Abstract
SIGNIFICANCE This cross-sectional study presented a link between contact lens wear and changes on the cellular morphology characteristics of the lid wiper (LW) epithelium, which was not visible by LW staining.
PURPOSE The aim of this study was to establish if the duration of contact lens (CL) wear affects the cellular morphology of the LW epithelium.
METHODS This was a cross-sectional study of 100 individuals with different exposures to CL wear: short, moderate, and long experience of CL wear; previous CL wearers; and nonwearers (NWs) as controls. Impression cytology samples were collected from the central upper lid margin (LW area). After fixing, samples were stained with periodic acid-Schiff and haematoxylin for cell morphology analysis and subsequently graded according to the Nelson 0- to 3-point scale. Lid wiper staining was assessed with the aid of lissamine green and graded using the Korb (0- to 3-point) scale. One-way Kruskal-Wallis analysis followed by the Dunn multiple-comparisons test was used for statistical comparison.
RESULTS The Nelson grade for LW epithelium morphology was significantly different between groups (P = .003). Abnormal epithelial morphology as defined by grade 2 or 3 was evident in 66.7% of CL wearers with short experience and 76.5% of CL wearers with moderate experience. This was significantly higher than NWs of whom only 21.5% showed greater than grade 1 (P = .02 and .005, respectively). There was no significant difference between NWs and other groups. Lid wiper staining did not significantly differ between groups (P = .50) or correlate with the Nelson grade (Spearman r = 0.02, P = .08).
CONCLUSIONS Metaplasia of the LW epithelium was significantly greater in the early to moderate stages of CL. This supports the view that mechanical irritation is responsible for LW changes in CL wear. Ceasing CL wear seems to lead to recovery. Lid wiper staining did not reflect the underlying morphological changes.