**5. Wrapping material**

Implant covering improves the volume of the orbit and motility of the prosthesis and provides an additional barrier for the implant. All of these are important factors for an optimal surgical result. It is usually done in nonintegrated implants like silicone but can be used in hydroxya‐ patite too in order to protect the Tenon's layer and the conjunctiva from the erosion of the rough implant surface.

#### **5.1. Donor sclera**

Once warmed up to room temperature, it is advisable to send cultures of the liquid in order to discard any possible microbiological contamination. Sclera is placed over the implant and sutured with 4-0 or 5-0 nonabsorbable running sutures. Due to its origin, there is a small possibility of infection transmission, including human immunodeficiency virus, hepatitis B or C virus, and Creutzfeldt-Jakob disease. These risks have made many surgeons abandon this wrapping material.

#### **5.2. Autologous tissue**

This type of tissue includes temporalis fascia, dermis, human donor pericardium, fascia lata, or posterior auricular muscle complex [43]. Their autologous origin prevents an immune host versus graft reaction. Nevertheless, they require an extra surgical procedure to harvest them and prepare them to cover the implant, which increases surgical time, and there is always the risk of donor site morbidity.

#### **5.3. Synthetic tissue**

Polyglactin 910 mesh (Vicryl mesh, Ethicon, Sommerville, NJ, USA) is used to wrap hydrox‐ yapatite and bioceramic orbital implants. It offers a series of advantages: there is no risk of disease transmission, there is no need of a second surgical site, and it is easy to use. It has a porous structure that allows fibrovascular ingrowth [33]. Polytetrafluoroethylene and polyglicolic acid (Dexon mesh style no8, Davis & Geck, Manati, Puerto Rico) have also been used as implant cover materials.

Hydroxyapatite polyglactin mesh-wrapped implants [44] have been used in secondary implants with good results both in prosthesis motility and low exposition rate.
