Product Detail

Replacing assumptions with measurements.

ZEISS IOLMaster 700 with Total Keratometry


Directly measure the posterior corneal surface

The IOLMaster® 700 from ZEISS with SWEPT Source OCT technology now allows you to directly measure the posterior corneal surface. It combines unique telecentric keratometry measurement of the anterior corneal surface with measurement of the posterior corneal surface in order to calculate Total Keratometry (TK®).

  • Three exclusive formulas: Barrett TK Universal II, Barrett TK Toric and the new Barrett True K with TK
  • Can be used in existing IOL calculation formulas – no need for a second device, third-party software or an online calculator
  • Existing ZEISS IOLMaster 700 can be upgraded

Total Keratometry for post-refractive patients

A recent study conducted by Michael Lawless, James Y. Jiang, Chris Hodge, Gerard Sutton, Timothy V. Robert and Graham Barrett found that in post-myopic LASIK eyes the Barrett True K formula with TK improved the outcome predictions compared to the Barrett True K with Classic Ks within ±0.5 D by >12 % (p = 0.04)1.

Graham Barrett M. D., Australia

The Barrett True K with TK formula elevates post corneal refractive surgery IOL power calculation to the next level.

All you need to know about Total Keratometry

Download the compendium now!

This compendium provides an overview on:

  • Why it’s important to measure the posterior corneal surface.
  • How TK differs from existing solutions.
  • Clinical outcomes with Total Keratometry

Scientific Papers

on Total Keratometry in ZEISS IOLMaster 700

IOL power calculation: standard cases to post laser vision correction

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Peer Insights

Stay up-to-date and expand your knowledge with the latest clinical articles, studies, cases, videos about technologies and applications from ZEISS.

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  • 1 Lawless M, Jiang JY, Hodge C, Sutton G, Roberts TV, Barrett G. Total keratometry in intraocular lens power calculations in eyes with previous laser refractive surgery. Clin Exp Ophthalmol. 2020 Aug;48(6):749-756