Investigation of the choroidal thickness in patients with hypothyroidism

The effect of hypothyroidism on the choroidal thickness (CT) was investigated in patients with subclinical hypothyroidism and overt hypothyroidism, and biochemically and clinically euthyroid patients receiving levothyroxine treatment. The patients were compared with healthy subjects.

One eye of 71 hypothyroid and 22 healthy subjects between 20 and 40 years of age were included in this study. CT measurements were taken at the fovea and at 2 points that were 1500 μm nasal and temporal to the fovea using spectral-domain optical coherence tomography. Independent sample t-test's and was used for statistical analysis of the data.

The CT was significantly thicker in hypothyroid patients compared to healthy subjects (P values were 0.013 for subfoveal, 0.015 for temporal and 0.020 for nasal segments). The intraocular pressure (IOP) and body mass index (BMI) were also significantly higher in hypothyroid patients (P values were 0.021 and 0.003, respectively). There was not a statistically significant difference in the BMI and IOP measurements between healthy subjects and euthyroid patients (P > 0.05). However, there was a statistically significant difference in the subfoveal, temporal and nasal CT measurements between healthy subjects and euthyroid patients (P values were 0.006, 0.031 and 0.013, respectively).

All subgroups of hypothyroid patients had thicker CT compared to healthy subjects. Euthyroid patients receiving levothyroxine treatment had lower IOP, BMI levels, and serum lipid levels than patients with subclinical hypothyroidism and overt hypothyroidism.