Thyroid Eye Disease Linked to Stromal Corneal Thinning

Manifestations of thyroid eye disease (TED) such as proptosis and strabismus may not only alter the mechanical environment of the globe, but potentially influence corneal shape or biomechanics. Some studies have observed changes in corneal microstructure and significantly higher permeability of the corneal epithelium in TED than control groups, yet consensus regarding central corneal thickness (CCT) in patients with TED is lacking. A new study, published in the journal Translational Vision Science & Technology, evaluated layer-specific and sector-specific differences in corneal thickness in these patients and found a clear link between TED and structural changes in the cornea, especially within the stromal layer. This retrospective study included 75 eyes of 38 patients (29 with inactive TED and nine healthy controls; 25 women and 13 men) from a tertiary medical center in Taiwan. Screening indices related to corneal irregularity, such as keratoconus prediction index and opposite sector index, were numerically higher in the TED group but remained within normal limits. In all corneal sectors, the mean total corneal thickness (TCT) and corneal stromal thickness (CST) were significantly lower in the TED group (e.g., central CST, 480.33μm in TED vs. 498.94μm in controls). Notably, no significant differences in corneal epithelial thickness were observed between the two groups across all evaluated sectors. A retrospective study published in Translational Vision Science & Technology found that patients with inactive thyroid eye disease exhibited significant reductions in total and stromal corneal thickness across most sectors, while epithelial thickness remained unchanged. Researchers showed that these structural changes were independent of age and sex, suggesting disease-specific stromal involvement with potential implications for clinical assessment and long-term monitoring. These corneal thickness maps from the study show representative findings from two TED cases (A and C) and two control cases (B and D). TED eyes demonstrate diffuse stromal thinning, particularly in the S and IN sectors, consistent with group-level quantitative findings. Control eyes show normal pachymetric contour and greater overall stromal thickness. Photo: Chang YM, et al. Trans Vis Sci Tech. February 20, 2026. Click image to enlarge. “This study is the first to investigate the thickness of different corneal layers in patients with TED,” the authors wrote in their paper. “Although the differences in most corneal surface indices did not attain statistical significance, a consistent pattern of corneal thinning—particularly involving the stromal layer—was observed in TED eyes.”Patients with TED had a significantly lower mean TCT in nearly all evaluated sectors, except the temporal region, where a decreasing trend was observed, but did not attain statistical significance, the authors continued. “Importantly, this same pattern was observed in CST, where the TED group exhibited a significantly thinner stroma in most sectors, again sparing only the temporal side,” they wrote. The observed stromal and total corneal thinning remained present after adjusting for age and sex, the researchers wrote, “supporting that these differences are attributable to disease status rather than demographic variation.” By contrast, corneal epithelial thickness remained largely comparable between the two groups in all regions. “The congruence of these findings in both TCT and CST reinforces the notion that the corneal thinning in TED predominantly reflects stromal involvement,” the researchers proposed.The authors recognized potential limitations, including the relatively small sample size, particularly in the control group, as well as the inclusion of only patients whose TED was inactive. They added, “Many patients with TED had dry eye disease, which could influence the measurement of corneal thickness. The dry-eye condition was managed with artificial tears; however, it remained a confounding factor when interpreting the results.” They concluded that their findings may have clinical relevance in the evaluation of TED-related ocular manifestations and suggest larger studies to corroborate this correlation.Click here for the journal source. Chang YM, Weng TH, Pao SI, Lin TY, Tai MC, Chien KH. Sectoral and layer-specific corneal thinning in thyroid eye disease: A cross-sectional study. Trans Vis Sci Tech. February 20, 2026. [Epub ahead of print.] This article was developed by the editorial staff in conjunction with experts in the field. In the process, AI may have been among the editorial tools used to meet the goals of human editors, who approved all content.