title: Inflammatory response to contact lenses in patients with keratoconus compared with myopic subjects.
abstract: OBJECTIVE
  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.
authors.affiliation: Instituto Galego de Oftalmoloxía, Universidad de Santiago de Compostela, Santiago de Compostela, Spain. isbellg@usc.es
authors.forename: Isabel
authors.initials: I
authors.lastname: Lema
authors.forename: Juan A
authors.initials: JA
authors.lastname: Durán
authors.forename: Consuelo
authors.initials: C
authors.lastname: Ruiz
authors.forename: Elío
authors.initials: E
authors.lastname: Díez-Feijoo
authors.forename: Arantxa
authors.initials: A
authors.lastname: Acera
authors.forename: Jesús
authors.initials: J
authors.lastname: Merayo
mesh_terms: D000328:Adult; D016022:Case-Control Studies; D003261:Contact Lenses; D016207:Cytokines / Q000378:metabolism*; D004797:Enzyme-Linked Immunosorbent Assay; D005136:Eye Proteins / Q000378:metabolism*; D005260:Female; D006801:Humans; D018836:Inflammation Mediators / Q000378:metabolism; D007640:Keratoconus / Q000378:metabolism / Q000628:therapy*; D008297:Male; D009216:Myopia / Q000378:metabolism / Q000628:therapy*; D011446:Prospective Studies; D013666:Tears / Q000378:metabolism*
chemical_list: D016207:Cytokines; D005136:Eye Proteins; D018836:Inflammation Mediators; C042434:tear proteins