The prevalence of strabismus, diplopia and optic nerve involvement is higher in patients with thyroid eye disease and diabetes, according to a recent study published in the journal Endocrine Practice.¹

Researchers examined patients with Graves’ disease or thyroid eye disease using data from the Symphony insurance claims database in the United States between 2010 and 2015. Majority of them were women (76.9%). Patients were also identified as having type 1 or type 2 diabetes using information from the database. Thyroid eye disease included proptosis, strabismus, diplopia, lid retraction, exposure keratoconjunctivitis and optic neuropathy, the last two were defined as sight-threatening thyroid eye disease.

Out of the total of 51,220 patients with Graves’ disease or thyroid eye disease included in the study, 12,846 had type 2 diabetes and 2618 had type 1 diabetes.

In patients with thyroid eye disease, the prevalence of strabismus was higher in patients with type 1 diabetes (25.4%) and type 2 diabetes (22.6%) compared to patients who did not have diabetes (~20%). Diplopia was also more common in patients with type 1 diabetes (38.6%) and type 2 diabetes (37.9%) compared to non-diabetic subjects (~30%). However, the prevalence of proptosis was lower in the diabetic population vs those without diabetes; 42.3% (type 1 diabetes) vs 46.3% (type 2 diabetes) vs 58.5% (non-diabetic), respectively.

Similarly, sight threatening thyroid eye disease also occurred more frequently among patients with diabetes, 13.3% (type 1 diabetes) vs 12.8% (type 2 diabetes) vs 11.2% (non-diabetic), respectively.

About 13.5% of the study subjects had undergone minimum one surgery for thyroid eye disease. Surgery rate was higher in patients with thyroid eye disease but no diabetes (14%) compared with those with type 2 diabetes (12.3%). While nearly 2% of patients with type 2 diabetes had full-thickness keratoplasty, less than one percent of non-diabetic patients underwent the same surgery. Patients without diabetes had higher rates of eyelid surgery compared to type 2 diabetes patients; 58.8% vs. ~55%, respectively. The surgery rates were comparable to those with type 1 diabetes.

This study has attempted to characterize thyroid eye disease among patients with diabetes. It has shown that patients with thyroid eye disease who also have diabetes have a higher prevalence of diplopia and strabismus in comparison to patients with thyroid eye disease but no diabetes suggesting that diabetes influences the severity of thyroid eye disease and is predictive of progression of disease. Hence, thyroid eye disease patients with diabetes, particularly type 1, need to be carefully monitored for optic nerve involvement, and preempt optic nerve involvement. Patients with Graves’ disease should be referred early to the ophthalmologist for early detection of thyroid eye disease.

Reference

1. Patel VK, et al. Characteristics of diabetic and nondiabetic patients with thyroid eye disease in the United States: a claims-based analysis. Endocr Pract. 2022 Feb;28(2):159-164. doi: 10.1016/j.eprac.2021.11.080.