Dyna Flat/Steep

From - £90.98

The DIL has been specifically designed for Pellucid Marginal Degeneration, Globus Keratoconus, Post Penetrating Keratoplasty, Tilted Grafts and other conditions not served well by traditional speciality cone designs.


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When to use

  •  For patients with irregular corneas, where traditional cone designs have been unsuccessful or are not an option



Materials:Optimum Extra / Boston XO
Base curve5.90 to 9.40mm
Average thickness0.18mm on all powers
Diameter10.80 to 12.00mm
BVP-25.00 to + 25.00D

Fitting Guide

Aim and ideal fit
  • The principles used in fitting all corneal conditions are the same. The fluorescein fit, however, will appear different depending on the condition
The ideal fit will have
  • A fluorescein pattern as close to alignment as possible
  • A light feather touch at the apex of the steepened area
  • 0.5 to 1mm of movement
Trial lens selection

Manual keratometer fitting:

  • The first trial lens has a base curve closest to 0.2mm flatter than the median K reading

Topography Fitting:

  • Start with a trial lens that is close to the measurement at the temporal 4-5mm position 
  • This allows one edge quadrant to be made flatter or steeper than the others. This will help combat edge stand-off which is usually found at 270º due to inferior steepening
  • Order one peripheral curve (PC) at 90º and another at 270º. Prism ballast to minimise rotation. i.e. standard P.C at 90º and 2 steps steep at 270º with 1.25D prism at 270º
  • 3 & 9 o/c staining can be corrected by adding toric peripheral curves
  • The appearance of a classic dumbbell pattern would indicate the need for a base toric or bi-toric addition