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Enucleation is performed to alleviate pain associated with nonresolvable ocular lesions (Figure 5.13) (da Silva et al. 2010; Lair et al. 2014) or severe injury. A prosthetic eye can be placed (Nadelstein et al. 1997), but keeping the prosthesis in place long‐term may be problematic (Harms and Wildgoose 2001).

After performing a local block with lidocaine, dissect and transect periorbital tissue, conjunctiva and oculomotor muscles off the globe with fine curved scissors. Branches of the trigeminal and facial nerves running along the caudolateral border of the orbit should not be transected (Wildgoose 2007b). If a hemostat is placed on the retro‐orbital pedicle, minimize traction on the optic nerve to prevent damage to the optic chiasm, which will result in blindness in the contralateral eye. Transect the pedicle, remove the globe, and ligate the retro‐orbital vessels. Supplement hemostasis by applying digital pressure and a hemostatic agent (Gelfoam^®, Pfizer, New York, NY). Suturing the periorbital tissue, with an H‐plasty if needed, enables one to close the orbit for esthetical purposes in some fish species such as cod (Gadus morhua) and saithe (Pollachius virens) (Figure 5.14). In fish where this is not possible, leave the orbit open to heal (Figure 5.15) and expect mild hemorrhagic discharge after recovery. Some authors recommended placing a waterproof paste containing pectin, gelatin, and methylcellulose (Orabase®, ConvaTec, Bridgewater Township, NJ) into the orbit over the next 24–72 hours (Harms and Wildgoose 2001).

Figure 5.13 Enucleation of a rockfish (Sebastes caurinus) with a retinal tumor.

Source: Photo courtesy: Aquarium du Québec.

Figure 5.14 Suture of the periorbital tissue after an enucleation in a saithe (Pollachius virens).

Source: Photo courtesy: Aquarium du Québec.

Figure 5.15 Enucleation of a sea horse (Hippocampus erectus) with a retro‐orbital abscess. The tube on the right of the image is used for anesthesia maintenance and Harmon–Bishop's forceps were used to elevate the globe from the orbit and allow section of the optic nerve and retro‐orbital pedicle. In this species, it is not possible to close the orbit after enucleation due to the dermal plates greatly reducing the elasticity of the skin.

Source: Photo courtesy: Companion Avian and Exotic Pet Medicine Service, University of California, Davis.