Optical Coherence Tomography: Retinal Imaging

Optical coherence tomography (OCT) is a noninvasive investigation that produces detailed, high-resolution images of ocular structures in both the anterior and posterior segments of the eye. OCT is used to assess the retina quantitatively and qualitatively, and these parameters have been used both in clinical practice and as outcome measures in multicenter randomized controlled clinical trials. The features identified on OCT are used for the diagnosis, monitoring of disease activity, and assessing response to treatment. Quantitative features measured using OCT include retinal thickness and volumes, and choroidal thickness. OCT can also detect features of disease activity, such as retinal thickening, intraretinal cysts, subretinal fluid, and choroidal neovascular membranes located in the subretinal and sub-retinal pigment epithelial space. In addition, OCT can provide structural information of the normal anatomy and pathological features seen in many retinal conditions. OCT has proven invaluable in the diagnosis and monitoring of diseases such as age-related macular degeneration, polypoidal choroidal vasculopathy, diabetic retinopathy, retinal vein occlusions, and pathological myopia. This chapter provides an evidence-based review on the features of some of these common retinal conditions, and discusses the application of OCT in their assessment and management.