In vivo confocal microscopy of bulbar conjunctiva in patients with Graves' ophthalmopathy

Abstract

Background/purpose: To investigate the bulbar conjunctival changes in patients with Graves' ophthalmopathy (GO) using in vivo confocal microscopy.

Methods: A total of 15 GO patients and 15 control patients were recruited. Images of the superior site and temporal bulbar conjunctivas were taken by the Heidelberg Retina Tomograph/Rostock Corneal Module. The conjunctival thickness and cell density of superior epithelium, basal epithelium, Langerhans cells, and goblet cells were analyzed. Conjunctival impression cytology was performed to assess the grading of squamous metaplasia of the conjunctival epithelium.

Results: The superficial epithelial cell density in the superior bulbar conjunctiva of the GO group was 856.93 ± 461.68 cells/mm(2), which was significantly lower than that in the control group (1581.13 ± 556.34 cells/mm(2); p = 0.002). However, the difference in superficial epithelial cell density in the temporal bulbar conjunctiva between the two groups was not statistically significant. No significant differences in conjunctival thickness and the basal epithelial cell density were noted between the two groups. Increased Langerhans cell density and reduced goblet cell density were noted in the GO group. Impression cytology of the conjunctival epithelium revealed significantly higher degree of squamous metaplasia in the GO group. The superficial epithelial cell density in the upper bulbar conjunctiva showed negative correlation with marginal reflex distance in the GO group.

Conclusion: GO patients suffered from more severe bulbar conjunctival damage and inflammation with the superior site than the temporal site. In vivo confocal microscopy can be a rapid and noninvasive tool for the quantitative evaluation of ocular surface changes in patients with GO.

Keywords: Graves' ophthalmopathy; bulbar conjunctiva; dry eye; impression cytology; in vivo confocal microscopy.