Correlation between Structural and Functional Changes in Patients with Raised Intraocular Pressure Due to Graves' Orbitopathy

This study explores the complication of secondary intraocular pressure (IOP) elevation and consequent glaucoma development in Graves' orbitopathy (GO), an autoimmune disorder associated with hyperthyroidism. Utilizing Octopus 900 visual field testing and optical coherence tomography (OCT), the research established correlations between functional and structural changes in optic nerve regions in patients with GO and patients with GO with elevated IOP (GO IOP) groups. A comparison with primary open-angle glaucoma (POAG) was conducted in a cohort of 182 subjects. The study identifies optic nerve head parameters that effectively differentiate changes in GO and GO IOP groups. In the GO group, the strongest correlation between structural and functional changes was observed in sector 7, while in the GO IOP group, it was in sectors 1 and 7. For POAG, correlation was found in six sectors. Elevated IOP in GO correlates with structural and functional impairments similarly to early glaucoma. Risk factors for GO-related elevated IOP included older age, longer duration of thyroid disease, and higher anti-thyroglobulin values. The study highlights the significance of regular IOP measurements, visual field assessments, and OCT examinations in GO patients. Early antiglaucoma intervention is warranted when characteristic structural and functional changes and/or risk factors are identified.