Abstract
Purpose: :
To investigate if subjects blinded by outer retinal dystrophies can recover the ability to read short sentences with the Argus II Retinal Prosthesis System.
Methods: :
Following last year’s report of the ability of 24 subjects implanted with the Argus II Retinal Prosthesis System to identify letters and short words (da Cruz et al., ARVO e-abstract 2010; Stanga et al, ARVO e-abstract, 2010), we selected the three highest-performing subjects on those tasks to participate in a follow-up study. This study consisted of two parts:1. Training: Subjects received a monthly magazine composed of 20-25 pages (A4 paper, white printing on a black background, Century Gothic font, 95-60 point - 4.5-2.9 cm). Each page contained a short sentence (e.g., a famous quote, idiom, or short poem, anagram). The subject took the magazine home and read it using the Argus II System.2. Testing on a computer monitor: Monthly, subjects were asked to read 6 open choice 4-word sentences (white printing on a black background) presented on a LCD monitor. Sentences were presented using PowerPoint (Century Gothic 95 point - 4.5 cm). Response time for each word was recorded.
Results: :
After 1 month, two blind subjects implanted with the Argus II System were able to correctly read 4-word sentences with an average reading speed of 0.65 (wd/min) and 1.14 (wd/min). Max performance were 0.84 (wd/min) and 2.53 (wd/min). At month 2, subjects increased their average reading speed to 3.07 (wd/min) and 1.41 (wd/min), with max performances of 5.10 (wd/min) and 2.35 (wd/min).
Conclusions: :
Subjects fitted with the Argus II System recovered the ability to read short sentences. The Argus II System is the first retinal prosthesis in which the feasibility of reading sentences with prosthetic vision has been demonstrated. This study also demonstrated that training can improve performance of subjects on this task, with reading speeds increasing over time.
Clinical Trial: :
http://www.clinicaltrials.gov http://clinicaltrials.gov/show/NCT00407602
Keywords: retinitis • reading