Campos M, Cuevas K, Shieh E, Garbus J J, McDonnell P J
Doheny Eye Institute, Los Angeles, CA 90033.
Refract Corneal Surg. 1992 Sep-Oct;8(5):378-81.
Photorefractive keratectomy for myopia can be performed using an expanding or contracting iris diaphragm, either of which allows for greater ablation centrally and less tissue ablation toward the edge of the treatment zone.
To compare the effects of these two strategies, eight rabbits underwent bilateral 5.00-diopter myopic ablations, performed with a contracting diaphragm in one eye and an expanding diaphragm in the other.
The rate of epithelial healing and degree of anterior stromal haze, monitored by a masked observer, were similar for the two groups, as was the amount of corneal flattening.
These results in rabbit corneas do not suggest a particular advantage of either the expanding or contracting apertures for achieving central corneal flattening in photorefractive keratectomy.
近视性准分子激光角膜切削术可使用扩张或收缩的虹膜光阑进行，这两种方法都能使中央消融量更大，而治疗区域边缘的组织消融量更小。
为比较这两种策略的效果，8只兔子接受了双侧5.00屈光度近视性消融，一只眼睛使用收缩光阑，另一只眼睛使用扩张光阑。
由一位不知情的观察者监测，两组的上皮愈合率、前基质混浊程度以及角膜变平量相似。
在兔角膜中的这些结果并未表明在准分子激光角膜切削术中，扩张或收缩孔径在实现中央角膜变平方面具有特别优势。
