Changes in retinal nerve fibre layer, ganglion cell layer and visual function in eyes with thyroid eye disease of different severities with and without orbital decompression.

PURPOSE: To evaluate progressive changes in retinal nerve fibre layer (RNFL), ganglion cell layer/inner plexiform layer (GCL/IPL) and visual function in thyroid eye disease (TED) patients with and without orbital decompression.

METHODS

Sixty TED patients (105 eyes) were included. All patients were divided into mild, moderate-to-severe and dysthyroid optic neuropathy (DON) groups. Orbital decompression was performed in the moderate-to-severe and DON groups. Optic coherence tomography (OCT), visual field (VF) and best-corrected visual acuity (BCVA) were performed pre- and postoperatively. Preoperative follow-up was performed in the mild group and in part of the moderate-to-severe and DON groups.

RESULTS

After decompression, the thickness of GCL/IPL and RNFL significantly decreased in DON group (p < 0.05), with varying degrees of decrease in eyes with optic disc swelling, atrophy and normal appearance. The mean GCL/IPL thickness significantly decreased in moderate-to-severe group (p < 0.05), the mean RNFL thickness slightly decreased with no statistical significance (p = 0.07). During the preoperative follow-ups, the mean GCL/IPL thickness significantly decreased (p = 0.04), whereas the mean RNFL thickness tended to increase (p = 0.13) in DON group. The thickness of GCL/IPL and RNFL did not change significantly in the mild and moderate-to-severe groups (p > 0.05). BCVA and VF did not change significantly in any group (p > 0.05) preoperatively.

CONCLUSION

Swelling and degeneration of retinal ganglion cells (RGCs) may coexist in DON eyes, leading to continuous changes in the RNFL and GCL/IPL thickness either before or after decompression. Slight swelling and degeneration of RGCs may exist in moderate-to-severe TED eyes, although OCT measurements and visual functions remain stable before surgery.