Trauma, infection, tumours, and chronic pain in a blind eye are the most common reasons for eye removal. Eyes are removed by either evisceration or enucleation.
EVISCERATION: The contents of the eye are removed, but the white shell (sclera) is retained.
ENUCLEATION: The entire globe (eyeball) is removed, but the muscles (extraocular muscles) are left behind.In select patients, enucleation and especially evisceration can be performed with local anesthesia and anesthetic sedation.
After the eye is removed, the orbit is deficient in volume, and will look sunken in unless an IMPLANT is placed. The standard OHIP implants stocked in our hospital are made of polymethyl-methacrylate (PMMA) and are smooth and relatively inert. The PMMA implants are good implants, but generally do not allow the eye to move. Implants with the potential for motility can be purchased by the patient, and generally cost in the range of $1,000.00 to purchase. The MOTILITY IMPLANTS have small pores that allow for tissue ingrowth. The motility implants are more abrasive than the PMMA implants and have a slightly increased risk of non-healing (expsoure) over time. Surgical surveys have found that most surgeons are not pegging their motility implants which defeats one of the major purposes of having a motility implant. Motility implants are not pegged until at least one year after surgery to ensure vascularization of the implant.
The eye is patched for about 3 days after the surgery. The first 3 days after surgery are generally the most uncomfortable, and it is common for patients to feel nauseous, and to vomit. A pain catheter and medicines can decrease discomfort.
POTENTIAL PROBLEMS: Infection and discomfort may persist. If the tissue does not heal well, or if there is not enough room to fit a prosthesis a patch may have to be placed.**
Conformers and Prostheses are like thick oval-shaped contact lenses. A temporary CONFORMER (clear plastic shell) is placed over the implant and conjunctiva following surgery to maintain the lid space and prevent the stitches from rubbing against the back of the eyelid.
It is not uncommon for the conformer to fall out in the early post-operative period. This is NOT an emergency. Bring the conformer in to the office and Dr. Ing or his assistant can replace it for you.
After 1-2 months, an OCULARIST can fit a PROSTHESIS (painted custom-moulded shell) to replace the clear stock conformer. The prosthesis is designed from the seeing eye, and looks very natural. We often encourage the prosthesis not be removed except perhaps once a month for cleaning.
Occasionally extra suturing may be required if the conjunctiva / Tenons covering the implant breaks down. Discharge may occur. The eye may be unable to close over the prosthesis in some cases. Volume supplementation may be required, especially in trauma cases. If the prosthesis does not fit, deepening of the eyelid space (fornices) with a graft from the mouth may be required.
Patients with only one eye should always wear polycarbonate safety lenses. (shatter resistant glasses) We do not have artificial eyes available that can see to replace removed eyes. At present the only routine transplant of the eye is the corneal transplant. Retinal chip technology is in its infancy, and will not work in severely traumatized eyes, and not possible after an eye has been enucleated or eviscerated.
** Rarely tumours may cause an eye to go blind, but mimic an infection, glaucoma. bleeding or chronic pain problem. If the pathologist notices tumour after eye removal you may require radiation or a visit to the cancer center. Sometimes eye cancer is not discovered until many years after the eye removal.