The IMT: A Primer for General Ophthalmologists
THE IMT: A PRIMER FOR GENERAL OPHTHALMOLOGISTS
A team approach helps severely visually impaired AMD patients.
BY HENRY HUDSON, MD, FACS
The daughter of a 79-year-old woman with bilateral geographic atrophy calls your practice and asks what’s available to help her mother. She says “Mom” had been prescribed handheld magnifiers already, but complains of not being comfortable walking in the neighborhood and is upset she can no longer entertain guests.
General ophthalmologists who have long-term relationships with such patients and their loved ones are commonly confronted with such situations. They used to be at a loss as to what to advise, especially after the patient had already received some level of low-vision care. This grandmother now represents a whole new patient population that can be treated. Here, I will explain the basic technology, selection criteria and team treatment approach for the Implantable Miniature Telescope (IMT by Dr. Isaac Lipshitz), developed by VisionCare Ophthalmic Technologies (Saratoga, Calif.) and recently approved by the FDA.
A New Option Offers Hope
We can now inform patients with vision loss in both eyes due to bilateral geographic atrophy and disciform scars, beyond the aid of anti-VEGF therapeutics, that this tiny telescope implant is a new treatment option that may improve their central vision and quality of life.
This end-stage AMD patient population, unable to recognize faces or perform everyday activities dependent on detailed central vision, accounts for approximately half of the statutorily blind population in the United States. Many of these patients have given up hope and no longer remain as established patients in our practices. After receiving FDA and Medicare approval, and now as awareness of the device grows, the telescope implant is emerging as the standard of care for eligible end-stage AMD patients.
A Novel Treatment Paradigm
Because of its intraocular position, the telescope implant confers a treatment solution that is integrated into the patient’s visual system, unlike hand-held or mounted external vision appliances. The device is implanted into one eye and the patient views and scans the environment with natural eye movements, which affords a normal vestibular reflex. Furthermore, indoors, outdoors and in social situations, patients can participate in real-world activities rather than only simple stationary tasks.
Secured into the capsular bag after crystalline lens extraction, the telescope implant renders a retinal image approximately 2.7 times larger than the natural lens provides. That allows central images to be seen on viable peri-macular retina around the macular degeneration. In the pivotal trial, 67% of implanted eyes achieved a three-line or more improvement in best-corrected distance visual acuity vs. 13% of fellow eye controls.1 FDA approval was ultimately granted on safety data encompassing more than four years. Patients must meet age, vision, cornea health and other requirements noted in product labeling. Stargardt’s maculopathy is contraindicated.
As part of the pivotal trial, patients reported less difficulty in performing activities of daily living and improvement in vision-targeted psychosocial domains.1 On the National Eye Institute Visual Functioning Questionnaire, results indicated patients are less dependent on others, less worried or frustrated with their visual acuity, less limited in their activities related to visual acuity, more able to visit others and better able to recognize facial expressions. An explanation includes both visual acuity improvement and the patients’ functional ability to use natural eye movements for detailed distance and near activities (with appropriate spectacle correction). Additional external magnification may be required for finer print or details (e.g., reading a prescription label).
The IMT is implanted in the place of the eye’s lens, projecting objects on to the healthy peri-macular retina not degenerated by the disease.
Implantable telescope technology helps improve vision in the most advanced form of macular degeneration, end-stage AMD, while being virtually unnoticeable in the eye.
The Four-Step Approach
As with any new breakthrough that is not a cure, proper patient selection and management of patient expectations are keys to successful outcomes. To that end, the telescope prosthesis is integral to the CentraSight treatment program (www.centrasight.com) utilized by clinicians offering the treatment. This comprehensive patient evaluation and management model integrates patient selection requirements and a multi-specialty treatment team that encompasses the skill sets, practice patterns and reimbursement policy aligned to provide the care these patients need. The evaluation and treatment process takes into account the capabilities of the implantable telescope technology, the patient’s visual and functional goals and medical considerations.
The CentraSight treatment program involves the following four steps, led by an ophthalmologist:
►Diagnosis by a retina specialist.
►Vision evaluation, including external telescope simulations by a low-vision specialist.
►Implantation by a cornea-trained cataract surgeon.
►Post-implantation visual rehabilitation by low-vision and occupational therapy specialists.
It Takes a Team
Just like a basketball team needs skills of guards, forwards and a center to score, the telescope implant patient needs the multidisciplinary team for his or her medical, visual and functional rehabilitation skills to achieve a good clinical outcome. The CentraSight program helps optimize the comprehensive care of the telescope implant patient for improved vision and quality of life.
General ophthalmologists can be involved in this new treatment option in various ways, including leading or participating in a regional CentraSight provider team. If an ophthalmologist chooses not to participate in an existing team, those patients who inquire about the telescope implant and meet general criteria can be referred to a trained regional provider team for more intensive evaluation and return to the referring provider for long-term management.
Although this most visually debilitated AMD population is likely to have previously seen a retina specialist, we are well aware that many with long-standing bilateral disease have given up hope because of the paucity of treatment options. But many patients could learn about the treatment through their general ophthalmologist, anterior segment surgeon or optometrist as they come in for various eye-care needs or learn about the telescope implant. Thus, all providers in the eye-care community can serve as a first link to the CentraSight program.
Patient candidates not only include those with bilateral non-foveal-sparing geographic atrophy, but also those who may have failed treatment of anti-VEGF or older therapies for neovascular AMD. If their neovascular AMD is stable, they could be a candidates. Patients with active CNV during the previous six months are not candidates per the FDA indications. From an anterior segment perspective, patients must have at least one phakic eye, as the telescope implant procedure requires the natural lens to be removed and the capsular bag to be intact for implant placement.
After the evaluation team determines a patient meets key retinal and other medical criteria, the patient is referred to other trained CentraSight team members to help the ophthalmologist and patient understand if the patient will be a good candidate who can gain both visually and functionally from the telescope implant. Low-vision professionals add expertise that is not part of retina or cornea specialists’ practice patterns.
An evaluation includes simulations with a specialized external telescope that mimic the qualities of the telescope implant. Visual improvement is one aspect of the evaluation, noting real-world potential (e.g., ability to see a face or TV) as well as traditional acuity testing. The potential benefits and associated tradeoffs are shown and explained to the patient.
The IMT is shown held on a fingertip, offering a stark perspective as to the relative size of the implant.
Importantly, helping ophthalmologists determine which eye is recommended to implant from a visual perspective is a key optometric role. An eye selection algorithm helps determine which eye is best suited to become the post-implantation better-seeing eye — and thus a target eye for this monocular implant. Low-vision specialists and occupational therapists also help set patient expectations on what functional goals are possible, as well as educate them on post-implantation visual rehabilitation to determine the patient’s willingness and ability to participate.
Patient-Oriented Case Management Coordination
The comprehensive evaluation process requires patient education and coordination between providers. Prospective patients are referred to the CentraSight Access Program to learn about who the treatment is indicated for, what they can ask their eye doctor to confirm (e.g., visual acuity, retinal status), where the closest trained regional providers are located, and to get answers to other frequently asked questions. A case manager guides patient candidates through the evaluation process with the CentraSight provider team the patient selects.
Surgery and Post-Implantation Patient Management
Patients deemed appropriate candidates by the providers receive the telescope implant in an outpatient surgery by a cornea-trained surgeon. The device is approximately five IOLs thick and is implanted in a procedure that is a hybrid of cornea and cataract procedures. The AMA granted this new procedure a unique CPT code in July: 0308T “Insertion of ocular telescope prosthesis including removal of crystalline lens.”
After surgery, the cornea specialist follows patients for post-surgical care before returning them to the referring ophthalmologist for long-term management. Critical to patient outcomes, patients must undergo visual rehabilitation to adapt to a new way of seeing. Accomplishing this has made the treatment a life-changing event for many patients.
This outcome follows a post-implant timeline of events necessary for patients to integrate the new vision into their everyday activities. It requires more time and provider skill sets than our more common ophthalmic procedures, and is another reason why the CentraSight treatment program was developed by integrating clinical trial investigator feedback, labeling and Medicare coverage requirements. After initial postoperative healing, patients require near and distance correction and visual rehabilitation care to use the telescope eye for central vision and the unimplanted eye for peripheral vision. We manage our patients’ expectations by telling them the process is akin to other surgical procedures that require post-implantation rehabilitation therapy.
A New Standard for End-Stage AMD
The availability of the telescope implant and comprehensive approach of the CentraSight program ushers in a new standard for end-stage AMD patient counseling and care. With the aging population and continued search for more effective AMD treatments, finding ways to increase independence and quality of life for people with end-stage AMD is a growing public health issue.
This previously underserved patient population can be screened for major treatment criteria, and referred through the program for evaluation to determine whether the patient may benefit. If a patient is not a candidate, the multidisciplinary team may help direct her or him to additional resources or new clinical trials. Moreover, for all providers participating with or referring to a CentraSight team, the IMT and the CentraSight Access Program offer a real opportunity for comprehensive ophthalmology, optometry, retina and occupational therapy to take a team approach to make an impact on central visual blindness from AMD. OM
1. Hudson HL, Lane SS, Heier JS, et al. Implantable miniature telescope for the treatment of visual acuity loss resulting from end-stage age-related macular degeneration. Ophthalmology. 2006; 113:1987–2001.
Henry Hudson, MD, FACS, is a retina specialist in Tucson, Ariz., and was lead investigator for the Implantable Miniature Telescope clinical trial. He may be reached via e-mail at firstname.lastname@example.org.
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