SIZE AND NUMBER OF EPITHELIAL-CELLS WASHED FROM THE CORNEA AFTER CONTACT-LENS WEAR

Using the technique of Fullard and Wilson, tear samples were collected atraumatically from the corneas of 14 rigid gas permeable (RGP) conta ct lens wearers, 14 soft contact lens (SCL) wearers, and 22 controls w ho did not wear contact lenses. Samples were analyzed for the number, size, and contiguity of the cellular contents. Both RGP and SCL groups had, on average, significantly fewer cells per sample than controls ( median values were Il and 12 cells vs. 44). The difference remained si gnificant even after a correction of three cells was applied to accoun t for cells adherent to the lenses. Approximately 80% of epithelial ce lls from both lens wear and control eyes were found ire isolation, whe reas 20% were contiguous with 1 or 2 other cells. This result is compa tible with the majority of epithelial cells having exfoliated from the surface of the cornea after detaching from their neighbors, rather th an detaching in sheets of cells. The cell length and cell area were an alyzed. RGP wearers had significantly smaller cells than controls, whe reas SCL wearers had slightly (but significantly) larger cells. These results may reflect changes in the exfoliation mechanism of the cornea l epithelium in contact lens wear.