September 2016
Volume 57, Issue 12
Open Access
ARVO Annual Meeting Abstract  |   September 2016
Comparisons of MAIA and Optos Microperimeters
Author Affiliations & Notes
  • Tiffany Arango
    Lighthouse Guild, New York, New York, United States
  • William H Seiple
    Lighthouse Guild, New York, New York, United States
    Department of Ophthalmology, New York University School of Medicine, New York, New York, United States
  • Meesa Maeng
    Chicago Lighthouse, Chicago, Illinois, United States
  • Janet P Szlyk
    Chicago Lighthouse, Chicago, Illinois, United States
  • Footnotes
    Commercial Relationships   Tiffany Arango, None; William Seiple, None; Meesa Maeng, None; Janet Szlyk, None
  • Footnotes
    Support  US Department of Veterans Affairs
Investigative Ophthalmology & Visual Science September 2016, Vol.57, 5183. doi:
  • Views
  • Share
  • Tools
    • Alerts
      ×
      This feature is available to Subscribers Only
      Sign In or Create an Account ×
    • Get Citation

      Tiffany Arango, William H Seiple, Meesa Maeng, Janet P Szlyk; Comparisons of MAIA and Optos Microperimeters. Invest. Ophthalmol. Vis. Sci. 2016;57(12):5183.

      Download citation file:


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

      ×
  • Supplements
Abstract

Purpose : Instruments that allow fundus-guided microperimetry (MP) are valuable for assessing visual function in patients with low vision. Although these instruments report sensitivities in decibels (dB), it is difficult to compare results among them due to differences in maximum light and in background levels. We compared the MAIA (MA) and optos (OP) microperimeters using the absolute luminance values for each machine.

Methods : 6 control subjects and 10 low-vision patients were tested on the MA and OP using the same pattern of test points and the same threshold algorithm. Repeatability was assessed for controls by testing both instruments on three separate days. To compare equivalent units, dB thresholds were converted to light increments in apostilbs (asb), and then to delta increment intensities (ΔI) relative to the background luminance of each instrument.

Results : The maximum stimulus intensity of the MA is 1,000 asb, and the minimum is 0.25 asb, equivalent to ΔIs of 322 and 0.08 above the 3.1-asb background, respectively. The maximum intensity of the OP is 439 asb, and the minimum is 5.2 asb, equivalent to ΔIs of 31.6 and 0.16 above the 31.4-asb background. When comparing across repeated tests, there was a significant effect for test day: average ΔI thresholds were 0.37 on Day 1 and 0.29 on Day 3. For patients, there were significant effects for instrument and subject. To test the gain associated with the larger ΔIs of the MA, we examined points where 0-dB thresholds were recorded on either instrument. 56% of these points had a 0-dB threshold on both instruments, 29.3% had measureable MA thresholds when the OP reported 0-dB thresholds, and 14.7% showed >0-dB thresholds on the OP when the MA had 0-dB thresholds. We also examined the benefit from the MA’s smaller ΔIs. Test points (in ΔI) at the smallest ΔIs produced by the OP (18-20 dB) were compared to the corresponding MA ΔI values. For 47.3% of these points, the MA recorded lower ΔI thresholds than the OP; for 52.7%, the MA recorded higher thresholds.

Conclusions : The background luminance of the MA is a log unit dimmer than the OP, which, in part, allows brighter and dimmer stimulus increments to be presented. However, this extended stimulus range only provided additional information in a small number of cases. Additionally, using a mesopic background level in the MA instrument confounds cone and rod contributions to thresholds.

This is an abstract that was submitted for the 2016 ARVO Annual Meeting, held in Seattle, Wash., May 1-5, 2016.

×
×

This PDF is available to Subscribers Only

Sign in or purchase a subscription to access this content. ×

You must be signed into an individual account to use this feature.

×