How the latest advances in orbital technology
make possible artificial eyes that move naturally
Anophthalmos means the absence of the globe (eye) from the orbit. Rarely, people can be born without an eye, but usually the cause is surgical removal due to trauma, infection, disease leading to blindness and pain, or cancer. Modern technology has created great advances in our ability to treat and cure most ocular conditions, but retinal detachment, corneal infections, glaucoma and even cataract surgery can rarely lead to a blind and extremely painful eye which must be removed. Rare ocular cancers such as retinoblastoma and uveal melanoma often require ocular removal (enucleation) for cure.
When an eye must be removed, the goal in surgery is to provide a socket that will allow an artificial eye (prosthesis) to be fit that looks and feels very natural. Newer techniques allow the prosthesis to move in concert with the normal eye in a very life-like fashion in many cases. An artificial eye prosthesis is not spherical but usually is like a thick contact lens fitting over the socket tissue.
The surgeon implants a sphere at the time of eye removal to take up volume lost by eye removal, and reattaches the eye movement muscles. This is covered by the socket lining tissues, and the prosthesis fits over this behind the lids. The prosthesis itself is made by a specialized technician called an ocularist. Dr. Oestreicher works in concert with the ocularist to produce the best result possible for each patient.
The single biggest advance in this field has been the development of vascularized implants. This is a sphere which contains pores of 300-400 microns diameter interconnecting through the implant allowing blood vessels to grow into the implant. In a sense, the implant becomes part of the patient's own body.
In the older system, the buried implant, to which the muscles are attached, moved the socket surface, which moved the prosthetic eye by friction. Naturally there was movement lost by this imperfect coupling, so that the prosthetic eye would look extremely realistic, but not move in a realistic fashion.
The vascularized implants move in a similar fashion but because they have a blood supply, Dr. Oestreicher can perform a second operation to place a motility-coupling peg which transmits the implant's movements directly to the prosthesis. This has revolutionized the treatment of the anophthalmic socket by allowing greatly improved results (see diagram).
This operation can be utilized for patients having an enucleation (eye removal) or evisceration (removal of the ocular contents), or for patients who had their eye removed years earlier with an older plastic or silicone implant who desire improved prosthetic movement or whose implant has migrated leading to prosthetic fitting difficulties.
Dr. Oestreicher is a leader in the use of these implants, having introduced them to Toronto, having produced several seminal publications on the topic, and having personally performed over 600 such implants, one of the largest series in the world. He currently utilizes the Bioeye (hydroxyapatite or coral) implant and the MEDPOR® (porous polyethylene) implant. Although the surgery and hospitization are covered by OHIP, there is a cost associated with the hospital's purchase of the implant for the patient, and for prosthetic fitting. Ontario's Assistive Devices Program covers part of the prosthesis cost; the rest is charged by the ocularist.
To see if you would be a candidate for motility improvement with these techniques, or for a preoperative assessment for those likely to require enucleation in the future, please schedule an appointment with Dr. Oestreicher. He can discuss the specifics of your case, the risks, costs, and potential benefits in appropriate detail with you.
For more information on new advances in orbital implants, visit:
MEDPOR is a registered trademark of Porex Surgical Inc.
"Elated...with the results"
It's been a year since my lower lid surgery and I just wanted to let Dr. O know how elated I am with the results. I couldn't have predicted, nor asked for, a better outcome!