Elevated serum IGF-1 level enhances retinal and choroidal thickness in untreated acromegaly patients

1) To compare the retinal, choroidal, Haller's layer, and Sattler's/choriocapillaris thicknesses of untreated acromegaly patients without chiasm compression or diabetes mellitus and healthy controls. 2) To evaluate the correlations of retinal and choroidal thicknesses with serum growth hormone (GH) and insulin-like growth factor 1 (IGF) burden.

This prospective, case-control study included 27 untreated acromegaly patients and 27 sex-matched and age-matched controls. Subfoveal choroidal, Haller's layer and Sattler's/choriocapillaris thicknesses were determined by enhanced-depth imaging optical coherence tomography (EDI-OCT). Foveal and macular retinal thicknesses were determined with SD-OCT. GH and IGF-1 burdens were defined as the product of disease duration and treatment-naïve serum GH and IGF-1 levels.

Compared with healthy controls, patients with acromegaly exhibited significantly increased foveal retinal (p = 0.003), subfoveal choroidal (p < 0.001), and Haller's layer (p < 0.001) thicknesses, with no differences in Sattler's/choriocapillaris layer thickness. Multiple point measurements in the posterior pole area showed equally increased nasal and temporal parts of the choroid. The retinal thickness maps of the two groups did not significantly differ. Correlation analysis indicated that choroidal thickness was significantly correlated with disease duration (p = 0.01), serum IGF-1 level (p = 0.03) and IGF-1 burden (p = 0.009). No significant correlations were detected between choroidal thickness and GH burden (p = 0.44). Retinal thickness was not significantly correlated with any factor.

The choroidal thickness of acromegaly patients was greater than that of healthy controls and was significantly correlated with disease duration, IGF-1 level and IGF-1 burden, indicating that excessive serum IGF-1 and its exposure time have a combined effect on choroidal thickness.