June 2013
Volume 54, Issue 15
ARVO Annual Meeting Abstract  |   June 2013
Comparison of a Novel Cell Phone-Based Refraction Technique (Netra-G) with Subjective Refraction
Author Affiliations & Notes
  • Hilary Gaiser
    New England College of Optometry, Boston, MA
  • Bruce Moore
    New England College of Optometry, Boston, MA
  • Vitor Pamplona
    EyeNetra Inc, Somerville, MA
  • Nadine Solaka
    New England College of Optometry, Boston, MA
  • David Schafran
    New England College of Optometry, Boston, MA
  • Dennis Merrill
    EyeNetra Inc, Somerville, MA
  • Nathaniel Sharpe
    EyeNetra Inc, Somerville, MA
  • Joe Geringer
    EyeNetra Inc, Somerville, MA
  • Ramesh Raskar
    EyeNetra Inc, Somerville, MA
  • Footnotes
    Commercial Relationships Hilary Gaiser, None; Bruce Moore, EyeNetra Inc. (I); Vitor Pamplona, EyeNetra (E); Nadine Solaka, None; David Schafran, EyeNetra Inc (R); Dennis Merrill, None; Nathaniel Sharpe, Eyenetra (E); Joe Geringer, Impact Product Development., LLC (C); Ramesh Raskar, EyeNetra Inc (I)
  • Footnotes
    Support None
Investigative Ophthalmology & Visual Science June 2013, Vol.54, 2340. doi:
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      Hilary Gaiser, Bruce Moore, Vitor Pamplona, Nadine Solaka, David Schafran, Dennis Merrill, Nathaniel Sharpe, Joe Geringer, Ramesh Raskar; Comparison of a Novel Cell Phone-Based Refraction Technique (Netra-G) with Subjective Refraction. Invest. Ophthalmol. Vis. Sci. 2013;54(15):2340.

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      © ARVO (1962-2015); The Authors (2016-present)

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Purpose: To assess the performance of a cell phone based refracting device (NETRA-G). This study determines the accuracy of this prototype in determining refractive error in comparison to subjective refraction (SR).

Methods: NETRA-G (NET) retrofits a high-resolution mobile phone (Sony Xperia U) by adding a pinhole mask, a film and a lens onto the display. The device is bi-ocular with the fellow eye viewing an object at infinity. The subject aligns red and green lines with the translation on screen proportional to refractive error. 27 subjects (mean + SD age 24.79 +/- 1.60) underwent SR, and NET refraction. Subjects refractive error ranged from plano to -6.0D (mean + SD refraction -3.34 +/- 1.46D). Exclusion criteria included amblyopia, floaters, divergent vertical deviation and any ocular pathology. The NET result was used as a starting point for SR.

Results: For all 27 subjects (54 eyes), the average absolute difference between NET and SR is 0.31 +/- 0.37D. The refraction determined by NET is well correlated with that of SR r=0.96 and the two measures were not statistically significantly different from each other (p=0.36>0.05). Orthogonal linear regression fit presented a slope of 0.92 and a y-intercept of -0.36D. Average difference on visual acuity between SR and NET 0.089 +/- 0.13 logMar and 77% received 20/25 or better vision directly from NET.

Conclusions: When compared to SR, NET slightly overestimated the myopic refractive errors and had a small myopic offset of -0.36D. On average, the visual acuity difference between SR and NET is less then a line on the logMar chart. The results show that NET has potential to be a used as an effective tool for rapidly estimating refractive errors by non-eyecare professionals. Accuracy of this novel technique is expected to increase as technology evolves.

Keywords: 676 refraction • 605 myopia  

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