Macular hole. Optical coherence tomography (OCT) scan of a section through the retina of the eye of a female patient with a macular hole (upper centre). The retina is the light-sensitive layer lining the inner surface of the eye that contains the rod and cone cells. The macula is the central area of the retina that contains the highest density of these cells. A macular hole is a small break in the macular. It is often caused by shrinking of the vitreous humour, the clear gel that fills the eyeball.