Aims: To evaluate by the Impression Cytology (IC) technique the expression of the MHC class II inflammatory marker HLA-DR by the conjunctival epithelium, the cytological modifications of the conjunctival surface according to the Nelson's classification and the eventual correlation between the two of them after severe ocular burns.
Methods: This prospective study adhered to the tenets of the Declaration of Helsinki. 24 patients (24 eyes) who presented with severe ocular burns underwent IC. We compared them with 18 healthy eyes. HLA-DR expression was studied in flow cytometry as well as the conjunctival histology evaluated with the Nelson's Classification from 2 to 24 months after the burn's onset.
Results: There was a significant upregulation of the expression of HLA-DR compared to the healthy population at 2 months (p<0.001), 6 months (p<0.001), 12 months (p=0.019), 18 months (p=0.0171) and 24 months (p=0.01766) after burn. A significant difference was found between the Grade of Nelson in the pathological population and those of the healthy population at 2 months (p=0.0157). HLA-DR upregulation was significantly correlated with the Nelson's Grades between 2 months (r=0.69, p<0.0001) and 6 months (r = 0.61, p = 0.0001).
Conclusion: IC technique can provide a useful tool for following-up ocular surface inflammation after severe ocular burns.
- Impression Cytology
- Limbal Grafting
- Nelson's Classification
- Ocular Burns