A retrospective clinical study of Xinjiang Uygur patients with corneal allograft rejection

Background: To explore the causes of corneal allograft rejection in Xinjiang Uygur patients and the factors that affect rejection through a retrospective clinical analysis.

Methods: A retrospective analysis of 126 Uygur cases from January 2010 to November 2014 in which corneal transplantation had been performed at the Xinjiang Urumqi ENT hospital. Of the treated patients, 85 eyes belonged to male patients and 41 eyes belonged to female patients. Patients were aged 10-77 years (mean age 46.14 ± 8.20 years). Surgical methods included penetrating keratoplasty (75 eyes) and lamellar keratoplasty (38 eyes). Follow-up time ranged from 0.5 to 3 years and a total of seven pre-operative keratopathies were observed: walleye, corneal ulcer, bullous keratopathy, corneal degeneration. Eye changes included 72 cases of limbal vascularization and 15 cases of high intraocular pressure. Allograft rejection was observed in 25 eyes.

Results: The pre-operative keratopathies associated with the highest incidences of allograft rejection were: viral corneal ulcer, bullous keratopathy, adhesive walleye, and fungal corneal ulcers. The rate of allograft rejection using avascular corneal tissue was 10%, while the rate was 36% with severly-vascularized cornea. The earliest time of rejection was 20 days after surgery, while the latest was 16.4 months after surgery. Heavy corneal vascularization is associated with more rapid post-operative rejection. The rate of allograft rejection was higher after combined surgery when compared to penetrating keratoplasty or lamellar keratoplasty alone, while the rate was higher with penetrating keratoplasty than with lamellar keratoplasty. With increasing graft diameter, there was an increase in post-operative allograft rejection. Allograft rejection was significantly increased when graft diameter was above 7.75 mm.

Conclusion: The major cause of corneal allograft rejection is viral corneal ulcers. High corneal vascularization, combined surgical methods, large diameter graft transplantation are all risk factors for allograft rejection.