The presence of mucin balls during continuous wear with
lotrafilcon A silicone hydrogel contact lenses may lead to a
decreased incidence of
corneal infiltrative events, a study found.
The Longitudinal Analysis of Silicone Hydrogel Contact Lens Study
evaluated 205 subjects who wore Night & Day silicone hydrogel lenses
Ciba Vision) for 12 months. Researchers used fluorescein
pooling of the corneal surface to grade mucin balls.
Of the subjects, 54.2% had mucin balls during at least one visit, and
32.8% of the subjects had repeated episodes. Mucin ball scores correlated
weakly with corneal curvature (P = .005), the study said.
According to univariate analyses, the relative hazard for a corneal
infiltrative event was 0.35 in subjects with a single episode of mucin balls.
The relative hazard decreased to 0.17 if more than one episode was detected.
In addition, multivariate analyses found that the hazard of developing a
corneal infiltrative event decreased by 84% with the repeated presence of mucin
"We hypothesize that the mucin ball presence represents a more
concentrated or viscous mucus layer, which prevents upregulation of the immune
response against bacterial ligands," the authors said.