Abstract
Purpose :
The prevalence of contact lens (CL) use is increasing worldwide owing to various factors. Albeit the many benefits, the adverse effects of CL wear on the ocular surface are no less important. To date, many studies had assessed the pathophysiology of CL use on tear film, the main component of the anterior eye that is directly affected by CLs. However, in-depth studies at the protein level are still lacking. Hence, this study endeavoured to elucidate the differentially expressed protein profiles in tears of hard and soft CL users and, to investigate for the first time the proteome changes associated with renouncement of CL employing the mass-spectrometry (MS)-based proteomic platform.
Methods :
Tear samples were collected from non-CL users (Controls) (N= 22), hard CL (N= 16) and soft CL (N= 18) users. Tears were collected before and after renouncement (for 4.7 ± 0.7 days) of CL use. Samples were pooled in each group and subjected to label-free quantitative MS analyses. The acquired MS spectra were analysed by MaxQuant computational proteomics platform, followed by functional annotation and pathways analyses.
Results :
A total of 261 proteins were identified in the tear samples with less than 1 % false discovery rate. Among these, 93 proteins were significantly (P <0.01) differentially expressed in both CL groups. The differential expressions of some proteins were exclusive to a particular CL type, such as the HSPA8 and PRR4 in the hard CL and, ENO1 and PROL1 in the soft CL group. The top clusters of proteins significantly upregulated in both CL users were involved in inflammatory responses and metabolic diseases. Interestingly, many of these were restored to near-normal after renouncement, namely AGT, PIP, TF and MSLN. Conversely, specific protein clusters did not revert back to normal levels after renouncement especially FABP5, which was a common up-regulated protein in both groups.
Conclusions :
In gist, this study elucidated the complex proteome alterations implicated in tears of both types of CL users. Importantly, these findings have provided first evidence that there are specific proteome changes attributed to renouncement of CL wear. These proteins might be the key players that maintain homeostasis and provide protection on the ocular surface.
This is an abstract that was submitted for the 2017 ARVO Annual Meeting, held in Baltimore, MD, May 7-11, 2017.