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Unlock TK with our experts

Kamran Riaz, Giacomo Savini, Tun Kuan Yeo, Mitch Weikert and Jascha Wendelstein

What is Total Keratometry?

Total Keratometry (TK®) combines unique telecentric keratometry measurement of the anterior corneal surface with measurement of the posterior corneal surface.

How it works

  • Traditional Keratometry: Measures only the front surface of the cornea and uses a mathematical estimate (a constant refractive index) to guess the curvature and power of the back surface.1,2
  • Total Keratometry: Uses advanced technology (like Swept-Source OCT) to measure the posterior cornea and corneal thickness, replacing estimations with exact measurements.3,4,5

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TK in post-LVC eyes

Discover how experts use Total Keratometry to reduce uncertainty and achieve greater confidence in post-refractive patients.
  • Measured posterior corneal data removes one of the biggest uncertainties in post-LVC IOL calculations. 
  • Leading surgeons6 rely on TK as a standard part of their post-LVC workflow to improve confidence and predictability. 
  • Barrett True-K with measured TK consistently delivers highly accurate outcomes in post-refractive patients. 
  • Simplifies planning by reducing dependence on historical data and multiple calculation methods.

Hear how experts are transforming post-LVC planning with TK.

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TK in toric eyes

Learn how measured posterior corneal data can refine toric planning and support confident IOL selection
  • Particularly valuable in against-the-rule and oblique astigmatism, posterior corneal contribution plays a critical role.
  • Helps identify patients who may benefit from toric correction more accurately.
  • Combined with Central Topography, TK supports more informed astigmatism management decisions.

Learn how experts use TK to refine toric decision-making.

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TK in keratoconus eyes

Explore how Total Keratometry helps experts navigate keratoconus cases and optimize cataract surgery planning.
  • Can be incorporated into both keratoconus-specific and standard formulas to calculate IOLs.
  • Helps surgeons better manage cataract surgery in patients with irregular corneas. 
  • Combine posterior corneal measurement with Central Topography insights for a more complete clinical picture.

Explore how experts approach keratoconus IOL calculation with TK.

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