A prospective evaluation of corneal curvature changes with 3.0- to 3.5-mm corneal tunnel phacoemulsification

To document the effects and results of cataract surgery through a corneal tunnel incision centered on the steepest corneal meridian.

The authors prospectively evaluated their first 172 eyes that received a 3.5-, 3.2-, or 3.0-mm corneal tunnel incision placed on the steepest corneal meridian followed by a plate haptic silicone lens implant. All surgeries were done by the same surgeon, and all eyes have completed a 12-month postoperative period. The keratometric changes were analyzed with the Holladay-Cravy-Koch method.

The incision in the vertical meridian produced more meridional flattening and more astigmatic change (0.90 diopter) than the incision in the horizontal meridian (0.60 diopter). Both incisions had good clinical results. Only 3.6% required a suture. Although the 3.0-mm incisions induced less corneal change than the 3.5-mm incisions, the difference was not usually statistically significant.

Three-plane corneal tunnel incisions placed on the steeper meridian are safe, consistently self-sealing, and rapidly stable; and they produce less than a 1.00-diopter astigmatic change. Vertical incisions produce slightly more astigmatic change and different effects compared with horizontal incisions.