Post penetrating keratoplasty glaucoma: Cumulative effect of quantifiable risk factors

PURPOSE: To ascertain the incidence, identify risk factors and calculate cumulative effect of risk factors in patients developing glaucoma following optical penetrating keratoplasty. MATERIALS AND METHODS: We carried out retrospective analysis of 445 patients, those underwent optical PK and had a minimum follow up of 6 m. Data on post-operative intra-ocular pressure (IOP) recorded at 3, 6, 9, 12 and 18 m or more was analyzed. Various risk factors including age, sex, indications for penetrating keratoplasty, pre-existing glaucoma and type of surgical procedures performed were analyzed by using univariate analysis and logistic regression technique. RESULTS: Ninety (21%) of eyes developed post-PK glaucoma. On applying logistic regression, age, sex, indication of surgery, pre-existing glaucoma were found to be significant risk factors for the development of post-PK glaucoma (P < 0.05). Using logistic regression equation the cumulative risk of developing post-PK glaucoma in an individual patient can be calculated. CONCLUSIONS: Male patients, aged more than 40 years, having opaque grafts as an indication and with pre-existing glaucoma were found to be higher risk of developing post-PK glaucoma. Patients at higher cumulative risk for development of post-PK glaucoma may be closely monitored during follow-up.