Meibomian Gland Dysfunction Correlates to the Tear Film Instability and Ocular Discomfort in Patients with Pterygium

Huping Wu,Nuo Dong,Xumin Shang,Fan Yang,Shunrong Luo,Zhirong Lin,Zuguo Liu,Xie Fang,Wei Li

doi:10.1038/srep45115

Abstract

Pterygium is a very common disease in an eye clinic characterized by a benign proliferation of local conjunctiva that often crosses the limber of cornea and extends into corneal surface. Variety of studies has showed that pterygium is able to result in ocular discomfort and the change of ocular surface environment, such as dry eye. However, the link between abnormal tear film function and pterygium is controversial. Meibomian gland dysfunction (MGD) is a common cause of dry eye and ocular discomfort but is often neglected, which may be the missing link between dry eye and pterygium. In this study, our data firstly revealed increased abnormality of meibomian gland structure and function in pterygium patients, representing with increased abnormality of MGD parameters such as meibum expression (P < 0.001) and meibomian gland loss (P < 0.001). Besides, the scores of MGD severity in patients with progressive pterygium were higher than those in patients with resting pterygium. The correlation between MGD parameters and ocular discomfort as well as dry eye indexes is also established. These findings suggest that MGD correlates to the tear film instability and ocular discomfort in patients with pterygium.

Highlights

Despite that there are many studies on the pterygium and itself function of tear film[3,4,5,6], the correlation between the two is controversial
The Ocular Surface Disease Index (OSDI) value was significantly higher in pterygium patients than that of volunteers (20.05 ± 8.09 and 12.00 ± 5.16, respectively, P < 0.001), while the non-invasive tear film break up time (NIBUT) was apparently lower than that of volunteers (5.39 ± 2.72 and 8.29 ± 3.96, respectively, P < 0.001)
It was generally considered that tear film instability in pterygium patients may arise from two major factors: altered tear dynamics and chronic ocular surface inflammation

Summary

Introduction

Despite that there are many studies on the pterygium and itself function of tear film[3,4,5,6], the correlation between the two is controversial. Some researchers reported that the epithelial cells of pterygium are in a status of high proliferation and differentiation, which resulted in a disability of mucin secretion or abnormal mucins leading to the abnormal protein layer of tear film[7,8]. Other scholar reported that pterygium itself could lead to a local conjunctival elevation and an uneven distribution of tear resulting in dry eye with tear dynamics abnormality[7]. MGD is a common cause of evaporative dry eye and ocular discomfort but is often neglected. We attempted to demonstrate and analyze the relationship between the meibomian gland function and parameters of dry eye as well as ocular discomfort

Methods

Results

Conclusion