COEXISTENT CORNEAL DISEASE AND GLAUCOMA MANAGED BY EITHER DRAINAGE SURGERY AND SUBSEQUENT KERATOPLASTY OR COMBINED DRAINAGE SURGERY AND PENETRATING KERATOPLASTY

The results of penetrating keratoplasty following trabeculectomy in 26 eyes where there was coexistent corneal disease and glaucoma are presented. Patients were aged 16-80 years at the time of drainage surgery (mean = 51 years) and there was a mean of 33.5 months between trabeculectomy and keratoplasty. The mean pressure fell from 35.3 mm Hg prior to trabeculectomy to 14.9 mm Hg at the time of keratoplasty and 20 mm Hg 12 months after keratoplasty. There was a 0.45 probability of maintaining normal intraocular pressure with medication at 5 years after keratoplasty; and a similar graft survival probability. The probability of maintaining both a clear graft and a normal pressure was only 0.27 at 5 years. In another 22 eyes combined trabeculectomy and penetrating keratoplasty was performed. Patients' ages ranged from 21-82 years (mean 55) at surgery, and 73% were aphakic. The intraocular pressure dropped from a mean of 28.9 mm Hg preoperatively to 14 mn Hg at 12 months. There was a 5 year probability of 0.7 of maintaining a clear graft but if both a clear graft and normal intraocular pressure are considered then the probability falls to 0.5 at 5 years. The hazard ratio for intraocular pressure control and graft survival between the two groups suggests that combined surgery may offer a better prognosis.