Skip to content

Efficacy and Safety of CLEAR in Myopia and Astigmatism in Chinese Population

A Multicentre, Prospective, Single-arm Clinical Trial to Evaluate Efficacy and Safety of Femtosecond Laser Corneal Lenticule Extraction for Advanced Refractive Correction (CLEAR) in Myopia and Astigmatism in Chinese Population

Status
UNKNOWN
Phases
NA
Study type
Interventional
Source
ClinicalTrials.gov
Registry ID
NCT05229133
Enrollment
215
Registered
2022-02-08
Start date
2021-11-29
Completion date
2023-03-01
Last updated
2022-02-08

For informational purposes only — not medical advice. Sourced from public registries and may not reflect the latest updates. Terms

Conditions

Myopic Astigmatism

Keywords

CLEAR, Ziemer, FEMTO LDV, Lenticule, Myopic astigmatism

Brief summary

In this multicenter, prospective, interventional, single-arm clinical trial, the aim is to determine safety and efficacy of CLEAR using the FEMTO LDV Z8 in Chinese patients in China. The primary objective is to evaluate the visual outcome after CLEAR using the FEMTO LDV Z8 in myopia and astigmatic myopia at the time point, when stability of manifest refraction spherical equivalent (MRSE) is reached. The corresponding hypothesis is that the percentage of treated eyes with satisfactory Uncorrected Distance Visual Acuity (UCDVA) at the point when stability of MRSE is reached after CLEAR is at least 85% of all treated eyes. This hypothesis has been chosen in line with the recommendations of the Checklist of Information Usually Submitted in an Investigational Device Exemptions (IDE) Application for Refractive Surgery Lasers issued by the FDA. The secondary objectives are to evaluate the efficacy and safety with respect to stability, predictability, device defects and adverse events of CLEAR using the FEMTO LDV Z8 in myopia and astigmatic myopia during follow-up.

Interventions

DEVICECLEAR

FEMTO LDV Z8 Surgical Laser is intended for use in Corneal Lenticule Extraction for Advanced Refractive correction (CLEAR), also called Curved Lamellar Resection (CLR), for the reduction or elimination of myopia from -0.50 D to -10.00 D, with astigmatism of 0 D to -5.00 D or without astigmatism, and MRSE of -0.50 D to -12.50 D in the eye to be treated in patients who are 18 years of age or older with documentation of stable manifest refraction over the past year as demonstrated by a change in sphere and cylinder of ≤ 0.50 D in magnitude.

Sponsors

Tigermed Consulting Co., Ltd
CollaboratorINDUSTRY
Ziemer Ophthalmic Systems AG
Lead SponsorINDUSTRY

Study design

Allocation
NA
Intervention model
SINGLE_GROUP
Primary purpose
TREATMENT
Masking
NONE

Eligibility

Sex/Gender
ALL
Age
18 Years to No maximum
Healthy volunteers
No

Inclusion criteria

1. Medically suitable for corneal refractive surgery 2. Signed informed consent form 3. Age ≥ 18 years 4. Pre-operative BCVA ≥ 5.0 (corresponding to 20/20 as per Snellen chart lines) 5. Myopia sphere from -0.5 D to -10.00 D 6. Maximum cylinder diopter of -5.00 D 7. Maximum resulting MRSE of -12.5 D 8. Calculated residual stromal thickness ≥ 250 microns 9. Non-contact IOP \< 21mmHg 10. Stable refraction for the past year, as demonstrated by a change in manifest refraction spherical equivalent (MRSE) of ≤ 0.50 D 11. A difference between cycloplegic refraction spherical equivalent and MRSE \< 0.75 D. 12. For contact lens wearers (where applicable) after pre-operative stop of contact lens wear: Stable refraction (within ±0.5 D), as determined by MRSE, on two consecutive examinations at least 1 week apart. 13. Patient willing and able to return to the study site for the follow-up visits, in the judgement of the investigator.

Exclusion criteria

1. Wearing of contact lenses pre-operatively i) soft contact lenses: \<2 weeks before Visit 1 OR from Visit 1 till the day of surgery ii) hard contact lenses: \<1 month before Visit 1 OR from Visit 1 till the day of surgery iii) therapeutic contact lenses (such as Ortho-K): \<3 months before Visit 1 OR from Visit 1 till the day of surgery 2. Corneal disease or pathology, such as corneal scaring or opacity, that precludes transmission of laser wavelength or that distorts laser light 3. Residual, recurrent, or active ocular disease or corneal abnormality (including, but not limited to ocular herpes zoster or simplex, active infections and inflammation) 4. History of ocular herpes simplex or herpes zoster keratitis 5. 3 months before the inclusion have taken systemic medication likely to negatively affect wound healing, such as glucocorticosteroide or antimetabolites 6. Severe dry eye 7. Glaucoma 8. Nystagmus or hemofacial spasm preventing placement of the patient interface 9. Previous corneal surgery of any kind, including any type of surgery for either refractive or therapeutic purposes 10. Unstable central keratometry readings 11. Mesopic pupil diameter \> 8.0 mm 12. Keratometry readings via Sim-K values less than 40.00 D 13. Allergy to medications required in surgery, pre- and post-operative treatment 14. Keratoconus or keratectasia, including patients with suspicion of keratoconus on corneal topography 15. At the time of inclusion, participation in other medical device clinical trials within one month or in drug clinical trials within 3 months 16. Diagnosis of autoimmune disease, connective tissue disease, clinically significant atopic disease, diabetes or AIDS and other acute or chronic illnesses that increases the risk to the subject or confounds the outcomes of this study in the opinion of the study principal investigator 17. Known psychotic disorders associated with delusions (e.g. schizophrenia) 18. Woman who is pregnant or nursing

Design outcomes

Primary

MeasureTime frameDescription
UCDVA (with cycloplegia)Pre-operativeThe primary outcome is the percentage of eyes that achieve satisfactory Uncorrected Distance Visual Acuity (UCDVA) after CLEAR using the FEMTO LDV Z8, at the time point, when stability of MRSE is reached. Satisfactory UCDVA is defined as 20/40, or better, as per Snellen chart lines.
UCDVA (without cycloplegia)Pre-operativeThe primary outcome is the percentage of eyes that achieve satisfactory Uncorrected Distance Visual Acuity (UCDVA) after CLEAR using the FEMTO LDV Z8, at the time point, when stability of MRSE is reached. Satisfactory UCDVA is defined as 20/40, or better, as per Snellen chart lines.
UCDVAday 1The primary outcome is the percentage of eyes that achieve satisfactory Uncorrected Distance Visual Acuity (UCDVA) after CLEAR using the FEMTO LDV Z8, at the time point, when stability of MRSE is reached. Satisfactory UCDVA is defined as 20/40, or better, as per Snellen chart lines.

Secondary

MeasureTime frameDescription
Stability of MRCYLAssessed at 3 months, 6 months, 9 months and 12 months post surgery.The stability of the manifest refractive cylinder (MRCYL) will be evaluated for the whole set of eyes treated for astigmatic myopia. The following statistics for the change in the MRCYL between two consecutive post-operative follow-up visits will be recorded: • percentage of eyes with a change in MRCYL within ±1.0 D and ±0.5 D Stability analyses will be performed on the eyes that had every follow-up exam from 1- month up to the stability time point (the Consistent Cohort), as well as on the eyes that had 2 consecutive post-op exams, but not necessarily every follow-up exam
Predictability of MRCYLUp to 12 monthsPercentage of eyes achieving MRCYL within ± 1.00 D of the intended outcome, and within ± 0.50 D of the intended outcome at the point at which stability of MRSE is achieved.
Vector analysis (IRC)Pre-operativeIntended Refractive Correction Vector (IRC) IRC = Preoperative cylinder - Target (attempted) cylinder
Vector analysis (SIRC)Assessed at 3 months, 6 months, 9 months and 12 months post surgery.Assessment of change in the Surgically Induced Refractive Correction Vector (SIRC) during follow up; assessed until the MRSE stability is reached. SIRC = Preoperative cylinder - Postoperative cylinder
Vector analysis (EV)Assessed at 3 months, 6 months, 9 months and 12 months post surgery.Assessment of change in the Error Vector during follow up; assessed until the MRSE stability is reached. Error Vector (EV) EV = IRC - SIRC
Stability of MRSEAssessed at 3 months, 6 months, 9 months and 12 months post surgery.The percentage of eyes with: * a change of less than or equal to 1.00 D of MRSE between two refractions * a change of less than or equal to 0.50 D of MRSE between two refractions will be reported for the corresponding time period.
Vector analysis (ER)Assessed at 3 months, 6 months, 9 months and 12 months post surgery.Assessment of change in the Error Ratio during follow up; assessed until the MRSE stability is reached. Error Ratio (ER) ER = magnitude of EV/ magnitude of IRC
Safety IndexUp to 12 monthsSafety Index defined as CDVA at the time point, when the stability of MRSE is reached, divided by CDVA at baseline (CDVA VX / CDVA V1).
Number of Adverse Events observed in the studyUp to 12 months.Complications, including all related (Serious) Adverse Events, during surgery day and follow-up.
Number of Device defects observed in the studyUp to 12 monthsNumber of device defects observed during the clinical trial.
Vector analysis (CR)Assessed at 3 months, 6 months, 9 months and 12 months post surgery.Assessment of change in the Correction Rate during follow up; assessed until the MRSE stability is reached. Correction Ratio (CR) CR = magnitude of SIRC / magnitude of IRC
Predictability of MRSEUp to 12 monthsPercentage of eyes achieving MRSE within ± 1.00 D and within ± 0.50 D of the intended outcome at the point at which MRSE stability is achieved.
Efficacy IndexUp to 12 monthsEfficacy Index is defined as UCDVA at the time point, when stability of MRSE is reached, divided by CDVA at baseline: (UCDVA VX /CDVA V1). Note: X corresponds to the visit, when stability of MRSE will have been reached. The Efficacy Index being above the efficacy cut-off level 0.8 indicates loss of less than two lines of UCDVA

Countries

China

Contacts

Primary ContactOlga Grossenbacher, MD, PhD
olga.grossenbacher@ziemergroup.com+41 79 671 67 25

Outcome results

None listed

Source: ClinicalTrials.gov · Data processed: Feb 4, 2026