A Powerful Predictor of Change Validated by OHTS to predict structural change rogression analysis validated with 10 year's of patient data Optic disc analysis outperforms expert interpretation. The HRT provides retinal thickness measurements with absolute millimeter measurement. Unlike the Edema Index, the Retinal Thickness function locates both the vitreo-retinal interface and the retinal pigmented epithelium (RPE). Large, ethnic-selectable databases Asymmetry analysis Upgradeable platform Network ready. Software Modules will vary depending on instrument; please call with your requirements for a system that is right for your practice.