Melles G R, Go A T, Beekhuis W H, van Rij G, Binder P S
Eye Hospital, Erasmus University Rotterdam, The Netherlands.
J Cataract Refract Surg. 1992 Jan;18(1):27-36. doi: 10.1016/s0886-3350(13)80380-x.
Radial keratotomy (RK) is currently performed with four or eight semi-radial incisions. To evaluate the effect of a theoretically more stable three-incision RK pattern, centripetal incisions were made in 16 human donor eyes (eight pairs), using a double-edged diamond blade set to 90% of central pachymetry and a 3.5 mm optical clear zone. Intraocular pressure was maintained at 15 mm Hg during surgery and while keratometry readings were made. One randomly selected eye of each pair had three radial incisions made at 12, 4 and 8 o'clock; the other eye had four radial incisions at 12, 3, 6, and 9 o'clock. Corneal flattening was 6.08 diopters (D) with four incisions and 4.84 D with three incisions (P less than .05). Astigmatism increased 0.44 D and 0.69 D, respectively (P greater than .1). Histologically measured mean incision depth (77.4%) did not differ significantly between the groups (P greater than .1). This study shows that 80% of the effect of a four-incision RK pattern can be obtained with a theoretically more stable three-incision pattern.
放射状角膜切开术（RK）目前是通过四个或八个半放射状切口进行的。为了评估理论上更稳定的三切口RK模式的效果，使用设置为中央角膜厚度90%的双刃金刚石刀片和3.5毫米光学透明区，在16只人类供体眼（八对）中制作了向心性切口。手术期间以及进行角膜曲率测量时，眼内压维持在15毫米汞柱。每对眼睛中随机选择一只，在12点、4点和8点处制作三个放射状切口；另一只眼睛在12点、3点、6点和9点处制作四个放射状切口。四个切口时角膜变平为6.08屈光度（D），三个切口时为4.84 D（P小于0.05）。散光分别增加了0.44 D和0.69 D（P大于0.1）。组织学测量的平均切口深度（77.4%）在两组之间无显著差异（P大于0.1）。本研究表明，理论上更稳定的三切口模式可获得四切口RK模式80%的效果。
