Optical Coherence TomographyOptical Coherence Tomography, or OCT, is a laser-based, noncontact, noninvasive imaging technique that is capable of obtaining high resolution images of the retina and its components.
OCT is analogous to ultrasound imaging except that light rather than sound waves are used, resulting in a much higher resolution of approximately 10µm in the retina. OCT provides direct, real-time, cross-sectional images of retinal tissue layers, allowing improved resolution and diagnostic capabilities of a variety of eye diseases.
|NFL: Nerve Fiber Layer||RPE: Retinal Pigment Epithelium|
|ILM: Inner Limiting Membrane||CC: Choriocapillaris|
|GCL: Ganglion Cell Layer||IPL: Inner Plexiform Layer|
|IS/IOS: Inner & Outer Photoreceptor Segment Junction||OPL: Outer Plexiform Layer|
OCT has been shown to be clinically useful for imaging and directly visualizing selected macular diseases including macular holes, macular edema, age-related macular degeneration, central serous chorioretinopathy, epiretinal membranes, schisis cavities associated with optic disc pits, and retinal inflammatory diseases.
Analysis of diabetic macular edema reveals thickening of the neurosensory retina with nonreflective cystic spaces visible in the fovea. Macular thickness is quantified; intraretinal or subretinal fluid accumulation can be monitored after treatment.
A macular hole can be detected even when otherwise unseen. Quantitative information aids in staging and in evaluating surgical intervention.
In age-related macular degeneration, geographic atrophy and other pathologic changes can be directly viewed. Measurements of retinal thickness provide an objective means of monitoring edema and subretinal fluid.