Epibulbar mucogenic subconjunctival cysts.

Two patients had freely movable epibulbar subconjunctival cysts that occurred in the absence of trauma, inflammation, and infection. Histopathologic examination of these cysts revealed them to be linked by nonkeratinizing epithelial cells and goblet cells. The cysts had little or no stroma and contained PAS-positive mucoid material. Electron microscopy of adjacent conjunctiva indicated that the epithelial cells were actively producing mucous granules and did not form many hemidesmosomes. The mechanical displacement of epithelial cells, as well as their mucous-producing ability, probably contribute to cyst formation. The relative lack of hemidesmosomes may explain why these cysts are freely movable.