Practitioner's Guide of EE-CONUS Lens for Keratoconus
Following these simple fitting procedures, we estimate that you can successfully fit 95% of your keratoconus patients with EE-Conus.
Step 1... Start the trial lens base curve 0.2mm steeper than mean K. e g. K = 7.10/7.35mm, mean K 7.25, choose base curve = 7.00 or 7.10 lens to try.
Step 2... You are advised to use corneal anesthetics on trial fitting, even when the patient is a long-time contact lens wearer. Anesthetics reduce tearing time and thus reduce chair time.
Step 3... Too much flouroscein will give false patterns - so be careful when instilling it.
Step 4... Trial fit for the base curve - but don’t worry about the periphery at first, A light touch at the apex of the cone is desirable. The lens is too steep if you can not discern where the apex of the cone is. The rest of the pattern should look as close to an alignment fit as possible.
Step 5... Next consider the peripheral fit. The trial lenses have a standard edge lift, but an increased or decreased edge lift on the same base curve can be ordered. If the central base curve looks good but you have inadequate peripheral edge lift, then order increased lift. Conversely, order decreased lift if there is excessive peripheral edge lift.
Step 6... The standard diameter is 9.0mm but any diameter is available. Smaller diameters of 8.0 to 8.3 work well on very steep corneas. A larger diameter will tend to make the lens ride higher.
Step 7... Do a careful over-refraction using 1.00 D steps initially and refine with 0.50 and 0.25 steps. Be sure the final over-refraction is performed in a well-lit room to approximate normal light conditions and pupil size.
EE-Conus lens Trial set parameter