Abstract
Purpose: :
To quantify dendritic cells (DC) in patients with limbal stem cell deficiency (LSCD), utilizing in vivo confocal microscopy (IVCM).
Methods: :
Retrospective analysis of IVCM (Heidelberg Retina Tomograph 3 with the Rostock Cornea Module [HRT3/RCM]) images of corneas with the diagnosis of limbal stem cell deficiency due to multiple surgeries (n=9), Stevens Johnson Syndrome (n=5), exposure keratopathy (n=3), neurotrophic keratopathy (n=3), chemical injury (n=2), dry eye (n=2), and medicamentosa (n=1). Dendritic cells in the superior, inferior, temporal and nasal limbus and central cornea were quantified and the average results were compared to 8 corneas of normal controls without history of contact lens wear. For each variable, results for three frames were averaged and analyzed utilizing the Student’s t-test.
Results: :
The DC were mostly found within the subepithelial and the basal epithelial layers. The DC density in normal controls was 25.0 ± 2.2 /mm2 in the limbus and 14.3 ± 1.2 /mm2 centrally. In comparison to controls, the DC density among all groups (n=25) was found to be 8.9 ± 0.7 /mm2 (p=0.0001) in the limbus and 8.1 ± 0.7 /mm2 (p=0.0001) centrally. In the multiple surgery group, the DC density was 5.4 ± 0.4 /mm2 (p=0.0001) in the limbus and 16.6 ± 1.6 /mm2 (p=0.0047) centrally. In the Stevens Johnson Syndrome group, the DC density was 13.6 ± 1.3 /mm2 (p=0.0001) in the limbus and 4.7 ± 0.3 /mm2 (p=0.0001) centrally. In exposure keratopathy, the DC density was 4.0 ± 0.2 /mm2 (p=0.0001) in the limbus and 5.4 ± 0.3 /mm2 (p=0.0001) centrally. In chemical injury, the DC was 11.0 ± 1.0 /mm2 (p=0.0001) in the limbus and 23.3 ± 2.3 /mm2 (p=0.0001) centrally.
Conclusions: :
DC density was overall lower in both the central cornea and limbus in LSCD when compared to normal controls, with the exception of iatrogenic and chemical injury induced LSCD in which the DC density was higher in the central cornea. The number of DC in the cornea and limbus alone may not be an important factor in LSCD pathogenesis.
Keywords: cornea: clinical science • microscopy: confocal/tunneling