Tear Film Changes and Ocular Symptoms Associated with Soft Contact Lens Wear

Discomfort is one of the leading causes associated with contact lens dropout. This study investigated changes in the tear film parameters induced by lens wear and their relationship with ocular symptomology. Thirty-four lens wearers (32.9 +/- 9.1 years, 7 men) and thirty-three non-lens wearers (29.4 +/- 6.8 years, 12 men) participated in this clinical setting. Subjects were categorised into asymptomatic (n = 11), moderate (n = 15), or severe symptomatic (n = 8). Clinical evaluations were performed in the morning, including blink frequency and completeness, pre-corneal (NIBUT) and pre-lens non-invasive break-up (PL-NIBUT), lipid interference patterns, and tear meniscus height. Contact lens wearers had a higher percentage of incomplete blinks (37% vs. 19%, p < 0.001) and reduced tear meniscus height compared to controls (0.24 +/- 0.08 vs. 0.28 +/- 0.10 mm, p = 0.014). PL-NIBUT was shorter than NIBUT (7.6 +/- 6.2 vs. 10.7 +/- 9.3 s. p = 0.002). Significant statistical differences between the groups were found in the PL-NIBUT (p = 0.01) and NIBUT (p = 0.05), with asymptomatic recording higher times than symptomatic. Long-term use of silicone-hydrogel lenses can affect tear stability, production, and adequate distribution through blinking. Ocular symptomology correlates with tear stability parameters in both lens wearers and non-wearers.