Mucin ball production in silicone hydrogel contact lens wearers may increase the risk of corneal infiltrative events in the long term, according to a study.
These conclusions were opposite to the original hypothesis pursued by the authors, who aimed to confirm the results of the LASH [Longitudinal Analysis of Silicone Hydrogel] study, where mucin ball presence was found to decrease the incidence of corneal infiltrative events. Theoretically, the protective effect of mucin balls could be related to their ability to incarcerate microbes or to prevent friction between the lens and the surface of the cornea. It was also hypothesized that mucin ball formation could be a biomarker for higher mucus concentration and consequently better defense against pathogens in some individuals.
The study included three participating sites and a total of 289 subjects. In phase 1, through 30 days of continuous lens wear, the authors aimed at classifying participants as mucin ball formers and non-mucin ball formers. In phase 2, the potential protective effect of mucin balls during extended wear (for 12 months) was tested.
Contrary to expectation, mucin ball formers in phase 1 had a statistically significant greater rate of eventual corneal infiltrative event formation in phase 2. According to the authors, although opposite to the original hypothesis, these findings are “consistent with some other literature.”
“These results suggest that the early appearance of mucin balls signifies changes to the mucus layer, which can precipitate a corneal infiltrative event through the disruption of an important barrier defense against bacterial antigens,” the authors concluded. – by Michela Cimberle
Disclosure: The authors report no personal financial disclosures but acknowledge that the study was supported by Johnson & Johnson Vision Care and coordinated by the Ohio Lions Eye Research Foundation.