Lowincidenci: of al. lograft rejection in khratoconus may be related to allergic conjunctivitis

Purpose: Keratoconus reportedly has a good rate of graft survival in penetrating keratopathy ( PKP). Some studies have reported an association between keratoconus and allergic disease, which is reported less cytolitic activity. We therefore hypothesized that presence of allergic disease might be related to the good graft survival in keratoconus. Methods: We retrospectively reviewed data on 40 patients who had undergone a PKP for keratoconus. and herpes keratitis(n-B). as inflanimator) disorder controls. Patients with keratoconus were primarily men (p=0. 005> and u ere younger than the controls (p=0. 0001 ). Simple PKP was performed in a greater number of cases of keratoconus vs. controls (p-0. 03t. Grafts done for keratoconus exhibited a higher incidence of survival as compared with those done for the controls ( p=0. 0009). Results: Patients with keratoconus had higher serum level of IgE ( p-0. 0001 ) and a higher positively for antigen specific IgE than the controls (P-0,002). A higher incidence of allergic conjunctivitis was also found in the keratoconus patients vs. the controls (p=0. 0001); such patients also experienced less graft rejection than controls ( p=0. 04). Conclusion: These results indicate that keratoconus is more closely associated with allergic disease and a low incidence of graft rejection as compared with herpes keratitis. The high incidence of graft survival in keratoconus patients may be related to the reduced cytolytic activity of Th2-type helper T cell, which is predominant in allergicdisease, as previously suggested.