Clinical Investigation of the CHEETAH SYSTEM FOR THE CORRECTION OF MYOPIA WITH AND WITHOUT ASTIGMATISM
Myopia, Astigmatism
About this trial
This is an interventional treatment trial for Myopia
Eligibility Criteria
Inclusion Criteria:
Note: All criteria apply to each Cheetah treated eye
- Age ≥18 years old at the time of consenting.
Subjects with refractive error within the following ranges:
- Phase I: Partially sighted eyes (as defined below)
- Phase II: Refractive error range in the Cheetah-treated eye/s between -2.00 D to -6.00 D and astigmatism up to -1.00 D based on manifest refraction at optical infinity. If cyclotorsion correction after docking is available, astigmatism greater than -1. 00 D can be included, provided that spherical equivalent (SE) is up to -6.00 D.
- Phase III: Myopic refractive error in the study eye up to -12.00 D spherical equivalent (SE) and astigmatism up to - 6.00 D based on manifest refraction at optical infinity.
- Anticipated residual corneal stromal thickness of at least 250 microns based on preoperative corneal pachymetry minus maximum lenticule thickness to be extracted.
- Uncorrected visual acuity of 20/40 or worse in Phase II and III subjects.
- Distance Best Spectacle Corrected Visual Acuity (BSCVA) of 20/20 or better for phase II and III subjects. For phase I subjects, BSCVA and pin-hole acuity of the iLEX treated eye is worse than 20/50, with at least a 2-line difference between the iLEX treated eye and the fellow eye.
Note: Potential phase I subjects to be evaluated on a case-by-case basis for interocular difference in visual acuity and enrollment to be confirmed through Medical Monitor and PI consensus.
- BSCVA ≥2 lines better than distance Uncorrected Visual Acuity (UCVA). Not applicable for phase I subjects.
- Less than or equal to 0.75 D difference between cycloplegic and manifest refraction sphere. Not applicable for phase I subjects.
- A stable refractive error (based on a previous exam, medical records, lensometry, or prescription at least 12 months prior to the preoperative manifest refraction), as defined by a change of ≤1.00 D in MRSE. Additionally, the astigmatic axis must also be within 15 degrees for eyes with >0.50 D of preoperative and historical manifest cylinder.
Any subject eye with a history of contact lens wear within the last 4 weeks must demonstrate refractive stability according to the following:
- Rigid contact lenses (toric or spherical) must be removed for at least 4 weeks and soft contact lenses (toric or spherical) for at least 2 weeks prior to the first refraction used to establish stability.
- Two consecutive manifest refractions and keratometry readings must be conducted at least 7 days apart.
- Refractive stability is defined as a change of not more than 0.50 D in manifest refractive sphere and cylinder as well as keratometry meridian (either axis) between measurements. If the subject/eye meets the refractive stability criteria, contact lens wear is not permitted prior to surgery, as specified above for rigid and soft contact lens wearers.
- Willing and capable of complying with follow-up examinations for the duration of the study.
- Signed informed consent or equivalent documentation necessary to comply with applicable privacy laws pertaining to medical treatment.
Exclusion Criteria:
Note: All criteria apply to each eye
- Concurrent use of systemic (including inhaled) medications that may impair healing, including but not limited to: antimetabolites, isotretinoin (Accutane®) within 6 months of treatment, and amiodarone hydrochloride (Cordarone®) within 12 months of treatment. NOTE: The use of inhaled or systemic corticosteroids, whether chronic or acute, is deemed to adversely affect healing and subjects using such medications are specifically excluded from eligibility. History of any of the following medical conditions, or any other condition that could affect wound healing: collagen vascular disease, autoimmune disease, immunodeficiency diseases, ocular herpes zoster or herpes simplex, endocrine disorders (including, but not limited to unstable thyroid disorders), lupus, and rheumatoid arthritis.
- Subjects with history of Diabetes Mellitus of 12 years or more and HbA1c measurement greater than 7% within a month prior to treatment.
- Subjects with a cardiac pacemaker, implanted defibrillator or other implanted electronic device.
- History of prior intraocular or corneal surgery (including cataract extraction), active ophthalmic disease or abnormality (including, but not limited to, symptomatic blepharitis, recurrent corneal erosion, history or evidence of corneal ulcer (including but not limited to presence of visible corneal scar, abnormal topography is NOT necessary), clinically significant dry eye syndrome, neovascularization > 1 mm from limbus), retinal detachment/repair, clinically significant lens opacity, clinical evidence of trauma, corneal opacity within the central 9 mm and visible on topography. Note: For phase I subjects (partially sighted eyes), history of intraocular surgery (including cataract extraction), retinal detachment/repair, and clinically significant lens opacity is acceptable for inclusion in the study.
- Evidence of glaucoma regardless of medication regimen or control, an IOP greater than 21 mmHg at screening or propensity for narrow angle glaucoma.
- NOTE: Phase I subjects with end-stage glaucoma and completely extinguished visual field are eligible to participate in the study.
- Evidence of keratoconus, pellucid marginal degeneration, corneal dystrophy or irregularity, unstable (distorted/not clear) corneal mires on central keratometry images, corneal edema, corneal lesion, hypotony, or abnormal topography. Corneal thickness less than 470 microns at the thinnest point
- Known sensitivity or inappropriate responsiveness to any of the medications used in the postoperative course.
- Either eye does not meet all inclusion criteria and does not fall within approved indications for treatment using femtosecond or excimer Laser. Not applicable for phase I subjects.
- Desire for monovision correction. Not applicable for phase I subjects.
- Women who are pregnant, breast-feeding, or intend to become pregnant during the study.
- Participation in any other clinical study.
Sites / Locations
- Svjetlost Eye ClinicRecruiting
- Narayana Nethralaya Eye HospitalRecruiting
- Centre For SightRecruiting
- Centro Oculistico Bresciano
- Singapore Eye Research InstituteRecruiting
- Tan Tock Seng Hospital PTE. LTD.
Arms of the Study
Arm 1
Experimental
Cheetah System
For each subject, surgeons will create an iLEX refractive correction using the investigational Cheetah femtosecond laser and Cheetah patient interface (regular or small diameter designs) on one eye (phase I) and one/both eyes based on refractive correction needs (phases II and III).