Scheimpflug densitometry may be an effective, supplementary tool for documenting keratoconus (KCN) disease stages, since a recent study found this testing method did well in pinpointing the cone area most affected by the ocular disease.
Researchers performed Scheimpflug densitometry on 20 healthy subjects and 90 keratoconus patients, and analyzed the findings using both one-layer and two-layer approaches. The first considered layer-by-layer corneal transparency at different depths, and the second averaged densitometry between two corneal layers selected by the examiner. The investigators repeated same-day scans and longitudinal series of scans to see whether the findings evolved over time.
Out of the 90 KCN cases, 88 displayed a bright area on the densitometry map that corresponded to the cone location. Of note: the area’s characteristics, including brightness, contrast and the presence of a delimiting arc, correlated with disease severity and was more noticeable in advanced cases. No similar marks were found in any of the normal subjects.
The shape, location and extent of the mark were consistent over consecutive measures taken on the same day, and changes over time were also seen in eyes with known clinical progression and in those considered clinically stable.
Further studies are warranted to ascertain whether Scheimpflug densitometry could prove useful in detecting KCN, determining progression and relating it to corneal biomechanical behavior, the researchers concluded in their paper.
Jiménez-García M, Ní Dhubhghaill S, Consejo A, et al. Scheimpflug densitometry in keratoconus a new method of visualizing the cone. Cornea. October 15, 2020. [Epub ahead of print].