Saturday, November 22, 2008

Implantable Telescope for End-Stage Age-related Macular Degeneration: Long-term Visual Acuity and Safety Outcomes

R. Doyle Stultingb, Jeffrey S. Heierc, Stephen S. Laned, David F. Change, Lawrence J. Singermanf, Cynthia A. Bradfordg, Robert E. Leonardg, IMT002 Study Group

Purpose
To evaluate long-term safety and best-corrected visual acuity (BCVA) results of a telescope prosthesis in patients with end-stage age-related macular degeneration (AMD).

Design
Prospective, open-label clinical trial with fellow-eye controls.

Methods
Patients with end-stage AMD (bilateral geographic atrophy or disciform scars; BCVA, 20/80 to 20/800) received the telescope prosthesis at 28 centers. Methods were similar to those described in the one-year results, with follow-up visits continuing at 18 and 24 months. Main outcome measures included BCVA change from baseline, endothelial cell density (ECD) and morphometry, and incidence of complications.

Results
At two years, data from 174 (92.6%) of 188 available patients were analyzed. Overall, 103 (59.5%) of 173 telescope-implanted eyes gained three lines or more (doubling of visual angle) of BCVA compared with 18 (10.3%) of 174 fellow control eyes (P < .0001). Mean BCVA improved 3.6 lines (standard deviation [SD], 1.9 lines) and 2.8 lines (SD, 2.3 lines) from baseline in eyes with the 3X and 2.2X device models, respectively. Mean ECD stabilized through two years, with 2.4% mean cell loss occurring from one to two years. There was no significant change in coefficient of variation or percentage of hexagonal endothelial cells from within six months to two years after surgery. The most common complication was inflammatory deposits.

Conclusions
Long-term results of this telescope prosthesis show the substantial BCVA improvement at one year is maintained at two years. Key indicators of corneal health demonstrate ECD change that reflects remodeling of the endothelium associated with the implantation procedure. ECD stabilizes over time, and there is no evidence of any ongoing endothelial trauma.

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