# Evaluation of retinal nerve fiber and ganglion cell layer abnormalities using optical coherence tomography in thyroid-associated orbitopathy

## TL;DR

This study uses optical coherence tomography to detect retinal changes in thyroid-associated orbitopathy patients and finds a link between retinal nerve fiber layer thinning and disease severity.

## Contribution

The study demonstrates that OCT can detect retinal nerve fiber layer changes in thyroid-associated orbitopathy, even in inactive phases.

## Key findings

- Thyroid-associated orbitopathy patients had significantly reduced peripapillary retinal nerve fiber layer thickness in the temporal quadrant.
- A strong correlation was found between orbitopathy severity and decreased retinal nerve fiber layer thickness.
- No significant differences were observed in ganglion cell layer thickness between patients and controls.

## Abstract

This study aimed to evaluate abnormalities in the retinal nerve fiber layer
and ganglion cell layer in patients with thyroid-associated orbitopathy
using optical coherence tomography and to examine their relationship with
disease severity.

A cross-sectional study was conducted involving 74 participants, comprising
45 individuals with thyroid-associated orbitopathy and 29 healthy controls.
All subjects underwent a comprehensive ophthalmological examination and
optical coherence tomography using the Cirrus HD-OCT. The clinical activity
score and the European Group on Graves’ Orbitopathy severity were also
evaluated.

In the thyroid-associated orbitopathy group, the mean peripapillary retinal
nerve fiber layer thickness was significantly reduced in the temporal
quadrant (p<0.05). No significant differences were found in ganglion cell
layer thickness across all sectors when compared with the control group.
Besides, a significant correlation was observed between orbitopathy severity
and decreased mean peripapillary retinal nerve fiber layer thickness
(p<0.001).

Optical coherence tomography may serve as a useful tool for identifying
changes in the retinal nerve fiber layer and ganglion cell layer in patients
with thyroid-associated orbitopathy, including in the inactive phase and
prior to the clinical manifestation of dysthyroid optic neuropathy. It may
be a helpful adjunct in monitoring disease progression.