Implantable Miniature Telescope for the Treatment of Visual Acuity Loss Resulting from End-Stage Age-Related Macular Degeneration: 1-Year Results
Received 18 October 2005; accepted 6 July 2006. published online 20 September 2006.
Purpose
To evaluate the safety and efficacy of an implantable visual prosthetic device (IMT; VisionCare Ophthalmic Technologies, Saratoga, CA) in patients with bilateral, end-stage age-related macular degeneration (AMD).
Design
Prospective, open-label, multicenter clinical trial with fellow eye controls.
Participants
A total of 217 patients (mean age, 76 years) with AMD and moderate to profound bilateral central visual acuity loss (20/80–20/800) resulting from bilateral untreatable geographic atrophy, disciform scars, or both were enrolled.
Methods
A visual prosthetic device (implantable telescope), designed to enlarge retinal images of the central visual field, was implanted monocularly in the capsular bag after lens extraction. Fellow eyes were not implanted to provide peripheral vision and served as controls. Study patients participated in 6 visual rehabilitation visits after surgery.
Main Outcome Measures
Best-corrected distance visual acuity (BCDVA) and best-corrected near visual acuity (BCNVA), quality-of-life scores from the National Eye Institute 25-item Visual Function Questionnaire (NEI VFQ-25) and the Activities of Daily Life scale, endothelial cell density (ECD), and incidence of complications and adverse events.
Results
At 1 year, 67% of implanted eyes achieved a 3-line or more improvement in BCDVA versus 13% of fellow eye controls (P<0.0001). Fifty-three percent of implanted eyes achieved a 3-line or more improvement in both BCDVA and BCNVA versus 10% of fellow eyes (P<0.0001). Mean BCDVA and BCNVA improved 3.5 lines and 3.2 lines, respectively, in implanted eyes versus 0.8 lines and 1.8 lines, respectively, in fellow eyes (P<0.0001). Change in visual acuity was not related to lesion type. Mean NEI VFQ-25 scores improved by more than 7 points from baseline (P<0.01) on 7 of 8 relevant subscales. Eleven eyes did not receive the device because of an aborted procedure. Endothelial cell density was reduced by 20% at 3 months and 25% at 1 year. The decrease in ECD was correlated with postsurgical edema (P<0.0001), and there was no evidence that endothelial cell loss is accelerated by ongoing endothelial trauma after implantation.
Conclusions
This implantable visual prosthesis can improve visual acuity and quality of life in patients with moderate to profound visual impairment caused by bilateral, end-stage AMD.
Correspondence to Henry L. Hudson, MD, 6585 North Oracle Road, Suite A, Tucson, AZ 85704.
Manuscript no. 2005-1000.
Neither the authors nor any of the participants in the IMT002 Study Group has a direct financial or proprietary interest with the subject matter. Drs Heier, Hudson, Lane, and Stulting serve on the medical advisory board for the study sponsor as consultants. All authors served as investigators in the clinical research trial of the Implantable Miniature Telescope (Dr Isaac Lipshitz), sponsored by VisionCare Ophthalmic Technologies, Inc., Saratoga, California.
ABSTRACT