ABSTRACT
BACKGROUND AND OBJECTIVE: A prospective study was performed to assess the effect of trephination on corneal curvature. MATERIALS AND METHODS: 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. RESULTS: 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. CONCLUSION: 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.
