β-Tricalcium Phosphate granules as an alternative material for ocular implantation
Background: Some types of implants used for orbital implantation have side effects and complications. In this study we have evaluated beta-tricalcium phosphate (β-TCP: ChronOS) granules as an orbital implant.
Methods: Eighteen rabbits randomly allocated to four groups. Right eye enucleation performed in groups I to III followed by filling with autologous bone particles (n=5), a mixture of autologous bone particles and pure β-TCP granules (n=5), a mixture of autologous bone marrow and pure β-TCP granules (n=5). Right eye evisceration was done in group IV (n=3), and then filled with one of the aforementioned materials used in groups I, II and III. After 12 weeks, exenterated contents were compared by determining the volumes of the globes, area densitometry using dual-energy x-ray absorptiometry.
Results: There was no significant difference between the volumes of enucleated globes before (groups I: 2.6±0.39, II: 2.6±0.12 and III: 2.5±0.3 (ml) and after surgery; (groups I: 2.5±0.4, II: 2.50±0.2 and III: 2.4±0.3). There was also no significant differences among the densities of exenterated contents of all groups; (I: 175±3, II: 165±1 and III: 174±3 mg/cm2). In all enucleated groups, histopathologic evaluations showed remarkable vascularization and fibrous ingrowth which were remarkable in eviscerated group. No significant complication was observed.
Conclusion: β-TCP granules offer good cosmetic results with low risk of infection and extrusion. However, further studies are required before they can be used in human as a new orbital implant.