**5. Conclusions**

In summary, we found strong associations between dry eye symptoms in GO patients and ocular surface parameters, including MGD and DED. These were characterized by meibomian gland dropout at the center of the eyelids, as well as eyelid margin vascular engorgemen<sup>t</sup> and inflammation. Inflammation and morphological changes of meibomian glands might be characteristic findings in patients with GO. Although further investigations are required to elucidate the mechanism underlying the association between the ocular surface state, including MGD and DED, and GO, the present findings indicate the possibility that MGD may be involved in causing eye discomfort in patients with GO.

**Author Contributions:** Conceptualization, M.K. and R.A.; formal analysis, S.I.; investigation, M.K. and S.I.; writing—original draft preparation, S.I.; writing—review and editing, M.K., R.A., A.K. and K.T.; visualization, M.K.; supervision, A.K., K.T.; project administration, M.K. All authors have read and agreed to the published version of the manuscript.

**Funding:** This research received no external funding.

**Conflicts of Interest:** R.A. holds the patent of the non-invasive meibography system (JP Patent Registration No. 5281846, US Patent Publication No. 2011-0273550A1, EP Patent Publication No. 2189108A1). R.A. is a consultant for Japan Focus Corporation. No conflicting relationship exists for the other authors.
