Date: 20 May 2008

Long-term functional and anatomical results of osteo- and osteoodonto-keratoprosthesis

Abstract

Purpose

To analyse the functional and anatomical results of keratoprosthesis using tooth and tibial autograft.

Methods

We reviewed 227 charts of patients that underwent osteo-keratoprosthesis (OKP) (n = 82) or osteo-odonto-keratoprosthesis (OOKP) (n = 145) at the Centro de Oftalmología Barraquer. Mean follow-up time was 8.4 years for OOKP and 3.5 years for OKP. Kaplan-Meier survival curves with 95% confidence interval (CI) were calculated for functional success, defined as BCVA >0.05. Anatomical success was defined as retention of the keratoprosthesis lamina. Visual Acuity by Time (VAT) Index with 95% CI was calculated for up to 2 years post-OKP and up to 6 years post-OOKP. Maximum visual acuity ever reached after the last step of the implantation of the keratoprosthesis was used as an indicator for the potential of the retina.

Results

Based on Kaplan-Meier analyses, 10-year anatomical survival was 66% (CI 57–76) for OOKP and 47% (CI 27–67) for OKP. Two-year functional survival was 63% (CI 55–71) for OOKP and 49% (CI 37–60) for OKP, and 10-year functional survival was 38% (CI 29–48) for OOKP and 17% (CI 5–28) for OKP. Multivariate analysis showed that neither surgical technique (OOKP or OKP), primary diagnosis nor age had a significant influence on the functional survival. However, a high maximum visual acuity ever reached post-op decreased the risk for functional failure. According to the VAT Index calculations, mean BCVA 2 years after OOKP was 0.33 (CI 0.28–0.41) and after OKP was 0.28 (CI 0.20–0.36).

Conclusion

Although we found a tendency that OOKP had better anatomical results than OKP, this difference was not statistically significant up to 10 years post-op. Functional results for both techniques were not significantly different at the 2-year follow-up, but at 10 years they were. However, this difference was influenced by the retinal potential and not by the technique itself.

There was no sponsoring organisation involved, and no financial relationship exists.The authors have full control of all primary data and they agree to allow Graefe’s Archive for Clinical and Experimental Ophthalmology to review their data upon request.