Guideline For Clinical Trial Of Orthokeratology Rigid Gas Permeable (RGP) Contact Lenses
2021-06-22
Scope This document describes the requirements of the regulations and rules for full pre-marketing clinical trials. This document applies only to clinical trials for Rigid Gas Permeable Contact Lens products that use a re-shaping method to alter the corneal topography to achieve a temporary correction of refractive error. The pre-marketing clinical trial plan for Orthokeratology lens products must demonstrate characteristics based on the claims of the declared product. Generally, the characteristics of the trial should not be lower than the requirements of this guidance.
Principles The applicant shall design, implement, monitor, record and summarize the clinical test results in accordance with the relevant requirements of the Quality Management Standards for Clinical Trials of Medical Devices, and ensure that the clinical trial process is standardized, and the results are true, scientific, reliable and traceable.
Clinical Trial Plan 3.1 Clinical trial objectives and precautions Clinical trial of Orthokeratology products is designed to evaluate whether the declared product has the expected safety and effectiveness. The LogMAR visual acuity chart (also known as the EDTRS eye chart) is recommended for the clinical trial, but a standard logarithmic visual acuity chart can also be used. Visual acuity measurements should be checked using standard methods. For multi-center clinical trials, the visual acuity methods used in different clinical trial sites must be consistent. If refractive error is one of the testing criteria, the subjects’ subjective refractive measurements (including degree of sphere and degree of cylinder) should be the endpoint; the objective optometry values (including degree of sphere and degree of cylinder) should be considered as reference only. 3.2 Clinical trial design The design of the clinical trial for Orthokeratology (Ortho-K) should be a prospective, randomized and have a control arm. Clinical trials should be conducted in two or more clinical trial centers. If the clinical trials are conducted by following the same clinical trial
protocol in three or more sites, this would be considered a multi-center trial. The medical device which is selected as the control device should be a similar product, and have been approved for listing in China. The functionality and wearing schedule should be the same as test product. Historical control or non-parallel control is not recommended. 3.3 Sample size of clinical trials Major evaluation indicators: 30 days of product efficiency. Effective definition: “effective” when both uncorrected visual acuity (UCVA) and refractive error should meet the following requirements: a. UCVA: The uncorrected visual acuity should be greater than or equal to 0.8. b. Residual diopter: The residual refractive error should be 0.00D ±0.50D The test hypothesis should be created, and the sample size should be calculated based on the evidence-based medical related data of the corresponding indicators of the Ortho-K product. Determination of the sample size is related to the type of hypothesis test selected (superior, non-inferiority, equivalence test) and type I and II errors, as well as clinically significant cut-off values (poor efficacy). The exclusion and the number of subjects lost to follow-up should also be considered while determining sample size. The clinical trial sample size should be determined in accordance with the purpose and statistical requirements of the clinical trial, and the subjects who completed all visits should not be less than the minimum sample size specified in this guidance. Currently, the keratoconus randomized controlled trial is a clinical trial of 1:1 with no less than 100 subjects in each arm fitted bilatereally (200 subjects total) with the control and test product. Both subjects are required to be enrolled in both eyes, and both eyes must be included into statistical analysis. Monocular patients are not recommended for enrollment. 3.4 Clinical trial follow-up time Currently the follow-up visit schedules for clinical trials of different contact lenses is not completely consistent. The determination of follow-up visit should be supported by literatures and should be based on medical consensus. Currently, the follow-up period is up to 12-month. At the same time, the interval of visit schedule should be set as 1 day, 1 week, 2 weeks, 30 days, 3 months, 6 months, 9 months, 12 months after wearing the lenses.
