Repeatability of a Dual-Scheimpflug Placido Disc Corneal Tomographer/Topographer in Eyes with Keratoconus

The dual-Scheimpflug placido disc corneal tomographer/topographer is highly repeatable in quantifying parameters used in monitoring KCN. Excellent placido images are difficult to capture in eyes with KCN, but when available, increase the reliability of the measurements. When clinicians find that a topographic index changes by more than the RLs defined herein, they can have confidence that this represents real change and may appropriately recommend interventions such as corneal cross-linking or intrastromal corneal ring segments.