The use of optical coherence tomography in macular diseases

With optical coherence tomography (OCT), a new technique has emerged that allows imaging of a transverse section of the retina with a resolution that has not been reached by other imaging techniques. The OCT technique can be used in the diagnosis and assessment of various diseases of both the anterior segment and the ocular fundus. This paper demonstrates that OCT can deliver useful information in the diagnosis and follow-up of several macular diseases that cannot be obtained with other fundus imaging techniques. The optical principle of OCT is based on visible-light interference. OCT allows imaging of the anatomical foveal appearance. This normal foveal appearance is disrupted when macular edema occurs, leading to thickening of the neuroretina and cyst formation. The anatomical difference between a neuro-retinal elevation and RPE elevations can be demonstrated using OCT. Epiretinal membranes and pseudo-macular holes can easily be visualized. Perhaps the most interesting addition of OCT in the retinal diagnostic field is the imaging of vitreo-macular traction syndromes and staging of macular holes, which are both difficult with ophthalmoscopy and fluorescein-angiography. Each of the above mentioned macular diseases will be illustrated by a typical case.