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General |
Study Status |
Completed |
Application Number / Requirement Number |
P040029 / PAS001 |
Date Original Protocol Accepted |
09/29/2004
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Date Current Protocol Accepted |
09/29/2004
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Study Name |
JSZ Orthokeratology Contact Lenses
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Device Name |
Euclid Orthokeratology (oprifocon A) Contact Lenses for Overnight Wear and Euclid Orthokeratology (tisilfocon A) Contact Lenses for Overnight Wear
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General Study Protocol Parameters |
Study Design |
Prospective Cohort Study
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Data Source |
New Data Collection
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Comparison Group |
No Control
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Analysis Type |
Descriptive
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Detailed Study Protocol Parameters |
Study Objectives |
Prospective Cohort-Study. The study was to evaluate the stability of the treatment post lens removal by analysis of measures such as uncorrected visual acuity, refraction and corneal changes for 150 subjects that have attained a predefined level of refractive stability within a 3 month period. The post approval study was to monitor regression toward pretreatment levels during a one week period following lens removal.
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Study Population |
The device is indicated for use in the reduction of myopic refractive error in non-diseased eyes. The lenses are indicated for overnight wear for the temporary reduction of myopia up to 5.00 diopters with eyes having astigmatism up to 1.50 diopters. The lenses may only be disinfected using a chemical disinfection system. The PAS was to include patients with documented stability of refraction for the prior 6 months, as demonstrated by spherical equivalent change of less than or equal to 0.50 diopters.
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Sample Size |
150 subjects
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Key Study Endpoints |
Data collection included: stability of the treatment post lens removal by analysis of measures such as uncorrected visual acuity, refraction and corneal changes, regression toward pretreatment levels during a one week period following lens removal.
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Follow-up Visits and Length of Follow-up |
3-months
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Interim or Final Data Summary |
Interim Results |
Study was not conducted because device was not marketed in the US
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Actual Number of Patients Enrolled |
138
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Actual Number of Sites Enrolled |
9
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Patient Follow-up Rate |
70%
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Final Safety Findings |
[Note: This Post-Approval Study Requirement was fulfilled using data from a post-approval study that was conducted for a similar device approved under a different PMA (P010062). This was considered appropriate because both devices use same design/materials and are approved for the same indication of use.]
There were no adverse events related to the study product. Three eyes reported to have a grade 3 slit lamp finding during the Treatment Phase (2 eyes completed, 1 eye discontinued) and no reports of a grade 4 slit lamp finding during the Treatment Phase.
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Final Effect Findings |
At the initial diagnostic visit, none (0%) of the eyes achieving stability had uncorrected visual acuity (UCVA) of 20/20 or better and only 12 eyes (6.5%) had UCVA of 20/40 or better. By the end of the Treatment Phase, 3-Month Visit, most eyes that achieved stability had an MRSE that was between - 1.00D and +1.00D (177 eyes/ 96.2%). The refractive change from pretreatment resulted in excellent uncorrected distance visual acuity where 144 eyes (78.2%) had UCVA of 20/20 or better and 184 eyes (100%) had UCVA of 20/40 or better. Following lens removal, the stability of the vision was good during the day. At the 5-Hour Visit in the Regression Phase, there were 141 eyes (76.6%) that had UCVA of 20/20 or better and 182 eyes (98.9%) with 20/40 or better. While the MRSE regressed toward the pretreatment MRSE as the Regression Phase continued, there were still 121eyes (66.5%) with UCVA of 20/40 or better at the 24-Hour visit and 52 eyes (28.6%) were 20/20 or better.
Although the there was no study requirement for eyes that achieved stability to be followed until complete return to pretreatment status, 128 of 184 eyes (69.6%) had regressed within ± 0.50D of pretreatment MRSE and 172 of 184 eyes (93.5%) had regressed within ± 1.00D of pretreatment MRSE by the 1-Week Regression Phase Visit. The BSCVA comparison of pretreatment to the final Regression Phase demonstrated that 177 eyes (97.8%) had no change (96.7%) or improved a line (1.1%) from the pretreatment BSCVA. The results demonstrated that subject¿s eyes were able to return to pretreatment values.
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Study Strengths & Weaknesses |
A strength of this study was the large sample size, which was enough to properly evaluate the safety of this device. However, lack of a control group limits interpretation of study results because findings could be due to factors related or unrelated to the device. The follow up rate was only 70%, increasing the likelihood for biased results as usually subjects that remain on the study may differ from those that are lost to follow-up.
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Recommendations for Labeling Changes |
It is recommended that the label be updated to reflect the long-term results. The post-approval study design, methods, safety and effectiveness results should be included in the labeling from both phases (i.e., treatment and regression phases).
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