Comparison of Corneal Flap Thickness Using Visumax Femto-Lasik With SubBowman Keratomileusis (SBK) Microkeratome
试验速览
- 阶段
- 不适用
- 状态
- 已完成
- 发起方
- 入组人数
- 50
- 试验地点
- 2
- 主要终点
- Right eye corneal flap thickness was measured by optical coherence tomography(OCT).
研究概览
简要总结
Laser Insitu keratomileusis (LASIK) has become the most popular procedure for refractive error correction. Lasik flap creation is the first and critical step during LASIK surgery because of its consensual effect on a residual stromal bed, corneal biomechanics, and hence the future risk of ectasia⁴.In the current study, we compared the Visumax FSL flap thickness predictability, accuracy, and variability with the flap created by single-use Moria SBK microkeratome.
详细描述
Flap creation techniques have evolved from the old manual procedure of mechanical microkeratome to the automated one with the use of microkeratome and more recently to Femto-laser procedure using a variety of machines.
Authors have reported that the primary vision nearly the same despite the different methods of flap creation in the first 6 months post LASER vision correction. Others have reported that a thinner flap is associated with better primary vision and refractive outcomes. SBK (Sub Bowman Keratomileusis), is a procedure in which the Lasik flap is thinner, and has the advantage of leaving a sufficient stromal bed for safer excimer Laser ablation.
There are five types of femtosecond Laser that were already approved currently for Lasik flap creation.
The Zeiss (Visumax FSL ) which has been used in the current study uses 1043 nm, a repetition rate of 500 kHz, and 220-580 femtoseconds pulse duration. Each laser pulse produces micro-photo disruption in the tissue, contiguous few microns sized photo disruptions will create a continuous cut in the corneal tissue at precise preset position and depth.
In the current study, the Visumax flap thickness predictability, accuracy, and variability were compared with the flap created by a single-use Moria SBK microkeratome.
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
- Double (Investigator, Outcomes Assessor)
入排标准
- 年龄范围
- 20 Years 至 38 Years（Adult）
- 性别
- All
- 接受健康志愿者
- 是
入选标准
- •Having refractive errors range from -2 to- 6 DS and from -1 to -3.00DC.
- •They have stable refraction for at least one year prior to surgery.
- •Normal topography by Placido-Scheimpflug (Sirius, Costruzione Strumenti Oftalmici, Florence, Italia) and normal corneal epithelial map by Anterior segment-OCT system (Optovue Inc, Fremont, California, USA)
排除标准
- •Patient with suspicious topography and or corneal epithelial map.
- •Patient with corneal pachymetry below 500µm.
- •Patients who have a history of previous ocular surgery or trauma.
- •Patient with a current or previous history of herpes simplex or herpes zoster.
- •Patient with severe dry eye, diabetes, thyrotoxicosis, and connective tissue diseases.
- •Patient with Combined ocular diseases like retinal dystrophy or glaucoma.
- •Patient with a history of contact lenses use was meant to stop the use of soft contact lenses for at least 2 weeks or hard type for at least 4 weeks before topography and other investigations were done.
- •Patient who refrains from the required follow-up visits; have been excluded from the study.
结局指标
主要结局
Right eye corneal flap thickness was measured by optical coherence tomography(OCT).
时间窗: 6-months postoperatively
The lasik flap thickness in the right eye in both groups were measured six months after the procedures using non touch method by anterior segment OCT without instillation of topical anaesthesia, at seven points in each eye (one central and 3 points at each sides of horizontal meridian).The three nasal points were located (1mm, 2mm, 3mm respectively) from the center and remaining three temporal points located again ( 1mm, 2mm, 3mm) from the center. Data from both groups were comparing to evaluate predictability and variability of the flap thickness.
次要结局
未报告次要终点
研究者
Suzan A Rattan
Assistant professor ophthalmologist
Al-Kindy College of Medicine