Paragon CRT Dual Axis
®
Quick Reference Guide
Page 1: ...Paragon CRT Dual Axis Quick Reference Guide ...
Page 2: ... force in the steep meridian and results in poor centration lens flexure and or undertreatment An example of an elevation map with elevation values at 4 mm from reference center in each meridian is shown in Image C A common rule in contact lens fitting holds that spherical lenses will always move freely along the steep meridian and exhibit restricted movement along the flat meridian The clinician ...
Page 3: ...orrect untreated or residual power Using this standard CRT lens example BC 8 7 RZD 550 LZA 33 The possible parameter alternatives for the Dual Axis product are 1 The RZD could have a second value and the LZA would remain a single parameter 8 7 550 600 33 2 The LZA could have a second value and the RZD remains a single parameter 8 7 550 33 34 3 The RZD and LZA could both have second values 8 7 550 ...
Page 4: ...ence of significant elevation difference BLUE vs RED in the periphery of the plot 2 Place the cursor on the shallow area BLUE in color 4 mm from the center of the plot and record the number of microns below the reference sphere 3 Repeat the measure 180 degrees away in the shallow area opposite to the first measurement 4 Place the cursor on the elevated area RED in color 4 mm from the center of the...
Page 5: ... RZD 90 degrees apart is offered to compensate for differences in peripheral corneal elevation The recommended method of fitting is to continue the use of the RZD suggested by the Initial Lens Selector ex 550 and observed to provide the recommended fluorescein pattern Image C This RZD continues to be recommended for the flat meridian with the respective higher peripheral elevation An RZD increase ...
Page 6: ...where there is excessive edge clearance A difference of one degree in the second meridian will be clinically significant and a difference of two degrees may be needed when there is a marked difference in the edge clearance observed in the fluorescein pattern If the Average Meridional Elevation difference is Use This RZD in the Elevated Red Meridian RZD suggested by CRT Lens Selector 550 Increased ...
Page 7: ...0 550 600 33 34 4 Over refract for the appropriate BCR and order the final Paragon CRT Dual Axis lens It is of critical importance that the desired meridian is identified relative to the shallow and deep RZD meridians In some cases you may need to deepen the LZA in the same meridian that is already made deeper by the RZD increase Prescribing Paragon CRT Dual Axis Lenses in the Absence of Topograph...
Page 8: ...r flexure is eliminated lens centration is improved circumferential landing is observed and the targeted treatment is achieved For additional information on Paragon CRT Dual Axis please call your Authorized CRT Laboratory Consultant or Paragon Consultation at 800 528 8279 option 2 ZQF100013E 11 17 1 Anderson D Map out Your Lens Fitting Optom Manag 2008 Oct 43 10 26 30 2 Anderson D Kojima R Underst...
