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Telescope implant helps end-stage AMD patients remain independent longer
The CentraSight implantable miniature telescope is indicated for those with central blindness affecting both eyes.
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Optometrists specializing in low vision are working with retinal and corneal surgeons and occupational therapists to restore central vision in patients with end-stage age-related macular degeneration.
Patients with AMD have a fear of losing their independence, Ed Paul Jr., OD, PhD, told Primary Care Optometry News. “If we can allow the patient through improved eyesight to reclaim their vision and prolong their independence, the procedure is more than worthwhile,” he said.
Paul comanaged his first patient with the implantable miniature telescope (IMT) by CentraSight (VisionCare Ophthalmic Technologies Inc., Saratoga, Calif.) in 2013.
The telescopic lens implant is smaller than a pea and uses micro-optical technology to magnify images normally spotted in one’s central vision. The enlarged images are projected onto the healthy portion of the retina not affected by AMD. This, in turn, reduces the impact of the blind spot, allowing a patient to see an enlarged image of the central vision object of interest, according to the company.
Patient selection
The implant is intended for patients 65 years or older with the most advanced form of wet or dry AMD, where central blindness affects both eyes, according to Reena Mishra, senior director of marketing, VisionCare Ophthalmic Technologies. Patients should no longer be receiving injections for active choroidal neovascularization and be phakic in at least one eye.
Image: Groat BJ
More than 500 patients have received the implant to date, she told PCON. The implant is typically placed in the eye with better vision. The telescope implant was first FDA approved in 2010 for patients at least 75 years old, and the indication was expanded in 2014 to include those as young as 65 years.
Removal of an intraocular lens and placement of the IMT is considered off-label, Mishra said.
However, CPT code 0308T reads: “Insertion of ocular telescope prosthesis including removal of crystalline lens or intraocular lens prosthesis.”
When considering a patient for the procedure, optometrists use an external telescope simulator within the eye that is the candidate for implantation to verify that improved visual acuity would result. To warrant the surgery, the simulator needs to verify an improvement of at least one line better than the other eye, according to Paul, who practices in Wilmington, N.C.
After the surgery, patients use their vision in a new way.
“We are doing a form of ‘modified monovision,’” he said. “Typically, when the OD uses the term ‘monovision,’ one eye is fit to see well up close and one for distance. In modified monovision it’s not distance and near, but central vision in the IMT eye and peripheral vision in the opposite eye.
The telescopic eye is used for central vision spotting, like seeing a face or reading a word. The other eye, without the implant, is used for peripheral vision, he said. The one downside to the telescopic eye is that peripheral vision is limited while central vision is much improved.
Paul noted that a four-person health care team of a retinal surgeon, corneal surgeon, occupational therapist and low vision optometrist work together from preoperative to postoperative rehabilitation.
Postsurgical care, rehab
“The cornea surgeon is focused on the health of the eye, how the surgery fared and any complications,” Rebecca Kammer, OD, PhD, explained. “The optometry-occupational therapy team is actively engaging the patient in using the device and image.”
Kammer has been a low vision educator for more than 14 years and is the founder of Kammer Consulting, an education and training firm dedicated to enhancing the practice of low vision rehabilitation.
“The OD is instrumental in keeping the patient motivated and on task with the hard work of understanding how to use their new vision,” she said.
Postoperatively, the optometrist will assess the need for magnification, glasses or other low vision devices, Paul said.
According to Kammer, rehabilitation can last from 2 to 4 months. The optometrist and occupational therapist communicate on how the patient is using the device and how it is starting to change their life. The occupational therapist works with the patient weekly and charts how he or she meets vision goals and achieves activities of daily living.
Basic vision skills such as localizing, fixating, scanning, tracing, tracking and navigating an object all need to be practiced and tested within several weeks postoperatively, Mishra said.
Kammer described three types of initial responses of postoperative patients who are in the dilated healing stage, which extends about 1 month after implantation. “Superstar” patients see the image immediately, have no delay in using it and are motivated to do so. “Intermittent viewers” are more typical; they see the image sometimes, but with large eye movements the enlarged view can be startling. “Infrequent viewers” may not recognize that they see the image initially, as the dilated pupil allows them to sneak a view around the telescope implant.
The first exam postoperatively helps the patient identify the telescopic image and establish eye movement control, she said. Once the patient is no longer dilated, the telescope is easier to use, and the rehabilitation team can help the patient learn to use the image for daily activities.
Certain patients may find it more difficult to adjust to using the implant; these patients may require prolonged occupational therapy, Paul said. However, 60% to 70% will follow a normal rehab schedule, which consists of four to eight occupational therapy visits over 2 to 3 months.
Glare is often an issue for all patients, as they are dilated for almost 1 month after surgery, he said. This can be alleviated with medical tint or glare filters in prescription eye wear or a glare filter in bright sun.
“One thing I am very big on, with not only my CentraSight IMT patients, but all my low vision patients, is that the end goal is improving quality of life. If we can allow the patient through improved eyesight to reclaim vision and prolong independence, that is the major goal,” Paul said.
Kammer and Paul are working to publish a paper about their retrospective study of all implant patients from Paul’s three clinics in North Carolina. They found that all cases achieved at least two out of three of their vision goals. These patients averaged 4.5 lines of vision improvement, with some achieving as much as 6 lines of improvement.
“The technology clearly works if the time is spent in choosing the right patients and managing expectations,” Paul stated.
“I believe in a model where optometry and occupational therapy work together,” Kammer said. “This model with CentraSight really emphasizes that team approach; it’s reinforcing a practice pattern that is still newer and not fully adopted by low vision optometry. It gives an incentive for doctors to raise their professional bar, learn more about each other and learn about better practice for patients. To me this is also a tool for professional improvement.” – by Abigail Sutton
- For more information:
- Rebecca Kammer, OD, PhD, can be reached at rebecca@kammerconsulting.com. For more information on her work in albinism in East Africa, visit: http://albinism.ohchr.org/story-rebecca-kammer.html.
- Reena Mishra is senior director of marketing for VisionCare Ophthalmic Technologies. She can be reached at reena@visioncareinc.net.
- Ed Paul Jr., OD, PhD, practices at Landfall Eye Associates in Wilmington, N.C. He can be reached at epauljr@aol.com.
Disclosures: Kammer is a consultant for VisionCare Ophthalmic Technologies. Mishra is employed by VisionCare Ophthalmic Technologies. Paul reports no relevant financial disclosures.