Use of a silicone shield to protect the optical cylinder following osteo- and osteo-odonto-keratoprosthesis (O/OKP) procedures

Purpose: To describe the placement of a silicone shield to protect the optical cylinder following osteo-keratoprosthesis or osteo-odonto-keratoprosthesis (O/OKP) procedures in four patients. Methods: In this retrospective observational study, we reviewed all patients who underwent O/OKP in our tertiary medical centre. We found four patients in whom a protective cellphone silicone shield (VisionGuard⁺, Zagg, Utah, USA) was cut with a 3 mm dermal punch and placed on the polymethyl methacrylate (PMMA) optical cylinder of an O/OKP 3–4 months after implantation to either correct or prevent abrasions. Results: The first patient presented with a severely abraded OOKP optic that reduced BCVA from 6/6 to 6/20. The shield smoothed the optical surface and filled minor scratches, leading to BCVA improvement to 6/9. In the subsequent three patients, the optic was relatively clear, and the shield was used as a preventive measure. In two patients, the shield fell off after a few weeks and was replaced. Conclusions: Placing a protective silicone shield on the optical cylinder of an O/OKP can prevent permanent abrasions and, in an already scratched polymethyl methacrylate (PMMA) optic cylinder, improve vision by smoothing the surface. This intervention can be clinically significant, considering that the optical cylinder cannot be removed after implantation.