Comparative study of graft rejection in keratoconus patients with and without self-reported atopy

To compare the incidence and characteristics of graft rejection in keratoconus patients with and without self-reported atopy.

From November 2007 to February 2008, 75 consecutive keratoconus patients who had undergone penetrating keratoplasty completed a questionnaire regarding personal history of atopy. The questionnaires were reviewed without knowledge of history of graft rejection. The patients were divided into three groups: nonatopic (group 1), mild atopic (group 2), and severe atopic (group 3). Charts were retrospectively reviewed with regard to the incidence and characteristics of graft rejection episodes for each patient.

There were 13 patients in group 1, 36 patients in group 2, and 26 patients in group 3. The incidence of graft rejection (rejection episodes per 100 person-years) in groups 1, 2, and 3 was 7.3, 15.8, and 13.4, respectively. Although the mild and severe atopic groups had roughly twice the rate of rejection of the nonatopic group, there was no statistically significant difference among the groups (P = 0.25). The mean age of 37.1 +/- 8.9 years at the time of surgery was significantly lower (P = 0.004) and the rate of bilateral penetrating keratoplasty was significantly higher (40/55 eyes 73%) (P = 0.01) in group 2 than in the two other groups. The majority of first graft rejection episodes were mild or moderate in atopic patients (69% in group 2 and 94% in group 3) and severe (50%) in nonatopic patients; however, no significant difference was found among the groups (P = 0.13).

Atopic conditions may increase the incidence of graft rejection in keratoconus patients, and the characteristics of graft rejection in atopic patients may differ from those in nonatopics because of the immune alteration, but differences in this study were not statistically significant.