Evaluation of Retinal Neurodegeneration and Choroidal Thickness in Patients with Inactive Graves' Ophthalmopathy.

Abstract

The study was conducted for the assessment of the retinal nerve fiber layer, ganglion cell layer, and subfoveal choroidal thickness changes in patients with inactive Graves' ophthalmopathy (GO) using swept-source optical coherence tomography (SS-OCT) before the development of active GO findings. The cross-sectional designed study consisted of patients with inactive Graves' ophthalmopathy (study group) and healthy subjects (control group). The thicknesses of the retinal ganglion cell layer, retinal nerve fiber layer, and subfoveal choroid (SFCT) were measured using SS-OCT with deep range imaging technology to compare these parameters between the study and control groups. Patients with inactive Graves' ophthalmopathy had higher values of intraocular pressure but similar best-corrected visual acuity (p = 0.001, p = 0.232, respectively). The retinal nerve fiber layer was thinner only in the superior zone of the study group (p = 0.039), whereas similar values were noted in the temporal, nasal, and inferior areas as well as the average thickness. We did not observe any statistically significant difference in any sector of the ganglion cell layer between the study and control groups. A thicker mean subfoveal choroidal thickness value was measured in patients with inactive Graves' ophthalmopathy than in healthy subjects (p = 0.013) in correlation with a clinical activity score (p = 0.046). SS-OCT showed minimal retinal neurodegenerative alteration and significant choroidal thickening in inactive GO. Thus, SS-OCT might be a beneficial technique to detect retinal neurodegenerative and choroidal changes earlier in the stage of inactive GO before the development of active GO signs, which may affect the time and type of treatment modalities to prevent further ocular or systemic complications. Additionally, SFCT may be a good indicator for assessment of the severity of Graves' disease.