Inflammatory response to contact lenses in patients with keratoconus compared with myopic subjects.

PURPOSE

To determine the levels of inflammatory molecules in the tears of patients who wore rigid gas permeable (RGP) contact lenses (CLs) and who had either keratoconus or myopia.

METHODS

A prospective, case-control study with 4 groups enrolled 20 RGP CL keratoconus wearers and 28 keratoconus non-lens wearers, 20 myopic CL wearers, and 20 subjects with myopia that were non-lens wearers (1 eye per patient). Fifteen microliters of tears were collected by capillary flow. The concentration of cytokines (interleukin-6 [IL-6], IL-10, and tumor necrosis factor [TNF]-alpha), cell adhesion molecules (intercellular adhesion molecule 1 [ICAM-1] and vascular cell adhesion molecule 1 [VCAM-1]), and matrix metalloproteinase (MMP-9) was measured by enzyme-linked immunosorbent assay.

RESULTS

The most significant differences associated with the wearing of RGP CLs in patients with keratoconus were seen in increased levels of proinflammatory cytokines (IL-6, 23.7 vs. 6.4 pg/mL, P = 0.001; TNF-alpha, 21.3 vs. 3.8 pg/mL, P = 0.028) and cell adhesion molecules (ICAM-1, 32.8 vs. 7.7 ng/mL, P < 0.0001; VCAM-1, 57.4 vs. 29.3 ng/mL, P < 0.0001). In patients with myopia, increased levels of TNF-alpha (4.2 vs. 1.8 pg/mL, P < 0.0001) and MMP-9 (12.9 vs. 6.1 ng/mL, P < 0.0001) were associated with the wearing of RGP CLs.

CONCLUSIONS

Wearing RGP CLs induces overexpression of IL-6, TNF-alpha, ICAM-1, and VCAM-1 in the tears of patients with keratoconus. These increased levels are higher in cases with severe keratoconus.