Abstract:  In recent years, the fastdeveloping optical coherence tomography (OCT) technology has provided us more details of the outer retina microstructure. The four hyperreflective lines in OCT images (external limiting membrane, ELM; inner segment/outer segment junction, IS/OS; cone outer segment tips, COST; retinal pigment epithelium, RPE) are associated with visual acuity and function in different retinal diseases, and are able to predict prognosis and clinical outcomes of retinal diseases. In the present review, the emerging knowledge about the microstructures of the outer retina and its relationship with visual function in different retinopathies will be discussed.  (Int Rev Ophthalmol, 2013, 37: 354-358)