Combined phacoemulsification and pars plana vitrectomy for macular hole treatment

Abstract

Editor, We read with great interest the article by Theocharis et al. (2005). In their paper, the authors presented the results of combined phacoemulsification and pars plana vitrectomy in treating patients with macular hole. We would like to raise a few points with regard to this article that may help to broaden the discussion. Firstly, 32 (84%) patients in a series of 38 were said to have achieved successful macular hole closure postoperatively. This is certainly an encouraging result, but we noticed that successful macular hole closure was defined by the authors as ‘flattening of the edges of the hole with no evidence of subretinal fluid’. We think this might be too loose a criterion for defining successful macular hole closure. We would suggest the addition of stricter and more objective criteria, including clinical methods such as the Watzke−Allen test and investigative methods such as optical coherence tomography (OCT). We believe OCT provides excellent resolution of a cross-section of the macula and can be used as an objective indicator of macular hole closure. We would be interested to know if OCT had been performed in this series of patients postoperatively and if so, what the results were. Secondly, the authors used indocyanine green (ICG) as a dye for assisting internal limiting membrane (ILM) peeling in all their patients. While we agree that ICG provides effective staining of the ILM, since 2004 an increasing number of studies have reported the toxic effects of ICG on the retina, which include retinal pigment epithelial changes and optic atrophy (Cheng et al. 2005; Posselt et al. 2005). We would like to know if the authors have observed any similar toxic effects that may have been induced by ICG in their series of patients. In order to avoid possible toxic effects of ICG on the retina, in 2004 our centre shifted to using alternative adjuncts, including trypan blue and triamcinolone actonide, to assist in ILM peeling. Both agents appear to have better safety profiles than ICG (Gale et al. 2004). According to our experience, trypan blue is as effective as ICG in staining the ILM and has certainly enhanced the process of membrane peeling. Finally, we would like to echo the authors' conclusion that combined phacoemulsification and pars plana vitrectomy for macular hole repair have many advantages, including clearer intraoperative visualization, which, in turn make the procedure safer and more effective and give a better postoperative visual outcome. On the other hand, we are also concerned about how much postoperative visual improvement is attributable to macular hole surgery alone if combined surgeries are attempted. We believe more prospective randomized trials will be needed to resolve this issue.