Epithelial pigment slide in contact lens wearers: a possible marker for contact lens-associated stress on corneal epithelium.

Abstract

To compare the incidence of epithelial pigment slide among wearers of various types of contact lenses. Prospectively, we studied 432 eyes of 432 patients. The patients were separated into 6 groups: hard contact lens (HCL) wearers (n = 166), conventional soft contact lens (CSCL) wearers (n = 30), extended disposable lens (EDCL) wearers (n = 46), frequent replacement SCL (FRCL) wearers (n = 60), daily disposable SCL (DDCL) wearers (n = 65), and normal controls (n = 65). The incidence of prominent pigment slide, defined as spike-like epithelial opacities in the corneal limbus and longer than 1 mm from the base to the apex of the wedges-shaped process detected by slit-lamp examination, was compared in these 6 groups. The relationship between the incidence of prominent pigment slide and the length of contact lens wear was examined. The overall incidence of prominent pigment slide in the CSCL, EDCL, HCL, FRCL, DDCL, and normal groups was 63.3, 23.9, 13.9, 8.3, 7.7, and 4.6%, respectively. The incidence of prominent pigment slide in the CSCL and EDCL groups was significantly higher than that in the control group. A higher incidence of prominent pigment slide was correlated with longer wearing period in each group. The presence of epithelial pigment slide may be a marker for contact lens-associated stress to the corneal epithelium.