An orbital implant is a medical device that replaces volume lost when an eye is surgically removed or shrinks. It fills the eye socket, restoring a natural facial appearance and supporting a prosthetic eye. The implant is a ball-shaped object, permanently buried beneath the pink tissue lining the eye socket.
Understanding Orbital Implants
Orbital implants are categorized into porous and non-porous types. Porous implants, such as those made from hydroxyapatite or porous polyethylene, allow surrounding tissues to grow into their structure. This tissue ingrowth helps with stability and can improve prosthetic eye movement. Non-porous implants, often made of acrylic or silicone, are inert and do not allow tissue integration, which can lead to migration within the eye socket. Some newer implants also feature coatings to which eye muscles can be directly attached, offering excellent mobility for a prosthetic eye.
Conditions Requiring an Orbital Implant
Orbital implants are necessary after eye removal, procedures such as enucleation or evisceration. Enucleation involves the complete removal of the entire eyeball for conditions like severe trauma, intraocular tumors (e.g., retinoblastoma), or end-stage ocular diseases (e.g., glaucoma, retinal detachment). Evisceration removes the internal contents of the eye while leaving the outer white shell (sclera) and eye muscles intact.
The orbital implant is inserted into the empty socket after these procedures. Without an implant, the orbital fat can shrink and move downward, leading to a sunken eye socket and difficulties fitting a prosthetic eye. They also reconstruct orbital fractures, especially larger defects causing enophthalmos (sunken eye), double vision, or hypoglobus (downward displacement of the eyeball).
The Implantation Procedure
A preoperative assessment evaluates patient health and eye socket condition. Imaging (CT or MRI) assesses orbital anatomy and determines implant material and size. Patients are also counseled on surgical goals, risks, and post-operative care.
The surgery is performed under general anesthesia. Depending on the patient’s condition, either an enucleation or evisceration is performed first. After the eye removal, the orbital implant is placed in the empty socket. For enucleation, extraocular muscles may reattach to the implant or a covering material to improve prosthetic eye movement.
After positioning the implant, the surgeon closes surrounding tissues, including Tenon’s capsule and conjunctiva. A clear plastic conformer shell is placed immediately after surgery to maintain the tissue space for the prosthetic eye and reduce swelling. The entire surgical procedure takes about one hour, and patients may go home the same day or stay overnight.
Living with an Orbital Implant
Recovery from orbital implant surgery involves managing swelling, which can take several weeks to subside. Patients avoid heavy lifting and keep their head elevated to reduce surgical area pressure. Pain management involves prescribed medications, and antibiotic drops are used to prevent infection during healing.
Approximately 6 to 8 weeks after surgery, once swelling decreases, an ocularist fits a custom artificial eye (ocular prosthesis). It fits over the orbital implant and under the eyelids, matching the natural eye’s appearance. While the prosthetic eye moves, its range of motion may not be as full as a natural eye. However, attaching eye muscles to the implant can improve movement.
Regular follow-up with an ophthalmologist and annual visits to an ocularist for prosthesis cleaning and polishing are required. Complications, though uncommon, include implant exposure, infection, or implant migration. Symptoms like discharge or visible implant material require immediate medical attention. Long-term care involves monitoring for eyelid changes like drooping or hollowness, which can be addressed with outpatient procedures.