Corneal topographic changes in thyroid eye disease

Background Thyroid eye disease (TED) causes lid retraction, extraocular muscle enlargement, and tear film changes, which can affect corneal topography. Aim To assess the corneal topographic changes associated with TED and relate these changes to disease activity and severity. Patients and methods This prospective cross-sectional case-control study was carried out on 50 eyes of 25 patients aged less than or equal to 50 years old, both sexes, diagnosed with TED and present or past serological evidence for thyroid disease (TED group). Patients were divided into two groups: the TED group: 30 eyes of 15 patients with TED and the control group: 20 eyes of 10 patients with age-matched and sex-matched without TED. Results In the TED group, axial proptosis was negatively correlated with minimal corneal thickness. Both upper and lower lid infrared meibography showed a positive correlation with axial proptosis. Active patients had considerably greater Baiocchi-Calossi-Versaci front and upper lid meibomian glands loss than inactive cases. In moderate to severe instances, upper and lower lid meibomian gland loss was much greater than in mild cases. Baiocchi-Calossi-Versaci front, Baiocchi-Calossi-Versaci back, Baiocchi-Calossi-Versaci total, and meibomian glands loss were considerably greater in TED than the control group. The TED group had significantly lower flat, steep, and average keratometry than the control group. Conclusion Corneal anterior surface flattening is the most characteristic topographic change in TED not related to disease activity or severity. TED increases meibomian gland loss, which is a major factor of ocular surface alteration in TED.