To Quantitatively Assess and Compare Choroidal and RNFL Thickness in Patients with Active and Inactive Thyroid Eye Disease.

Introduction: Thyroid eye disease (TED) can be classified into an active phase with rapid progression and an inactive phase with symptom stabilization. Recent studies found a higher choroidal thickness in patients with active TED. Less is known about the effect of disease on the retina. More extensive study is warranted for generalizing the role of choroidal thickness as a biomarker for disease severity. The study aims to investigate the correlation between the subfoveal choroidal and circumpapillary retinal nerve fibre layer (cp RNFL) thickness with the severity of the disease. TED.

Methods: This cross-sectional study was conducted in the Ophthalmology department of a tertiary hospital in Central Kerala. A total of 16 participants with TED were included in the study after obtaining informed consent. Based on the CAS score, participants were divided into active and inactive TED groups. Visual acuity, colour vision, and contrast sensitivity were measured. SD-OCT was used to measure choroidal and RNFL thickness. Karl Pearson's correlation coefficient was used to assess the correlation between choroidal thickness and RNFL thickness with CAS.

Results: The difference in the choroidal thickness between the active and inactive groups was statistically significant. There was a significant correlation between the CAS and choroidal thickness (P < 0.05). The difference in the RNFL thickness and different functions of vision between active and inactive groups was statistically insignificant.

Conclusion: In conclusion, our study states that different phases of TED can have a profound effect on choroid.