Using ATP measurements to rapidly evaluate the cleanliness of spectacle surfaces

Microbial contamination on used spectacles poses a potential health risk to spectacle wearers and people regularly working with worn spectacles, such as opticians. ATP measurement is widely used to evaluate the cleanliness of surfaces based on the detection of adenosine triphosphate, a molecule found in and around living cells. In this study, we investigated the suitability of this method to rapidly and easily evaluate the efficacy of different cleaning methods for spectacles. Additionally, we examined the correlation between ATP content on spectacle surfaces with aerobic and anaerobic bacterial colony counts. We swab-sampled worn spectacles and used an ATP bioluminescence assay to assess the level of cellular contamination.

Six cleaning methods were tested on ten worn spectacles each, and ATP levels were correlated with both aerobic and anaerobic bacterial counts. All investigated cleaning methods showed a significant median reduction of the ATP content on spectacle surfaces, between 75 and 93%. Germ counts and ATP levels showed no significant correlation for aerobic but for anaerobic cultivation. Higher anaerobic germ counts correlated positively with higher ATP levels. ATP measurement is a suitable method to rapidly and easily demonstrate the efficacy of cleaning measures for spectacle surfaces also under non laboratory conditions.