Dr. Orwa Nasser MD MPH - Eye Tests

OCT Exam

What is Optical Coherence Tomography (OCT):
Optical Coherence Tomography (OCT) is a great diagnostic and imaging tool to diagnose retinal and optic nerve pathologies. Moreover, it can be used to image and diagnose anterior segment pathologies in the cornea, anterior chamber of the eye and the iris. 

Optical Coherence Tomography (OCT) is a non-invasive diagnostic technique that renders a cross sectional view of the retina, optic disc, cornea and iris. OCT creates a cross-sectional map of these structures that is accurate to within at least 10-15 microns and even less than that with the newer technologies and may approach to 3 microns resolution. 
OCT Angiography is an advanced technology to visualize the blood vessels of the retina and optic nerve in a non-invasive way and without the need to inject a dye. It can save the need for FA Angiography) that requires injecting a dye to visualize the retinal and choroidal vessels. Uses: 

1. Retinal OCT (Macular OCT): Macular OCT is useful in the diagnosis of many retinal conditions. OCT can be particularly helpful in diagnosing like macular edema and exudates (mostly caused by diabetic retinopathy, wet AMD and other conditions), macular hole, macular pucker/epiretinal membrane, Vitreomacular traction, detachments of the neurosensory retina, detachments of the retinal pigment epithelium (e.g. central serous retinopathy or age-related macular degeneration), retinoschisis, Choroidal tumors

2. Optic nerve OCT (RNFL OCT): RNFL OCT is helpful in diagnosing optic nerve disorders by accurately and reproducibly evaluate the retinal nerve fiber layer and ganglion cell layer thickness. RNFL OCT can be particularly helpful in glaucoma, Optic neuritis, Non-glaucomatous optic neuropathies, alzheimer's disease, drusen of the optic nerve.

3. Anterior segment OCT: Anterior segment OCT is helpful in diagnosing anterior segment (cornea, anterior chamber, iris and angle) pathologies. OCT can be particularly helpful in corneal edema, corneal scars, corneal erosions, angle closure glaucoma, iris pathologies
 

How is the test performed? 
The test is very simple and fast. It takes few seconds to perform the test on each eye. It is noninvasive and no injection is needed. In some cases a dilating eye drop may be administered for better visualization. During the test, you will sit in front of the OCT machine and rest your head on a support to keep it motionless. The equipment will then scan your eye without touching it. Scanning takes few seconds.