Purpose: To test the hypothesis that there is an association between hypothyroidism and primary open-angle glaucoma.
Methods: The study was conducted in a case-control fashion. Sixty-four patients with primary open-angle glaucoma were evaluated for hypothyroidism by history and by undergoing a thyroid-stimulating hormone immunoradiometric assay. Sixty-four control subjects from the general eye clinic were evaluated in the same manner. Patients found to have elevated thyroid-stimulating hormone immunoradiometric assay were evaluated by an endocrinologist for hypothyroidism.
Results: Of the primary open-angle glaucoma group, 23.4% had hypothyroidism. A diagnosis was made previously in 12.5% patients, and 10.9% were newly diagnosed. Of the control subjects, 4.7% had hypothyroidism. A diagnosis had been made previously in 1.6% of the control subjects, and 3.1% were newly diagnosed. The difference between the two groups was found to be statistically significant.
Conclusion: A statistically significant association between hypothyroidism and primary open-angle glaucoma is demonstrated. There is a large group (10.9%) of patients with primary open-angle glaucoma with undiagnosed hypothyroidism.