Objective: Corneal allograft rejection is a major complication of penetrating keratoplasty (PK). We used the laser flare-cell meter that allows, for the first time, non-invasive quantification of aqueous flare in vivo to analyze alterations of the blood-aqueous barrier following uncomplicated PK and in acute corneal graft rejection.
Patients and methods: Examination with the laser flare-cell meter was performed in 67 eyes of 62 patients (mean +/- SD age, 46.2 +/- 15.1 years) 12.8 +/- 13.2 months (range, 5 days to 60 months) after uncomplicated PK, in 82 normal control eyes of 82 age-and gender-matched patients (mean age, 49.0 +/- 17.1 years) and in 10 eyes of 10 patients (mean age, 51.6 +/- 15.1 years) with acute diffuse endothelial corneal graft rejection in nonherpetic eyes 15.1 +/- 12.9 months after PK.
Results: Compared with the normal unoperated control group (4.43 +/- 1.13 photon counts/ms), aqueous flare was significantly increased during the first 2 weeks following uncomplicated PK (14.73 +/- 8.30 photon counts/ms; P < .0001) but returned to normal levels more than 6 weeks after surgery (4.48 +/- 1.55 photon counts/ms; P > .1). In acute corneal graft rejection, aqueous flare values (17.10 +/- 6.05 photon counts/ms) increased to significantly higher levels than in eyes following uncomplicated PK and in the normal control group (P < .0001), but decreased significantly 9.5 +/- 3.3 days after treatment with systemic and topical corticosteroids (5.78 +/- 2.16; P < .0005).
Conclusions: Application of the laser flare-cell meter appears promising for following up patients after PK and for detecting early corneal allograft rejection.