Department of Ophthalmology, Buddhist Tzu Chi General Hospital and Institute of Medicine and Medicine Science, College of Medicine, Tzu Chi University, Hualien, Taiwan.
Eye (Lond). 2009 Dec;23(12):2200-5. doi: 10.1038/eye.2008.435.
To investigate the accuracy of corneal flap thickness (FT) using two different age MK-2000 microkeratomes.
The prospective cohort study enroled 260 patients with refractive error. Flaps were created using two microkeratomes A and B (new and aged, respectively) with 130-mum heads in two patient groups and two times the same blade in both treated eyes of each patient. The variations in FTs were compared between two groups and between both operated eyes of each patient. The correlations were analysed between FT and CCT or keratometric power.
In the A and B groups, the average FTs were 123.3+/-18.7 and 147.5+/-19.1 mum respectively. Difference in measurements between the actual FTs of first eye operations in the A group and intended 130 mum of FTs was not significant (P=0.462), but those of second operated eyes in the A group and both treated eyes in the B group were significant (P<0.001). Second cut achieved a thinner flap and increased the variability in FT, and an aged microkeratome achieved a thicker flap than a new microkeratome and than that claimed by the manufacturer. Positive correlations were observed between preoperative CCT and FT (P<0.05).
The first eye operation by a new MK-2000 microkeratome achieves the accuracy of the intended FT. FTs varied between first and second cuts of each patient and between two different age MK-2000 microkeratomes. LASIK surgeons should compare FT when using an aged MK-2000 microkeratome, and frequent and periodic comparison of FT achieved by all microkeratomes may be also recommended.
研究两种不同年代的 MK-2000 微型角膜刀角膜瓣厚度（FT）的准确性。
前瞻性队列研究纳入 260 例屈光不正患者。使用两种微型角膜刀 A 和 B（分别为新型和老化型）在两组患者和每位患者的双眼各治疗眼上两次使用 130μm 刀头进行角膜瓣制作。比较两组之间以及每位患者双眼之间 FT 的差异。分析 FT 与 CCT 或角膜屈光力之间的相关性。
在 A 组和 B 组中，平均 FT 分别为 123.3±18.7μm 和 147.5±19.1μm。A 组第一只眼手术的实际 FT 与预期 130μm FT 之间的测量差异无统计学意义（P=0.462），但 A 组第二只眼手术和 B 组双眼治疗眼之间的差异有统计学意义（P<0.001）。第二次切割可获得更薄的角膜瓣并增加 FT 的可变性，且老化的微型角膜刀可获得比新型微型角膜刀和制造商声称的更厚的角膜瓣。术前 CCT 与 FT 呈正相关（P<0.05）。
新型 MK-2000 微型角膜刀的第一只眼手术可达到预期 FT 的准确性。每位患者的第一和第二次切割之间以及两种不同年代的 MK-2000 微型角膜刀之间的 FT 存在差异。使用老化的 MK-2000 微型角膜刀时，LASIK 外科医生应比较 FT，也可能建议对所有微型角膜刀的 FT 进行频繁和定期比较。
