Optical Coherence Tomography
Optical 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.