Greenfield D S, Jivanjee S Q, Raizman M B
New England Eye Center, New England Medical Center, Tufts University School of Medicine, Boston, MA 02111, USA.
Ophthalmic Surg Lasers. 1995 Nov-Dec;26(6):560-7.
A prospective study was performed to assess the effect of trephination on corneal curvature.
Thirty-seven fresh porcine globes with intact corneal epithelium were used. Radius of curvature, central dioptric power, and powers and axes of the steepest and flattest meridians were obtained using a vertically mounted computerized videokeratography unit. Following 8-mm vacuum trephination of the central donor corneas, the said parameters were reassessed on the resultant buttons. No globes with epithelial defects were included in the study.
The mean corneal radius of curvature (mm) increased from 8.68 +/- 0.79 to 10.46 +/- 3.24 (P = .005), the central dioptric power (D) decreased from 39.36 +/- 3.84 to 36.31 +/- 10.15 (P = .08), and the total corneal asphericity (D) increased from 5.03 +/- 2.99 to 7.47 +/- 3.42 (P = .0001). No significant changes in the axes of the steepest and the flattest meridians were noted following trephination.
Trephination leads to significant corneal flattening and increased asphericity. Corneal topography can be used successfully as a research tool for whole globes and trephined buttons.
进行一项前瞻性研究以评估环钻术对角膜曲率的影响。
使用37个角膜上皮完整的新鲜猪眼球。使用垂直安装的计算机化视频角膜地形图仪获取曲率半径、中央屈光力以及最陡和最平子午线的屈光力与轴位。在对中央供体角膜进行8毫米真空环钻术后，对所得角膜片重新评估上述参数。研究未纳入有上皮缺损的眼球。
平均角膜曲率半径（毫米）从8.68±0.79增加至10.46±3.24（P = 0.005），中央屈光力（D）从39.36±3.84降至36.31±10.15（P = 0.08），角膜总非球面性（D）从5.03±2.99增加至7.47±3.42（P = 0.0001）。环钻术后最陡和最平子午线的轴位未发现显著变化。
环钻术导致角膜显著变平且非球面性增加。角膜地形图可成功用作整个眼球和环钻角膜片的研究工具。
