The study aimed to validate traditional SPF measurement methods by comparing visual scoring with non-invasive techniques like HR-LDI and colorimetry.
Four different sunscreens were tested on 10 subjects using a solar simulator, with specific criteria established for assessing skin redness.
Results indicated that all three methods produced similar SPF values, with HR-LDI showing the least variability; however, none of the methods improved sensitivity for detecting suberythemal reactions.