Keratoprosthesis: current techniques

Purpose: To compare and contrast the techniques and results of keratoprosthesis (KPro) using the Cardona device (1975-1985) with those related to the use of the Dohlman-Doane type 1 device (2003-2005). Methods: We conducted a retrospective review of 31 cases of Cardona KPro implanted between 1975 and 1981 and a review of 25 cases of Dohlman-Doane type 1 KPro implanted between 2003 and 2005. Procedures were limited to eyes with a poor prognosis for traditional penetrating keratoplasty. Results: In the Cardona cases, 39% (12/31) of patients achieved a visual acuity of 20/40 or better at some point postoperatively, degrading to 16% (5/31) at the end of the observation period. Fifty percent (15/31) required subsequent surgical revision of the KPro. Sixteen percent of cases (5/31) developed endophthalmitis, and 58% (18/31) developed retroprosthetic membranes. There were 5 dislocations of the prosthesis and an additional 3 frank extrusions (26%). Of the 25 Dohlman-Doane cases, there have been no reoperations, endophthalmitis, dislocations, or extrusions to date (8/15/05). Forty-eight percent (12/25) achieved 20/200 acuity or better, and 12% (3/25) achieved 20/40 or better. Retroprosthetic membranes formed in 3 cases. Conclusion: Although KPro remains a technique to be used in poor prognosis keratoplasty, improvements in the design of the device and surgical technique over the past 30 years have reduced the overall morbidity and severity of complications and improved the prognosis for visual rehabilitation.