Knowing what terminology to look for will help your coding To correctly code and bill for SLGTs, you need to understand that ophthalmologists get diagnostic images from SLGTs through a variety of technologies. Remember, however, that regardless of which of the following technologies your ophthalmologist uses, you'll still report 92135 (Scanning computerized ophthalmic diagnostic imaging [e.g., scanning laser] with interpretation and report, unilateral): • Confocal laser scanning topography uses simultaneous stereoscopic (confocal) digital video images to produce a three-dimensional image of the eye's posterior chamber and provides a quantitative measurement of the optic nerve head and surrounding retina. Also known as: HRT1 or HRT2 (Heidelberg retina tomograph), optic nerve head imaging. • Scanning laser polarimetry uses a polarimeter to measure linear polarization change and a scanning laser ophthalmoscope to measure the thickness of the nerve fiber layer of the retina. Also known as: SLP, GDX, GDx-VCC, nerve fiber analyzer. • Optical coherence tomography produces high-resolution longitudinal cross-sectional tomographs of the eye's structures. It's similar to a B-scan, only using light instead of sound to produce the image. Also known as: OCT, RTA (retinal thickness analyzer). Note: SLGTs in general are sometimes referred to as scanning computerized ophthalmic diagnostic imaging (SCODI).