- Removal of globe from Tenon's capsule plus a variable amount of extraocular muscles.
- Two techniques:
- Removal of a permanently blind eye causing chronic pain or irritation. Indications involve, but are not limited to, intraocular neoplasia , globe rupture , chronic recurrent uveitis , microphthalmos and phthisis bulbi .
- Simple technique for removal of painful eye in most cases, except where pyogenic infection or diffuse neoplasia are present.
- Transpalpebral - preferable if any external eye infection or neoplasia is present.
- Cosmetically may be unsatisfactory but cosmesis is improved by placement of an intraorbital prosthesis.
- Orbital infection may cause wound breakdown and rejection of prosthesis (if used).
- Entire diseased tissue may not be resectable, ie orbital neoplasm.
- Transpalpebral technique is slightly more difficult with slightly increased risk of hemorrhage from the skin.
- Standard surgical kit .
- (Fig. 1) .
- Eye speculum for transconjunctival approach.
- 2/0 polyglactin 910 (Vicryl) or polydioxanone (PDS II).
- 2/0 non-absorbable suture material .
- Sterile intraorbital silicone prosthesis 40-47 mm diameter.
- 2/0 polypropylene (Prolene) .
- Stent bandage.
- 0 non-absorbable suture material for stent bandage.
- 15 min.
- Horse is left with sunken orbit (no prosthesis).
- Orbital infection with wound breakdown and prosthesis rejection: remove prosthesis, administer local and systemic antibiotics and either partially close or leave to heal by secondary intention.
- Regrowth/continued growth of orbital neoplasm → slowly distending orbit.
- Blunt trauma to orbit causing prosthesis to rotate and skin to necrose.
- Cyst formation- usually results from retained conjunctiva or perforation of the third eyelid.
- Good - very low incidence of complications.
Reasons for treatment failure
- Wound breakdown.
- Failure to remove diseased tissue.
- Rejection of prothesis.