Optical Coherence Tomography
Optical coherence tomographyThe OCT is the first instrument that allows doctors to see a direct cross-sectional image of the retina.  The OCT is similar to a CT scan of internal organs, except it doesn t use X-rays.  Instead a beam of light is used to rapidly scan the eye and generate an image without ever touching the patient.  This painless scan takes less than 10 minutes.  Since there is no patient contact, patient comfort is improved and the test is performed in less time.  These images are critical to assess the anatomical structures of the eye and any retinal changes.

This scan can provide practitioners with a guidepost to determine how a specific patient s retinal nerve fiber layer compares to a normal range on the instruments database.  Therefore, changes in the thickness of the retinal nerve fiber layer could be an indication of early glaucomatous changes.  Besides glaucoma, the OCT analyses the appearance of various changes in the posterior segment of the eye.  These include diabetic retinopathy, macular holes, epiretinal membranes, cystoid macular edema, central serous choroidopathy, choroidal nevus, disc edema in inflammatory optic neuropathy, and congenital pits of the optic nerve head.  In order to properly diagnose an ophthalmic disease involving the peripapillary retinal nerve fiber layer knowledge regarding the expected thickness and normal limits are needed.  Thickness is dependent on the age of the patient and can also vary with right eye vs. left eye and gender.  The OCT offers information that can be used to help make a diagnosis, as well as assess the efficacy of therapy over time.