| |
Paragon CRT®
Technology White Paper
The Paragon
CRT System for Corneal Refractive Therapy is an FDA
approved, scientifically designed and precision manufactured nighttime
contact lens corneal reshaping system.
|
|
|
FDA approval
includes patient candidates with up to -6.00D sphere and -1.75D
cylinder. There is no age restriction.
Corneal Refractive
Therapy is safe, effective, predictable and reversible.
|
 |
|
|
|
|
|
| Highlights
of Clinical Study |
|
|
|
|
|
|
In January of
2002, the FDA Ophthalmic Device Panel, a public advisory committee
of the Food and Drug Administration, by unanimous vote, recommended
approval of Paragon CRT for overnight contact lens corneal reshaping.
This recommendation was based on the results of the most extensive
overnight contact lens corneal reshaping study undertaken to date.
Some key findings from the Paragon commissioned study follow.
The study involved
11 investigational sites and 205 patients ages 12 and above. The
study involved overnight lens wear only and patient follow-up was
for nine months. Over 93% of the study participants were soft contact
lens wearers or non-contact wearers. Some key demographic data is
shown:
|
|
 |
|
|
|
|
|
|
|
|
|
Patients
in the Overnight Study achieved the following results: |
|
|
|
|
|
|
|
67.4%
with 20/20 or better**
93.3% with 20/32 or better
|
 |
|
|
|
|
|
|
|
This scatter
gram of data illustrates
attempted vs. achieved vision correction
and the accuracy of Corneal Refractive
Therapy with Paragon CRT
(visual results
based on binocular vision
estimated fromacuity in betterseeing
eye).The diagonalmidline is the targeted
Rx and the diagonal lines aboveand
below are one diopter ranges.
|
|
|
|
As
part of the FDA study, patients completed a vision satisfaction questionnaire
rating their vision before and after treatment with Paragon CRT lenses
for Corneal Refractive Therapy. The results were as follows: 91.7%
of post-treatment patients rated their unaided vision as, good, very
good or excellent compared to a rating of 91.3% for their pre-treatment
habitual correction. |
|
|
|
|
|
|
|
Unique,
Patent-pending Design |
|
|
The
Paragon CRT design (Fig.1)
consists of a central 6mm Treatment
Zone, a 1mm wide Return Zone of
variable depth, a non-curve Landing Zone
available in 1 degree angle steps (Fig.2)
and an ellipse edge profile. Paragon CRT
is manufactured with the most
sophisticated, computerized equipment
available to 5-micron surface
smoothness tolerances. This provides for
a seamless, junctionless surface that
eliminates the need for variability
inducing polishing. Lenses are LASER
marked for parameter verification. |
 |
|
|
|
|
|
|
|
An
important feature of the Paragon
CRT design is the plano curve Landing
Zone. Since the Landing Zone can only
be tangent to the cornea, the potential
for impingement on the peripheral
cornea, which may occur at the
junctions in traditional reverse
geometry contact lens designs, is
virtually eliminated. |
 |
|
|
|
|
|
|
|
Paragon
CRT achieves precise and effective treatment through patent-pending
Proximity Control Technology™. In the Paragon CRT design, sigmoid
mathematics describes the curve that "returns" the lens
to the peripheral cornea as the flatter base curve or "treatment
zone" leaves the corneal plane.
The depth of
this Return Zone is a variable in the lens design available in 25-micron
increments, assuring predictable and precise application of the
desired treatment through accurate sagittal depth management.
|
|
|
|
|
|
|
|
 |
|
|
|
|
|
|
|
Paragon
CRT lenses are fabricated in Paragon HDS® 100 (paflufocon D),
a super high Dk material, cleared by the FDA for up to seven days
extended wear and having an ISO/ANSI rating of 100 Dk. **
Paragon CRT
Dispensing System
Paragon CRT
for Corneal Refractive Therapy is prescribed through a Diagnostic
Dispensing System utilizing routine clinical data: patient refraction,
corneal measurement and fluorescein pattern evaluation.
The Paragon
CRT Diagnostic Dispensing System includes 100 lenses with a range
of Base Curves, Return Zone Depths and Landing Zone Angles carefully
selected based on outcomes analysis of successful patient data.
Practitioners can expect to successfully dispense and begin immediate
treatment on four out of five patients directly from their 100-lens
diagnostic dispensing inventory.
Corneal Refractive
Therapy patient management is topography driven. Baseline corneal
information, support for initial diagnostic lens selection and effective
patient follow-up are best achieved with corneal topography. Topography-based
prescribing software is available exclusively for the Humphrey®
ATLAS™ Topography system from Humphrey Division, Carl Zeiss
Meditec†, Paragon's topography system of choice.
|
|
|
|
|
|
|
|
Paragon
exclusively recommends the following care regimen for Paragon CRT:
Alcon® Unique-pH™ Multi-Purpose Solution, SupraClens®,
and Clerz® Plus.† |
 |
|
|
|
|
|
|
|
Paragon
CRT Standard Parameters |
|
|
|
|
|
|
|
|
|
|
Paragon
CRT Specialty Range Parameters |
|
|
|
|
|
|
|
|
|
