Outcome of corneal transplantation: can a prioritisation system predict outcome?

In 1995 a prioritisation system for patients waiting for corneal transplantation surgery was adopted in British Columbia. In 1997 a routine outcome assessment programme was adopted. The authors sought to determine the outcomes of corneal transplant surgery in the province of British Columbia and to evaluate if they were associated with waiting list prioritisation.

Since May 1997 all patients who receive a corneal transplant are enrolled in the Eye Bank of British Columbia (EBBC) outcome assessment programme. Each patient fills out a visual function assessment (VFA) questionnaire before and 12 months after surgery. Data on visual acuity, pain, demographics, and other ocular complications are collected from both patients and surgeons before and after operation.

269 patients were enrolled in the programme between May 1997 and April 1998. 12 month follow up showed that visual acuity improved in 69.9% of patients, while it remained the same in 20.8%, and got worse in 5.9%. Overall, at follow up 16.6% of patients had intermittent pain and 5.0% had constant pain. 78.6% of patients who experienced intermittent or constant pain before surgery reported no pain at follow up. Visual function improved in 72.4% of patients, remained the same in 4.1%, and worsened in 23.5%. 88% of patients improved in at least one of the three outcome categories. Patients who had the greatest improvement had been assigned the highest priority for surgery. The 11% of patients who did not improve in any of the three categories (visual acuity, pain, or visual function) were more likely to have a preoperative visual acuity better than 20/60, most likely to have old trauma or Fuchs' dystrophy as their primary diagnosis, and to have had fewer points in the EBBC priority scoring system.

The finding that patients who had a high preoperative priority score were more likely to have a good outcome suggests that the priority system was accurately identifying patients at greatest need for surgery. These findings also suggest that outcome from corneal transplant surgery is best measured as a combination of clinical indices and patient derived indices. A routine outcome assessment programme and prioritisation system can assist surgeons and eye banks in better case selection and in anticipating both objective and subjective improvement following surgery.