Comparison of Morphological and Biomechanical Outcomes of FS-LASIK with Visumax-MEL90 and Wavelight FS200-EX500 Lasers- a Randomised Controlled Trial
试验速览
- 阶段
- 不适用
- 状态
- 尚未招募
- 入组人数
- 110
- 试验地点
- 1
- 主要终点
- Central Flap Thickness
研究概览
简要总结
Corneal laser ablative procedures are the most commonly practiced refractive surgery.
Femtosecond laser is an infrared laser (1053nm) that works by producing photodisruption or photoionisation of optically transparent tissue such as Cornea.
LASIK surgery involves creation of corneal flaps done by either Microkeratome(produces meniscus shape flaps) or Femtosecond Laser (produce planar flaps) followed by Excimer Laser Ablation.
Femtosecond laser has gained superiority over microkeratome for creating corneal flaps due to more planar architecture , greater precision in flap diameter and thickness, uniform flap thickness across the flap diameter, customisable by surgeon to programme angulation of flap periphery.
Two FS lasers available in our Centre are Zeiss Visumax MEL-90 and Alcon Wavelight FS200. Zeiss Visumax laser system has a low suction pressure of about 35mmHgwith a suction time of about 30 seconds**.**It Creates corneal flap by acurvation method by maintaining corneal curvature by spiral pattern. Alcon Wavelight FS200 laser system has a high suction pressure (80-100 mmHg) with a longer suction time (35-40 seconds). It creates corneal flap by applanation method by making cornea flat by raster pattern. The difference in suction pressure and suction time during femtosecond laser application for flap creation may also produce anterior and posterior segment changes.
研究设计
- 研究类型
- Interventional
- 分配方式
- Computer generated randomization
- 盲法
- Participant and Investigator Blinded
入排标准
- 年龄范围
- 18.00 Year(s) 至 40.00 Year(s)（—）
- 性别
- All
入选标准
- •Patients undergoing FS-LASIK for myopia or myopic astigmatism 2)Stable refractive error for >1 year 3)Minimum calculated RSBT- 300 microns 4)Patients willing to give informed consent 5)Patients willing for follow up.
排除标准
- •Progressive or unstable myopia 2)External ocular disease/ keratoconus (including forme-fruste)/ Pellucid marginal degeneration.
- •Diabetes, connective tissue disease, Atopy; pregnant or nursing patients.
- •Corticosteriods or antimetabolites use 5)Previous corneal surgery/ Re-treatment, not willing to follow up.
- •Soft contact lens use in past 2 weeks or rigid gas permeable contact lens wear in past 4 weeks.
结局指标
主要结局
Central Flap Thickness
时间窗: Day 1, 1 week, 1 month, 3 months
次要结局
- 1)Corneal Biomechanical outcomes (Including DA, A length, A velocity, CBI-LVC index)(2)Anterior chamber angle parameters (ACD, ARA, TIA, TISA, AOD))