Analysis of corneal surface evolution after moderate alkaline burns by using impression cytology

PURPOSE: To compare corneal surface evolution after moderate alkaline burns by impression cytology in patients treated with medical therapy or with amniotic membrane transplantation (AMT). METHODS: A prospective study of 24 eyes from 18 patients (13 men and 5 women) with moderate alkaline burns was performed. All patients were divided according to the clinical ocular severity and the therapy used. Twelve eyes were treated surgically with AMT and the other 12 eyes received only medical therapy. Corneal cytology was obtained immediately after the burns, and 1, 2, 5, and 9 months later. We differentiated between samples obtained from affected areas and areas not affected by the burns. Cellular size, nuclear size, and nuclear-cytoplasmic (N:C) ratio were examined in corneal epithelial cells, as was the presence of goblet cells in corneal epithelium. RESULTS: Nuclear size, cellular size, and N:C ratio in non-burn-affected corneal areas had no significant alterations in comparison with normal eyes. In contrast, in burn-affected corneal areas, these parameters were significantly worse, and the presence of goblet cells in corneal epithelium was frequent 1 month after severe burns. Cellular size, nuclear size, N:C ratio, and corneal conjunctivalization improved during the study in all patients, but corneal reepithelialization occurred earlier in patients treated with AMT than in patients with only medical therapy. CONCLUSION: Morphologic and morphometric analysis of corneal cells by impression cytology after ocular burns permits the establishment of cellular reepithelialization patterns in relation with limbal deficiency level and with clinical ocular severity. AMT improves corneal reepithelialization earlier than medical therapy in moderate alkaline burns.