Modified osteo-odonto-keratoprosthesis for treatment of corneal blindness - Long-term anatomical and functional outcomes in 181 cases

Objective: To evaluate long-term anatomical and functional outcomes of a modified osteo-odonto-keratopros-thesis (OOKP) technique for treatment of corneal blindness from various etiologies. Methods: Two-hundred three patients (224 eyes) underwent modified OOKP surgery between 1973 and 1999. Of the original cohort, 181 patients (98 men and 83 women; mean [ SD 1, age 54.3 [ 15] years) in whom a standardized 2-step surgical procedure was performed were included in the study. Preoperative diagnoses were dry eye (n = 70) due to ocular pemphigoid (n= 39), Sjogren syndrome (n = 11), trachoma (n = 8), Lyell syndrome (n = 6), Stevens-Johnson syndrome (n = 4), and graft-vs-host disease (n = 1) and congenital lid coloboma (n = 1), severe corneal burns (n = 68), bullous keratopathy (n = 13), keratitis sequelae (n = 15), and bullous keratopathy secondary to antiglaucoma surgery (n = 15). Several innovations were made to the original Strampelli technique. Median follow-up duration was 12 years (range, 1-25 years). Results: Anatomical complications leading to OOKP loss were found in 11 (6.07%) of 181 patients. Survival analysis estimated that 18 years after surgery, the probability of retaining an intact OOKP was 85% (95% confidence interval, 79.3%-90.7%). Pooling patient groups, mean (SD) best postoperative visual acuity was 0.76 (0.34). Mean (SD) final acuity at the end of follow-up declined slightly (0.69 [0.39]) but significantly (P<.01). In individual diagnostic groups, mean acuity decline reached statistical significance (P<.05) only in the pemphigoid (1 line), trachoma (1 line), and bullous keratopathy secondary to antiglaucoma surgery (2 lines) groups. Survival analysis estimated that 18 years after surgery, the probability of retaining best postoperative visual acuity (within 2 lines) was mean (SD) 55.5% (12.9%). Conclusion: Modified OOKP surgery for corneal blindness of different etiologies may provide, in the longterm, anatomically stable corneal prosthesis as well as an effective, rehabilitating recovery in visual acuity.