Abstract
Purpose:
To quantify and compare the concentration of selected tear lipids and proteins in symptomatic and asymptomatic lens (CL) wearers.
Methods:
Evening tears were collected using fine glass capillary tubes from forty five healthy, adapted CL wearers. Twenty two had self-described symptoms of dryness and discomfort with CLs and 23 were asymptomatic. Tears were assayed for concentration of proteins using selected reaction monitoring mass spectrometry. Enzyme immunoassay kits were used to measure prostaglandins, leukotriene B4 and cysteinyl leukotriene (C4, D4 and E4). Subjects were asked to rate their ocular comfort on the scale of 1 (very uncomfortable) to 100 (completely comfortable) at the time of tear collection.
Results:
The average evening comfort level in the subjects was above 70 for the asymptomatic group (83.96 ± 9.51, Mean ± SE) and equal or below 70 for the symptomatic (57.28 ± 12.38) (p < 0.001). LTB4 was significantly higher in symptomatic than asymptomatic CL wearers (0.32 ± 0.06 ng/µL vs 0.17 ± 0.04 ng/µL respectively) (p = 0.03). Lysozyme was slightly but not significantly lower in symptomatic subjects (Symp 0.58 ± 0.10 mg/mL vs Asymp 1.73 ± 0.46 mg/mL; p = 0.10). The levels of lactoferrin, lipocalin 1, proline rich 4, prolactin-induced protein, prostaglandins and cysteinyl leukotrienes were unchanged (p > 0.1) across the comfort groups.
Conclusions:
The LTB4 concentration was significantly higher in symptomatic CL wearers compared to the asymptomatic group, and this may partly mediate the discomfort response during lens wear in the symptomatic lens wearers. No other differences were found in the level of tear factors of interest between the two groups.