Twelve-Month Outcome of Single-step Transepithelial Photorefractive Keratectomy for Moderate Hyperopia and Hyperopic Astigmatism
试验速览
- 阶段
- 不适用
- 状态
- 已完成
- 入组人数
- 30
- 试验地点
- 2
- 主要终点
- Cycloplegic refraction
研究概览
简要总结
Hyperopia is one of the commonest refractive errors encountered in ophthalmology practice.
Laser in situ keratomileusis (LASIK) has been widely used to correct hyperopia especially with the advent of femtosecond laser technology allowing larger flap creation suitable for peripheral hyperopic ablations with resultant predictable, effective, and safe refractive outcomes. However, the encountered LASIK flap complications encouraged many surgeons to assess efficiency and safety of surface ablation techniques such as photorefractive keratectomy (PRK) to correct hyperopia.
详细描述
Although the initial refractive results of conventional manual or alcohol assisted PRK for hyperopia were encouraging, the frequently encountered post-PRK complications including undercorrection, overcorrection and regression of the hyperopic error had downgraded the conventional PRK as a preferred procedure for hyperopic correction.
Transepithelial PRK provides an alternative technique to uniformly remove the epithelium using the excimer laser to minimize the potential complications caused by mechanical or alcohol assisted epithelial removal in conventional PRK. Advances in transepithelial PRK technology have allowed refractive surgeons to remove the epithelium followed by stromal laser ablation in a single step instead of performing the procedure in 2 separate steps known as phototherapeutic keratectomy-photorefractive keratectomy (PTK-PRK).
Most of the previous studies paid particular attention to investigate the accuracy and safety of single-step transepithelial PRK in correcting myopia and myopic astigmatism. The aim of the current study is to evaluate the visual and refractive outcomes of the single-step transepithelial PRK procedure in correcting moderate hyperopia and hyperopic astigmatism.
研究设计
- 研究类型
- Interventional
- 分配方式
- Na
- 干预模型
- Single Group
- 主要目的
- Treatment
- 盲法
- None
入排标准
- 年龄范围
- 18 Years 至 —（Adult, Older Adult）
- 性别
- All
- 接受健康志愿者
- 是
入选标准
- •Patients with moderate hyperopia with a hyperopic cycloplegic spherical equivalent between +2 and + 4.5 diopters D.
- •A steep keratometry (Ks) ≤ 46 D.
- •Minimum pachymetry of 500 μm with a calculated residual stromal bed exceeding 350 μm after epithelial and stromal ablation.
排除标准
- •Patients not candidate for corneal refractive surgery,
- •Steep cornea (Ks > 46 D) with an expected postoperative keratometry > 48 D,
- •Large angle kappa as estimated by Chord mu > 0.25 mm,
- •Hyperopic amblyopia whether unilateral or bilateral with CDVA less than 0.2 . logMAR acuity,
- •Recent contact lens wear, dry eye disease and autoimmune disorders.
结局指标
主要结局
Cycloplegic refraction
时间窗: 12 months
Cycloplegic sphere, cylinder and refractive spherical equivalent (SEQ) were measured with auto-keratorefractometer (KR-8900:Topcon, Korea republic)
Visual acuity
时间窗: 12 months
Uncorrected and corrected distance visual acuity (UDVA,CDVA) measurement using logMAR distant charts.
次要结局
- Keratometry and corneal asphericity(12 months)
- Post-PRK haze(12 months)
研究者
Mahmoud Abdel-Radi
Principal Investigator
Assiut University