Quantification of Conjunctival Dendritiform Cells under In Vivo Confocal Microscopy for Clinical Activity Evaluation in Thyroid Eye Disease.

Purpose: To quantify the conjunctival dendritiform cells of patients with thyroid eye disease by in vivo confocal microscopy and to investigate its correlation with thyroid eye disease clinical activity.

Methods: In total, 60 thyroid eye disease patients with 60 eyes were recruited and divided into active and inactive groups based on their clinical activity scores. The dendritiform cells at the conjunctiva were examined by in vivo confocal microscopy. The correlation of the conjunctival dendritiform cell density with the clinical activity scores of the thyroid eye disease patients was analyzed. The receiver operating characteristics curve was used to assess the differentiation of active and inactive thyroid eye disease by the dendritiform cells.

Results: The densities of dendritiform cells in the nasal, temporal, and total conjunctiva of the patients with active thyroid eye disease were significantly higher than that of the patients with inactive thyroid eye disease (p < .001). There was no significant difference in dendritiform cell density between the nasal and temporal conjunctiva of the same patient (p = .122). Total conjunctival dendritiform cell density showed a significant positive correlation with the clinical activity scores (r = 0.519, p < .001). The area under the receiver operating characteristics curve for total conjunctival dendritiform cells to differentiate active and inactive thyroid eye disease was 0.827 with a sensitivity of 77.80% and specificity of 78.80%.

Conclusion: Quantification of conjunctival dendritiform cells by the in vivo confocal microscopy can help to assess the clinical activity of thyroid eye disease. The in vivo confocal microscopy can visualize the conjunctival lesions at the cellular level and possess potential clinical applications in thyroid eye disease.