Macular Holes

Abstract

A full-thickness macular hole (FTMH) is an anatomic discontinuity of the foveal retina, involving all the neural layers between the internal limiting membrane (ILM) and the retinal pigment epithelium (RPE). Mechanical forces mainly arising from the vitreous are thought to be responsible for FTMH formation, including the development of tractional foveal cystoid space, breakdown and elevation of the external retina, and traction on the inner retina. The hole’s edge is usually rounded and possibly contains intraretinal pseudocysts. Intraretinal fluid can accumulate, leading to edge thickening and elevation from the RPE plane. Vitreous can be either attached or separated from the hole’s edge. A FTMH is usually easily diagnosed via multiple optical coherence tomography (OCT) foveal B-scans, even though in many cases just a single B-scan is sufficient. As far as shape is concerned, the OCT scans usually show an hourglass shape, varying depending on OCT scan orientation (Fig. 3.1). If the defect involves the retinal thickness only partially, this condition is named lamellar macular hole (LMH). A macular pseudohole, instead, is a circle- or oval-shaped lesion in the presence of an epiretinal membrane, which clinically mimics the appearance of a FTMH [1, 2].