Mucus secretory vesicles in conjunctival epithelial cells of wearers of contact lenses
J. V. Greiner, K. R. Kenyon, A. S. Henriquez, D. R. Korb, T. A. Weidman and M. R. Allansmith
Biopsy specimens from the upper tarsal conjunctivae of ten patients with
clinically evident contact-lens-associated giant papillary conjunctivitis
(GPC) and eight asymptomatic contact lens wearers without clinically
evident conjunctival changes were compared by light and transmission
electron microscopy to determine the contribution of nongoblet epithelial
cells to increased mucus. A control group consisted of five subjects who
had never worn contact lenses. The apical cytoplasm of superficial
nongoblet epithelial cells in specimens from all groups showed
single-membrane-limited vesicular inclusions that stained metachromatically
with toluidine blue and were positive with PAS staining, which indicated
muco-protein content. Some vesicles appeared to discharge their contents
into the conjunctival sac. More vesicles were found in the GPC subjects and
the asymptomatic contact lens wearers than in the normal subjects. These
observations, coupled with the sign of increased or excessive mucus
discharge in GPC subjects and in asymptomatic lens wearers, support the
premise that the superficial layers of non-goblet conjunctival epithelial
cells can contribute to an increase in mucus production.
