Evaluation of orbital soft tissue parameters in patients with thyroid ophthalmopathy Using the Dynamic Scheimpflug Analyzer (Corvis ST)
Mohammad Yaser Kiarudi1 *, Arman Moein Rad2 , Siamak Zarei-Ghanavati1 , Aliakbar Sabermoghaddam3
- Eye research center, Mashhad University of Medical Sciences, Mashhad, Iran
- Mashhad University of Medical Sciences, Mashhad, Iran
- Eye research center, Mashhad University of Medical Sciences, Mashhad, Iran
Abstract: In thyroid eye disease (TED), all orbital contents such as muscles, eyelids, tear glands and fatty tissues behind the globe could be affected. In this study, we aimed to quantify the biomechanical parameters of the orbital soft tissues by measuring and comparing whole eye movement (WEM) and other parameters using the Corvis-ST (CST, Oculus Wetzlar, Germany).
Methods: In this study, thirty eyes of 30 consecutive patients, known cases of thyroid eye disease were recruited. The age, gender, exophthalmometry, severity, and activity of disease were gathered and Biomechanical response parameters (intraocular pressure (IOP), whole eye movement length (WEMl) and time (WEMt), deflection amplitude max, and stiffness parameter were measured in patients and in age- and gender-matched healthy subjects using the CST.
Results: The mean age of patients was 39.67±11.8 years old. Eleven out of 30 TED patients and nine of 30 healthy subjects were male. The median duration of thyroid disease and thyroid eye disease was 36 months and 21 months, respectively. Seven out of 30 patients had active disease. Based on the severity of the disease, 22 patients had severe disease. Regarding corneal biomechanical properties, the Deflection Amplitude max was statistically different between TED group and healthy subjects (p = 0.001). The mean of WEMl was 0.213±0.072 mm in TED group and 0.262±0.063 mm in healthy subjects which was statistically significant (p = 0.008). The mean of WEMt was 23.23 ms in TED group and 37.77 ms in healthy subjects (p = 0.001). The mean of WEMl was statistically lower in patients with active disease (p = 0.006). Also, the patients with active disease had shorter WEMt compared with patients with inactive disease (p = 0.039).
Conclusion: The orbital biomechanical properties including WEM length and time of patients with thyroid eye disease were significantly decreased compared with normal subjects. Furthermore, these parameters were significantly decreased in active phase of TED. So, WEMl and WEMt might be useful diagnostic tools to evaluate the compliance of orbit in patients with TED.
