Zooming in on the implantable telescope

September 10, 2007

A long-term Phase II/III study (IMT002) of an implantable telescope prosthesis for end-stage macular degeneration has demonstrated that it can improve quality of life and sustain visual acuity (VA) improvements.

A long-term Phase II/III study (IMT002) of an implantable telescope prosthesis for end-stage macular degeneration has demonstrated that it can improve quality of life and sustain visual acuity (VA) improvements, according to Mark Packer, one of the trial investigators from the USA.

The prospective, observational clinical trial enrolled 206 subjects across 28 US centres. Patients were over 55 years of age (mean age 76 years) with bilateral central scotomas due to untreatable age-related macular degeneration (AMD). Exclusion criteria included evidence or treatment of active choroidal neovascularization (CNV) in the preceding six months, diabetic retinopathy, history of retinal detachment, endothelial cell density <1,600 cells/mm2 and previous intraocular or corneal surgery.

Mean best corrected visual acuity (BCVA) at baseline was 20/312. At two years, mean BCVA had improved by 3.2 lines, within three letters of one year BCVA. A gain of more than three lines of distance BCVA was observed in 59.2% of implanted eyes, compared with 10.3% of fellow eye controls (p<0.0001).

The National Eye Institute Visual Function Questionnaire (NEI VFQ) scores, at one year, demonstrated relevant VFQ subscales improved from seven to 14 points. Mean endothelial cell density decreased by 20% at three months, 25.3% at one year and an additional 2.5% in year two. Two cases of corneal decompensation were recorded during year one, while none were seen in year two.

This pivotal study is the first to demonstrate that the implantable telescope can improve and sustain VA as well as improving quality of life.