1. Financial Disclosure: Authors do not have financial or commercial interest in mentioned equipments Dr Arce is Consultant & Territory Manager for Latin America, Vista Optics Limited, Widnes, UK; R&D Consultant, Ziemer Group AG, Port, Switzerland; Speaker, Bausch & Lomb do Brasil, and Diretor Geral, R.E.I. Comércio Ltda., Campinas, SP ( and Diretor Geral, R.E.I. Comércio Ltda., Campinas, SP (cgarce@terra.com.br) Carlos G. Arce MD, Paulo Schor MD, Mauro Campos MD Carlos G. Arce MD, Paulo Schor MD, Mauro Campos MD Ocular Bioengineering and Refractive Surgery Sectors, Institute of Vision Department of Ophthalmology, Paulista School of Medicine Federal University of São Paulo, Brazil Traffic Light Color Distribution for Custom Color Scales: Application to Elevation, Curvature, Power, and Thickness Maps

2. INTRODUCTION Most topographic color scales use a normal fixed value in one of their green steps Orbscan II and IIZ use as default the 42 D for curvature and the 600 μm for pachymetry Galilei uses as default 43 D and 550 μm, respectively In these cases when steps are small (≤ 0.5 D or ≤10 μm) extreme colors are achieved fast When steps are big (≥ 1.5 D or ≥25 μm) typical patterns may be diluted or missed Therefore, colors do not have specific or constant meaning in default scales METHOD AND PARAMETERS Color scales were modified by using a border line value as a fixed step in the yellow range ORBSCAN II and IIZ (Bausch and Lomb, Rochester, NY): Anterior Elevation : 30 μm in the 4th yellow with a 7 μm step Posterior Elevation : 50 μm in the 4th yellow with a 13 μm step Axial Keratometric Curvature: 47 D in the 2nd yellow with a 1 D step Pachymetry: 500 μm in the 2nd yellow with a 15 μm step GALILEI (Ziemer Ophthalmics, Port, Switzerland): Anterior Elevation : 15 μm in the 2nd yellow with a 5 μm step Posterior Elevation : 15 μm in the 2nd yellow with a 5 μm step Sagital Anterior Curvature: 47 D in the 2nd yellow (1st orange) with a 1 D step Pachymetry: 500 μm in the 2nd yellow (1st orange) with a 15 μm step Traffic Light Color Distribution for Custom Color Scales

3. Orbscan Default Scale (35 colors) Anterior and Posterior Elevation: 5 μm steps Axial Curvature: 0.5 D steps Pachymetry: 10 μm steps Orbscan Default Scales Anterior and Posterior Elevation: 10 μm steps Axial Curvature: 1.5 D steps Pachymetry: 20 μm steps Colors and patterns change according to size of steps in default scales

4. Traffic Light Color Distribution for Custom Color Scales Orbscan Custom Scale (35 colors) Anterior Elevation: 7 μm steps Posterior Elevation: 13 μm steps Axial Curvature: 1.0 D steps Pachymetry: 15 μm steps Orbscan Custom Scale (70 colors) Anterior Elevation: 4 μm steps Posterior Elevation: 6 μm steps Axial Curvature: 0.50 D steps Pachymetry: 7 μm steps Patterns and colors become independent of size of steps in these custome scales

5. Examples with Orbscan II Flat and t Thick Cornea Flat Cornea and Normal Thickness Violet  Blue  Green  Yellow  Orange  Red Normal Curvature and Thickness “Go for it...!” Green light Border line Curvature and Thickness “Caution…!” Yellow light Asymmetric Border Line Curvature and Normal Thickness Very Asymmetric Steep Curvature and Normal Thickness Very Asymmetric Steep Curvature and Thin Pachymetry “Stop…..!” Red light

6. “Caution…!” Yellow light “Stop…..!” Red light Examples with Galilei Violet  Blue  Green  Yellow  Orange  Red Steep Curvature and Normal Thickness Default Galilei Scale for Anterior and Posterior Sagital Curvatures and for Thickness 2nd Yellow: 47 D in Curvature 500 μm in Pachymetry Steep Asymmetric Curvature and Border Line Thickness ANSI Scale for Anterior and Posterior Elevation Green at the middle: Zero value for Anterior and Posterior Elevation Steep Asymmetric Anterior and Posterior Curvatures

7. Traffic Light Color Distribution for Custom Color Scales