Optos Optomap
The optomap ultra-wide digital retinal imaging system captures more than 80% of your retina in one panoramic image. Traditional methods typically reveal only 10-12% of your retina at one time. The unique optomap ultra-wide view enhances your eye doctor’s ability to detect even the earliest sign of disease that presents on your retina. Seeing most of the retina at once allows your eye doctor more time to review your images and educate you about your eye health. Numerous clinical studies have demonstrated the power of optomap as a diagnostic tool.
Optical Coherence Tomography
Optical coherence tomography (OCT), first described in 1991, is a noncontact, noninvasive imaging technique that can reveal layers of the retina by looking at the interference patterns of reflected laser light. Automated software segmentation algorithms are able to outline the retinal nerve fiber layer with much precision, which is relevant in glaucoma since this layer is thinned as ganglion cells are lost. OCT became widely popular in 2002 with the release of Stratus OCT, a time-domain technology (TD-OCT) that was well-studied and validated for use in glaucoma and retina and went on to become a standard structural imaging test. Only four years later, several companies started to release the next generation technology, spectral-domain OCT (SD-OCT), AKA fourier-domain OCT, which improved upon TD-OCT by capturing more data in less time at a higher axial image resolution, around 5 µm. Ultrahigh speed swept source OCT, ultrahigh resolution OCT, polarization sensitive OCT, and adaptive optics OCT are all on the horizon.
Currently, the most common four commercially available SD-OCT devices in the US are: Cirrus HD-OCT (Carl Zeiss Meditec, Dublin, CA, USA), RTVue-100 (Optovue Inc., Fremont, CA, USA), Spectralis OCT (Heidelberg Engineering, Heidelberg, Germany), and Topcon 3D-OCT 2000 (Topcon Corporation, Tokyo, Japan). Each machine has different glaucoma scan patterns, proprietary software segmentation algorithms, and display outputs. Our review focuses on the Cirrus HD-OCT in diagnosing glaucoma and glaucoma progression.
SD-OCT Parameters
There are three main parameters relevant to the detection of glaucomatous loss: retinal nerve fiber layer, optic nerve head, and the “ganglion cell complex.” The numeric values for all parameters are shaded as white, green, yellow, or red, with the yellow and red representing, < 5% and < 1%, respectively compared to the normative database.