Visual and Refractive Outcomes Following Stream Light Photorefractive Keratectomy (55μm Epithelial Removal) Versus Conventional Photorefractive Keratectomy
试验速览
- 阶段
- 不适用
- 状态
- 进行中（未招募）
- 入组人数
- 100
- 试验地点
- 1
- 主要终点
- Post operative distant uncorrected visual acuity
研究概览
简要总结
Photorefractive keratectomy (PRK) is a well-established corneal refractive surgery that involves epithelial removal followed by stromal ablation to correct myopia, hyperopia, and astigmatism. The method of epithelial removal in PRK significantly impacts healing, pain levels, and visual outcomes.
Trans-epithelial PRK (StreamLight) performed on the EX500 excimer laser platform removes the epithelium and reshapes the corneal stroma in a single laser-guided step, potentially reducing tissue manipulation and enhancing epithelial healing. In contrast, manual epithelial removal PRK involves mechanical debridement, with epithelial removal depth being manually controlled. The variability of epithelial thickness in StreamLight PRK may influence visual outcomes, whereas in manual PRK, a fixed epithelial removal depth of 55 microns provides a standardized approach.
详细描述
This study aimed to compare the visual and refractive outcomes of StreamLight PRK versus manual PRK with fixed epithelial removal.
Type of the study: Retrospective cross-sectional study
- Study Setting: Alforsan Eye Centre
- Study subjects:
a. Inclusion criteria:
-
Patients aged 18-40 years.
-
Myopia up to -6.00 D and astigmatism up to -3.00 D.
-
Stable refraction for at least one year.
-
No history of ocular surgery or corneal pathology. b. Exclusion criteria:
-
Presence of keratoconus or suspected corneal ectasia.
-
Severe dry eye disease or significant ocular surface disease.
-
History of autoimmune disease or systemic conditions affecting wound healing.
-
Prior herpetic eye disease. c. Sample Size Calculation: A sample size calculation will be performed to ensure adequate statistical power. Anticipated enrollment: [e.g., 50 eyes per group] based on previous PRK outcome studies (Marshall et al., 2018).
-
Study tools (in detail, e.g., lab methods, instruments,steps, chemicals, …):
-
Alcon Wavelight EX500 excimer laser (Alcon Laboratories, Fort Worth, TX, USA)
-
Wavelight Oculyzer II Am Wolfsmantel 5, Erlangen, Germany
-
Autorefractor KR-8900 (Topcon, Tokyo, Japan)
研究设计
- 研究类型
- Observational
- 观察模型
- Other
- 时间视角
- Retrospective
入排标准
- 年龄范围
- 18 Years 至 40 Years（Adult）
- 性别
- All
- 接受健康志愿者
- 否
入选标准
- •Patients aged 18-40 years.
- •Myopia up to -6.00 D and astigmatism up to -3.00 D.
- •Stable refraction for at least one year.
- •No history of ocular surgery or corneal pathology.
排除标准
- •Presence of keratoconus or suspected corneal ectasia.
- •Severe dry eye disease or significant ocular surface disease.
- •History of autoimmune disease or systemic conditions affecting wound healing.
- •Prior herpetic eye disease.
结局指标
主要结局
Post operative distant uncorrected visual acuity
时间窗: 1 year
using snellen chart
次要结局
- Post operative spherical equivalent of refractive error(1 year)
研究者
Menatallah Gamal Saleh
lecturer of ophthalmology
Assiut University