There is a long and venerable debate about the relative merits of enucleations and eviscerations (Mules 1885, Lang 1887, Frost 1887) that began with the first medical report of an evisceration. While this debate is by no means concluded, some consider that an evisceration yields the best cosmetic result because it is less damaging to the structures of the orbit. However, there are many cases in which an enucleation may be indicated. These include cases in which the majority of the contents of the eye must be removed, such as in cases of uveal melanoma, choroidal melanoma, or other malignant intraorbital tumors (Boyd 1980, Shields 1992). Other indications may include objectionable appearance, chronic pain, atrophy bulbi, blindness with unilateral iritis, blindness with unilateral glaucoma, childhood hypoplasia (Nunery 1990), prophylaxis against sympathetic ophthalmia (Nunery 1990, Meltzer 1987), and whenever a complete histological examination of the globe is required (Meltzer 1987, Tenzel 1980, Soll 1987b, Stephenson 1990).
An evisceration is indicated in the cases listed above, where an enucleation is not specifically indicated. Some surgeons prefer an evisceration over an enucleation wherever possible. Classically, the clearest indication for an evisceration has been in cases of virulent endophthalmitis, to reduce the risk of the infection spreading via the optic nerve sheath. (Nunery 1990, Meltzer 1987, Stephenson 1990). In addition, an evisceration is often less psychologically traumatic for the patient because it involves the loss of what is perceived as only a portion of the eye, as compared with the entire eye.
A secondary implant has been traditionally indicated in cases of chronic exposure, migration, or extrusion of the primary implant. In recent years, however, a rapidly growing number of patients are requesting secondary implants using the Bio-eye HA orbital implant in order to recover lost motility and to counteract lid sag via a motility/support peg. In most cases, the motility provided by the Bio-eye HA orbital implant hydroxyapatite implant is equal to or better than that provided by the primary implant. If the rectus muscles can be identified and attached directly to the implant, even greater motility can be expected. Fortunately, the rectus muscles can usually be identified because check ligaments attached to the fornices and Tenon’s capsule prevent them from retracting too deeply after they are cut from the globe (Perry 1991c). If a socket containing a previously placed implant shows no motility, then damage to the rectus muscles or to the innervation to the rectus muscles is expected. There is no known implant design that will improve the motility of either the socket or the artificial eye in such cases.