financial disclosure: authors do not have financial or commercial interest in mentioned equipments...

Financial Disclosure: Financial Disclosure: Authors do not have financial or commercial interest in mentioned equipmentsAuthors do not have financial or commercial interest in mentioned equipments

Dr Arce is Consultant & Territory Manager for Latin America, Vista Optics Limited, Widnes, UK; 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, 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 ([email protected])

Carlos G. Arce MD, Paulo Schor MD, Mauro Campos MDCarlos G. Arce MD, Paulo Schor MD, Mauro Campos MD

Ocular Bioengineering and Refractive Surgery Sectors, Institute of VisionOcular Bioengineering and Refractive Surgery Sectors, Institute of VisionDepartment of Ophthalmology, Paulista School of MedicineDepartment of Ophthalmology, Paulista School of Medicine

Federal University of São Paulo, BrazilFederal University of São Paulo, Brazil

Traffic Light Color Distribution for Custom Color Scales: Traffic Light Color Distribution for Custom Color Scales: Application to Elevation, Curvature, Power, and Thickness MapsApplication to Elevation, Curvature, Power, and Thickness Maps

• 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 ScalesTraffic Light Color Distribution for Custom Color Scales


Orbscan Default Scale (35 colors)Anterior and Posterior Elevation: 5 μm steps

Axial Curvature: 0.5 D stepsPachymetry: 10 μm steps

Orbscan Default ScalesAnterior and Posterior Elevation: 10 μm steps

Axial Curvature: 1.5 D stepsPachymetry: 20 μm steps

Colors and patterns change according to size of steps in default scales


Orbscan Custom Scale (35 colors)Anterior Elevation: 7 μm steps

Posterior Elevation: 13 μm stepsAxial Curvature: 1.0 D stepsPachymetry: 15 μm steps

Orbscan Custom Scale (70 colors)Anterior Elevation: 4 μm stepsPosterior Elevation: 6 μm stepsAxial Curvature: 0.50 D steps

Pachymetry: 7 μm steps

Patterns and colors become independent of size of steps in these custome scales

Examples with Orbscan IIExamples with Orbscan II

Flat and tThick Cornea

Flat Cornea and Normal Thickness

VioletViolet BlueBlue Green Green Yellow Yellow OrangeOrange RedRed

Normal Curvature and Thickness

““Go for it...!”Go for it...!”Green lightGreen light

Border line Curvature and Thickness

“Caution…!” Yellow light

Asymmetric Border Line Curvature and Normal Thickness

Very Asymmetric Steep Curvatureand Normal Thickness

Very Asymmetric Steep Curvature and Thin Pachymetry

““Stop…..!” Red lightStop…..!” Red light

““Why?...”Why?...”Blue signBlue sign

““Caution…!” Yellow Caution…!” Yellow lightlight

““Stop…..!” Red lightStop…..!” Red light

Examples with GalileiExamples with Galilei

VioletViolet BlueBlue Green Green Yellow Yellow OrangeOrange RedRedSteep Curvature and Normal Thickness

• Default Galilei Scale for Anterior and Posterior

Sagital Curvatures and for Thickness

2nd Yellow: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:Green at the middle:• Zero value for Anterior and

Posterior Elevation

Steep Asymmetric Anteriorand Posterior Curvatures

CONCLUSIONS

• By the simple strategy of using a border line value as a fixed yellow step, each color of topographic scales begin to have the same meaning despite the step size or the type of map

• Identification of color patterns is easy and simplifies the interpretation of maps

• Similar approach may be used with both the Orbscan II, IIZ and the Galilei

• Everything above 47 D or below 500 μm (STEEP, THIN, or HIGHSTEEP, THIN, or HIGH) will be orange or REDRED meaning STOP!STOP!• Everything close to these selected border line value ((LIMIT OF NORMALITYLIMIT OF NORMALITY) ) will be YELLOWYELLOW meaning CAUTION!CAUTION!• Everything within the NORMALNORMAL values will be GREENGREEN suggesting GO FOR IT!GO FOR IT!• BLUEBLUE will indicate the opposite (FLAT, THICK, or DEEPFLAT, THICK, or DEEP) of the pathologic sign


financial disclosure: authors do not have financial or commercial interest in mentioned equipments...

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