Piccolo M G, Berkeley R G, Baker R N, Souchek J
University of Houston, College of Optometry, TX 77204-6052, USA.
J Am Optom Assoc. 1995 Oct;66(10):603-7.
Patients scheduled to undergo radial keratotomy in both eyes received redeepening incisions in one eye and single pass incisions in the other. Eye and order of surgery were assigned randomly and surgical parameters were otherwise identical in the two eyes.
This study was designed to measured the improvements in myopia obtained by radial keratotomy, with and without redeepening incisions.
There was a greater decrease in spherical equivalent manifest refraction in the redeepening group than in the control group at 1 week (0.41 D) and 1 month (0.36 D) after surgery, as measured by keratometry. The difference in change between groups was 0.41 D at one week, 0.36 D at 1 month, and 0.26 D at 3 months. Change in spherical equivalent was significantly more in the redeepened group at 3 months after surgery (0.37 D); however, the improvement constituted only 8.8 percent of the decrease in myopia achieved by radial keratotomy without redeepening (3.87 D).
Although redeepening yields an incremental effect in the correction of myopia, the technical difficulties of redeepening and the increased chance of perforation of the cornea with redeepening outweigh the benefits of the procedure.
计划双眼接受放射状角膜切开术的患者，一只眼睛接受再次加深切口，另一只眼睛接受单次切口。手术眼别和顺序随机分配，两只眼睛的手术参数在其他方面相同。
本研究旨在测量放射状角膜切开术（无论有无再次加深切口）所获得的近视改善情况。
通过角膜曲率计测量，术后1周（0.41D）和1个月（0.36D）时，再次加深切口组的等效球镜明显屈光度数下降幅度大于对照组。两组之间的变化差异在1周时为0.41D，1个月时为0.36D，3个月时为0.26D。术后3个月时，再次加深切口组的等效球镜变化明显更大（0.37D）；然而，这种改善仅占未再次加深的放射状角膜切开术所降低近视度数（3.87D）的8.8%。
尽管再次加深切口在近视矫正中产生了增量效果，但再次加深切口的技术难度以及再次加深时角膜穿孔几率的增加超过了该手术的益处。
