efficacy and safety of clear in myopia and astigmatism in chinese population

Conditions: Myopic Astigmatism

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.


Eligibility criteria:
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

Keywords: clear ziemer femto ldv lenticule myopic astigmatism