K Shiraki¹, T Yasunari¹, H Tabuchi¹, T Miki¹, T Ando², H Nakamura3, S Yamaguchi4, E Shimizu5
¹Osaka City University, Graduate School of Medicine, Ophthalmology, Osaka, Japan; ²Sanyo Electrical Co.,Ltd., Hypermedia Research Center, Osaka, Japan; 3Osaka City University, Graduate School of Medicine, Medical Informatics & Medical Economics, Osaka, Japan; 4Times Corporation Ltd., Product Development, Osaka, Japan; 5Osaka City University, Graduate School of Engineering, Electrical Engineering, Osaka, Japan
Purpose: To develop a device, Retina Projection System, for a low vision aid with the Maxwelian view and to compare the new system with a face-mounted display for reading.
Materials and Methods: A digital image was formed with a spatial light modulator, and the image was projected onto a retina with a red diode laser. The projecting light was focused at the pupillary area, producing the Maxwellian view. A reading speed with the new device was compared with that with a face-mounted display in 12 low vision patients with central scotoma, because of age-related macular degeneration or high myopia.
Results: With the new device, the image was seen extrafoveally without correction of a refraction error. When the device was used as a reading aid such as a closed circuit TV, a reading speed with the new device was 0.12 to 1.01 Japanese characters / second with an average of 0.53 Japanese characters / second and that with a face-mounted display was 0.12 to 1.49 Japanese characters / second with an average of 0.70 Japanese characters / second. There was no significant difference between the two reading speeds. Six patients reported a clearer image of characters with the Retina Projection Display than that with a face-mounted display.
Conclusion: Though it takes time to bring the focused light of the Retina Projection Display to the pupillary area of a patient, the new Retina Projection System was thought to provide a clear image without any special adjustment. This new device was thought to be used as a low vision aid.
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