What To Use When…. Ken Kopp FCLSA Paragon Vision Sciences. Paragon CRT CRT Dual Axis. All are laser marked. RG-4. (Domestic only). Paragon CRT. Patented design using Proximity Control Technology Certification necessary/up to -6.00 with up to -1.75 D of astig.
Ken Kopp FCLSA
Paragon Vision Sciences
All are laser marked
The CRT DDS should be the “go-to” tool for all reshaping candidates. It will be the design of choice to trial for proper centration, tear patterns, and correct BC selection.
The pre-treatment data is a “clue” as to what option choices you may need.
Flat K and Spherical Manifest
Options – RG-4 or CRT
Options – CRT or CRT Dual Axis depending on elevation differences
CRT Dual Axis
Apical / Incomplete
CRT or RG-4
Refractive vs. Corneal Astigmatism
CRT – 10.0 to 12.0mm, CRT DA – 10.5 & 11.0 mm, RG-4 = 10.0 to 12.4
Fissure and Pupil Size
CRT/CRT DA/RG-4 have fixed 6 mm OZ
CRT – Spherical
proper positioning or edge lift appearance
If the spherical CRT trial shows an incomplete “bulls eye” pattern or does not center properly…consider CRT Dual Axis
CRT Dual Axis
Dual Axis CRT
appearance – 2 degree maximum
Without DDS trial option
* SureFit has limited parameter specifications and only available in the US
The decision to choose a specific design is best derived from;
If the CRT Trial lens does not display proper centration or incomplete “bull’s eye” pattern;
Can either the CRT, Dual Axis , or the RG-4 lens be the initial lens choice and ordered empirically?
If you are not sure…contact your authorized Paragon CRT laboratory
Send email to;
Your authorized CRT laboratory or firstname.lastname@example.org