Mismatch between flap and stromal areas after laser in situ keratomileusis as source of flap striae
Mismatch between flap and stromal areas after laser in situ keratomileusis as source of flap striae
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DOI：
10.1016/s0886-3350(02)01636-x
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发表时间：
2002-12-01
影响因子：
2.8
通讯作者：
Charman, WN
中科院分区：
文献类型：
--
作者：
Charman, WN
目的：从理论上计算角膜瓣下表面与角膜基质层之间的过剩面积。方法：根据不可伸展的角膜瓣和球状角膜的初始假设，在角膜半径(7.8 mm)和角膜瓣厚度(160微米)的典型值，以及不同的消融区直径(4.0 mm，6.0 mm，8.0 mm，8.0 mm)的范围内，确定角膜瓣和切削基质面积作为近视矫正的函数。结果：超额角膜瓣面积随屈光矫正度数和消融区直径的增大而增大。对于-6.0D矫正和8.0 mm的消融区，过剩面积名义上约为1.0 mm(2)，在与铰链相对的边缘处存在潜在的重叠约100 mm。结论：过大的皮瓣面积可能因皱纹而产生条纹。虽然在模型中假设了不可伸展的瓣，但由于切割瓣而引起的任何拉伸或收缩都将与屈光矫正无关。因此，地区之间的不匹配仍然会发生。这种几何效应可能在临床上造成光学像差、屈光回退或伤口愈合不良。(C)2002年《儿童权利公约》和《经济、社会和文化权利国际公约》。
Purpose: To calculate theoretically the magnitude of the excess area between the lower surface of the flap and the underlying ablated stroma.Methods: On the initial assumptions of a nonextensible flap and a spherical cornea, flap and ablated stromal areas were determined as a function of myopic correction in the range of 0 to -12 diopters (D) for typical values of corneal radius (7.8 mm) and flap thickness (160 mum), together with a range of ablation zone diameters (4.0 mm, 6.0 mm, 8.0 mm, and 10.0 mm).Results: Excess flap area increases with the magnitude of the refractive correction and the diameter of the ablated zone. For a -6.0 D correction and an 8.0 mm ablation zone, the excess area is nominally about 1.0 mm(2), giving a potential overlap of the flap at the edge opposite the hinge of about 100 mum.Conclusions: Excess flap area may cause striae because of wrinkling. Although a nonextensible flap is assumed in the model, any stretching or contraction due to cutting the flap will be independent of the refractive correction. Hence, a mismatch in areas must still occur. This geometric effect may have clinical consequences in optical aberration, refractive regression, or impaired wound healing. (C) 2002 ASCRS and ESCRS.