The IMT is a micro-sized precision telescope, about the size of a pea, that is implanted in one eye in an outpatient surgical procedure conducted under local anesthesia. The IMT provides magnification of 3.0X or 2.2X, depending on the IMT model used. A magnified image is projected over a wide field of the retina to improve the ability to recognize images that were previously either difficult or impossible to see. The IMT is implanted in one eye of patients who present with untreatable late-stage AMD (end-stage AMD). The telescope provides central vision, while the non-implanted eye provides peripheral vision.
Stephen Lane, M.D., principal investigator at Associated Eye Care, Stillwater, MN who implanted six IMTs in VisionCare's Phase I trial, commented, "We are excited about the potential the IMT provides for improving visual acuity and the quality of life for individuals with severe AMD. We are encouraged with the results produced in the Phase I trial and look forward to studying the IMT in a larger patient population in this Phase II/III evaluation."
"We see many patients in the clinic with advanced AMD for whom we have no real viable treatment options. The IMT technology may give ophthalmologists a method of improving vision and function in the more than 500,000 U.S. patients who have bilateral permanent vision loss due to macular degeneration," said vitreo-retina disease specialist and Phase I investigator, Baruch D. Kuppermann, M.D., Ph.D., University of California, Irvine.
Fourteen patients were implanted with the IMT in the Phase I trial. Patients were monitored for safety and efficacy. One year after implantation, the majority of patients gained three or more lines (a doubling) of distance or near visual acuity and improvement in their activities of daily living. The most common complication was transient inflammation.
Patients at over 25 leading medical universities and ophthalmic centers into its US Phase II/III pivotal trial for untreatable end-stage AMD and Stargardt's macular dystrophy.
In a presentation to the joint meeting of the American Academy of Ophthalmology (AAO) and the European Society of Ophthalmology (SOE) in New Orleans, LA, on October 23-26, 2004, VisionCare reported that the ongoing Phase II/III trial was assessing the safety and efficacy of the IMT. Phase I trial results demonstrated that one year after implantation, 77% (10/13) of patients gained two or more lines of distance or near visual acuity and 62% (8/13) of patients gained three or more lines (a doubling) of visual acuity as measured on a standard (ETDRS) eye chart. The most common complication was transient inflammation.
On October 19, 2005, Paul Sternberg, M.D. and Henry Hudson, M.D., announced positive results from VisionCare's Phase I/III clinical trials of the IMT. After one year, subjects showed a mean improvement of over 3 lines in both distance and near visual acuity. 90% exceeded the primary endpoint of the trial with a 2-line improvement. Significant improvement in quality of life and daily living activities was also measured. A 2-year follow-up has revealed no serious safety issues. In July 2006, however, the company suffered a setback when the IMT was voted down for approval by an FDA advisory panel.
The November 2006 issue of Ophthalmology (Volume 113, Issue 11, Pages 1895-2134) published an article titled "Implantable Miniature Telescope for the Treatment of Visual Acuity Loss Resulting from End-Stage Age-Related Macular Degeneration" (Hudson HL, Lane SS, Heier JS, Stulting RD, Singerman L, Lichter PR, Sternberg P, Chang DF, IMT-002 Study Group) which detailed the results from the IMT002 trial. 217 patients at 28 U.S. investigational sites had severe vision loss due to the characteristic central blind spot caused by end-stage macular degeneration. The publication reports 90% of patients met or exceeded the protocol-specified primary efficacy endpoint of visual improvement, defined as a 2-line gain in either distance or near vision on the study eye chart. The protocol stated the endpoint would be achieved if at least 50% of patients met this target.
At 1 year after the telescope implantation procedure, 67% of patients achieved a 3-line (doubling of vision) or greater improvement in their study eye distance visual acuity, compared with 13% of unimplanted fellow eye controls. Approximately 25% of telescope-implanted eyes achieved a 5-line or greater improvement in visual acuity, compared with 2% of fellow eyes. Loss of 3 lines or more was encountered in 1.6% of implanted eyes, compared with 3.1% of fellow eyes. Secondary efficacy outcome measures suggest improvement in patients' vision-related quality of life and activities of daily living. On the National Eye Institute 25-item Visual Function Questionnaire, patients improved significantly from baseline (range 7 to 14 points) in 7 of 8 relevant vision-specific and psychosocial subscales, including General Vision, Social Functioning, and Dependency. Corneal endothelial cell density, a safety endpoint, was reduced 20% from preoperative at 3 months and 25% at one year (compared with the 17% protocol-specified target).
Patients enrolled in the study were at least 55 years of age and had central vision loss caused by disciform scars (end-stage wet AMD) or geographic atrophy (advanced dry AMD). Exclusion criteria included active choroidal neovascularization (wet AMD) or treatment of wet AMD in the preceding six months. Patients with early-stage AMD, mildly visually impairing AMD, or unilateral affection were not eligible.
The IMT002 trial was a prospective, open-label, multicenter clinical trial conducted under an investigational device exemption from the U.S. Food and Drug Administration (FDA). Patients averaged 76 years of age. The telescope prosthesis was generally well tolerated in the eye. 206 of the 217 enrolled patients had the device successfully implanted in their study eye, while 11 patients received a standard intraocular lens due to an aborted procedure. The most common complications or adverse events included transient intraocular pressure, transient corneal edema, iris prolapse, and inflammatory deposits on the device. There were 2 cases of corneal decompensation. The published results were published online at www.ophsource.org/periodicals/ophtha/article/PIIS016164200600933X/abstract.
For more information on the research, see www.visioncareinc.net or call (408) 872-0526.
On December 28, 2007, Optolight Vision Technology announced success from implantation of a second generation of the IMT, called the Lipshitz macular implant (LMI). The LMI is named for its inventor, Dr. Isaac Lipshitz, who also developed the IMT.
Researchers at Dr. Agarwal's Eye Hospital and Eye Research Centre, Chennai, India, investigated visual and surgical outcomes of the intraocular mirror telescopic intraocular lens implanted in patients with bilateral macular pathology and visual acuity worse than 20/200 in whom vision improved with a ?2.5 external telesco pe preoperatively. They reported that the LMI may be an effective solution for optical rehabilitation of patients with ARMD or other macular pathology by increasing the central image on the retina while preserving peripheral vision. The abstract of this research was published online at www.sciencedirect.com.