Corneal graft rejection in African Americans at Howard University Hospital

There is scarcity of data in the literature on cornel graft rejection rate in patients exclusively of African ancestry. The purpose of this study was to evaluate the rejection rate of corneal transplant surgery performed at Howard University Hospital on such patients over a 15 year period.

A retrospective evaluation was performed of the cornea graft rejection and corneal graft failure rate in 125 penetrating keratoplasties (PKPs) done by one corneal specialist at Howard University Hospital from January 1, 1990 to August 31, 2005.

Of the 125 patients, 62 were eliminated from the study because of re-grafted eyes, non-African descent, primary graft failures, follow-up less than 1 month and lack of availability of charts. This study, therefore, studied and recorded data from 63 penetrating keratoplasties of 63 eyes from 60 patients.

Episodes of graft rejection were documented in 23 eyes (36.5% of cases). Nine out of the 23 graft rejections manifested to secondary graft failure (39%). Overall, there were nine out of the 63 PKPs (14.3%) that resulted in secondary graft failure over the past 15 years. The major diagnostic categories were bullous keratopathy 24 (38%), keratoconus 10 (15.8%), Fuch's dystrophy 4 (6.3%), other 20 (31.7%). Of the cases with episodes of rejection and failure, 4.3% and none were attributable to keratoconus, 30.4% and 22.2% for bullous keratopathy, and 8.7% and 22.2% for Fuch's dystrophy, respectively. Also, best visual acuity was looked at in patients with rejection episodes. None of the patients had a pre-op visual acuity 20/40 or better; however, post-op PKP 2 (8.7%) of patients achieved 20/40 or better. Also, 4 (17.4%) of patients had a pre-op visual acuity between 20/50 and 20/150, but post-op PKP best visual acuity between 20/50 and 20/150 was increased to 9 (39.1%).

At 36% the prevalence of corneal graft rejection was one of the highest in the reported literature. But only 14% of those episodes resulted in graft failure which is one of the lowest in the published literature. This study demonstrates that patients of African ancestry may have a higher rejection rate which does not necessarily result in graft failure.