Evaluation of Different Lenticule Diameters in Myopic Astigmatism Correction With SMILE Procedures
试验速览
- 阶段
- 不适用
- 状态
- 招募中
- 入组人数
- 50
- 试验地点
- 2
- 主要终点
- The safety index of using 7 and 6.5 mm lenticule diameters SMILE to treat myopic astigmatism
研究概览
简要总结
Small incision lenticule extraction (SMILE) is a refractive intrastromal procedure for myopia and myopic astigmatism correction. Most of the studies evaluating astigmatic correction by SMILE reported astigmatic under-correction, especially in high degrees of astigmatism.
This under-correction could be due to: first, the active eye tracker or the iris registration is not yet available to overcome the cyclotorsion that occurred during the treatment with the VisuMax femtosecond laser system (Carl Zeiss Meditec, Jena, Germany) which could be overcome by manual compensation technique, especially in higher degrees of cylinders (> 1.5 diopters (D)). Second, in patients with small lenticule diameters, the more abrupt change in thickness at the edge of the treated area could induce more stromal and epithelial healing in this area. Thus, the astigmatic correction would be less effective with small than large lenticule diameters for similar high preoperative astigmatism.
This study assessed the outcome of using a 0.5 millimeter (mm) larger lenticule diameter in the fellow eyes of myopic astigmatic correction SMILE participants. This assessment included the safety and effectiveness indices, the refractive and visual outcomes, the contrast sensitivity, and some morphological outcomes such as corneal curvature and epithelial and corneal thickness.
详细描述
Study Title: Evaluation of different lenticule diameters in myopic astigmatic correction with SMILE procedures Primary Investigator: Dr. Ahmed Sedky (Eye Subspecialty Center, Cairo, Egypt, 18 Elkhalifa Elmamoun Street, Heliopolis, Cairo, Egypt) Co-Investigators: Sherine S Wahba, Maged M Roshdy, Nermeen A Refaat Study Objectives Primary Objective: To study the effect of changing the lenticule diameter on the safety and effectiveness of myopic astigmatism correction with the SMILE procedure.
Secondary Objective: To compare other outcomes such as visual outcomes including immediate visual acuity, contrast sensitivity, and epithelial remodeling.
Participants and Methods:
Study Setting: Eye Subspecialty Center, Cairo, Egypt, 18 Elkhalifa Elmamoun Street, Heliopolis, Cairo, Egypt and Al Watany Eye Hospital, Althawra Street, Cairo, Egypt Study design: Hospital-based, comparative, prospective, interventional contralateral eye study Sample size and randomization: 50 participants fulfilling the inclusion criteria will be enrolled in the study. Their right eyes undergo SMILE procedure using the standard 6.5 mm lenticule diameter and their left eyes undergo SMILE procedure but using a larger lenticule diameter of 7.0 mm.
Ethical issues:
研究设计
- 研究类型
- Interventional
- 分配方式
- Non Randomized
- 干预模型
- Parallel
- 主要目的
- Treatment
- 盲法
- None
入排标准
- 年龄范围
- 18 Years 至 50 Years（Adult）
- 性别
- All
- 接受健康志愿者
- 是
入选标准
- •Age groups between 18 and 50 years
- •Myopic astigmatism with up to -10.00 D spherical equivalent (SE) and a minimum astigmatism of -1.0 D and a maximum of -5 D. The astigmatism will be divided into low astigmatism (<0.75 D), moderate astigmatism (1.5- 3 D) and high astigmatism (>3 D).
- •Corrected distance visual acuity (CDVA) of 0.7 or better (decimal)
排除标准
- •Thin corneas (< 490 μm)
- •Proven or suspicious cases of corneal ectatic conditions by corneal tomography
- •Previous ocular surgeries
- •Patients taking systemic steroids, immunosuppressants, oral contraceptives, or antidepressants
- •Pregnant females
- •Corneal scars or any ocular pathology likely to affect visual outcomes
结局指标
主要结局
The safety index of using 7 and 6.5 mm lenticule diameters SMILE to treat myopic astigmatism
时间窗: up to 6 months
The safety index (unitless parameter) is calculated as postoperative CDVA/ preoperative CDVA (both in decimal units).
The efficacy index of using 7 and 6.5 mm lenticule diameters SMILE to treat myopic astigmatism
时间窗: up to 6 months
The efficacy index (unitless parameter) is calculated as postoperative UDVA/ preoperative CDVA (both in decimal units).
次要结局
- Corneal curvature changes after SMILE procedure using 7 and 6.5 mm lenticule diameters SMILE to treat myopic astigmatism.(up to 6 months)
- Refractive outcomes of using 7 and 6.5 mm lenticule diameters SMILE to treat myopic astigmatism.(up to 6 months)
- Visual acuity outcomes of using 7 and 6.5 mm lenticule diameters SMILE to treat myopic astigmatism.(up to 6 months)
- Contrast sensitivity outcomes of using 7 and 6.5 mm lenticule diameters SMILE to treat myopic astigmatism.(up to 6 months)
- Corneal structural changes after SMILE procedure using 7 and 6.5 mm lenticule diameters SMILE to treat myopic astigmatism.(up to 6 months)