Blood-aqueous barrier breakdown after penetrating keratoplasty with simultaneous extracapsular cataract extraction and posterior chamber lens implantation

Abstract.

Background: The purpose of this study was to quantify breakdown of the blood-aqueous barrier (BAB) following penetrating keratoplasty (PK) with simultaneous extracapsular cataract extraction and posterior chamber lens implantation (triple procedure) and compare it with the alterations following PK only. Methods: This study included 72 eyes after triple procedure and 227 eyes after PK only. The diagnosis for PK was Fuchs´ dystrophy in 39%, keratokonus in 44%, stromal corneal dystrophy in 3% and avascular corneal scars in 6% of cases. The postoperative topical steroid treatment was standardized in both groups. Aqueous flare was quantified using the laser flare-cell meter (FC-1000, Kowa) at defined postoperative intervals (10 days , 6 weeks, then every 3 months until 1 year postoperatively). Patients with conditions associated with impairment of the BAB were excluded from the study. Results: In the early postoperative course, aqueous flare values (photon counts/ms) were significantly higher in patients with triple procedure (21.9±11.0) than in patients with PK only (9.8±3.2; P=0.001). At 6 weeks postoperatively, aqueous flare returned to normal levels in patients after PK only (5.2±2.3), whereas patients with triple procedure still showed significantly increased flare values (10.8±5.6; P=0.01). At 6 months postoperatively, aqueous flare values of patients with triple had returned to normal levels (6.8±3.8) and did not differ significantly from those after PK only (5.2±1.9; P=0.09). Conclusion: Our results indicate that triple procedure causes a more extensive and longer-lasting breakdown of the blood-aqueous barrier than PK only. Quantification of aqueous flare with the laser flare-cell meter is useful in the postoperative follow-up after triple procedure. Further studies are required to investigate the clinical relevance of BAB breakdown on endothelial cell count and the incidence of subsequent immunological graft rejection.