Corneal oedema after cataract surgery: predisposing factors and corneal graft outcome

Pseudophakic bullous keratopathy (PBK) is one of the main indications for corneal transplantation. Graft survival and visual outcome in this group are often poorer than for other indications. The aim of this study was to find risk factors for developing corneal oedema after cataract surgery and factors that influence the subsequent survival of the graft and the visual outcome. We carried out an observational, retrospective cohort study using data from the Swedish Cornea Transplant Register and patient medical records. A total of 273 patients whose indication for corneal transplantation was corneal oedema after cataract surgery were included in the study. Multiple logistic regression analysis and, where appropriate, univariate analyses were applied. A total of 43% of the patients developed persistent corneal oedema immediately after cataract surgery, the main risk factors for which were phacoemulsification and pre-existing endothelial disease. Almost a third (32%) of the transplants for PBK failed within 2 years, for which rejection and other postoperative complications increased the risk. Half (50%) the patients had visual acuity <= 0.1 at 2 years after keratoplasty. Comorbidity, increasing duration of the bullous keratopathy and increasing age affected the visual outcome negatively. Phacoemulsification was a risk factor for immediate persistent corneal oedema after cataract surgery, although it did not increase the overall risk of developing PBK. However, transplants for immediate PBK had a better survival rate than those for later onset PBK. Shorter duration of PBK and intraocular lens exchange at the time of penetrating keratoplasty increased the likelihood of good visual acuity.