TECNIS Eyhance Toric Planning Tool
Enter pre-op corneal astigmatism and incision assumptions to estimate net astigmatism and compare Eyhance Toric II options.
Lens options use common approximate corneal-plane values for Eyhance Toric II models (DIU150 to DIU600). Verify against your biometer and manufacturer calculator before surgery.
What is an Eyhance toric calculator?
An Eyhance toric calculator estimates which TECNIS Eyhance Toric II intraocular lens (IOL) cylinder power may best reduce corneal astigmatism during cataract surgery. In practice, surgeons combine keratometry, topography, posterior corneal assumptions, incision planning, and surgeon-specific SIA data. This page gives an educational planning estimate in a clean format.
How this calculator works
Astigmatism is a vector, not just a single number. That means both magnitude (in diopters) and axis (in degrees) matter. To account for this, the tool uses double-angle vector math:
- Converts pre-op corneal astigmatism into x/y vector components.
- Converts SIA at the planned incision axis into a second vector.
- Subtracts SIA from pre-op astigmatism to estimate post-incision net corneal astigmatism.
- Compares the result with available Eyhance Toric II cylinder steps.
- Applies optional alignment error to estimate residual astigmatism.
Why alignment matters so much
Toric correction is sensitive to rotation. A small rotational error lowers effective correction and increases residual cylinder. This is why image-guided alignment, reference marks, and capsule stability are critical. The misalignment field gives a quick scenario estimate for this effect.
Eyhance Toric II models included
The calculator compares these common model steps:
- DIU150
- DIU225
- DIU300
- DIU375
- DIU450
- DIU525
- DIU600
Each model has an IOL-plane cylinder and an approximate corneal-plane effect used in this estimator.
How to use the results
1) Check net corneal astigmatism after SIA
This value is often the most informative intermediate output. If this estimate changes significantly when you alter incision axis or SIA, your case is sensitive to surgical technique and planning assumptions.
2) Review recommendation and full comparison table
The recommended model is selected by the lowest predicted residual among listed options. The table also shows over/under correction tendencies. In borderline cases, surgeons may still choose a different model based on posterior cornea, incision location, patient preference, or tolerance for axis flip risk.
3) Confirm with official sources
Always cross-check with your device-integrated formulas and official manufacturer tools. This page is intended for educational and workflow prototyping, not a definitive surgical order set.
Practical planning tips for better toric outcomes
- Use surgeon-specific SIA from audited outcomes, not generic defaults.
- Be consistent with keratometry source and dry eye optimization pre-op.
- Minimize cyclotorsion and mark/align carefully.
- Re-check axis and rotational stability post-op in early follow-up.
- Counsel patients about realistic residual refractive targets.
Frequently asked questions
Does this include posterior corneal astigmatism directly?
No. This simplified tool does not separately model posterior corneal astigmatism. It can still be useful for quick educational checks, but final calculations should include posterior effects using validated methods.
Can I use this for final lens selection?
Use it only as a secondary estimate. Final selection should rely on complete pre-op diagnostics, surgeon nomograms, and official manufacturer calculators.
What if residual astigmatism remains high?
Recheck input quality first: keratometry repeatability, axis transcription, SIA assumption, and planned incision axis. Small data-entry mistakes can produce large toric planning differences.