Optical Coherence Tomography in the Diagnosis, Monitoring and Treatment of Macular Disorders

Optical coherence tomography (OCT) has revolutionized the way we look at the retina, by being able to offer cross-sectional images of the retinal layers, comparable to the histological specimens, in a non-invasive manner. OCT technology is based on the principle of low coherence interferometry. The new spectral domain OCT devices have axial resolution of 2 μm - 5 μm, scanning speed of 27 000 - 100 000 scans per second, perform large, dense raster scans and display three-dimensional data of the target tissue. The practical impact of these capabilities is translated by: better image quality, less artifacts associated with eye motion and the obtaining of detailed surfaces of the retinal layers over large areas resulting in segmentation maps. The most important quantitative parameter measured by OCT, that cannot be precisely evaluated by any other method, is the macular thickness. With the help of this information, surface maps of the internal limiting membrane and retinal pigment epithelium and retinal thickness maps are generated. Registering these maps over time is very useful in identifying and monitoring the dynamics of disease progression and response to therapy. The macular diseases that benefited the most from the development of the OCT technology are: age-related macular degeneration, diabetic macular edema, vitreo-macular interface disorders (vitreo-macular traction, epiretinal membranes, macular hole). The purpose of this paper is to present the principle of OCT technology and its impact on the diagnosis, monitoring and treatment of the macular disorders. Our personal cases are presented in order to illustrate the impact of OCT in the clinical practice.