RESUMO
PURPOSE: To investigate the ocular inflammatory response, using clinical and immunological techniques, in people experiencing contact lens (CL) discomfort. METHODS: This study involved 38 adults who were full-time, silicone-hydrogel CL wearers. Participants were categorized into groups based upon a validated CL dry-eye questionnaire (CLDEQ-8) (nâ¯=â¯17 'asymptomatic', CLDEQ-8 score <9; nâ¯=â¯21 'symptomatic', CLDEQ-8 score ≥13). Examinations were performed at two visits (one with, and one without, CL wear), separated by one-week. Testing included: tear osmolarity, ocular redness, tear stability, ocular surface staining, meibography, tear production and tear collection. Tear osmolarity was taken from the inferior-lateral and superior-lateral menisci. The 'Inferior-Superior Osmotic Difference', I-SOD, was the absolute osmolarity difference between these menisci. Concentrations of seven cytokines (IL-2, IL-4, IL-6, IL-10, IL-17A, IFN-gamma, TNF-alpha) were assayed from basal tears using multiplex cytometric bead array. RESULTS: At baseline, there was no significant difference in key clinical signs between asymptomatic and symptomatic CL wearers (pâ¯>â¯0.05). The I-SOD was greater in symptomatic than asymptomatic CL wearers (23.1⯱â¯2.6 versus 11.3⯱â¯1.4 mOsmol/L, pâ¯=â¯0.001). People experiencing CL discomfort had higher tear IL-17A (122.6⯱â¯23.7 versus 44.0⯱â¯10.0â¯pg/mL, pâ¯=â¯0.02) and reduced tear stability (6.3⯱â¯1.1 versus 10.4⯱â¯1.6â¯s, pâ¯=â¯0.03) after several hours of CL wear. Tear IL-17A levels correlated with both the I-SOD (râ¯=â¯0.43, pâ¯=â¯0.01) and CLDEQ-8 score (râ¯=â¯0.40, pâ¯=â¯0.01). CONCLUSIONS: CL discomfort occurs in individuals having no clinical dry eye signs, and is associated with higher tear levels of the pro-inflammatory cytokine IL-17A. These findings support an association between the discomfort response and low-grade, ocular surface inflammation.
Assuntos
Túnica Conjuntiva/metabolismo , Lentes de Contato Hidrofílicas/efeitos adversos , Citocinas/biossíntese , Síndromes do Olho Seco/metabolismo , Inflamação/metabolismo , Lágrimas/metabolismo , Regulação para Cima , Adulto , Síndromes do Olho Seco/etiologia , Feminino , Humanos , Masculino , Concentração OsmolarRESUMO
Purpose: To assess whether tear hyperosmolarity, being diagnostic of dry eye disease (DED), is associated with specific alterations to the cytokine content of human tears that may provide a biomarker for DED. Methods: In this prospective, cross-sectional, clinical study, participants (n = 77) were recruited from a single clinical site and categorized into groups based upon tear osmolarity status (n = 62 hyperosmolar, n = 15 normo-osmolar). Comprehensive anterior eye clinical assessments were undertaken. Concentrations of seven cytokines (IL-2, IL-4, IL-6, IL-10, IL-17A, IFN-γ, and TNF-α) in basal tears were assayed using multiplex cytometric bead array. The main outcome measure was difference in cytokine concentration between groups. Group comparisons were undertaken using 2-tailed t-tests. Cohen's effect size was calculated for each finding. Spearman correlations between cytokine concentrations, clinical symptoms, and clinical parameters of DED were calculated. Results: Tear hyperosmolarity was specifically associated with increased tear IFN-γ levels (13.3 ± 2.0 vs. 4.4 ± 1.4 pg/mL, P = 0.03). Cohen's effect size was large (0.8) for changes to tear IFN-γ levels. Significant correlations were observed between IFN-γ concentration and each of: tear osmolarity (r = 0.34; P = 0.007), total ocular surface staining (r = 0.56, P < 0.0001), and Schirmer test score (r = -0.33, P = 0.003). Conclusions: Tear hyperosmolarity is specifically associated with higher levels of the proinflammatory cytokine IFN-γ, which correlate with key clinical parameters of DED. The calculated effect size (0.8) suggests that this assay has diagnostic power as a biomarker for evaporative DED.