Meibomian gland dysfunction, but not atrophy, was associated with lower tear lactoferrin concentration, greater dry eye, and allergic symptoms, indicating greater inflammation and discomfort in patients with lower meibomian gland expressibility.
Meibomian gland dysfunction can potentially damage adjacent palpebral structures, which may induce inflammation in accessory lacrimal glands and affect lactoferrin secretion. This study aimed to examine the relationships between the severity of meibomian gland dysfunction with tear lactoferrin, conjunctival cell morphology, and clinical features of ocular allergy.
Forty subjects were divided into two groups based on the severity of meibomian gland plugging and expressibility and secondarily based on its atrophy. Dry eye and allergy questionnaires; slit-lamp examination, including lid telangiectasia; and meibography were performed. Tear lactoferrin concentration was measured using TearScan 270 MicroAssay. Impression cytology was performed on the upper palpebral conjunctiva, and goblet cell density and epithelial squamous metaplasia were quantified.
Twenty-two subjects with meibomian gland dysfunction were categorized into severely obstructed group (case), whereas 19 subjects had minimal/no obstruction (comparison). Lower lactoferrin (1.3 ± 0.4 vs. 1.7 ± 0.4 mg/mL, P = .007), greater dry eye (7 [1 to 10] vs. 2 [0 to 5], P = .03), and allergy symptoms (9 [4 to 23] vs. 6 [0 to 9], P = .05) were found in the cases compared with the comparisons. There were no differences in conjunctival cell morphology between groups. The plugging score was correlated with lactoferrin concentration (ρ = −0.43, P = .006), dry eye (ρ = 0.36, P = .02), and allergic symptoms (ρ = 0.33, P = .04). Greater lid margin telangiectasia was associated with meibomian gland obstruction, but not atrophy.
Meibomian gland activity/dysfunction, but not atrophy, may be associated with increased inflammation on the ocular surface. The inflammation may be sufficient to reduce tear lactoferrin production from damage to accessory lacrimal glands and/or meibomian gland and result in increased symptoms.
1Singapore Eye Research Institute, Singapore
2Center for Translational Ocular Immunology, Department of Ophthalmology and Cornea Service, Tufts Medical Center, Boston, Massachusetts
3UNSW School of Optometry and Vision Science, University of New South Wales, Sydney, New South Wales, Australia
4Singapore National Eye Centre, Singapore
5Duke-NUS Medical School, Singapore
6Yong Loo Lin School of Medicine, National University of Singapore, Singapore *firstname.lastname@example.org
Submitted: January 29, 2018
Accepted: June 3, 2018
Funding/Support: National Medical Research Council (NMRC/CSA/045/2012; to LT).
Conflict of Interest Disclosure: None of the authors have reported a financial conflict of interest.
Study Registration Information: CIRB ref. no.: 2015/2346.
Author Contributions and Acknowledgments: Conceptualization: CC, LT; Data Curation: CC; Formal Analysis: CC; Funding Acquisition: LT; Investigation: CC, LT; Methodology: CC; Project Administration: CC; Resources: CC, LT; Supervision: LT; Validation: CC; Writing – Original Draft: CC; Writing – Review & Editing: CC, LT.
The authors thank Sharon Yeo Wan Jie and Cynthia Boo Shiao Khee for their help on recruitment. This work has not been previously presented at any scientific meetings.