Corneal Involvement in Crohn Disease : An in vivo Confocal Microscopy Study

Purpose:To evaluate the corneal changes of patients with Crohn Disease (CD) using confocal microscopy and to investigate the correlation between corneal alterations and CD activity. Methods:Twenty eyes of 20 consecutive patients (age: 42 ± 12 years; F/M=14/6) affected by CD and 20 control eyes (age- and gender-matched) received a complete ophthalmic examination and corneal confocal laser-scanning microscopy (Rostock Corneal Module® of Heidelberg Retina Tomograph II®, HRTII-RCM) in a randomized eye. The following confocal parameters were evaluated: density of basal epithelial cells, epithelial dendritic cells, anterior and posterior stromal activated keratocytes, endothelial cells; the sub-basal plexus was assessed for number, tortuosity, and reflectivity of the nerve fibres and the presence of bead-like formations. The parameters of the two groups were compared using t-test. Activity of the disease was evaluated by Crohn Disease Index (CDI). Results:No study subject showed any abnormal finding at ophthalmic evaluation, while 40% CD patients had hyper-reflective dots in the basal epithelium at HRTII-RCM. Compared to controls, CD group showed a statistically significant (p<0.05) increased density of epithelial dendritic cells, anterior and posterior stromal activated keratocytes and higher nerve reflectivity. No statistically significant difference was found for epithelial and endothelial cells and for the other nerve parameters. No correlation between CDI and confocal microscopy parameters was found. Conclusions:Recent studies have shown confocal microscopy alterations in patient affected by systemic inflammatory diseases (e.g. Sjogren disease). Our results suggest that HRTII-RCM may allow to detect subclinical corneal changes in CD patients.