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Variation of online Amsler grid from mobile apps, YouTube and Google
Author(s) -
LUK S,
CHEN K,
DAVIES N
Publication year - 2013
Publication title -
acta ophthalmologica
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.534
H-Index - 87
eISSN - 1755-3768
pISSN - 1755-375X
DOI - 10.1111/j.1755-3768.2013.f060.x
Subject(s) - computer science , grid , mobile phone , computer graphics (images) , telecommunications , mathematics , geometry
Purpose To analyse and evaluate the dimensions and instructions of Amsler grid from three sources: Mobile Phone Apps, YouTube and Google. Methods Searches were performed for Amsler grid in the three areas. Mobile Apps were viewed on a smartphone with 8.9 cm screen. Grids were measured on a 33.7cm computer screen with 1368 x768 resolution. Grids were assessed for number of squares, size, viewing distance and instructions on use. Calculation of subtended visual angle was made where possible. Results 10 apps and 7 videos were identified. Over 2 million Amsler grids were found from Google and the first 100 grids were chosen. Black grid on white background design was used in 72%, 11% with white‐on‐black and other formats in 17%. Instructions about monocular testing, distortion and scotoma detection were described in 96%, 97% and 89% respectively. Frequency of testing was only stated in 24%, of which most advised between daily to weekly (75%) and up to monthly (1%). 66% of the grids were presented as 20x20, range from 8x8 to 30x30. Viewing distance was specified in 51%, range 30–40cm. The average calculated retina projection was 12.3° (range 6.8° to 21.4°). Only two grids would project to 20°of the macula. Google and YouTube are freely available and Mobile Apps can cost up to £28.99. Most of the sources are produced by ophthalmologist practices (39%) followed by Optometrist related groups (16%). Conclusion Video‐sharing media and Internet may be an effective way to disseminate the test for patients. Our study show there is wide variation in the charts that are available which may affect the result of self monitoring tool.