Ocular Surface Disease Related to the Inflammatory and Non-Inflammatory Phases of Thyroid Eye Disease

Purpose: This study evaluated the ocular surface disease (OSD), especially dry eye disease (DED) parameters by combining qualitative and quantitative tools, including tear matrix metalloproteinase 9 (MMP-9), in patients with Graves' disease (GD) with and without Thyroid eye disease (TED).Patients and Methods: A total of 17 active TED, 16 inactive TED, 16 GD without ophthalmopathy, and 16 healthy controls were included. All patients were assessed with CAS, ophthalmometry, qualitative tear MMP-9, Ocular Surface Disease Index (OSDI), ocular surface staining, Schirmer test, meibography, tear meniscus height, conjunctival hyperemia, and non-invasive tear film break-up time. Patients were classified into three subtypes of DED: aqueous tear deficiency, meibomian gland dysfunction (MGD) and mixed dry eye.Results: Inactive TED was shown to be an associated factor with DED (odds ratio 14, confidence interval 2.24-87.24, p=0.0047), and presented more DED than healthy controls (87.5% versus 33.3%, p=0.0113). MGD was also more prevalent among these subjects than in healthy control (62.5% versus 6.7%; p=0.0273). No significant differences were found in other ophthalmological parameters, except for more intense conjunctival redness among active TED than GD without ophthalmopathy (p=0.0214). Qualitative MMP-9 test was more frequently positive in both eyes among active TED than in other groups (p < 0.0001).Conclusion: Patients with GD were symptomatic and presented a high prevalence of ocular surface changes and DED, particularly the subgroup with inactive TED. Tear MMP-9 detection was associated with active TED suggesting a relationship between ocular surface changes and the initial inflammatory phase of ophthalmopathy.