different staining techniques and possible toxicity of dyes.

Recent literature on macular hole surgery report very high success rates, but regardless of the specific surgical techniques used, not all macular holes are able to be closed after primary surgery. A meta-analysis on 1654 eyes treated using different techniques reported that 87.5% of eyes achieved anatomic success, with 12.5% failing to close.1 Therefore, persistence of a macular hole after vitrectomy is still one of the major complications of this type of surgery.

When a macular hole remains open, usually the size and diameter of the hole increases markedly, visual acuity drops, and the surgeon is confronted with the question as to whether retreatment is worthwile or not. It is an accepted fact that anatomic and functional success in eyes having failed previous macular hole surgery is lower than after primary surgery, although different studies have demonstrated appreciable results.2 3 This also implies that the benefit–risk ratio for repeat surgery is lower in persistent macular holes. Certainly, it should be our goal to further refine our surgical technique to allow closure of all holes, but we should not forget to also focus our efforts on the analysis of predictive factors determining not only surgical but also functional success in order to better advise our patients. In this issue of the journal, Hillenkamp et al have addressed this problem …