New insights into the pathoanatomy of macular holes based on features of optical coherence tomography

Various important findings related to the development and progression of idiopathic macular holes (MHs) have been described using optical coherence tomography since Gass first staged MH development using biomicroscopy in 1988 and 1995. We believe that a system for classifying and staging MHs should reflect the degree of disease status and its progression and have value not only from a practical point of view (by predicting the chance of closure or visual recovery), but also provide researchers and clinicians with insights into the pathogenesis and disease progression of MH. These data pave the way for the development of more effective strategies. In this review, we integrate the morphologic features of MHs observed by optical coherence tomography with Gass's biomicroscopic classification and anatomic interpretations. As a result, we propose a conceptual model of a modified classification system for MHs: (1) there are 2 types of MHs starting from the earliest developmental phases of the condition; (2) differences between the types of MHs result from the peculiar characteristics of Müller cells in the fovea; and (3) this classification system, which is based on the degree of preoperative tissue defects, determines closure patterns as well as visual outcomes after an MH is surgically repaired.