Correcting refractive error with SMILE
试验速览
- 阶段
- 1/2 期
- 状态
- 尚未招募
- 入组人数
- 100
- 试验地点
- 1
- 主要终点
- Uncorrected and corrected distance visual acuity
研究概览
简要总结
SMILE (small incision lenticule extraction) is a commonly used technique for correction of refractive error. It involves making a small incision in the peripheral cornea followed by cutting a lenticule in the stroma. Both the incision and lenticule are cut with a femtosecond laser. Since its introduction, SMILE has received both CE and FDA approval. There are several studies which demonstrate the clinical safety and efficacy of SMILE [1-4]. Further, SMILE may be associated with less dryness, pain and faster wound healing compared to LASIK (laser assisted in situ keratomileusis) and PRK (photorefractive keratectomy) [1-4].
References
1. Kobashi H, Kamiya K, Shimizu K. Dry Eye After Small Incision Lenticule Extraction and Femtosecond Laser-Assisted LASIK: Meta-Analysis. Cornea. 2017 Jan;36(1):85-91.
2. Liu YC, Teo EP, Lwin NC, Yam GH, Mehta JS. Early Corneal Wound Healing and Inflammatory Responses After SMILE: Comparison of the Effects of Different Refractive Corrections and Surgical Experiences. J Refract Surg. 2016 May 1;32(5):346-53.
3. Zhang Y, Shen Q, Jia Y, Zhou D, Zhou J. Clinical Outcomes of SMILE and FS-LASIK Used to Treat Myopia: A Meta-analysis. J Refract Surg. 2016 Apr;32(4):256-65.
4. Blum M, Täubig K, Gruhn C, Sekundo W, Kunert KS. Five-year results of Small Incision Lenticule Extraction (ReLEx SMILE). Br J Ophthalmol. 2016 Sep;100(9):1192-5.
We propose to conduct the following studies:
1) In a small cohort of 20 patients with myopic refractive error, SMILE with the Schwind Laser (Titan) will be performed (n=40 eyes maximum or 20 patients). The efficacy parameter will be percentage of patients’ with manifest refractive error of ±0.25D of targeted refraction at 3 month follow-up. The preoperative refractive error would be limited to -3D spherical and 2D cylindrical error. If at least 80% efficacy is obtained, then the study will be expanded.
2) The study then will be expanded to include 80 additional patients. SMILE with the Schwind laser (n=80 patients or 160 eyes maximum) will be performed. The main efficacy parameter will be percentage of patients’ with manifest refractive error of ±0.5D of targeted refraction at 3 month follow-up. The preoperative refractive error would be limited to -8D spherical and -5D cylindrical error.
Preoperative and postoperative examination will include:
1) Cycloplegic refraction
2) Visual Acuity – uncorrected and corrected distance visual acuity under mesopic conditions
3) Corneal tomography – Measured with Pentacam (OCULUS Optikegerate Gmbh, Germany)
4) Optical Coherence Tomography - Measured with RTVue (Optovue Inc, USA) to map epithelium thickness and curvature of the Bowman’s layer
5) Aberrometry and contrast sensitivity- Measured with Visual Adaptive Optics simulator (Voptica Inc, Spain)·
6) Corneal endothelial examination with specular microscopy
7) Dry eye assessment
If target refraction is not attained in any of the procedures, a retreatment will be done. Measurements will be performed at preoperative, week 1, month 1, month 3 and month 6. Study enrollment should take around 6 months.
研究设计
- 研究类型
- Interventional
- 分配方式
- Computer generated randomization
- 盲法
- Not Applicable
入排标准
- 年龄范围
- 18.00 Year(s) 至 60.00 Year(s)（—）
- 性别
- All
入选标准
- •Subjects 18 years of age or older.
- •Able to comprehend and sign an ICF.
- •Willing and able to complete all post-surgery visits.
- •Myopia requiring (a) refractive error correction of -0.5 to -8.0 D manifest refraction sphere with (b) astigmatism correction of -0.75 to -5.0 D manifest refraction cylinder and (c) at least 0.75 D of corneal astigmatism.
- •Intended treatment is targeted for emmetropia.
- •Pre-surgery BCVA of 0 logarithm of the minimum angle of resolution (logMAR) (20/20) or better.
- •Spherical equivalent difference of ≤ 0.5 D between the manifest and cycloplegic refraction outcomes.
- •Spherical equivalent difference of ≤ 0.5 D between refractive error corrections for a minimum of 12 months prior to surgery verified by consecutive refractions and/or medical records or prescription history.
- •For contact lens wearers.
- •Spherical equivalent difference of ≤ 0.5 D between outcomes from consecutive manifest refraction outcomes performed at least 7 days apart after the contact lens wear has been stopped for the appropriate period of time as follows: Soft (extended and daily wear) for 3 days Rigid Gas Permeable (RGP) or Toric for 2 weeks Hard polymethyl methacrylate (PMMA) for 3 weeks.
排除标准
- •Pregnancy or lactation, current or planned, during the course of the study.
- •Mixed astigmatism refractive error.
- •Degenerations of structure of the cornea including diagnosed keratoconus, forme fruste kerataconus or pellucid marginal degeneration.
- •A calculated residual stromal bed thickness that is less than 250 µm.
- •History or evidence of active or inactive corneal or other anterior segment disease (e.g, herpes simplex keratitis, recurrent erosion syndrome).
- •Diagnosed advanced glaucoma.
- •Uncontrolled diabetes.
- •Nystagmus or any other condition that would prevent a steady gaze during the treatment.
- •Previous intraocular or corneal surgery.
- •Weakened immune system, including diagnosed collagen vascular, autoimmune or immunodeficiency disease.
- •Systemic medications that may affect corneal healing including, but not limited to steroids, antimetabolites, immune response modifying drugs, etc.
- •Presence or history of any condition or finding that makes the subject unsuitable as a candidate for refractive surgery or study participation or may confound the outcome of the study, in the opinion of the Investigator.
- •Any subject currently participating in another investigational drug or device study that may confound the results of this investigation.
- •A known sensitivity to medications used during the study.
结局指标
主要结局
Uncorrected and corrected distance visual acuity
时间窗: Uncorrected and corrected distance visual acuity
次要结局
- Wavefront aberrations, •Corneal endothelial examination, dry eye(Preoperative, 1 week, 1 month, 3 month and 6 month)