Purpose
To determine whether (1) thyroid conditions (hyperthyroidism or hypothyroidism) are associated with open-angle glaucoma (OAG) and (2) whether treatment of thyroid conditions is associated with OAG in the United States Medicare population.
Methods
The 2010 Denominator and Physician/Supplier Part B files for a 5% sample of Medicare beneficiaries were used to identify patients with the diagnosis of thyroid conditions, including hyperthyroidism or hypothyroidism, and OAG in 2010 using the International Classification of Diseases version 9 (ICD-9) codes. Surgical treatment of thyroid conditions in 2010 was identified using the Current Procedural Terminology (CPT) codes. Potential confounding factors examined included demographics, Charlson Comorbidity Index (CCI) score, and systemic co-morbidities, including rheumatoid arthritis and Parkinson’s disease. Adjusted odds ratios (OR) of Medicare patients with a diagnosis of OAG during 2010 were estimated for any thyroid conditions and treatment of thyroid conditions using multivariable logistic regression models controlling for all potential confounding factors.
Results
In the 5% sample of Medicare beneficiaries in 2010, there were 249945 (20.2%) patients diagnosed with thyroid conditions, including 18364 (1.5%) with hyperthyroidism and 240899 (19.5%) with hypothyroidism. Among them, 812 (0.3%) subjects had surgical treatment for thyroid conditions. There were 96127 (7.8%) OAG patients. Compared to those without any thyroid conditions, adjusted OR (95% confidence interval [CI]) of having OAG was 1.12 (1.10, 1.14; p<0.0001) for all thyroid conditions, 1.14 (1.08, 1.20; p<0.0001) for hyperthyroidism, and 1.12 (1.11, 1.14; p<0.0001) for hypothyroidism. Compared to thyroid patients without surgical treatment, adjusted OR (95% CI) of having OAG was 0.76 (0.58, 1.00; p=0.047) for thyroid patients who received surgical treatment.
Conclusions
Reports regarding the association between thyroid conditions and OAG have been limited and inconsistent. This study found that a diagnosis of any thyroid condition is associated with a 12% increased odds of OAG, and this association was similar for hyperthyroidism and hypothyroidism. Among patients with thyroid conditions, surgical treatment is associated with a 24% reduced odds of OAG. Further prospective studies are warranted to investigate the relationship between thyroid dysfunction and OAG.
Keywords: 463 clinical (human) or epidemiologic studies: prevalence/incidence