Penetrating keratoplasty in the Singapore National Eye Centre and donor cornea acquisition in the Singapore Eye Bank.

We analyzed all penetrating keratoplasties performed in the Singapore National Eye Centre from 1 January 1991 to 31 December 1995, using records of the Singapore Eye Bank Registry, evaluating the indications, complications, causes of graft failure, visual outcome and graft survival rate. We also looked into donor cornea acquisition in the Singapore Eye Bank and its influence on the development of corneal transplantation in the Singapore National Eye Centre. A total of 327 penetrating keratoplasties were performed during the 5-year period. Bullous keratopathy was an indication in 26.3% of cases. Of these, aphakic bullous keratopathy accounted for 11.6% of all cases, while pseudophakic bullous keratopathy accounted for 11.3%. Other indications were regrafts (11.9%), corneal dystrophies (10.4%), traumatic corneal scarring (10.1%) and keratoconus (9.8%). Graft rejection was a complication in 20% of all cases. Of these, 40.9% led to graft failure. Other major complications were raised intraocular pressure (18%), epithelium-related problems (7.3%), wound dehiscence (4.3%), cataract (3.3%) and microbial keratitis (3.1%). The main causes of graft failure were graft rejection (8.2%), endothelial failure (2.4%), infection (2.4%) and glaucoma (2.1%). Of the 327 grafts, 40.3% achieved best corrected visual acuity of 6/12 or better; 70.8% achieved vision of 6/24 or better. The overall graft survival rate was 82.3% after a mean follow-up period of 2 years. Donor corneas for the penetrating keratoplasties were obtained from foreign eye banks as well as locally, with the local donation rate steadily increasing from 1991 to 1996, with the establishment of proper eye banking facilities and the Singapore Eye Bank. These results show that the indications and outcome of penetrating keratoplasty in the Singapore National Eye Centre are similar and comparable to that of other centres with established corneal grafting programmes. The establishment of the Singapore Eye Bank has ensured the proper co-ordination of acquisition of donor material which has been vital to the development of corneal transplantation in the Singapore National Eye Centre.

Duke Scholars

Author Tien Yin Wong Ophthalmology